Import and assembly of mitochondrial outer membrane proteins - identification of new factors and import signals

• Antragstellerinnen / Antragsteller: Professorin Dr. Vera Kozjak-Pavlovic; Professor Dr. Thomas Rudel
• Fachliche Zuordnung: Zellbiologie
• Förderung: Förderung von 2009 bis 2012
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 139572885

Beta (β) barrel proteins are found in the outer membrane of gram-negative bacteria and mitochondria and in chloroplasts. In mitochondria, these proteins are transported from the cytosol over the outer membrane and are then assembled into the outer membrane via the sorting and assembly machinery (SAM) complex. We have generated and functionally validated mammalian cell lines for the inducible silencing of components of the Sam complex. These cell lines will be used to identify new components for the import and assembly of β-barrel proteins by modern highthroughput proteome approaches. We will use PorB proteins, bacterial β-barrel porins from the outer membrane of Neisseria species, as models to investigate the structural and functional requirements for protein transport and assembly into the outer mitochondrial membrane. PorB from N. gonorrhoeae is transported over the mitochondrial membrane but is not recognized by the Sam complex whereas the structural highly homologues PorB from N. mucosa is neither transported. We aim to understand the functional and structural details of the interaction of β-barrel proteins with the mitochondrial protein import machinery.

• DFG-Verfahren: Sachbeihilfen