Mitochondrial Machineries for Protein Import and Assembly

Annu Rev Biochem. 2017 Jun 20;86:685-714. doi: 10.1146/annurev-biochem-060815-014352. Epub 2017 Mar 15.

Abstract

Mitochondria are essential organelles with numerous functions in cellular metabolism and homeostasis. Most of the >1,000 different mitochondrial proteins are synthesized as precursors in the cytosol and are imported into mitochondria by five transport pathways. The protein import machineries of the mitochondrial membranes and aqueous compartments reveal a remarkable variability of mechanisms for protein recognition, translocation, and sorting. The protein translocases do not operate as separate entities but are connected to each other and to machineries with functions in energetics, membrane organization, and quality control. Here, we discuss the versatility and dynamic organization of the mitochondrial protein import machineries. Elucidating the molecular mechanisms of mitochondrial protein translocation is crucial for understanding the integration of protein translocases into a large network that controls organelle biogenesis, function, and dynamics.

Keywords: inner membrane; mitochondrial architecture; outer membrane; preprotein; protein sorting; translocase.

Publication types

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

MeSH terms

  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Eukaryotic Cells / metabolism
  • Eukaryotic Cells / ultrastructure
  • Gene Expression
  • Humans
  • Isoenzymes / chemistry
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Mitochondria / metabolism*
  • Mitochondria / ultrastructure
  • Mitochondrial Membrane Transport Proteins / chemistry
  • Mitochondrial Membrane Transport Proteins / genetics
  • Mitochondrial Membrane Transport Proteins / metabolism*
  • Mitochondrial Membranes / metabolism*
  • Mitochondrial Membranes / ultrastructure
  • Mitochondrial Proteins / chemistry
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Organelle Biogenesis
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Precursors / chemistry
  • Protein Precursors / genetics
  • Protein Precursors / metabolism*
  • Protein Transport

Substances

  • Carrier Proteins
  • Isoenzymes
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Proteins
  • Protein Precursors
  • TIMM23 protein, human