Protein import into mitochondria

Annu Rev Biochem. 1997:66:863-917. doi: 10.1146/annurev.biochem.66.1.863.


Mitochondria import many hundreds of different proteins that are encoded by nuclear genes. These proteins are targeted to the mitochondria, translocated through the mitochondrial membranes, and sorted to the different mitochondrial subcompartments. Separate translocases in the mitochondrial outer membrane (TOM complex) and in the inner membrane (TIM complex) facilitate recognition of preproteins and transport across the two membranes. Factors in the cytosol assist in targeting of preproteins. Protein components in the matrix partake in energetically driving translocation in a reaction that depends on the membrane potential and matrix-ATP. Molecular chaperones in the matrix exert multiple functions in translocation, sorting, folding, and assembly of newly imported proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Animals
  • Bacterial Proteins / metabolism
  • Biological Transport
  • Cytosol / metabolism
  • Escherichia coli Proteins*
  • HSP70 Heat-Shock Proteins / metabolism
  • Humans
  • Membrane Transport Proteins*
  • Mitochondria / metabolism*
  • Protein Folding
  • Protein Precursors / metabolism
  • Proteins / metabolism*
  • SEC Translocation Channels
  • SecA Proteins
  • Signal Transduction


  • Bacterial Proteins
  • Escherichia coli Proteins
  • HSP70 Heat-Shock Proteins
  • Membrane Transport Proteins
  • Protein Precursors
  • Proteins
  • SEC Translocation Channels
  • Adenosine Triphosphatases
  • SecA Proteins