Tim17 Updates: A Comprehensive Review of an Ancient Mitochondrial Protein Translocator

Biomolecules. 2020 Dec 7;10(12):1643. doi: 10.3390/biom10121643.

Abstract

The translocases of the mitochondrial outer and inner membranes, the TOM and TIMs, import hundreds of nucleus-encoded proteins into mitochondria. TOM and TIMs are multi-subunit protein complexes that work in cooperation with other complexes to import proteins in different sub-mitochondrial destinations. The overall architecture of these protein complexes is conserved among yeast/fungi, animals, and plants. Recent studies have revealed unique characteristics of this machinery, particularly in the eukaryotic supergroup Excavata. Despite multiple differences, homologues of Tim17, an essential component of one of the TIM complexes and a member of the Tim17/Tim22/Tim23 family, have been found in all eukaryotes. Here, we review the structure and function of Tim17 and Tim17-containing protein complexes in different eukaryotes, and then compare them to the single homologue of this protein found in Trypanosoma brucei, a unicellular parasitic protozoan.

Keywords: TIM; TOM; Tim17; mitochondria; protein import; trypanosomes.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Conserved Sequence
  • Fungi / genetics
  • Fungi / metabolism
  • Gene Expression
  • Humans
  • Membrane Transport Proteins / chemistry
  • Membrane Transport Proteins / genetics
  • Membrane Transport Proteins / metabolism*
  • Mitochondria / metabolism
  • Mitochondrial Membrane Transport Proteins / chemistry
  • Mitochondrial Membrane Transport Proteins / genetics
  • Mitochondrial Membrane Transport Proteins / metabolism*
  • Mitochondrial Membranes / metabolism*
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Mitochondrial Proteins / chemistry
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / genetics
  • Multiprotein Complexes / metabolism*
  • Plants / genetics
  • Plants / metabolism
  • Protein Binding
  • Protein Structure, Secondary
  • Protein Transport
  • Trypanosoma brucei brucei / genetics
  • Trypanosoma brucei brucei / metabolism*

Substances

  • Membrane Transport Proteins
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Mitochondrial Proteins
  • Multiprotein Complexes
  • TIM22 protein, human
  • TIMM17A protein, human
  • TIMM23 protein, human