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The budding yeast mei5 and sae3 proteins act together with dmc1 during meiotic recombination

Hideo Tsubouchi1, G Shirleen Roeder

  • 1Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06520-8103, USA.

Genetics
|December 8, 2004
PubMed

Insights

Mei5 and Sae3 proteins are essential accessory factors for Dmc1 function during yeast meiosis. These proteins, along with Dmc1, are crucial for DNA repair, recombination, and successful spore formation.

Area of Science:

  • Cell Biology
  • Genetics
  • Molecular Biology

Background:

  • Meiosis is a fundamental process for sexual reproduction, involving DNA replication, homologous recombination, and chromosome segregation.
  • RecA-like recombinases, such as Dmc1, play critical roles in mediating homologous recombination during meiosis.
  • Accessory proteins are often required to facilitate the function of key recombination enzymes.

Purpose of the Study:

  • To investigate the functional relationship between Mei5, Sae3, and Dmc1 proteins in budding yeast.
  • To determine the role of Mei5 and Sae3 in Dmc1-mediated DNA repair and recombination during meiosis.
  • To elucidate the mechanism by which Mei5 and Sae3 influence Dmc1 activity.

Main Methods:

  • Genetic analysis of mei5, sae3, and dmc1 mutants in budding yeast.
  • Assessment of sporulation efficiency, spore viability, and crossing over rates.
  • Analysis of cell-cycle progression and suppression of mutant phenotypes.
  • Immunolocalization studies to determine protein co-localization and dependency on meiotic chromosomes.

Main Results:

  • Mutations in mei5 and sae3 phenocopy dmc1 mutations, impairing sporulation, spore viability, and crossing over.
  • Overproduction of Rad51 suppresses the meiotic defects observed in mei5, sae3, and dmc1 mutants.
  • Mei5, Sae3, and Dmc1 proteins exhibit mutually dependent co-localization on meiotic chromosomes.
  • Rad51 localization is unaffected in mei5 and sae3 mutants, indicating a specific role for Mei5/Sae3 with Dmc1.

Conclusions:

  • Mei5 and Sae3 function as specific accessory factors for the Dmc1 recombinase during budding yeast meiosis.
  • These proteins are likely essential for the efficient assembly of Dmc1-containing nucleoprotein filaments on meiotic chromosomes.
  • The findings provide insights into the regulation of homologous recombination and genome stability during meiosis.

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