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Analysis of the Expression and Complexes Assembly of the Mitochondrial Respiratory Chain Proteins in the Fission Yeast Schizosaccharomyces pombe
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Mmr1p is a mitochondrial factor for Myo2p-dependent inheritance of mitochondria in the budding yeast

Takashi Itoh1, Akio Toh-E, Yasushi Matsui

  • 1Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan.

The EMBO Journal
|June 18, 2004
PubMed

Insights

Mmr1p is crucial for mitochondrial distribution in yeast, working with Myo2p. This pathway is independent of Ypt11p, revealing two distinct Myo2p systems for organelle transport.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Genetics

Background:

  • Class V myosins are vital for organelle distribution.
  • Myo2p, a class V myosin, is essential for mitochondrial distribution in budding yeast.

Purpose of the Study:

  • To investigate the role of MMR1 in Myo2p-dependent mitochondrial distribution.
  • To elucidate the relationship between Mmr1p, Myo2p, and Ypt11p in mitochondrial transport.

Main Methods:

  • Genetic screening for high-dose suppressors of myo2 mitochondrial defects.
  • Co-immunoprecipitation to analyze protein complex formation.
  • Mitochondrial localization studies using microscopy.
  • Genetic interaction analysis.

Main Results:

  • MMR1 was identified as a high-dose suppressor of the myo2 mitochondrial defect.
  • Mmr1p localizes to bud-localizing mitochondria and forms a complex with the Myo2p tail.
  • Loss of Mmr1p delays mitochondrial transfer and abolishes distribution in ypt11p mutants.
  • A specific myo2 mutation disrupts Mmr1p-Myo2p association and Mmr1p localization.

Conclusions:

  • Mmr1p is a key mitochondrial component linking Myo2p to mitochondria for distribution.
  • Two independent Myo2p pathways (Mmr1p-Myo2p and Ypt11p-Myo2p) constitute the essential mitochondrial distribution system.

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