Mitochondrial Hsp70/MIM44 complex facilitates protein import

Nature. 1994 Oct 27;371(6500):768-74. doi: 10.1038/371768a0.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Base Sequence
  • Biological Transport
  • Carrier Proteins / metabolism*
  • Cross-Linking Reagents
  • DNA / chemical synthesis
  • HSP70 Heat-Shock Proteins / metabolism*
  • Intracellular Membranes / metabolism
  • Membrane Proteins / metabolism*
  • Mitochondria / metabolism*
  • Mitochondrial Membrane Transport Proteins*
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Molecular Sequence Data
  • Mutation
  • Protein Precursors / metabolism*
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Succinimides
  • Tetrahydrofolate Dehydrogenase / metabolism

Substances

  • Carrier Proteins
  • Cross-Linking Reagents
  • HSP70 Heat-Shock Proteins
  • Membrane Proteins
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Protein Precursors
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • Succinimides
  • TIM44 protein, S cerevisiae
  • Adenosine Triphosphate
  • DNA
  • Tetrahydrofolate Dehydrogenase
  • disuccinimidyl suberate