From powerhouse to processing plant: conserved roles of mitochondrial outer membrane proteins in tRNA splicing

Genes Dev. 2018 Oct 1;32(19-20):1309-1314. doi: 10.1101/gad.316257.118. Epub 2018 Sep 18.

Abstract

The mitochondrial cytoplasmic surface serves as a processing site for numerous RNAs from budding yeast to metazoans. We report that budding yeast mitochondrial outer membrane (MOM) proteins that are subunits of the translocase of the outer mitochondrial membrane (Tom70 and Tom 22) and sorting and assembly machinery (Sam37) are required for efficient pretransfer RNA (pre-tRNA) splicing. Defective pre-tRNA splicing in MOM mutants is due not to loss of respiratory metabolism but instead inefficient targeting/tethering of tRNA splicing endonuclease (SEN) subunits to mitochondria. Schizosaccharomyces pombe SEN subunits also localize to mitochondria, and Tom70 is required for this localization and pre-tRNA splicing. Thus, the role of MOM protein in targeting/tethering SEN subunits to mitochondria has been conserved for >500 million years.

Keywords: RNA processing on the mitochondrial surface; Sam37; Tom70; tRNA splicing endonuclease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Respiration
  • Endoribonucleases / metabolism*
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Mitochondria / enzymology
  • Mitochondrial Membrane Transport Proteins / genetics
  • Mitochondrial Membrane Transport Proteins / physiology*
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Mutation
  • Protein Subunits / metabolism
  • RNA Splicing*
  • RNA Transport
  • RNA, Transfer / metabolism*
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / physiology*
  • Schizosaccharomyces / enzymology
  • Schizosaccharomyces / metabolism
  • Schizosaccharomyces pombe Proteins / metabolism
  • Schizosaccharomyces pombe Proteins / physiology

Substances

  • Membrane Proteins
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Protein Subunits
  • SAM37 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Schizosaccharomyces pombe Proteins
  • TOM22 protein, S cerevisiae
  • TOM70 protein, S cerevisiae
  • RNA, Transfer
  • Endoribonucleases
  • splicing endonuclease