Mia40, a novel factor for protein import into the intermembrane space of mitochondria is able to bind metal ions

FEBS Lett. 2005 Jan 3;579(1):179-84. doi: 10.1016/j.febslet.2004.11.072.

Abstract

Many proteins located in the intermembrane space (IMS) of mitochondria are characterized by a low molecular mass, contain highly conserved cysteine residues and coordinate metal ions. Studies on one of these proteins, Tim13, revealed that net translocation across the outer membrane is driven by metal-dependent folding in the IMS . We have identified an essential component, Mia40/Tim40/Ykl195w, with a highly conserved domain in the IMS that is able to bind zinc and copper ions. In cells lacking Mia40, the endogenous levels of Tim13 and other metal-binding IMS proteins are strongly reduced due to the impaired import of these proteins. Furthermore, Mia40 directly interacts with newly imported Tim13 protein. We conclude that Mia40 is the first essential component of a specific translocation pathway of metal-binding IMS proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence / genetics
  • Cell Extracts / chemistry
  • Conserved Sequence / genetics
  • Copper / metabolism
  • Intracellular Membranes / metabolism
  • Ions / metabolism
  • Mitochondria / metabolism*
  • Mitochondrial Membrane Transport Proteins / analysis
  • Mitochondrial Membrane Transport Proteins / genetics
  • Mitochondrial Membrane Transport Proteins / metabolism*
  • Mitochondrial Membrane Transport Proteins / physiology
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Molecular Sequence Data
  • Protein Transport
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / physiology
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins / physiology
  • Sequence Deletion / genetics
  • Zinc / metabolism

Substances

  • Cell Extracts
  • Ions
  • MIA40 protein, S cerevisiae
  • Mitochondrial Membrane Transport Proteins
  • Mitochondrial Precursor Protein Import Complex Proteins
  • Saccharomyces cerevisiae Proteins
  • TIM13 protein, S cerevisiae
  • Copper
  • Zinc