Two distinct surveillance mechanisms monitor meiotic chromosome metabolism in budding yeast

Curr Biol. 2006 Dec 19;16(24):2473-9. doi: 10.1016/j.cub.2006.10.069.

Abstract

Meiotic recombination is initiated by Spo11-generated DNA double-strand breaks (DSBs) . A fraction of total DSBs is processed into crossovers (CRs) between homologous chromosomes, which promote their accurate segregation at meiosis I (MI) . The coordination of recombination-associated events and MI progression is governed by the "pachytene checkpoint", which in budding yeast requires Rad17, a component of a PCNA clamp-like complex, and Pch2, a putative AAA-ATPase . We show that two genetically separable pathways monitor the presence of distinct meiotic recombination-associated lesions: First, delayed MI progression in the presence of DNA repair intermediates is suppressed when RAD17 or SAE2, encoding a DSB-end processing factor , is deleted. Second, delayed MI progression in the presence of aberrant synaptonemal complex (SC) is suppressed when PCH2 is deleted. Importantly, ZIP1, encoding the central element of the SC , is required for PCH2-dependent checkpoint activation. Analysis of the rad17Deltapch2Delta double mutant revealed a redundant function regulating interhomolog CR formation. These findings suggest a link between the surveillance of distinct recombination-associated lesions, control of CR formation kinetics, and regulation of MI timing. A PCH2-ZIP1-dependent checkpoint in meiosis is likely conserved among synaptic organisms from yeast to human .

Publication types

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

MeSH terms

  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Chromosomes, Fungal / metabolism*
  • Crossing Over, Genetic*
  • DNA-Binding Proteins / genetics
  • Endonucleases
  • Meiosis / genetics*
  • Nuclear Proteins / genetics
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Synaptonemal Complex / metabolism

Substances

  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • Nuclear Proteins
  • RAD17 protein, S cerevisiae
  • SAE2 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Zip1 protein, S cerevisiae
  • rad9 protein
  • Endonucleases