Mitochondrial protein import: from transport pathways to an integrated network

Trends Biochem Sci. 2012 Mar;37(3):85-91. doi: 10.1016/j.tibs.2011.11.004. Epub 2011 Dec 16.


Mitochondria, the powerhouses of the cell, import most of their proteins from the cytosol. It was originally assumed that mitochondria imported precursor proteins via a general pathway but recent studies have revealed a remarkable variety of import pathways and mechanisms. Currently, five different protein import pathways can be distinguished. However, the import machineries cooperate with each other and are connected to other systems that function in the respiratory chain, mitochondrial membrane organization, protein quality control and endoplasmic reticulum-mitochondria junctions. In this Opinion, we propose that mitochondrial protein import should not be seen as an independent task of the organelle and that a network of cooperating machineries is responsible for major mitochondrial functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytosol / metabolism
  • Endoplasmic Reticulum / metabolism*
  • Metabolic Networks and Pathways
  • Metalloendopeptidases / metabolism
  • Mitochondria / metabolism*
  • Mitochondrial Membrane Transport Proteins / metabolism*
  • Protein Precursors / metabolism
  • Protein Transport*


  • Mitochondrial Membrane Transport Proteins
  • Protein Precursors
  • Metalloendopeptidases
  • mitochondrial processing peptidase