title: Biogenesis of the essential Tim9-Tim10 chaperone complex of mitochondria: site-specific recognition of cysteine residues by the intermembrane space receptor Mia40.
abstract: The mitochondrial intermembrane space (IMS) contains an essential machinery for protein import and assembly (MIA). Biogenesis of IMS proteins involves a disulfide relay between precursor proteins, the cysteine-rich IMS protein Mia40 and the sulfhydryl oxidase Erv1. How precursor proteins are specifically directed to the IMS has remained unknown. Here we systematically analyzed the role of cysteine residues in the biogenesis of the essential IMS chaperone complex Tim9-Tim10. Although each of the four cysteines of Tim9, as well as of Tim10, is required for assembly of the chaperone complex, only the most amino-terminal cysteine residue of each precursor is critical for translocation across the outer membrane and interaction with Mia40. Mia40 selectively recognizes cysteine-containing IMS proteins in a site-specific manner in organello and in vitro. Our results indicate that Mia40 acts as a trans receptor in the biogenesis of mitochondrial IMS proteins.
authors.affiliation: Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung, Universität Freiburg, D-79104 Freiburg, Germany.
authors.forename: Dusanka
authors.initials: D
authors.lastname: Milenkovic
authors.forename: Kipros
authors.initials: K
authors.lastname: Gabriel
authors.forename: Bernard
authors.initials: B
authors.lastname: Guiard
authors.forename: Agnes
authors.initials: A
authors.lastname: Schulze-Specking
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Pfanner
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Chacinska
mesh_terms: D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism; D003553:Cystine / Q000378:metabolism; D004220:Disulfides; D004926:Escherichia coli / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D006639:Histidine / Q000737:chemistry; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000378:metabolism*; D008957:Models, Genetic; D050862:Oxidoreductases Acting on Sulfur Group Donors; D011485:Protein Binding; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D004220:Disulfides; C495320:MIA40 protein, S cerevisiae; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D029701:Saccharomyces cerevisiae Proteins; C107250:TIM10 protein, S cerevisiae; C116366:Tim9 protein, S cerevisiae; D003553:Cystine; D006639:Histidine; D050862:Oxidoreductases Acting on Sulfur Group Donors; C073790:ERV1 protein, S cerevisiae; D003545:Cysteine