Membrane protein import in yeast mitochondria.
The protein import pathway that targets proteins to the mitochondrial matrix has been extensively characterized in the past 15 years. Variations of this import pathway account for the sorting of proteins to other compartments as well, but the insertion of integral inner membrane proteins lacking a presequence is mediated by distinct translocation machinery. This consists of a complex of Tim9 and Tim10, two homologous, Zn(2+)-binding proteins that chaperone the passage of the hydrophobic precursor across the aqueous intermembrane space. The precursor is then targeted to another, inner-membrane-bound, complex of at least five subunits that facilitates insertion. Biochemical and genetic experiments have identified the key components of this process; we are now starting to understand the molecular mechanism. This review highlights recent advances in this new membrane protein insertion pathway.
Tokatlidis
K
K
School of Biological Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, U.K. tokatlidis@man.ac.uk
Vial
S
S
Luciano
P
P
Vergnolle
M
M
Clémence
S
S
D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism*; D007477:Ions; D008565:Membrane Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones / Q000378:metabolism; D011485:Protein Binding; D029701:Saccharomyces cerevisiae Proteins; D015003:Yeasts / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism
D002352:Carrier Proteins; D005656:Fungal Proteins; D007477:Ions; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; C107250:TIM10 protein, S cerevisiae; C116366:Tim9 protein, S cerevisiae; D015032:Zinc