Ändra sökning
Avgränsa sökresultatet
1 - 7 av 7
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.
  • 1.
    Gruschke, Steffi
    et al.
    Technische Universität Kaiserslautern, Germany.
    Groene, Kerstin
    Heublein, Manfred
    Technische Universität Kaiserslautern, Germany.
    Hoelz, Stefanie
    Israel, Lars
    Imhof, Axel
    Herrmann, Johannes M.
    Ott, Martin
    Proteins at the Polypeptide Tunnel Exit of the Yeast Mitochondrial Ribosome2010Ingår i: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 285, nr 25, s. 19022-19028Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Oxidative phosphorylation in mitochondria requires the synthesis of proteins encoded in the mitochondrial DNA. The mitochondrial translation machinery differs significantly from that of the bacterial ancestor of the organelle. This is especially evident from many mitochondria-specific ribosomal proteins. An important site of the ribosome is the polypeptide tunnel exit. Here, nascent chains are exposed to an aqueous environment for the first time. Many biogenesis factors interact with the tunnel exit of pro- and eukaryotic ribosomes to help the newly synthesized proteins to mature. To date, nothing is known about the organization of the tunnel exit of mitochondrial ribosomes. We therefore undertook a comprehensive approach to determine the composition of the yeast mitochondrial ribosomal tunnel exit. Mitochondria contain homologues of the ribosomal proteins located at this site in bacterial ribosomes. Here, we identified proteins located in their proximity by chemical cross-linking and mass spectrometry. Our analysis revealed a complex network of interacting proteins including proteins and protein domains specific to mitochondrial ribosomes. This network includes Mba1, the membrane-bound ribosome receptor of the inner membrane, as well as Mrpl3, Mrpl13, and Mrpl27, which constitute ribosomal proteins exclusively found in mitochondria. This unique architecture of the tunnel exit is presumably an adaptation of the translation system to the specific requirements of the organelle.

  • 2.
    Heublein, Manfred
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Mitochondrial Energy Metabolism: Kgd4 is a novel subunit of the α-ketoglutarate dehydrogenase complex2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Mitochondria are essential organelles of eukaryotic cells and are responsible for their energy metabolism. The citric acid cycle, a chain of redox reactions in the mitochondrial matrix, is a central metabolic hub. The energy of these redox reactions is preserved in reducing equivalents, which are fed into the electron transport chain of the inner mitochondrial membrane. This process ultimately produces ATP.

    Mitochondrial ribosomes are responsible for the synthesis of the hydrophobic core components of the respiratory chain complexes. Using the baker’s yeast Saccharomyces cerevisiae as a eukaryotic model organism, the composition of the polypeptide tunnel exit of mitochondrial ribosomes was defined. We identified novel mitochondria-specific ribosomal proteins and generated insights into how they contribute to the specialization of mitochondrial ribosomes.

    In a second approach, Kgd4 was identified as a novel structural component of the a-ketoglutarate dehydrogenase complex (KGDH), which is part of the citric acid cycle. We demonstrate that this protein is responsible for recruiting one essential subunit to the catalytic core of the complex. By ensuring the structural integrity, Kgd4 indirectly maintains the catalytic function of the enzyme complex. Kgd4 also represents a rare exception from the standard protein synthesis process. There are two isofroms of the protein, which differ in the length of the amino acid sequence. Both Kgd4 forms contribute to KGDH stability and activity. Translation of the long isoform starts from a non-canonical UUG codon upstream of the commonly used start-codon AUG. This provides insights into the flexibility of translation initiation in yeast. Finally, we purified the fully intact and functional KGDH complex from isolated yeast mitochondria for future structural studies. These experiments also revealed details about the interaction of the complex with the inner mitochondrial membrane.

  • 3.
    Heublein, Manfred
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Burguillos, Miguel A.
    Vögtle, F. Nora
    Teixeira, Pedro F.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Imhof, Axel
    Meisinger, Chris
    Ott, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    The novel component Kgd4 recruits the E3 subunit to the mitochondrial alpha-ketoglutarate dehydrogenase2014Ingår i: Molecular Biology of the Cell, ISSN 1059-1524, E-ISSN 1939-4586, Vol. 25, nr 21, s. 3342-3349Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mitochondrial citric acid cycle is a central hub of cellular metabolism, providing intermediates for biosynthetic pathways and channeling electrons to the respiratory chain complexes. In this study, we elucidated the composition and organization of the multienzyme complex alpha-ketoglutarate dehydrogenase (alpha-KGDH). In addition to the three classical E1-E3 subunits, we identified a novel component, Kgd4 (Ymr31/MRPS36), which was previously assigned to be a subunit of the mitochondrial ribosome. Biochemical analyses demonstrate that this protein plays an evolutionarily conserved role in the organization of mitochondrial alpha-KGDH complexes of fungi and animals. By binding to both the E1-E2 core and the E3 subunit, Kgd4 acts as a molecular adaptor that is necessary to a form a stable alpha-KGDH enzyme complex. Our work thus reveals a novel subunit of a key citric acid-cycle enzyme and shows how this large complex is organized.

  • 4.
    Heublein, Manfred
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Burguillos, Miguel
    Vögtle, Nora
    Teixeira, Pedro
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Imhof, Axel
    Meisinger, Chris
    Ott, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    The novel component Kgd4 recruits the E3 subunit to the mitochondrial α-ketoglutarate dehydrogenaseManuskript (preprint) (Övrigt vetenskapligt)
  • 5.
    Heublein, Manfred
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Ndi, Mama
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Vazquez-Calvo, Carmela
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Vögtle, F.-Nora
    Ott, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Alternative Translation Initiation at a UUG Codon Gives Rise to Two Functional Variants of the Mitochondria! Protein Kgd42019Ingår i: Journal of Molecular Biology, ISSN 0022-2836, E-ISSN 1089-8638, Vol. 431, nr 7, s. 1460-1467Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Kgd4 is a novel subunit of the mitochondria! a-ketoglutarate dehydrogenase complex (KGDH). In yeast, the protein is present in two forms of unknown origin, as there is only one open reading frame and no alternative splicing. Here, we show that the two forms of Kgd4 derive from one mRNA that is translated by employing two alternative start sites. The standard, annotated AUG codon gives rise to the short form of the protein, while an upstream UUG codon is utilized to generate the larger form. However, both forms can be efficiently imported into mitochondria and stably incorporate into KGDH to support its activity. Translation of the long variant depends on sequences directly upstream of the alternative initiation site, demonstrating that translation initiation and its efficiency are dictated by the sequence context surrounding a specific codon. In summary, the two forms of Kgd4 follow a very unusual biogenesis pathway, supporting the notion that translation initiation in yeast is more flexible than it is widely recognized.

  • 6.
    Heublein, Manfred
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Ott, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    KGDH membrane association, purification and structureManuskript (preprint) (Övrigt vetenskapligt)
  • 7.
    Heublein, Manfred
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Vögtle, Nora
    Meisinger, Chris
    Ott, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik.
    Alternative initiation at a UUG codon gives rise to two functional variants of the mitochondrial protein Kgd4Manuskript (preprint) (Övrigt vetenskapligt)
1 - 7 av 7
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