Mitochondrial Hsp70/MIM44 complex facilitates protein import.
Protein translocation into mitochondria requires the mitochondrial protein Hsp70. This molecular chaperone of the mitochondrial matrix is recruited to the protein import machinery by MIM44, a component associated with the inner membrane of the mitochondria. Formation of the mt-Hsp70/MIM44 complex is regulated by ATP. MIM44 and mt-Hsp 70 interact in a sequential manner with incoming segments of unfolded preproteins and thereby facilitate stepwise vectorial translocation of proteins across the mitochondrial membranes. The complex appears to act as a molecular ratchet which is energetically driven by the hydrolysis of ATP.
Schneider
H C
HC
Institut für Physiologische Chemie der Universität München, Germany.
Berthold
J
J
Bauer
M F
MF
Dietmeier
K
K
Guiard
B
B
Brunner
M
M
Neupert
W
W
D000255:Adenosine Triphosphate / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism*; D003432:Cross-Linking Reagents; D004247:DNA / Q000138:chemical synthesis; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D011498:Protein Precursors / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013388:Succinimides; D013762:Tetrahydrofolate Dehydrogenase / Q000378:metabolism
D002352:Carrier Proteins; D003432:Cross-Linking Reagents; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D013388:Succinimides; C077016:TIM44 protein, S cerevisiae; D000255:Adenosine Triphosphate; D004247:DNA; D013762:Tetrahydrofolate Dehydrogenase; C019358:disuccinimidyl suberate