Ändra sökning
Avgränsa sökresultatet
1234567 51 - 100 av 549
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 51. Binder, Zev A.
    et al.
    Haseley Thorne, Amy
    Bakas, Spyridon
    Wileyto, E. Paul
    Bilello, Michel
    Akbari, Hamed
    Rathore, Saima
    Ha, Sung Min
    Zhang, Logan
    Ferguson, Cole J.
    Dahiya, Sonika
    Bi, Wenya Linda
    Reardon, David A.
    Idbaih, Ahmed
    Felsberg, Joerg
    Hentschel, Bettina
    Weller, Michael
    Bagley, Stephen J.
    Morrissette, Jennifer J. D.
    Nasrallah, MacLean P.
    Ma, Jianhui
    Zanca, Ciro
    Scott, Andrew M.
    Orellana, Laura
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Davatzikos, Christos
    Furnari, Frank B.
    O'Rourke, Donald M.
    Epidermal Growth Factor Receptor Extracellular Domain Mutations in Glioblastoma Present Opportunities for Clinical Imaging and Therapeutic Development2018Ingår i: Cancer Cell, ISSN 1535-6108, E-ISSN 1878-3686, Vol. 34, nr 1, s. 163-177Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We explored the clinical and pathological impact of epidermal growth factor receptor (EGFR) extracellular domain missense mutations. Retrospective assessment of 260 de novo glioblastoma patients revealed a significant reduction in overall survival of patients having tumors with EGFR mutations at alanine 289 (EGFR(A289D/T/V)). Quantitative multi-parametric magnetic resonance imaging analyses indicated increased tumor invasion for EGFR(A289D/T/V) mutants, corroborated in mice bearing intracranial tumors expressing EGFR(A289V) and dependent on ERK-mediated expression of matrix metalloproteinase-1. EGFR(A289V) tumor growth was attenuated with an antibody against a cryptic epitope, based on in silico simulation. The findings of this study indicate a highly invasive phenotype associated with the EGFR(A289V) mutation in glioblastoma, postulating EGFR(A289V) as a molecular marker for responsiveness to therapy with EGFR-targeting antibodies.

  • 52.
    Björkholm, Patrik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Ernst, Andreas M.
    Hacke, Moritz
    Wieland, Felix
    Bruegger, Britta
    von Heijne, Gunnar
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Identification of novel sphingolipid-binding motifs in mammalian membrane proteins2014Ingår i: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1838, nr 8, s. 2066-2070Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Specific interactions between transmembrane proteins and sphingolipids is a poorly understood phenomenon, and only a couple of instances have been identified. The best characterized example is the sphingolipid-binding motif VXXTLXXIY found in the transmembrane helix of the vesicular transport protein p24. Here, we have used a simple motif-probability algorithm (MOPRO) to identify proteins that contain putative sphingolipid-binding motifs in a dataset comprising proteomes from mammalian organisms. From these motif-containing candidate proteins, four with different numbers of transmembrane helices were selected for experimental study: i) major histocompatibility complex II Q alpha chain subtype (DQA1), ii) GPI-attachment protein 1 (GAA1), iii) tetraspanin-7 TSN7, and iv), metabotropic glutamate receptor 2 (GRM2). These candidates were subjected to photo-affinity labeling using radiolabeled sphingolipids, confirming all four candidate proteins as sphingolipid-binding proteins. The sphingolipid-binding motifs are enriched in the 7TM family of G-protein coupled receptors, predominantly in transmembrane helix 6. The ability of the motif-containing candidate proteins to bind sphingolipids with high specificity opens new perspectives on their respective regulation and function.

  • 53. Boije, Henrik
    et al.
    Ring, Henrik
    Fard, Shahrzad Shirazi
    Grundberg, Ida
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Uppsala University .
    Hallbook, Finn
    Alternative Splicing of the Chromodomain Protein Morf4l1 Pre-mRNA Has Implications on Cell Differentiation in the Developing Chicken Retina2013Ingår i: Journal of Molecular Neuroscience, ISSN 0895-8696, E-ISSN 1559-1166, Vol. 51, nr 2, s. 615-628Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The proliferation, cell cycle exit and differentiation of progenitor cells are controlled by several different factors. The chromodomain protein mortality factor 4-like 1 (Morf4l1) has been ascribed a role in both proliferation and differentiation. Little attention has been given to the existence of alternative splice variants of the Morf4l1 mRNA, which encode two Morf41l isoforms: a short isoform (S-Morf4l1) with an intact chromodomain and a long isoform (L-Morf4l1) with an insertion in or in the vicinity of the chromodomain. The aim of this study was to investigate if this alternative splicing has a function during development. We analysed the temporal and spatial distribution of the two mRNAs and over-expressed both isoforms in the developing retina. The results showed that the S-Morf4l1 mRNA is developmentally regulated. Over-expression of S-Morf4l1 using a retrovirus vector produced a clear phenotype with an increase of early-born neurons: retinal ganglion cells, horizontal cells and cone photoreceptor cells. Over-expression of L-Morf4l1 did not produce any distinguishable phenotype. The over-expression of S-Morf4l1 but not L-Morf4l1 also increased apoptosis in the infected regions. Our results suggest that the two Morf4l1 isoforms have different functions during retinogenesis and that Morf4l1 functions are fine-tuned by developmentally regulated alternative splicing. The data also suggest that Morf4l1 contributes to the regulation of cell genesis in the retina.

  • 54.
    Bonath, Franziska
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Domingo-Prim, Judit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Tarbier, Marcel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Friedländer, Marc R.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Visa, Neus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Next-generation sequencing reveals two populations of damage-induced small RNAs at endogenous DNA double-strand breaks2018Ingår i: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962, Vol. 46, nr 22, s. 11869-11882Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent studies suggest that transcription takes place at DNA double-strand breaks (DSBs), that transcripts at DSBs are processed by Drosha and Dicer into damage-induced small RNAs (diRNAs), and that diRNAs are required for DNA repair. However, diRNAs have been mostly detected in reporter constructs or repetitive sequences, and their existence at endogenous loci has been questioned by recent reports. Using the homing endonuclease I-PpoI, we have investigated diRNA production in genetically unperturbed human and mouse cells. I-PpoI is an ideal tool to clarify the requirements for diRNA production because it induces DSBs in different types of loci: the repetitive 28S locus, unique genes and intergenic loci. We show by extensive sequencing that the rDNA locus produces substantial levels of diRNAs, whereas unique genic and intergenic loci do not. Further characterization of diRNAs emerging from the 28S locus reveals the existence of two diRNA subtypes. Surprisingly, Drosha and its partner DGCR8 are dispensable for diRNA production and only one diRNAs subtype depends on Dicer processing. Furthermore, we provide evidence that diRNAs are incorporated into Argonaute. Our findings provide direct evidence for diRNA production at endogenous loci in mammalian cells and give insights into RNA processing at DSBs.

  • 55.
    Bonath, Franziska
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Domingo-Prim, Judit
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Tarbier, Marcel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Friedländer, Marc
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Visa, Neus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Next-generation sequencing reveals two populations of damage- induced small RNAs at endogenous DNA double-strand breaksIngår i: Nucleic Acids Research, ISSN 0305-1048, E-ISSN 1362-4962Artikel i tidskrift (Refereegranskat)
  • 56. Borroto-Escuela, Dasiel O.
    et al.
    Rodriguez, David
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Romero-Fernandez, Wilber
    Kapla, Jon
    Jaiteh, Mariama
    Ranganathan, Anirudh
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Lazarova, Tzvetana
    Fuxe, Kjell
    Carlsson, Jens
    Mapping the Interface of a GPCR Dimer: A Structural Model of the A(2A) Adenosine and D-2 Dopamine Receptor Heteromer2018Ingår i: Frontiers in Pharmacology, ISSN 1663-9812, E-ISSN 1663-9812, Vol. 9, artikel-id 829Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The A(2A) adenosine (A(2A)R) and D-2 dopamine (D2R) receptors form oligomers in the cell membrane and allosteric interactions across the A(2A)R-D2R heteromer represent a target for development of drugs against central nervous system disorders. However, understanding of the molecular determinants of A(2A)R-D2R heteromerization and the allosteric antagonistic interactions between the receptor protomers is still limited. In this work, a structural model of the A(2A)R-D2R heterodimer was generated using a combined experimental and computational approach. Regions involved in the heteromer interface were modeled based on the effects of peptides derived from the transmembrane (TM) helices on A(2A)R-D2R receptor-receptor interactions in bioluminescence resonance energy transfer (BRET) and proximity ligation assays. Peptides corresponding to TM-IV and TM-V of the A(2A)R blocked heterodimer interactions and disrupted the allosteric effect of A(2A)R activation on D2R agonist binding. Protein-protein docking was used to construct a model of the A(2A)R-D2R heterodimer with a TM-IV/V interface, which was refined using molecular dynamics simulations. Mutations in the predicted interface reduced A(2A)R-D2R interactions in BRET experiments and altered the allosteric modulation. The heterodimer model provided insights into the structural basis of allosteric modulation and the technique developed to characterize the A(2A)R-D2R interface can be extended to study the many other G protein-coupled receptors that engage in heteroreceptor complexes.

  • 57. Borroto-Escuela, Dasiel O.
    et al.
    Wydra, Karolina
    Li, Xiang
    Rodriguez, David
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Uppsala University BMC, Sweden.
    Carlsson, Jens
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Uppsala University BMC, Sweden.
    Jastrzebska, Joanna
    Filip, Malgorzata
    Fuxe, Kjell
    Disruption of A2AR-D2R Heteroreceptor Complexes After A2AR Transmembrane 5 Peptide Administration Enhances Cocaine Self-Administration in Rats2018Ingår i: Molecular Neurobiology, ISSN 0893-7648, E-ISSN 1559-1182, Vol. 55, nr 8, s. 7038-7048Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Antagonistic allosteric A2AR-D2R receptor-receptor interactions in heteroreceptor complexes counteract cocaine self-administration and cocaine seeking in rats as seen in biochemical and behavioral experiments. It was shown that the human A2AR transmembrane five (TM5) was part of the interface of the human A2AR-D2R receptor heteromer. In the current paper, the rat A2AR synthetic TM5 (synthTM5) peptide disrupts the A2AR-D2R heteroreceptor complex in HEK293 cells as shown by the bioluminescence resonance energy transfer method. Rat A2AR synthTM5 peptide, microinjected into the nucleus accumbens, produced a complete counteraction of the inhibitory effects of the A2AR agonist CGS21680 on cocaine self-administration. It was linked to a disappearance of the accumbal A2AR-D2R heteroreceptor complexes and the A2AR agonist induced inhibition of D2R recognition using proximity ligation assay and biochemical binding techniques. However, possible effects of the A2AR synthTM5 peptide on accumbal A2AR-D3R and A2AR-D4R heteroreceptor complexes remain to be excluded. Evidence is provided that accumbal A2AR-D2R-like heteroreceptor complexes with their antagonistic receptor-receptor interactions can be major targets for treatment of cocaine use disorder.

  • 58. Branca, Rui M. M.
    et al.
    Orre, Lukas M.
    Johansson, Henrik J.
    Granholm, Viktor
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Huss, Mikael
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Perez-Bercoff, Åsa
    Forshed, Jenny
    Käll, Lukas
    Lehtio, Janne
    HiRIEF LC-MSMS enables deep proteome coverage and unbiased proteogenomics2014Ingår i: Nature Methods, ISSN 1548-7091, E-ISSN 1548-7105, Vol. 11, nr 1, s. 59-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a liquid chromatography-mass spectrometry (LC-MSMS)-based method permitting unbiased (gene prediction-independent) genome-wide discovery of protein-coding loci in higher eukaryotes. Using high-resolution isoelectric focusing (HiRIEF) at the peptide level in the 3.7-5.0 pH range and accurate peptide isoelectric point (pI) prediction, we probed the six-reading-frame translation of the human and mouse genomes and identified 98 and 52 previously undiscovered protein-coding loci, respectively. The method also enabled deep proteome coverage, identifying 13,078 human and 10,637 mouse proteins.

  • 59. Brate, Jon
    et al.
    Neumann, Ralf S.
    Fromm, Bastian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Oslo University Hospital, Norway.
    Haraldsen, Arthur A. B.
    Tarver, James E.
    Suga, Hiroshi
    Donoghue, Philip C. J.
    Peterson, Kevin J.
    Ruiz-Trillo, Inaki
    Grini, Paul E.
    Shalchian-Tabrizi, Kamran
    Unicellular Origin of the Animal MicroRNA Machinery2018Ingår i: Current Biology, ISSN 0960-9822, E-ISSN 1879-0445, Vol. 28, nr 20, s. 3288-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The emergence of multicellular animals was associated with an increase in phenotypic complexity and with the acquisition of spatial cell differentiation and embryonic development. Paradoxically, this phenotypic transition was not paralleled by major changes in the underlying developmental toolkit and regulatory networks. In fact, most of these systems are ancient, established already in the unicellular ancestors of animals [1-5]. In contrast, the Microprocessor protein machinery, which is essential for microRNA (miRNA) biogenesis in animals, as well as the miRNA genes themselves produced by this Microprocessor, have not been identified outside of the animal kingdom [6]. Hence, the Microprocessor, with the key proteins Pasha and Drosha, is regarded as an animal innovation [7-9]. Here, we challenge this evolutionary scenario by investigating unicellular sister lineages of animals through genomic and transcriptomic analyses. We identify in Ichthyosporea both Drosha and Pasha (DGCR8 in vertebrates), indicating that the Microprocessor complex evolved long before the last common ancestor of animals, consistent with a pre-metazoan origin of most of the animal developmental gene elements. Through small RNA sequencing, we also discovered expressed bona fide miRNA genes in several species of the ichthyosporeans harboring the Microprocessor. A deep, pre-metazoan origin of the Microprocessor and miRNAs comply with a view that the origin of multicellular animals was not directly linked to the innovation of these key regulatory components.

  • 60.
    Brindefalk, Björn
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Ekman, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Ininbergs, Karolina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Dupont, Christopher L.
    Yooseph, Shibu
    Pinhassi, Jarone
    Bergman, Birgitta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Distribution and expression of microbial rhodopsins in the Baltic Sea and adjacent waters2016Ingår i: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 18, nr 12, s. 4442-4455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rhodopsins are light-driven ion-pumping membrane proteins found in many organisms and are proposed to be of global importance for oceanic microbial energy generation. Several studies have focused on marine environments, with less exploration of rhodopsins in brackish waters. We investigated microbial rhodopsins in the Baltic Sea using size-fractionated metagenomic and metatranscriptomic datasets collected along a salinity gradient spanning from similar to 0 to 35 PSU. The normalised genomic abundance of rhodopsins in Bacteria, as well as rhodopsin gene expression, was highest in the smallest size fraction (0.1-0.8 mu m), relative to the medium (0.8-3.0 mu m) and large (> 3.0 mu m) size fractions. The abundance of rhodopsins in the two smaller size fractions displayed a positive correlation with salinity. Proteobacteria and Bacteroidetes rhodopsins were the most abundant while Actinobacteria rhodopsins, or actinorhodopsins, were common at lower salinities. Phylogenetic analysis indicated that rhodopsins have adapted independently to the marine-brackish transition on multiple occasions, giving rise to green light-adapted variants from ancestral blue light-adapted ones. A notable diversity of viral-like rhodopsins was also detected in the dataset and potentially linked with eukaryotic phytoplankton blooms. Finally, a new clade of likely proton-pumping rhodopsin with non-canonical amino acids in the spectral tuning and proton accepting site was identified.

  • 61. Briones, Rodolfo
    et al.
    Biau, Christian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Kutzner, Carsten
    de Groot, Bert L.
    Aponte-Santamaria, Camilo
    GROma rho s: A GROMACS-Based Toolset to Analyze Density Maps Derived from Molecular Dynamics Simulations2019Ingår i: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 116, nr 1, s. 4-11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We introduce a computational toolset, named GROma rho s, to obtain and compare time-averaged density maps from molecular dynamics simulations. GROma rho s efficiently computes density maps by fast multi-Gaussian spreading of atomic densities onto a three-dimensional grid. It complements existing map-based tools by enabling spatial inspection of atomic average localization during the simulations. Most importantly, it allows the comparison between computed and reference maps (e.g., experimental) through calculation of difference maps and local and time-resolved global correlation. These comparison operations proved useful to quantitatively contrast perturbed and control simulation data sets and to examine how much biomolecular systems resemble both synthetic and experimental density maps. This was especially advantageous for multimolecule systems in which standard comparisons like RMSDs are difficult to compute. In addition, GROma rho s incorporates absolute and relative spatial free-energy estimates to provide an energetic picture of atomistic localization. This is an open-source GROMACS-based toolset, thus allowing for static or dynamic selection of atoms or even coarse-grained beads for the density calculation. Furthermore, masking of regions was implemented to speed up calculations and to facilitate the comparison with experimental maps. Beyond map comparison, GROma rho s provides a straightforward method to detect solvent cavities and average charge distribution in biomolecular systems. We employed all these functionalities to inspect the localization of lipid and water molecules in aquaporin systems, the binding of cholesterol to the G protein coupled chemokine receptor type 4, and the identification of permeation pathways through the dermicidin antimicrobial channel. Based on these examples, we anticipate a high applicability of GROma rho s for the analysis of molecular dynamics simulations and their comparison with experimentally determined densities.

  • 62. Brocke, Ekaterina
    et al.
    Bhalla, Upinder S.
    Djurfeldt, Mikael
    Hellgren Kotaleski, Jeanette
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Numerisk analys och datalogi (NADA). KTH Royal Institute of Technology, Sweden; Karolinska Institute, Sweden.
    Hanke, Michael
    Efficient Integration of Coupled Electrical-Chemical Systems in Multiscale Neuronal Simulations2016Ingår i: Frontiers in Computational Neuroscience, ISSN 1662-5188, E-ISSN 1662-5188, Vol. 10, artikel-id 97Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multiscale modeling and simulations in neuroscience is gaining scientific attention due to its growing importance and unexplored capabilities. For instance, it can help to acquire better understanding of biological phenomena that have important features at multiple scales of time and space. This includes synaptic plasticity, memory formation and modulation, homeostasis. There are several ways to organize multiscale simulations depending on the scientific problem and the system to be modeled. One of the possibilities is to simulate different components of a multiscale system simultaneously and exchange data when required. The latter may become a challenging task for several reasons. First, the components of a multiscale system usually span different spatial and temporal scales, such that rigorous analysis of possible coupling solutions is required. Then, the components can be defined by different mathematical formalisms. For certain classes of problems a number of coupling mechanisms have been proposed and successfully used. However, a strict mathematical theory is missing in many cases. Recent work in the field has not so far investigated artifacts that may arise during coupled integration of different approximation methods. Moreover, in neuroscience, the coupling of widely used numerical fixed step size solvers may lead to unexpected inefficiency. In this paper we address the question of possible numerical artifacts that can arise during the integration of a coupled system. We develop an efficient strategy to couple the components comprising a multiscale test problem in neuroscience. We introduce an efficient coupling method based on the second-order backward differentiation formula (BDF2) numerical approximation. The method uses an adaptive step size integration with an error estimation proposed by Skelboe (2000). The method shows a significant advantage over conventional fixed step size solvers used in neuroscience for similar problems. We explore different coupling strategies that define the organization of computations between system components. We study the importance of an appropriate approximation of exchanged variables during the simulation. The analysis shows a substantial impact of these aspects on the solution accuracy in the application to our multiscale neuroscientific test problem. We believe that the ideas presented in the paper may essentially contribute to the development of a robust and efficient framework for multiscale brain modeling and simulations in neuroscience.

  • 63. Brodin, Johanna
    et al.
    Mild, Mattias
    Hedskog, Charlotte
    Sherwood, Ellen
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Leitner, Thomas
    Andersson, Bjoern
    Albert, Jan
    PCR-Induced Transitions Are the Major Source of Error in Cleaned Ultra-Deep Pyrosequencing Data2013Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, nr 7, artikel-id e70388Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Ultra-deep pyrosequencing (UDPS) is used to identify rare sequence variants. The sequence depth is influenced by several factors including the error frequency of PCR and UDPS. This study investigated the characteristics and source of errors in raw and cleaned UDPS data. Results: UDPS of a 167-nucleotide fragment of the HIV-1 SG3Denv plasmid was performed on the Roche/454 platform. The plasmid was diluted to one copy, PCR amplified and subjected to bidirectional UDPS on three occasions. The dataset consisted of 47,693 UDPS reads. Raw UDPS data had an average error frequency of 0.30% per nucleotide site. Most errors were insertions and deletions in homopolymeric regions. We used a cleaning strategy that removed almost all indel errors, but had little effect on substitution errors, which reduced the error frequency to 0.056% per nucleotide. In cleaned data the error frequency was similar in homopolymeric and non-homopolymeric regions, but varied considerably across sites. These site-specific error frequencies were moderately, but still significantly, correlated between runs (r = 0.15-0.65) and between forward and reverse sequencing directions within runs (r = 0.33-0.65). Furthermore, transition errors were 48-times more common than transversion errors (0.052% vs. 0.001%; p<0.0001). Collectively the results indicate that a considerable proportion of the sequencing errors that remained after data cleaning were generated during the PCR that preceded UDPS. Conclusions: A majority of the sequencing errors that remained after data cleaning were introduced by PCR prior to sequencing, which means that they will be independent of platform used for next-generation sequencing. The transition vs. transversion error bias in cleaned UDPS data will influence the detection limits of rare mutations and sequence variants.

  • 64.
    Bromstrup, Torben
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Howard, Rebecca J.
    Trudell, James R.
    Harris, R. Adron
    Lindahl, Erik
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Inhibition versus Potentiation of Ligand-Gated Ion Channels Can Be Altered by a Single Mutation that Moves Ligands between Intra- and Intersubunit Sites2013Ingår i: Structure, ISSN 0969-2126, E-ISSN 1878-4186, Vol. 21, nr 8, s. 1307-1316Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pentameric ligand-gated ion channels (pLGICs) are similar in structure but either inhibited or potentiated by alcohols and anesthetics. This dual modulation has previously not been understood, but the determination of X-ray structures of prokaryotic GLIC provides an ideal model system. Here, we show that a single-site mutation at the F14' site in the GLIC transmembrane domain turns desflurane and chloroform from inhibitors to potentiators, and that this is explained by competing allosteric sites. The F14'A mutation opens an intersubunit site lined by N239 (15'), 1240 (16'), and Y263. Free energy calculations confirm this site is the preferred binding location for desflurane and chloroform in GLIC F14'A. In contrast, both anesthetics prefer an intrasubunit site in wild-type GLIC. Modulation is therefore the net effect of competitive binding between the intersubunit potentiating site and an intrasubunit inhibitory site. This provides direct evidence for a dual-site model of allosteric regulation of pLGICs.

  • 65. Brown, Alan
    et al.
    Rathore, Sorbhi
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Kimanius, Dari
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Aibara, Shintaro
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Bai, Xiao-chen
    Rorbach, Joanna
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Karolinska Institutet, Sweden.
    Amunts, Alexey
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). MRC Laboratory of Molecular Biology, UK.
    Ramakrishnan, V.
    Structures of the human mitochondrial ribosome in native states of assembly2017Ingår i: Nature Structural & Molecular Biology, ISSN 1545-9993, E-ISSN 1545-9985, Vol. 24, nr 10, s. 866-869Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mammalian mitochondrial ribosomes (mitoribosomes) have less rRNA content and 36 additional proteins compared with the evolutionarily related bacterial ribosome. These differences make the assembly of mitoribosomes more complex than the assembly of bacterial ribosomes, but the molecular details of mitoribosomal biogenesis remain elusive. Here, we report the structures of two late-stage assembly intermediates of the human mitoribosomal large subunit (mt-LSU) isolated from a native pool within a human cell line and solved by cryo-EM to similar to 3-angstrom resolution. Comparison of the structures reveals insights into the timing of rRNA folding and protein incorporation during the final steps of ribosomal maturation and the evolutionary adaptations that are required to preserve biogenesis after the structural diversification of mitoribosomes. Furthermore, the structures redefine the ribosome silencing factor (RsfS) family as multifunctional biogenesis factors and identify two new assembly factors (L0R8F8 and mt-ACP) not previously implicated in mitoribosomal biogenesis.

  • 66. Buetti-Dinh, Antoine
    et al.
    Dethlefsen, Olga
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Friedman, Ran
    Dopson, Mark
    Transcriptomic analysis reveals how a lack of potassium ions increases Sulfolobus acidocaldarius sensitivity to pH changes2016Ingår i: Microbiology, ISSN 1350-0872, E-ISSN 1465-2080, Vol. 162, nr 8, s. 1422-1434Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Extremely acidophilic microorganisms (optimum growth pH of <= 3) maintain a near neutral cytoplasmic pH via several homeostatic mechanisms, including an inside positive membrane potential created by potassium ions. Transcriptomic responses to pH stress in the thermoacidophilic archaeon, Sulfolobus acidocaldarius were investigated by growing cells without added sodium and/or potassium ions at both optimal and sub-optimal pH. Culturing the cells in the absence of added sodium or potassium ions resulted in a reduced growth rate compared to full-salt conditions as well as 43 and 75 significantly different RNA transcript ratios, respectively. Differentially expressed RNA transcripts during growth in the absence of added sodium ions included genes coding for permeases, a sodium/proline transporter and electron transport proteins. In contrast, culturing without added potassium ions resulted in higher RNA transcripts for similar genes as a lack of sodium ions plus genes related to spermidine that has a general role in response to stress and a decarboxylase that potentially consumes protons. The greatest RNA transcript response occurred when S. acidocaldarius cells were grown in the absence of potassium and/or sodium at a sub-optimal pH. These adaptations included those listed above plus osmoregulated glucans and mechanosensitive channels that have previously been shown to respond to osmotic stress. In addition, data analyses revealed two co-expressed IcIR family transcriptional regulator genes with a previously unknown role in the S. acidocaldarius pH stress response. Our study provides additional evidence towards the importance of potassium in acidophile growth at acidic pH.

  • 67. Bugiardini, Enrico
    et al.
    Mitchell, Alice L.
    Dalla Rosa, Ilaria
    Horning-Do, Hue-Tran
    Pitmann, Alan M.
    Poole, Olivia
    Holton, Janice L.
    Shah, Sachit
    Woodward, Cathy
    Hargreaves, Iain
    Quinlivan, Rosaline
    Amunts, Alexey
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Karolinska Institutet, Sweden.
    Wiesner, Rudolf J.
    Houlden, Henry
    Holt, Ian J.
    Hanna, Michael G.
    Pitceathly, Robert D. S.
    Spinazzola, Antonella
    MRPS25 mutations impair mitochondrial translation and cause encephalomyopathy2019Ingår i: Human Molecular Genetics, ISSN 0964-6906, E-ISSN 1460-2083, Vol. 28, nr 16, s. 2711-2719Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mitochondrial disorders are clinically and genetically heterogeneous and are associated with a variety of disease mechanisms. Defects of mitochondrial protein synthesis account for the largest subgroup of disorders manifesting with impaired respiratory chain capacity; yet, only a few have been linked to dysfunction in the protein components of the mitochondrial ribosomes. Here, we report a subject presenting with dyskinetic cerebral palsy and partial agenesis of the corpus callosum, while histochemical and biochemical analyses of skeletal muscle revealed signs of mitochondrial myopathy. Using exome sequencing, we identified a homozygous variant c.215C>T in MRPS25, which encodes for a structural component of the 28S small subunit of the mitochondrial ribosome (mS25). The variant segregated with the disease and substitutes a highly conserved proline residue with leucine (p.P72L) that, based on the high-resolution structure of the 28S ribosome, is predicted to compromise inter-protein contacts and destabilize the small subunit. Concordant with the in silico analysis, patient's fibroblasts showed decreased levels of MRPS25 and other components of the 28S subunit. Moreover, assembled 28S subunits were scarce in the fibroblasts with mutant mS25 leading to impaired mitochondrial translation and decreased levels of multiple respiratory chain subunits. Crucially, these abnormalities were rescued by transgenic expression of wild-type MRPS25 in the mutant fibroblasts. Collectively, our data demonstrate the pathogenicity of the p.P72L variant and identify MRPS25 mutations as a new cause of mitochondrial translation defect.

  • 68. Bustamante, M.
    et al.
    Hernandez-Ferrer, C.
    Tewari, A.
    Sarria, Y.
    Harrison, G. I.
    Puigdecanet, E.
    Nonell, L.
    Kang, Wenjing
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Friedländer, Marc R.
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Estivill, X.
    González, J. R.
    Nieuwenhuijsen, M.
    Young, A. R.
    Dose and time effects of solar-simulated ultraviolet radiation on the in vivo human skin transcriptome2020Ingår i: British Journal of Dermatology, ISSN 0007-0963, E-ISSN 1365-2133Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background Terrestrial ultraviolet (UV) radiation causes erythema, oxidative stress, DNA mutations and skin cancer. Skin can adapt to these adverse effects by DNA repair, apoptosis, keratinization and tanning.

    Objectives To investigate the transcriptional response to fluorescent solar-simulated radiation (FSSR) in sun-sensitive human skin in vivo.

    Methods Seven healthy male volunteers were exposed to 0, 3 and 6 standard erythemal doses (SED). Skin biopsies were taken at 6 h and 24 h after exposure. Gene and microRNA expression were quantified with next generation sequencing. A set of candidate genes was validated by quantitative polymerase chain reaction (qPCR); and wavelength dependence was examined in other volunteers through microarrays.

    Results The number of differentially expressed genes increased with FSSR dose and decreased between 6 and 24 h. Six hours after 6 SED, 4071 genes were differentially expressed, but only 16 genes were affected at 24 h after 3 SED. Genes for apoptosis and keratinization were prominent at 6 h, whereas inflammation and immunoregulation genes were predominant at 24 h. Validation by qPCR confirmed the altered expression of nine genes detected under all conditions; genes related to DNA repair and apoptosis; immunity and inflammation; pigmentation; and vitamin D synthesis. In general, candidate genes also responded to UVA1 (340-400 nm) and/or UVB (300 nm), but with variations in wavelength dependence and peak expression time. Only four microRNAs were differentially expressed by FSSR.

    Conclusions The UV radiation doses of this acute study are readily achieved daily during holidays in the sun, suggesting that the skin transcriptional profile of 'typical' holiday makers is markedly deregulated.

  • 69. Bustamante, Mariona
    et al.
    Hernandez-Ferrer, Caries
    Sarria, Yaris
    Harrison, Graham I.
    Nonell, Lara
    Kang, Wenjing
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Friedlander, Marc R.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Estivill, Xavier
    Gonzalez, Juan R.
    Nieuwenhuijsen, Mark
    Young, Antony R.
    The acute effects of ultraviolet radiation on the blood transcriptome are independent of plasma 25OHD(3)2017Ingår i: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 159, s. 239-248Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The molecular basis of many health outcomes attributed to solar ultraviolet radiation (UVR) is unknown. We tested the hypothesis that they may originate from transcriptional changes in blood cells. This was determined by assessing the effect of fluorescent solar simulated radiation (FSSR) on the transcriptional profile of peripheral blood pre- and 6 h, 24 h and 48 h post-exposure in nine healthy volunteers. Expression of 20 genes was down regulated and one was up-regulated at 6 h after FSSR. All recovered to baseline expression at 24 h or 48 h. These genes have been associated with immune regulation, cancer and blood pressure; health effects attributed to vitamin D via solar UVR exposure. Plasma 25-hydroxyvitamin D-3 [250HD(3)] levels increased over time after FSSR and were maximal at 48 h. The increase was more pronounced in participants with low basal 250HD(3) levels. Mediation analyses suggested that changes in gene expression due to FSSR were independent of 250HD(3) and blood cell subpopulations.

  • 70.
    Calado Botelho, Salomé
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Tatsuta, Takashi
    von Heijne, Gunnar
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Kim, Hyun
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Seoul National University, South Korea.
    Dislocation by the m-AAA Protease Increases the Threshold Hydrophobicity for Retention of Transmembrane Helices in the Inner Membrane of Yeast Mitochondria2013Ingår i: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 288, nr 7, s. 4792-4798Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sorting of mitochondrial inner membrane proteins is a complex process in which translocons and proteases function in a concerted way. Many inner membrane proteins insert into the membrane via the TIM23 translocon, and some are then further acted upon by the mitochondrial m-AAA protease, a molecular motor capable of dislocating proteins from the inner membrane. This raises the possibility that the threshold hydrophobicity for the retention of transmembrane segments in the inner membrane is different depending on whether they belong to membrane proteins that are m-AAA protease substrates or not. Here, using model transmembrane segments engineered into m-AAA protease-dependent proteins, we show that the threshold hydrophobicity for membrane retention measured in yeast cells in the absence of a functional m-AAA protease is markedly lower than that measured in its presence. Whether a given hydrophobic segment in a mitochondrial inner membrane protein will ultimately form a transmembrane helix may therefore depend on whether or not it will be exposed to the pulling force exerted by the m-AAA protease during biogenesis.

  • 71. Campos, Alexandre
    et al.
    Danielsson, Gabriela
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Farinha, Ana Paula
    Kuruvilla, Jacob
    Warholm, Per
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Cristobal, Susana
    Shotgun proteomics to unravel marine mussel (Mytilus edulis) response to long-term exposure to low salinity and propranolol in a Baltic Sea microcosm2016Ingår i: Journal of Proteomics, ISSN 1874-3919, E-ISSN 1876-7737, Vol. 137, s. 97-106Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pharmaceuticals, among them thep-adrenoceptor blocker propranolol, are an important group of environmental contaminants reported in European waters. Laboratory exposure to pharmaceuticals on marine species has been performed without considering the input of the ecosystem flow. To unravel the ecosystem response to long-term exposure to propranolol we have performed long-term exposure to propranolol and low salinity in microcosms. We applied shotgun proteomic analysis to gills of Mytilus edulis from those Baltic Sea microcosms and identified 2071 proteins with a proteogenomic strategy. The proteome profiling patterns from the 587 highly reproductive proteins among groups define salinity as a key factor in the mussel's response to propranolol. Exposure at low salinity drives molecular mechanisms of adaptation based on a decrease in the abundance of several cytoskeletal proteins, signalling and intracellular membrane trafficking pathway combined with a response towards the maintenance of transcription and translation. The exposure to propranolol combined with low salinity modulates the expression of structural proteins including cilia functions and decreases the expression of membrane protein transporters. This study reinforces the environment concerns of the impact of low salinity in combination with anthropogenic pollutants and anticipates critical physiological conditions for the survival of the blue mussel in the northern areas. Biological significance: Applying shotgun proteomic analysis to M. edulis gills samples from a long-term microcosm exposure to propranolol and following a proteogenomic identification strategy, we have identified 2071 proteins. The proteomic analysis unrevealed which molecular mechanisms drive the adaptation to low salinity stress and how salinity modulates the effects of exposure to propranolol. These results reinforce the idea of the impact of low salinity in combination with anthropogenic pollutants and anticipate critical physiological condition.

  • 72. Carinelli, S.
    et al.
    Kühnemund, M.
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Pividori, M. I.
    Yoctomole electrochemical genosensing of Ebola virus cDNA by rolling circle and circle to circle amplification2017Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 93, s. 65-71Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work addresses the design of an Ebola diagnostic test involving a simple, rapid, specific and highly sensitive procedure based on isothermal amplification on magnetic particles with electrochemical readout. Ebola padlock probes were designed to detect a specific L-gene sequence present in the five most common Ebola species. Ebola cDNA was amplified by rolling circle amplification (RCA) on magnetic particles. Further re-amplification was performed by circle-to-circle amplification (C2CA) and the products were detected in a double-tagging approach using a biotinylated capture probe for immobilization on magnetic particles and a readout probe for electrochemical detection by square-wave voltammetry on commercial screen-printed electrodes. The electrochemical genosensor was able to detect as low as 200 ymol, corresponding to 120 cDNA molecules of L-gene Ebola virus with a limit of detection of 33 cDNA molecules. The isothermal double-amplification procedure by C2CA combined with the electrochemical readout and the magnetic actuation enables the high sensitivity, resulting in a rapid, inexpensive, robust and user-friendly sensing strategy that offers a promising approach for the primary care in low resource settings, especially in less developed countries.

  • 73. Carow, Berit
    et al.
    Hauling, Thomas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Qian, Xiaoyan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Kramnik, Igor
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Rottenberg, Martin E.
    Spatial and temporal localization of immune transcripts defines hallmarks and diversity in the tuberculosis granuloma2019Ingår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, artikel-id 1823Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Granulomas are the pathological hallmark of tuberculosis (TB) and the niche where bacilli can grow and disseminate or the immunological microenvironment in which host cells interact to prevent bacterial dissemination. Here we show 34 immune transcripts align to the morphology of lung sections from Mycobacterium tuberculosis-infected mice at cellular resolution. Colocalizing transcript networks at <10 mu m in C57BL/6 mouse granulomas increase complexity with time after infection. B-cell clusters develop late after infection. Transcripts from activated macrophages are enriched at subcellular distances from M. tuberculosis. Encapsulated C3HeB/FeJ granulomas show necrotic centers with transcripts associated with immunosuppression (Foxp3, Il10), whereas those in the granuloma rims associate with activated T cells and macrophages. We see highly diverse networks with common interactors in similar lesions. Different immune landscapes of M. tuberculosis granulomas depending on the time after infection, the histopathological features of the lesion, and the proximity to bacteria are here defined.

  • 74. Carreras-Puigvert, Jordi
    et al.
    Zitnik, Marinka
    Jemth, Ann-Sofie
    Carter, Megan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Unterlass, Judith E.
    Hallström, Björn
    Loseva, Olga
    Karem, Zhir
    Calderón-Montaño, José Manuel
    Lindskog, Cecilia
    Edqvist, Per-Henrik
    Matuszewski, Damian J.
    Blal, Hammou Ait
    Berntsson, Ronnie P. A.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Häggblad, Maria
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Martens, Ulf
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Studham, Matthew
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Lundgren, Bo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Wählby, Carolina
    Sonnhammer, Erik L. L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Lundberg, Emma
    Stenmark, Pål
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Zupan, Blaz
    Helleday, Thomas
    A comprehensive structural, biochemical and biological profiling of the human NUDIX hydrolase family2017Ingår i: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, artikel-id 1541Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The NUDIX enzymes are involved in cellular metabolism and homeostasis, as well as mRNA processing. Although highly conserved throughout all organisms, their biological roles and biochemical redundancies remain largely unclear. To address this, we globally resolve their individual properties and inter-relationships. We purify 18 of the human NUDIX proteins and screen 52 substrates, providing a substrate redundancy map. Using crystal structures, we generate sequence alignment analyses revealing four major structural classes. To a certain extent, their substrate preference redundancies correlate with structural classes, thus linking structure and activity relationships. To elucidate interdependence among the NUDIX hydrolases, we pairwise deplete them generating an epistatic interaction map, evaluate cell cycle perturbations upon knockdown in normal and cancer cells, and analyse their protein and mRNA expression in normal and cancer tissues. Using a novel FUSION algorithm, we integrate all data creating a comprehensive NUDIX enzyme profile map, which will prove fundamental to understanding their biological functionality.

  • 75. Carstens, Adam
    et al.
    Roos, Annika
    Andreasson, Anna
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Stressforskningsinstitutet. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Karolinska Institute, Sweden.
    Magnuson, Anders
    Agreus, Lars
    Halfvarson, Jonas
    Engstrand, Lars
    Differential clustering of fecal and mucosa-associated microbiota in 'healthy' individuals2018Ingår i: Journal of Digestive Diseases, ISSN 1751-2972, E-ISSN 1751-2980, Vol. 19, nr 12, s. 745-752Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective Fecal samples are often used to characterize gut microbiota. However, whether or not fecal microbiota differs from mucosa-associated microbiota remains largely unknown. This may be specifically relevant in conditions that are characterized by complex mucosal microbe-host interactions, such as Crohn's disease. We aimed to determine the degree of agreement between fecal and mucosal microbiota profiles in 'healthy' individuals, using two commonly used collection procedures. Methods The gut microbiota composition of fecal samples (sent at ambient temperature before storage at -70 degrees C) and of colonic biopsies (obtained at endoscopy and immediately stored at -70 degrees C) was determined by sequencing the 16S rRNA gene. Altogether 31 randomly selected 'healthy' individuals from the population-based colonoscopy (Popcol) study were included. Results The fecal samples were characterized by a reduced degree of richness (P < 0.0001) and diversity (P = 0.016), and also differences in several phyla, including a lower relative abundance of Proteobacteria (P < 0.0001) and Verrucomicrobia (P = 0.008) than in biopsies. Only three of 30 individuals had a similar fecal and mucosal microbiota profile, based on weighted UniFrac analysis. A difference in Crohn's disease dysbiosis-associated bacteria was observed, including a lower relative abundance of Faecalibacterium (P = 0.004) and a higher relative abundance of Ruminococcus (P = 0.001) in feces than in biopsies. Conclusions The observed differences between fecal samples, transported at ambient temperature, and the colonic mucosa-associated microbiota have implications for the interpretation of the previous literature, and may be specifically relevant to studies on Crohn's disease.

  • 76. Cedernaes, Jonathan
    et al.
    Schonke, Milena
    Orzechowski Westholm, Jakub
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Mi, Jia
    Chibalin, Alexander
    Voisin, Sarah
    Osler, Megan
    Vogel, Heike
    Hornaeus, Katarina
    Dickson, Suzanne L.
    Lind, Sara Bergstrom
    Bergquist, Jonas
    Schioth, Helgi B.
    Zierath, Juleen R.
    Benedict, Christian
    Acute sleep loss results in tissue-specific alterations in genome-wide DNA methylation state and metabolic fuel utilization in humans2018Ingår i: Science Advances, ISSN 0036-8156, E-ISSN 2375-2548, Vol. 4, nr 8, artikel-id eaar8590Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Curtailed sleep promotes weight gain and loss of lean mass in humans, although the underlying molecular mechanisms are poorly understood. We investigated the genomic and physiological impact of acute sleep loss in peripheral tissues by obtaining adipose tissue and skeletal muscle after one night of sleep loss and after one full night of sleep. We find that acute sleep loss alters genome-wide DNA methylation in adipose tissue, and unbiased transcriptome-, protein-, and metabolite-level analyses also reveal highly tissue-specific changes that are partially reflected by altered metabolite levels in blood. We observe transcriptomic signatures of inflammation in both tissues following acute sleep loss, but changes involving the circadian clock are evident only in skeletal muscle, and we uncover molecular signatures suggestive of muscle breakdown that contrast with an anabolic adipose tissue signature. Our findings provide insight into how disruption of sleep and circadian rhythms may promote weight gain and sarcopenia.

  • 77.
    Celepli, Narin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Sundh, John
    Ekman, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Dupont, Chris L.
    Yooseph, Shibu
    Bergman, Birgitta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Ininbergs, Karolina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Meta-omic analyses of Baltic Sea cyanobacteria: diversity, community structure and salt acclimation2017Ingår i: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 19, nr 2, s. 673-686Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cyanobacteria are important phytoplankton in the Baltic Sea, an estuarine-like environment with pronounced north to south gradients in salinity and nutrient concentrations. Here, we present a metagenomic and -transcriptomic survey, with subsequent analyses targeting the genetic identity, phylogenetic diversity, and spatial distribution of Baltic Sea cyanobacteria. The cyanobacterial community constituted close to 12% of the microbial population sampled during a pre-bloom period (June-July 2009). The community was dominated by unicellular picocyanobacteria, specifically a few highly abundant taxa (Synechococcus and Cyanobium) with a long tail of low abundance representatives, and local peaks of bloom-forming heterocystous taxa. Cyanobacteria in the Baltic Sea differed genetically from those in adjacent limnic and marine waters as well as from cultivated and sequenced picocyanobacterial strains. Diversity peaked at brackish salinities 3.5-16psu, with low N:P ratios. A shift in community composition from brackish to marine strains was accompanied by a change in the repertoire and expression of genes involved in salt acclimation. Overall, the pre-bloom cyanobacterial population was more genetically diverse, widespread and abundant than previously documented, with unicellular picocyanobacteria being the most abundant clade along the entire Baltic Sea salinity gradient.

  • 78.
    Celorio-Mancera, Maria de la Paz
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för zoologisk ekologi.
    Sundmalm, Sara M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för zoologisk ekologi.
    Vogel, Heiko
    Rutishauser, Dorothea
    Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Ytterberg, A. Jimmy
    Zubarev, Roman A.
    Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Janz, Niklas
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen, Avdelningen för zoologisk ekologi.
    Chemosensory proteins, major salivary factors in caterpillar mandibular glands2012Ingår i: Insect Biochemistry and Molecular Biology, ISSN 0965-1748, E-ISSN 1879-0240, Vol. 42, nr 10, s. 796-805Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Research in the field of insect-host plant interactions has indicated that constituents of insect saliva play an important role in digestion and affect host chemical defense responses. However, most efforts have focused on studying the composition and function of regurgitant or saliva produced in the labial glands. Acknowledging the need for understanding the role of the mandibular glands in herbivory, we sought to make a qualitative and semi-quantitative comparison of soluble luminal fractions between mandibular and labial glands of Vanessa gonerilla butterfly larvae. Amylase and lysozyme were inspected as possible major enzymatic activities in the mandibular glands aiding in pre-digestion and antimicrobial defense. Although detected, neither of these enzymatic activities was prominent in the luminal protein preparation of a particular type of gland. Proteins isolated from the glands were identified by mass spectrometry and by searching an EST-library database generated for four other nymphalid butterfly species, in addition to the public NCBI database. The identified proteins were also quantified from thedata using “Quanty”, an in-house program. The proteomic analysis detected chemosensory proteins as the most abundant luminal proteins in the mandibular glands. In comparison to these proteins, the relative amounts of amylase and lysozyme were much lower in both gland types. Therefore, we speculate that the primary role of the mandibular glands in Lepidopteran larvae is chemoreception which may include the detection of microorganisms on plant surfaces, host plant recognition and communication with conspecifics.

  • 79. Chen, Dan
    et al.
    Ranganathan, Anirudh
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Ijzerman, Adriaan P.
    Siegal, Gregg
    Carlsson, Jens
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Complementarity between in Silico and Biophysical Screening Approaches in Fragment-Based Lead Discovery against the A(2A) Adenosine Receptor2013Ingår i: Journal of Chemical Information and Modeling, ISSN 1549-9596, E-ISSN 1549-960X, Vol. 53, nr 10, s. 2701-2714Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fragment-based lead discovery (FBLD) is becoming an increasingly important method in drug development. We have explored the potential to complement NMR-based biophysical screening of chemical libraries with molecular docking in FBLD against the A(2A) adenosine receptor (A(2A)AR), a drug target for inflammation and Parkinson's disease. Prior to an NMR-based screen of a fragment library against the A(2A)AR, molecular docking against a crystal structure was used to rank the same set of molecules by their predicted affinities. Molecular docking was able to predict four out of the five orthosteric ligands discovered by NMR among the top 5% of the ranked library, suggesting that structure-based methods could be used to prioritize among primary hits from biophysical screens. In addition, three fragments that were top-ranked by molecular docking, but had not been picked up by the NMR-based method, were demonstrated to be A2AAR ligands. While biophysical approaches for fragment screening are typically limited to a few thousand compounds, the docking screen was extended to include 328,000 commercially available fragments. Twenty-two top-ranked compounds were tested in radioligand binding assays, and 14 of these were A(2A)AR ligands with K-i values ranging from 2 to 240 mu M. Optimization of fragments was guided by molecular dynamics simulations and free energy calculations. The results illuminate strengths and weaknesses of molecular docking and demonstrate that this method can serve as a valuable complementary tool to biophysical screening in FBLD.

  • 80. Cheng, Jianlin
    et al.
    Choe, Myong‐Ho
    Elofsson, Arne
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Han, Kun-Sop
    Hou, Jie
    Maghrabi, Ali H. A.
    McGuffin, Liam J.
    Menéndez-Hurtado, David
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Olechnovič, Kliment
    Schwede, Torsten
    Studer, Gabriel
    Uziela, Karolis
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Venclovas, Česlovas
    Wallner, Björn
    Estimation of model accuracy in CASP132019Ingår i: Proteins: Structure, Function, and Bioinformatics, ISSN 0887-3585, E-ISSN 1097-0134, Vol. 87, nr 12, s. 1361-1377Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Methods to reliably estimate the accuracy of 3D models of proteins are both a fundamental part of most protein folding pipelines and important for reliable identification of the best models when multiple pipelines are used. Here, we describe the progress made from CASP12 to CASP13 in the field of estimation of model accuracy (EMA) as seen from the progress of the most successful methods in CASP13. We show small but clear progress, that is, several methods perform better than the best methods from CASP12 when tested on CASP13 EMA targets. Some progress is driven by applying deep learning and residue‐residue contacts to model accuracy prediction. We show that the best EMA methods select better models than the best servers in CASP13, but that there exists a great potential to improve this further. Also, according to the evaluation criteria based on local similarities, such as lDDT and CAD, it is now clear that single model accuracy methods perform relatively better than consensus‐based methods.

  • 81. Chinh, Bkrong
    et al.
    Alsøe, Lene
    Lindvall, Jessica M.
    Stockholms universitet, Science for Life Laboratory (SciLifeLab). Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Sulheim, Dag
    Fagermoen, Even
    Winger, Anette
    Kaarbø, Mari
    Nilsen, Hilde
    Bruun Wyller, Vegard
    Whole blood gene expression in adolescent chronic fatigue syndrome: an exploratory cross-sectional study suggesting altered B cell differentiation and survival2017Ingår i: Journal of Translational Medicine, ISSN 1479-5876, E-ISSN 1479-5876, Vol. 15, artikel-id 102Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    Chronic fatigue syndrome (CFS) is a prevalent and disabling condition affecting adolescents. The pathophysiology is poorly understood, but immune alterations might be an important component. This study compared whole blood gene expression in adolescent CFS patients and healthy controls, and explored associations between gene expression and neuroendocrine markers, immune markers and clinical markers within the CFS group.

    Methods

    CFS patients (12-18 years old) were recruited nation-wide to a single referral center as part of the Nor-CAPITAL project. A broad case definition of CFS was applied, requiring 3 months of unexplained, disabling chronic/ relapsing fatigue of new onset, whereas no accompanying symptoms were necessary. Healthy controls having comparable distribution of gender and age were recruited from local schools. Whole blood samples were subjected to RNA sequencing. Immune markers were blood leukocyte counts, plasma cytokines, serum C-reactive protein and immunoglobulins. Neuroendocrine markers encompassed plasma and urine levels of catecholamines and cortisol, as well as heart rate variability indices. Clinical markers consisted of questionnaire scores for symptoms of post-exertional malaise, inflammation, fatigue, depression and trait anxiety, as well as activity recordings.

    Results

    A total of 29 CFS patients and 18 healthy controls were included. We identified 176 genes as differentially expressed in patients compared to controls, adjusting for age and gender factors. Gene set enrichment analyses suggested impairment of B cell differentiation and survival, as well as enhancement of innate antiviral responses and inflammation in the CFS group. A pattern of co-expression could be identified, and this pattern, as well as single gene transcripts, was significantly associated with indices of autonomic nervous activity, plasma cortisol, and blood monocyte and eosinophil counts. Also, an association with symptoms of post-exertional malaise was demonstrated.

    Conclusion

    Adolescent CFS is characterized by differential gene expression pattern in whole blood suggestive of impaired B cell differentiation and survival, and enhanced innate antiviral responses and inflammation. This expression pattern is associated with neuroendocrine markers of altered HPA axis and autonomic nervous activity, and with symptoms of post-exertional malaise.

  • 82.
    Ciftci, Sibel
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Neumann, Felix
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Abdurahman, Samir
    Appelberg, Sofia
    Mirazimi, Ali
    Madaboosi, Narayanan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Multiplexed rolling circle amplification detection of Ebola, Zika and Dengue towards point-of-care diagnosticsManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Emerging tropical viruses have caused serious outbreaks during the recent years, such as Ebola virus (EBOV) in 2014 and the most recent 2018-19 outbreak in Congo. Immediate diagnostic attention is demanded, and most importantly at the point-of-care in resource-limited settings. The performance and the operational parameters of conventional EBOV testing are limited by either their sensitivity, specificity, or both, and often do not cover other tropical disease viruses. We present a padlock probe (PLP)-based rolling circle amplification (RCA) method for the detection of EBOV from cell culture isolates as well as clinical samples obtained from patients of West Africa outbreak. For this, a set of PLPs, separately targeting the vRNA and cRNA of all the seven genes of EBOV, were used in the RCA and validated on virus isolates from cell culture. The assay was then translated for testing clinical samples, and simultaneous duplex detection of both EBOV vRNA and cRNA was demonstrated. For increased sensitivity, the RCA products were enriched on a simple and pump-free microfluidic chip. As PLPs and RCA are inherently mulitplexable, we demonstrate the extension of the probe panel to the simultaneous detection of the tropical viruses Ebola, Zika and Dengue. The simple, rapid, specific and multiplexable isothermal assay developed for tropical virus detection suits the point-of-care needs, bringing RCA a step closer to bedside diagnostics.

  • 83.
    Ciftci, Sibel
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Neumann, Felix
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Hernández-Neuta, Iván
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Hakhverdyan, Mikhayil
    Bálint, Ádám
    Herthnek, David
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Madaboosi, Narayanan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    A novel mutation tolerant padlock probe design for multiplexed detection of hypervariable RNA viruses2019Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, artikel-id 2872Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The establishment of a robust detection platform for RNA viruses still remains a challenge in molecular diagnostics due to their high mutation rates. Newcastle disease virus (NDV) is one such RNA avian virus with a hypervariable genome and multiple genotypes. Classical approaches like virus isolation, serology, immunoassays and RT-PCR are cumbersome, and limited in terms of specificity and sensitivity. Padlock probes (PLPs) are known for allowing the detection of multiple nucleic acid targets with high specificity, and in combination with Rolling circle amplification (RCA) have permitted the development of versatile pathogen detection assays. In this work, we aimed to detect hypervariable viruses by developing a novel PLP design strategy capable of tolerating mutations while preserving high specificity by targeting several moderately conserved regions and using degenerate bases. For this, we designed nine padlock probes based on the alignment of 335 sequences covering both Class I and II NDV. Our PLP design showed high coverage and specificity for the detection of eight out of ten reported genotypes of Class II NDV field isolated strains, yielding a detection limit of less than ten copies of viral RNA. Further taking advantage of the multiplex capability of PLPs, we successfully extended the assay for the simultaneous detection of three poultry RNA viruses (NDV, IBV and AIV) and combined it with a paper based microfluidic enrichment read-out for digital quantification. In summary, our novel PLP design addresses the current issue of tolerating mutations of highly emerging virus strains with high sensitivity and specificity.

  • 84.
    Ciftci, Sibel
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Neumann, Felix
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Paulraj, Thomas
    Crespo, Gaston
    Madaboosi, Narayanan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    The sweet detection of rolling circle amplification: Glucose-based electrochemical detection of virus nucleic acidManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Infectious diseases remain a constant threat on a global scale by recurring pandemics. Rapid and portable diagnostics hold the promise to tackle the spreading of diseases and decentralizing healthcare to point-of-care needs. Ebola, a hypervariable RNA virus causing fatalities of up to 90% for recent outbreaks in Africa, demands immediate attention for bedside diagnostics. Nucleic acid amplification technology (NAAT) has proven to be a powerful tool for the control of outbreak with high sensitivity and specificity. However, NAAT is mostly based on amplification methods that require specialized instrumentation and trained personnel, such as PCR with sophisticated detectors. Here, we present an isothermal padlock probe-based assay for the detection of pathogens coupled with a glucose oxidase (GOx)-based electrochemical approach as the read-out. The assay design is based on rolling circle amplification (RCA) upon magnetic beads, connecting the RCA products (RCPs) via streptavidin-biotin bridges to GOx needed for the electrochemical measurement with externally provided glucose. The RCPs forming on the surface of beads are imaged using scanning electron microscopy, and the presence of the GOx to the RCP complex is confirmed using atomic force microscopy. Parameters such as the choice of buffers, concentrations of glucose and GOx and measurement time were optimized, as well as the mode of addition of glucose was tested. 125 μg/mL of GOx with 5 mM glucose using PBS as washing buffer, monitored for 15 min were chosen as the optimized conditions. The effect of temperature was tested and found to be critical at 37 °C for enhanced performance of the sensor. Finally, we evaluate the analytical performance of our sensor system by using cell culture isolate and clinical samples of Ebola virus. The study provides a proof-of-concept of simple and portable molecular diagnostics for emerging pathogens, beneficial especially for resource-limited settings. 

  • 85. Clausson, Carl-Magnus
    et al.
    Arngården, Linda
    Ishaq, Omer
    Klaesson, Axel
    Kühnemund, Malte
    Grannas, Karin
    Koos, Björn
    Qian, Xiaoyan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Ranefall, Petter
    Krzywkowski, Tomasz
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Brismar, Hjalmar
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Wählby, Carolina
    Söderberg, Ola
    Compaction of rolling circle amplification products increases signal integrity and signal-to-noise ratio2015Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, artikel-id 12317Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rolling circle amplification (RCA) for generation of distinct fluorescent signals in situ relies upon the self-collapsing properties of single-stranded DNA in commonly used RCA-based methods. By introducing a cross-hybridizing DNA oligonucleotide during rolling circle amplification, we demonstrate that the fluorophore-labeled RCA products (RCPs) become smaller. The reduced size of RCPs increases the local concentration of fluorophores and as a result, the signal intensity increases together with the signal-to-noise ratio. Furthermore, we have found that RCPs sometimes tend to disintegrate and may be recorded as several RCPs, a trait that is prevented with our cross-hybridizing DNA oligonucleotide. These effects generated by compaction of RCPs improve accuracy of visual as well as automated in situ analysis for RCA based methods, such as proximity ligation assays (PLA) and padlock probes.

  • 86. Coenen-Stass, Anna M. L.
    et al.
    Sork, Helena
    Gatto, Sole
    Godfrey, Caroline
    Bhomra, Amarjit
    Krjutskov, Kaarel
    Hart, Jonathan R.
    Westholm, Jakub O.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    O'Donovan, Liz
    Roos, Andreas
    Lochmueller, Hanns
    Puri, Pier Lorenzo
    EL Andaloussi, Samir
    Wood, Matthew J. A.
    Roberts, Thomas C.
    Comprehensive RNA-Sequencing Analysis in Serum and Muscle Reveals Novel Small RNA Signatures with Biomarker Potential for DMD2018Ingår i: Molecular Therapy - Nucleic Acids, ISSN 2162-2531, E-ISSN 2162-2531, Vol. 13, s. 1-15Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Extracellular small RNAs (sRNAs), including microRNAs (miRNAs), are promising biomarkers for diseases such as Duchenne muscular dystrophy (DMD), although their biological relevance is largely unknown. To investigate the relationship between intracellular and extracellular sRNA levels on a global scale, we performed sRNA sequencing in four muscle types and serum from wild-type, dystrophic mdx, and mdx mice in which dystrophin protein expression was restored by exon skipping. Differentially abundant sRNAs were identified in serum (mapping to miRNA, small nuclear RNA [snRNA], and PIWI-interacting RNA [piRNA] loci). One novel candidate biomarker, miR-483, was increased in both mdx serum and muscle, and also elevated in DMD patient sera. Dystrophin restoration induced global shifts in miRNA (including miR-483) and snRNA-fragment abundance toward wild-type levels. Specific serum piRNA-like sRNAs also responded to exon skipping therapy. Absolute miRNA expression in muscle was positively correlated with abundance in the circulation, although multiple highly expressed miRNAs in muscle were not elevated in mdx serum, suggesting that both passive and selective release mechanisms contribute to serum miRNA levels. In conclusion, this study has revealed new insights into the sRNA biology of dystrophin deficiency and identified novel DMD biomarkers.

  • 87. Conti, Luca
    et al.
    Renhorn, Jakob
    Gabrielsson, Anders
    Turesson, Fredrik
    Liin, Sara I.
    Lindahl, Erik
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). KTH Royal Institute of Technology, Sweden.
    Elinder, Fredrik
    Reciprocal voltage sensor-to-pore coupling leads to potassium channel C-type inactivation2016Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, artikel-id 27562Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Voltage-gated potassium channels open at depolarized membrane voltages. A prolonged depolarization causes a rearrangement of the selectivity filter which terminates the conduction of ions - a process called slow or C-type inactivation. How structural rearrangements in the voltage-sensor domain (VSD) cause alteration in the selectivity filter, and vice versa, are not fully understood. We show that pulling the pore domain of the Shaker potassium channel towards the VSD by a Cd2+ bridge accelerates C-type inactivation. Molecular dynamics simulations show that such pulling widens the selectivity filter and disrupts the K+ coordination, a hallmark for C-type inactivation. An engineered Cd2+ bridge within the VSD also affect C-type inactivation. Conversely, a pore domain mutation affects VSD gating-charge movement. Finally, C-type inactivation is caused by the concerted action of distant amino acid residues in the pore domain. All together, these data suggest a reciprocal communication between the pore domain and the VSD in the extracellular portion of the channel.

  • 88. Corcoran, Martin M.
    et al.
    Phad, Ganesh E.
    Bernat, Nestor Vazquez
    Stahl-Hennig, Christiane
    Sumida, Noriyuki
    Persson, Mats A. A.
    Martin, Marcel
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Hedestam, Gunilla B. Karlsson
    Production of individualized V gene databases reveals high levels of immunoglobulin genetic diversity2016Ingår i: nature communications, ISSN 2041-1723, Vol. 7, artikel-id 13642Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Comprehensive knowledge of immunoglobulin genetics is required to advance our understanding of B cell biology. Validated immunoglobulin variable (V) gene databases are close to completion only for human and mouse. We present a novel computational approach, IgDiscover, that identifies germline V genes from expressed repertoires to a specificity of 100%. IgDiscover uses a cluster identification process to produce candidate sequences that, once filtered, results in individualized germline V gene databases. IgDiscover was tested in multiple species, validated by genomic cloning and cross library comparisons and produces comprehensive gene databases even where limited genomic sequence is available. IgDiscover analysis of the allelic content of the Indian and Chinese-origin rhesus macaques reveals high levels of immunoglobulin gene diversity in this species. Further, we describe a novel human IGHV3-21 allele and confirm significant gene differences between Balb/c and C57BL6 mouse strains, demonstrating the power of IgDiscover as a germline V gene discovery tool.

  • 89. Cossu, Rosa Maria
    et al.
    Casola, Claudio
    Giacomello, Stefania
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). Royal Institute of Technology, Sweden.
    Vidalis, Amaryllis
    Scofield, Douglas G.
    Zuccolo, Andrea
    LTR Retrotransposons Show Low Levels of Unequal Recombination and High Rates of Intraelement Gene Conversion in Large Plant Genomes2017Ingår i: Genome Biology and Evolution, ISSN 1759-6653, E-ISSN 1759-6653, Vol. 9, nr 12, s. 3449-3462Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The accumulat on and removal of transposable elements (TEs) is a major driver of genome size evolution in eukaryotes. In plants, long terminal repeat (LTR) retrotransposons (LTR-RTs) represent the majority of TEs and form most of the nuclear DNA in large genomes. Unequal recombination (UR) between LTRs leads to removal of intervening sequence and formation of solo-LTRs. UR is a major mechanism of LTR-RT removal in many angiosperms, but our understanding of LTR-RT-associated recombination within the large, LTR-RT-rich genomes of conifers is quite limited. We employ a novel read based methodology to estimate the relative rates of LTR-RT-associated UR within the genomes of four conifer and seven angiosperm species. We found the lowest rates of UR in the largest genomes studied, conifers and the angiosperm maize. Recombination may also resolve as gene conversion, which does not remove sequence, so we analyzed LTR-RT-associated gene conversion events (GCEs) in Norway spruce and six angiosperms. Opposite the trend for UR, we found the highest rates of GCEs in Norway spruce and maize. Unlike previous work in angiosperms, we found no evidence that rates of UR correlate with retroelement structural features in the conifers, suggesting that another process is suppressing UR in these species. Recent results from diverse eukaryotes indicate that heterochromatin affects the resolution of recombination, by favoring gene conversion over crossing-over, similar to our observation of opposed rates of UR and GCEs. Control of LTR-RT proliferation via formation of heterochromatin would be a likely step toward large genomes in eukaryotes carrying high LTR-RT content.

  • 90.
    Cymer, Florian
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Hedman, Rickard
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Ismail, Nurzian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    von Heijne, Gunnar
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Exploration of the Arrest Peptide Sequence Space Reveals Arrest-enhanced Variants2015Ingår i: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 290, nr 16, s. 10208-10215Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Translational arrest peptides (APs) are short stretches of polypeptides that induce translational stalling when synthesized on a ribosome. Mechanical pulling forces acting on the nascent chain can weaken or even abolish stalling. APs can therefore be used as in vivo force sensors, making it possible to measure the forces that act on a nascent chain during translation with single-residue resolution. It is also possible to score the relative strengths of APs by subjecting them to a given pulling force and ranking them according to stalling efficiency. Using the latter approach, we now report an extensive mutagenesis scan of a strong mutant variant of the Mannheimia succiniciproducens SecM AP and identify mutations that further increase the stalling efficiency. Combining three such mutations, we designed an AP that withstands the strongest pulling force we are able to generate at present. We further show that diproline stretches in a nascent protein act as very strong APs when translation is carried out in the absence of elongation factor P. Our findings highlight critical residues in APs, show that certain amino acid sequences induce very strong translational arrest and provide a toolbox of APs of varying strengths that can be used for in vivo force measurements.

  • 91.
    Cymer, Florian
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Ismail, Nurzian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    von Heijne, Gunnar
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Weak pulling forces exerted on N-in-orientated transmembrane segments during co-translational insertion into the inner membrane of Escherichia coli2014Ingår i: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 588, nr 10, s. 1930-1934Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Transmembrane helices (TMHs) in membrane proteins can be orientated with their N-terminus towards the cytoplasm (N-in), or facing the non-cytoplasmic side (N-out). Most membrane proteins are inserted co-translationally into membranes, aided by Sec-type translocons. Since the final orientation of N-in-and N-out-orientated TMHs differs, they could also interact differently with the translocon and the surrounding membrane during insertion. We measured pulling forces exerted on N-in-orientated TMHs during co-translational insertion into the inner membrane of Escherichia coli. Our results demonstrate that Nin-orientated TMHs experience a weaker pulling force but retain the overall biphasic force profile seen previously for Nout-orientated TMHs (Ismail et al., 2012 [1]).

  • 92.
    Cymer, Florian
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    von Heijne, Gunnar
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Cotranslational folding of membrane proteins probed by arrest-peptide-mediated force measurements2013Ingår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 110, nr 36, s. 14640-14645Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polytopic membrane proteins are inserted cotranslationally into target membranes by ribosome-translocon complexes. It is, however, unclear when during the insertion process specific interactions between the transmembrane helices start to form. Here, we use a recently developed in vivo technique to measure pulling forces acting on transmembrane helices during their cotranslational insertion into the inner membrane of Escherichia coli to study the earliest steps of tertiary folding of five polytopic membrane proteins. We find that interactions between residues in a C-terminally located transmembrane helix and in more N-terminally located helices can be detected already at the point when the C-terminal helix partitions from the translocon into the membrane. Our findings pinpoint the earliest steps of tertiary structure formation and open up possibilities to study the cotranslational folding of polytopic membrane proteins.

  • 93.
    Cymer, Florian
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    von Heijne, Gunnar
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    White, Stephen H.
    Mechanisms of Integral Membrane Protein Insertion and Folding2015Ingår i: Journal of Molecular Biology, ISSN 0022-2836, E-ISSN 1089-8638, Vol. 427, nr 5, s. 999-1022Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The biogenesis, folding, and structure of alpha-helical membrane proteins (MPs) are important to understand because they underlie virtually all physiological processes in cells including key metabolic pathways, such as the respiratory chain and the photosystems, as well as the transport of solutes and signals across membranes. Nearly all MPs require translocons-often referred to as protein-conducting channels-for proper insertion into their target membrane. Remarkable progress toward understanding the structure and functioning of translocons has been made during the past decade. Here, we review and assess this progress critically. All available evidence indicates that MPs are equilibrium structures that achieve their final structural states by folding along thermodynamically controlled pathways. The main challenge for cells is the targeting and membrane insertion of highly hydrophobic amino acid sequences. Targeting and insertion are managed in cells principally by interactions between ribosomes and membrane-embedded translocons. Our review examines the biophysical and biological boundaries of MP insertion and the folding of polytopic MPs in vivo. A theme of the review is the under-appreciated role of basic thermodynamic principles in MP folding and assembly. Thermodynamics not only dictates the final folded structure but also is the driving force for the evolution of the ribosome-translocon system of assembly. We conclude the review with a perspective suggesting a new view of translocon-guided MP insertion. (C) 2014 Elsevier Ltd. All rights reserved.

  • 94. Dalin, Martin G.
    et al.
    Engström, Pär G.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Ivarsson, Emil G.
    Unneberg, Per
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Light, Sara
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Schaufelberger, Maria
    Gilljama, Thomas
    Andersson, Bert
    Bergo, Martin O.
    Massive parallel sequencing questions the pathogenic role of missense variants in dilated cardiomyopathy2017Ingår i: International Journal of Cardiology, ISSN 0167-5273, E-ISSN 1874-1754, Vol. 228, s. 742-748Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Germline genetic variants are an important cause of dilated cardiomyopathy (DCM). However, recent sequencing studies have revealed rare variants in DCM-associated genes also in individuals without known heart disease. In this study, we investigate variant prevalence and genotype-phenotype correlations in Swedish DCM patients, and compare their genetic variants to those detected in reference cohorts. Methods and results: We sequenced the coding regions of 41 DCM-associated genes in 176 unrelated patients with idiopathic DCM and found 102 protein-altering variants with an allele frequency of <0.04% in reference cohorts; the majority were missense variants not previously described in DCM. Fifty-five (31%) patients had one variant, and 24 (14%) patients had two or more variants in the analysed genes. Detection of genetic variants in any gene, and in LMNA, MYII7 or TTN alone, was associated with early onset disease and reduced transplant-free survival. As expected, nonsense and frameshift variants were more common in DCM patients than in healthy individuals of the reference cohort 1000 Genomes Europeans. Surprisingly however, the prevalence, conservation and pathogenicity scores, and localization of missense variants were similar in DCM patients and healthy reference individuals. Conclusion: To our knowledge, this is the first study to identify correlations between genotype and prognosis when sequencing a large number of genes in unselected DCM patients. The similar distribution of missense variants in DCM patients and healthy reference individuals questions the pathogenic role of many variants, and suggests that results from genetic testing of DCM patients should be interpreted with caution.

  • 95. Danielsson, Frida
    et al.
    James, Tojo
    Gomez-Cabrero, David
    Huss, Mikael
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Assessing the consistency of public human tissue RNA-seq data sets2015Ingår i: Briefings in Bioinformatics, ISSN 1467-5463, E-ISSN 1477-4054, Vol. 16, nr 6, s. 941-949Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sequencing-based gene expression methods like RNA-sequencing (RNA-seq) have become increasingly common, but it is often claimed that results obtained in different studies are not comparable owing to the influence of laboratory batch effects, differences in RNA extraction and sequencing library preparation methods and bioinformatics processing pipelines. It would be unfortunate if different experiments were in fact incomparable, as there is great promise in data fusion and meta-analysis applied to sequencing data sets. We therefore compared reported gene expression measurements for ostensibly similar samples (specifically, human brain, heart and kidney samples) in several different RNA-seq studies to assess their overall consistency and to examine the factors contributing most to systematic differences. The same comparisons were also performed after preprocessing all data in a consistent way, eliminating potential bias from bioinformatics pipelines. We conclude that published human tissue RNA-seq expression measurements appear relatively consistent in the sense that samples cluster by tissue rather than laboratory of origin given simple preprocessing transformations. The article is supplemented by a detailed walkthrough with embedded R code and figures.

  • 96. Danielsson, Frida
    et al.
    Skogs, Marie
    Huss, Mikael
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Rexhepaj, Elton
    O'Hurley, Gillian
    Klevebring, Daniel
    Ponten, Fredrik
    Gad, Annica K. B.
    Uhlen, Mathias
    Lundberg, Emma
    Majority of differentially expressed genes are down-regulated during malignant transformation in a four-stage model2013Ingår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 110, nr 17, s. 6853-6858Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The transformation of normal cells to malignant, metastatic tumor cells is a multistep process caused by the sequential acquirement of genetic changes. To identify these changes, we compared the transcriptomes and levels and distribution of proteins in a four-stage cell model of isogenically matched normal, immortalized, transformed, and metastatic human cells, using deep transcriptome sequencing and immunofluorescence microscopy. The data show that similar to 6% (n = 1,357) of the human protein-coding genes are differentially expressed across the stages in the model. Interestingly, the majority of these genes are down-regulated, linking malignant transformation to dedifferentiation. The up-regulated genes are mainly components that control cellular proliferation, whereas the down-regulated genes consist of proteins exposed on or secreted from the cell surface. As many of the identified gene products control basic cellular functions that are defective in cancers, the data provide candidates for follow-up studies to investigate their functional roles in tumor formation. When we further compared the expression levels of four of the identified proteins in clinical cancer cohorts, similar differences were observed between benign and cancer cells, as in the cell model. This shows that this comprehensive demonstration of the molecular changes underlying malignant transformation is a relevant model to study the process of tumor formation.

  • 97.
    de Jong, Jasper
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Dethlefsen, Olga
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Cannon, Barbara
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Nedergaard, Jan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Utilization of fetal and newborn serum to uncover novel regulators of subcutaneous adipocyte differentiationManuskript (preprint) (Övrigt vetenskapligt)
  • 98.
    De Marothy, Minttu T.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Elofsson, Arne
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Marginally hydrophobic transmembrane alpha-helices shaping membrane protein folding2015Ingår i: Protein Science, ISSN 0961-8368, E-ISSN 1469-896X, Vol. 24, nr 7, s. 1057-1074Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Cells have developed an incredible machinery to facilitate the insertion of membrane proteins into the membrane. While we have a fairly good understanding of the mechanism and determinants of membrane integration, more data is needed to understand the insertion of membrane proteins with more complex insertion and folding pathways. This review will focus on marginally hydrophobic transmembrane helices and their influence on membrane protein folding. These weakly hydrophobic transmembrane segments are by themselves not recognized by the translocon and therefore rely on local sequence context for membrane integration. How can such segments reside within the membrane? We will discuss this in the light of features found in the protein itself as well as the environment it resides in. Several characteristics in proteins have been described to influence the insertion of marginally hydrophobic helices. Additionally, the influence of biological membranes is significant. To begin with, the actual cost for having polar groups within the membrane may not be as high as expected; the presence of proteins in the membrane as well as characteristics of some amino acids may enable a transmembrane helix to harbor a charged residue. The lipid environment has also been shown to directly influence the topology as well as membrane boundaries of transmembrane helices-implying a dynamic relationship between membrane proteins and their environment.

  • 99. de Miranda, Noel F. C. C.
    et al.
    Peng, Roujun
    Georgiou, Konstantinos
    Wu, Chenglin
    Sörqvist, Elin Falk
    Berglund, Mattias
    Chen, Longyun
    Gao, Zhibo
    Lagerstedt, Kristina
    Lisboa, Susana
    Roos, Fredrik
    van Wezel, Tom
    Teixeira, Manuel R.
    Rosenquist, Richard
    Sundström, Christer
    Enblad, Gunilla
    Nilsson, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab).
    Zeng, Yixin
    Kipling, David
    Pan-Hammarström, Qiang
    DNA repair genes are selectively mutated in diffuse large B cell lymphomas2013Ingår i: Journal of Experimental Medicine, ISSN 0022-1007, E-ISSN 1540-9538, Vol. 210, nr 9, s. 1729-1742Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    DNA repair mechanisms are fundamental for B cell development, which relies on the somatic diversification of the immunoglobulin genes by V(D)J recombination, somatic hypermutation, and class switch recombination. Their failure is postulated to promote genomic instability and malignant transformation in B cells. By performing targeted sequencing of 73 key DNA repair genes in 29 B cell lymphoma samples, somatic and germline mutations were identified in various DNA repair pathways, mainly in diffuse large B cell lymphomas (DLBCLs). Mutations in mismatch repair genes (EXO1, MSH2, and MSH6) were associated with microsatellite instability, increased number of somatic insertions/deletions, and altered mutation signatures in tumors. Somatic mutations in nonhomologous end-joining (NHEJ) genes (DCLRE1C/ARTEMIS, PRKDC/DNA-PKcs, XRCC5/KU80, and XRCC6/KU70) were identified in four DLBCL tumors and cytogenetic analyses revealed that translocations involving the immunoglobulin-heavy chain locus occurred exclusively in NHEJ-mutated samples. The novel mutation targets, CHEK2 and PARP1, were further screened in expanded DLBCL cohorts, and somatic as well as novel and rare germline mutations were identified in 8 and 5% of analyzed tumors, respectively. By correlating defects in a subset of DNA damage response and repair genes with genomic instability events in tumors, we propose that these genes play a role in DLBCL lymphomagenesis.

  • 100. Desai, Nirupa
    et al.
    Brown, Alan
    Amunts, Alexey
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Stockholms universitet, Science for Life Laboratory (SciLifeLab). MRC Laboratory of Molecular Biology, UK.
    Ramakrishnan, V.
    The structure of the yeast mitochondrial ribosome2017Ingår i: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 355, nr 6324, s. 528-531Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mitochondria have specialized ribosomes (mitoribosomes) dedicated to the expression of the genetic information encoded by their genomes. Here, using electron cryomicroscopy, we have determined the structure of the 75-component yeast mitoribosome to an overall resolution of 3.3 angstroms. The mitoribosomal small subunit has been built de novo and includes 15S ribosomal RNA (rRNA) and 34 proteins, including 14 without homologs in the evolutionarily related bacterial ribosome. Yeast-specific rRNA and protein elements, including the acquisition of a putatively active enzyme, give the mitoribosome a distinct architecture compared to the mammalian mitoribosome. At an expanded messenger RNA channel exit, there is a binding platform for translational activators that regulate translation in yeast but not mammalian mitochondria. The structure provides insights into the evolution and species-specific specialization of mitochondrial translation.

1234567 51 - 100 av 549
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf