Molecular and General Genetics MGG

, Volume 261, Issue 4–5, pp 831–840 | Cite as

The topoisomerase II-associated protein, Pat1p, is required for maintenance of rDNA locus stability in Saccharomyces cerevisiae

  • X. Wang
  • P. M. Watt
  • R. H. Borts
  • E. J. Louis
  • I. D. Hickson
ORIGINAL ARTICLE

Abstract

The Pat1 protein of Saccharomyces cerevisiae was identified during a screen for proteins that interact with topoisomerase II. Previously, we have shown that pat1Δ mutants exhibit a slow-growth phenotype and an elevated frequency of both mitotic and meiotic chromosome mis-segregation. Here, we have studied the effects of deleting the PAT1 gene on chromosomal stability, with particular reference to rates of homologous recombination within the rDNA locus. This locus was analyzed because rDNA-specific hyperrecombination is known to occur in conditional top2 mutants. We show that pat1Δ strains mimic top2 mutants in displaying an elevated rate of intrachromosomal excision recombination at the rDNA locus, but not elsewhere in the genome. The elevated rate of recombination is dependent upon Rad52p, but not upon Rad51p or Rad54p. However, pat1Δ strains display additional manifestations of more general genomic instability, in that they show mild sensitivity to UV light and an increased incidence of interchromosomal recombination between heteroalleles.

Key words Genetic recombination Ribosomal DNA Topoisomerase II Radiation Genome instability 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • X. Wang
    • 1
  • P. M. Watt
    • 1
  • R. H. Borts
    • 2
  • E. J. Louis
    • 2
  • I. D. Hickson
    • 1
  1. 1.Imperial Cancer Research Fund Laboratories, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UK e-mail: hickson@icrf.icnet.uk Tel.: +44-1865-222417; Fax: +44-1865-222431GB
  2. 2.Yeast Genetics, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, OX3 9DS, UKGB

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