Change search
Refine search result
1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Baldassarre, Maurizio
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Maggiore, Beatrice
    Scire, Andrea
    Tanfani, Fabio
    Amyloid fibril formation by bovine alpha(1)-acid glycoprotein in a reducing environment: The role of disulfide bridges on the observed aggregation kinetics2015In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 118, p. 244-252Article in journal (Refereed)
    Abstract [en]

    Bovine alpha(1)-acid glycoprotein (bAGP), a thermostable counterpart of its human homologue, is a positive acute phase protein involved in binding and transportation of a large number of bin-active molecules and drugs across the body. We have investigated the effect of low pH and reducing conditions on the structure of the protein and found that it aggregates at high temperatures. The aggregates show a fibrillar structure when observed with electron microscopy. Aggregation assays using the amyloid-specific dye Thioflavin T show the presence of a lag phase which was neither abolished nor shortened when seeds were added. A priori reduction of the two disulfide bridges of bAGP, on the other hand, abolished the lag phase and reveals a connection between the kinetics of reduction and aggregation. We provide a kinetic interpretation and the corresponding rate laws allowing to model the process of fibril formation by bAGP under reducing conditions. Our interpretation allows to assess the role of disulfide bridges on the fibrillation kinetics of bAGP and can provide a more accurate interpretation of the fibrillation kinetics of other amyloidogenic proteins containing disulfide bridges.

  • 2.
    Croitoru, Victor
    et al.
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Semrad, Katharina
    Prenninger, Silvia
    Rajkowitsch, Lukas
    Vejen, Max
    Laursen, Brian Sogaard
    Sperling-Petersen, Hans Uffe
    Isaksson, Leif A.
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    RNA chaperone activity of translation initiation factor IF12006In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 88, no 12, p. 1875-1882Article in journal (Refereed)
    Abstract [en]

    Translation initiation factor IF1 is an indispensable protein for translation in prokaryotes. No clear function has been assigned to this factor so far. In this study we demonstrate an RNA chaperone activity of this protein both in vivo and in vitro. The chaperone assays are based on in vivo or in vitro splicing of the group I intron in the thymidylate synthase gene (td) from phage T4 and an in vitro RNA annealing assay. IF1 wild-type and mutant variants with single amino acid substitutions have been analyzed for RNA chaperone activity. Some of the IF1 mutant variants are more active as RNA chaperones than the wild-type. Furthermore, both wild-type IF1 and mutant variants bind with high affinity to RNA in a band-shift assay. It is suggested that the RNA chaperone activity of IF1 contributes to RNA rearrangements during the early phase of translation initiation.

  • 3.
    Daniel, Chammiran
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Lagergren, Jens
    Öhman, Marie
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    RNA editing of non-coding RNA and its role in gene regulation2015In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 117, p. 22-27Article, review/survey (Refereed)
    Abstract [en]

    It has for a long time been known that repetitive elements, particularly Alu sequences in human, are edited by the adenosine deaminases acting on RNA, ADAR, family. The functional interpretation of these events has been even more difficult than that of editing events in coding sequences, but today there is an emerging understanding of their downstream effects. A surprisingly large fraction of the human transcriptome contains inverted Alu repeats, often forming long double stranded structures in RNA transcripts, typically occurring in introns and UTRs of protein coding genes. Alu repeats are also common in other primates, and similar inverted repeats can frequently be found in non-primates, although the latter are less prone to duplex formation. In human, as many as 700,000 Alu elements have been identified as substrates for RNA editing, of which many are edited at several sites. In fact, recent advancements in transcriptome sequencing techniques and bioinformatics have revealed that the human editome comprises at least a hundred million adenosine to inosine (A-to-I) editing sites in Alu sequences. Although substantial additional efforts are required in order to map the editome, already present knowledge provides an excellent starting point for studying cis-regulation of editing. In this review, we will focus on editing of long stem loop structures in the human transcriptome and how it can effect gene expression.

  • 4.
    Davies, Victoria S.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Lindsund, Erik
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Petrovic, Natasa
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Repeated short excursions from thermoneutrality suffice to restructure brown adipose tissue2023In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 210, p. 40-49Article in journal (Refereed)
    Abstract [en]

    Given the presence of brown adipose tissue in adult humans, an important issue is whether human brown adipose tissue is recruitable. Cold exposure is the canonical recruitment treatment; however, in experimental animals (mice), recruitment of brown adipose tissue is normally induced by placing the mice in constant cold, a procedure not feasible in humans. For possible translational applications, we have therefore investigated whether shorter daily excursions from thermoneutrality would suffice to qualitatively and quantitatively induce recruitment in mice. Mice, housed at thermoneutrality (30 °C) to mimic human conditions, were transferred every day for 4 weeks to cool conditions (18 °C), for 0, 15, 30, 120 and 420 min (or placed constantly in 18 °C). On the examination day, the mice were not exposed to cold. Very short daily exposures (≤30 minutes) were sufficient to induce structural changes in the form of higher protein density in brown adipose tissue, changes that may affect the identification of the tissue in e.g. computer tomography and other scan studies. To estimate thermogenic capacity, UCP1 protein levels were followed. No UCP1 protein was detectable in inguinal white adipose tissue. In the interscapular brown adipose tissue, a remarkable two-phase reaction was seen. Very short daily exposures (≤30 minutes) were sufficient to induce a significant increase in total UCP1 levels. For attainment of full cold acclimation, the mice had, however, to remain exposed to the cold. The studies indicate that marked alterations in brown adipose tissue composition can be induced in mammals through relatively modest stimulation events.

  • 5.
    Kalinovich, Anastasia V.
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    de Jong, Jasper M. A.
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Cannon, Barbara
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    Nedergaard, Jan
    Stockholm University, Faculty of Science, Department of Molecular Biosciences, The Wenner-Gren Institute.
    UCP1 in adipose tissues: two steps to full browning2017In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 134, p. 127-137Article in journal (Refereed)
    Abstract [en]

    The possibility that brown adipose tissue thermogenesis can be recruited in order to combat the development of obesity has led to a high interest in the identification of "browning agents", i.e. agents that increase the amount and activity of UCP1 in brown and brite/beige adipose tissues. However, functional analysis of the browning process yields confusingly different results when the analysis is performed in one of two alternative steps. Thus, in one of the steps, using cold acclimation as a potent model browning agent, we find that if the browning process is followed in mice initially housed at 21 °C (the most common procedure), there is only weak molecular evidence for increases in UCP1 gene expression or UCP1 protein abundance in classical brown adipose tissue; however, in brite/beige adipose depots, there are large increases, apparently associating functional browning with events only in the brite/beige tissues. Contrastingly, in another step, if the process is followed starting with mice initially housed at 30 °C (thermoneutrality for mice, thus similar to normal human conditions), large increases in UCP1 gene expression and UCP1 protein abundance are observed in the classical brown adipose tissue depots; there is then practically no observable UCP1 gene expression in brite/beige tissues. This apparent conundrum can be resolved when it is realized that the classical brown adipose tissue at 21 °C is already essentially fully differentiated and thus expands extensively through proliferation upon further browning induction, rather than by further enhancing cellular differentiation. When the limiting factor for thermogenesis, i.e. the total amount of UCP1 protein per depot, is analyzed, classical brown adipose tissue is by far the predominant site for the browning process, irrespective of which of the two steps is analyzed. There are to date no published data demonstrating that alternative browning agents would selectively promote brite/beige tissues versus classical brown tissue to a higher degree than does cold acclimation. Thus, to restrict investigations to examine adipose tissue depots where only a limited part of the adaptation process occurs (i.e. the brite/beige tissues) and to use initial conditions different from the thermoneutrality normally experienced by adult humans may seriously hamper the identification of therapeutically valid browning agents. The data presented here have therefore important implications for the analysis of the potential of browning agents and the nature of human brown adipose tissue.

  • 6.
    Kmiec, Beata
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Teixeira, Pedro F.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Glaser, Elzbieta
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Phenotypical consequences of expressing the dually targeted Presequence Protease, AtPreP, exclusively in mitochondria2014In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 100C, p. 167-170Article in journal (Refereed)
    Abstract [en]

    Endosymbiotic organelles, mitochondria and chloroplasts, are sites of an intensive protein synthesis and degradation. A consequence of these processes is production of both free targeting peptides, i.e. mitochondrial presequences and chloroplastic transit peptides, and other short unstructured peptides. Mitochondrial, as well as chloroplastic peptides are degraded by Presequence Protease (Prep), which is dually targeted to mitochondrial matrix and chloroplastic stroma. Elimination of PreP in Arabidopsis thaliana leads to growth retardation, chlorosis and impairment of mitochondrial functions potentially due to the accumulation of targeting peptides. In this work we analyzed the influence of the restoration of mitochondrial peptide degradation by AtPreP on plant phenotype. We showed that exclusive mitochondrial expression of AtPreP results in total restoration of the proteolytic activity, but it does not restore the wild-type phenotype. The plants grow shorter roots and smaller rosettes compared to the plants expressing AtPreP1 in both mitochondria and chloroplasts. With this analysis we are aiming at understanding the physiological impact of the role of the dually targeted AtPreP in single type of destination organelle.

  • 7. Kodama, Yutaka
    et al.
    Tamura, Takashi
    Hirasawa, Wataru
    Nakamura, Kimiyo
    Sano, Hiroshi
    Stockholm University, Faculty of Science, Department of Botany.
    A novel protein phosphorylation pathway involved in osmotic-stress response in tobacco plants2009In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 91, no 4, p. 533-539Article in journal (Refereed)
    Abstract [en]

    Osmotic stress is one of the severest environmental pressures for plants, commonly occurring under natural growing condition due to drought, salinity, cold and wounding. Plants sensitively respond to these stresses by activating a set of genes, which encode proteins necessary to overcome the crises. We screened such genes from tobacco plants, and identified a particular clone, which encoded a 45 kDa protein kinase belonging to the plant receptor-like cytoplasmic protein kinase class-VII, NAK (novel Arabidopsis protein kinase) group. The clone was consequently designated as NtNAK (Nicotiana tabacum AK, accession number: DQ447159). GFP-NtNAK fusion protein was localized in both cytoplasm and nucleus, and bacterially expressed NtNAK exhibited in vitro kinase activity. Its transcripts were clearly induced upon treatments of leaves with salt, mannitol, low temperature and also with abscisic and jasmonic acids and ethylene. These properties indicated NtNAK to be a typical osmo-stress-responsive protein kinase. Its target protein(s) were then screened by the yeast two-hybrid system, and one clone encoding a 32 kDa protein was identified. The protein resembled a potato stress-responsive protein CK251806, and designated as NtCK25 (accession number: DQ448851). Bacterially expressed NtCK25 was phosphorylated by NtNAK, and NtCK25-GFP fusion protein was exclusively localized in nucleus. The structure of NtCK25 was found to be similar to a human nuclear body protein, SP110, which is involved in DNA/protein binding regulation. This suggested that, perceiving osmo-stress signal, NtNAK phosphorylates and activates NtCK25, which might function in regulation of nucleus function. The present study thus suggests that NtNAK/NtCK25 constitutes a novel phosphorylation pathway for osmotic-stress response in plants.

  • 8. Pata, Jorgaq
    et al.
    Moreno, Alexis
    Wiseman, Benjamin
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Magnard, Sandrine
    Lehlali, Idriss
    Dujardin, Marie
    Banerjee, Atanu
    Högbom, Martin
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    Boumendiel, Ahccne
    Chaptal, Vincent
    Prasad, Rajendra
    Falson, Pierre
    Purification and characterization of Cdr1, the drug-efflux pump conferring azole resistance in Candida species2024In: Biochimie, ISSN 0300-9084, E-ISSN 1638-6183, Vol. 220, p. 167-178Article in journal (Refereed)
    Abstract [en]

    Candida albicans and C. glabrata express exporters of the ATP -binding cassette (ABC) superfamily and address them to their plasma membrane to expel azole antifungals, which cancels out their action and allows the yeast to become multidrug resistant (MDR). In a way to understand this mechanism of defense, we describe the purification and characterization of Cdr1, the membrane ABC exporter mainly responsible for such phenotype in both species. Cdr1 proteins were functionally expressed in the baker yeast, tagged at their C -terminal end with either a His -tag for the glabrata version, cgCdr1-His, or a green fluorescent protein (GFP) preceded by a proteolytic cleavage site for the albicans version, caCdr1-P-GFP. A membrane Cdr1-enriched fraction was then prepared to assay several detergents and stabilizers, probing their level of extraction and the ATPase activity of the proteins as a functional marker. Immobilized metal -affinity and size -exclusion chromatographies (IMAC, SEC) were then carried out to isolate homogenous samples. Overall, our data show that although topologically and phylogenetically close, both proteins display quite distinct behaviors during the extraction and purification steps, and qualify cgCdr1 as a good candidate to characterize this type of proteins for developing future inhibitors of their azole antifungal efflux activity. 

1 - 8 of 8
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf