The cytosolic domain of human Tom22 modulates human Bax mitochondrial translocation and conformation in yeast

FEBS Lett. 2012 Jan 20;586(2):116-21. doi: 10.1016/j.febslet.2011.12.003. Epub 2011 Dec 17.

Abstract

The role of the mitochondrial protein receptor Tom22p in the interaction of pro-apoptotic protein Bax with yeast mitochondria was investigated. Co-immunoprecipitation assays showed that human Bax interacted with different TOM subunits, including Tom22p. Expression of the cytosolic receptor domain of human Tom22 increased Bax mitochondrial localization, but decreased the proportion of active Bax. BN-PAGE showed that the cytosolic domain of Tom22 interfered with the oligomerization of Bax. These data suggest that the interaction with the cytosolic domain of Tom22 helps Bax to acquire a conformation able to interact with the outer mitochondrial membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cells, Cultured
  • Cytosol / metabolism
  • Humans
  • Mitochondrial Membrane Transport Proteins / chemistry*
  • Mitochondrial Membrane Transport Proteins / genetics
  • Mitochondrial Membrane Transport Proteins / metabolism
  • Mitochondrial Membrane Transport Proteins / physiology*
  • Mitochondrial Membranes / metabolism
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Molecular Sequence Data
  • Organisms, Genetically Modified
  • Protein Binding / genetics
  • Protein Conformation
  • Protein Interaction Domains and Motifs / genetics
  • Protein Interaction Domains and Motifs / physiology*
  • Protein Transport
  • Sequence Homology, Amino Acid
  • Yeasts / genetics
  • Yeasts / metabolism*
  • bcl-2-Associated X Protein / chemistry*
  • bcl-2-Associated X Protein / metabolism*

Substances

  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Precursor Protein Import Complex Proteins
  • TOMM22 protein, human
  • bcl-2-Associated X Protein