Identification of new genes required for meiotic recombination in Saccharomyces cerevisiae

Department of Biology, Faculty of Science, Osaka University, Japan.
Genetics (Impact Factor: 4.87). 02/1993; 133(1):51-66.
Source: PubMed

ABSTRACT Mutants defective in meiotic recombination were isolated from a disomic haploid strain of Saccharomyces cerevisiae by examining recombination within the leu2 and his4 heteroalleles located on chromosome III. The mutants were classified into two new complementation groups (MRE2 and MRE11) and eight previously identified groups, which include SPO11, HOP1, REC114, MRE4/MEK1 and genes in the RAD52 epistasis group. All of the mutants, in which the mutations in the new complementation groups are homozygous and diploid, can undergo premeiotic DNA synthesis and produce spores. The spores are, however, not viable. The mre2 and mre11 mutants produce viable spores in a spo13 background, in which meiosis I is bypassed, suggesting that these mutants are blocked at an early step in meiotic recombination. The mre2 mutant does not exhibit any unusual phenotype during mitosis and it is, thus, considered to have a mutation in a meiosis-specific gene. By contrast, the mre11 mutant is sensitive to damage to DNA by methyl methanesulfonate and exhibits a hyperrecombination phenotype in mitosis. Among six alleles of HOP1 that were isolated, an unusual pattern of intragenic complementation was observed.

  • Source
    • "However, there are mutants of the MRN(X) complex that are competent for Spo11 cleavage, but which are unable to remove the covalently bound Spo11 protein. These include alleles of Rad50 (termed rad50-S, (Cao et al. 1990)) and nuclease-deficient alleles of Mre11 (Ajimura et al. 1993; Moreau et al. 1999). Interestingly, the same phenotype is seen in null alleles of Sae2 (Keeney and Kleckner 1995; Prinz et al. 1997). "
    [Show abstract] [Hide abstract]
    ABSTRACT: 18.1 Introduction Topoisomerase II (Top2) is an important anticancer drug target. Agents such as etoposide and doxorubicin are broadly used in a wide variety of malignancies (Baldwin and Osheroff 2005; Choi et al. 2008; Dombernowsky et al. 1996; Lieu et al. 2009; Verborg et al. 2008; Walker and Nitiss 2002). Most drugs that target Top2 generate DNA damage as a direct consequence of the catalytic activity of the enzyme. All topoisomerases cleave DNA by forming a covalent complex between the enzyme and DNA, and agents that perturb the catalytic cycle have the potential to trap the enzyme and introduce DNA damage. The DNA damage caused by interfering with a topoisomerase is unique because it includes both DNA strand breaks and protein covalently bound to DNA. Agents that lead to the trapping of topoisomerases on DNA have been termed topoisomerase poisons to highlight the importance of cellular damage induced by these agents. Because topoisomerase poisons lead to cell killing largely through enzyme-mediated damage, pathways that repair this damage are critical determinants of clinical response to these agents. A major goal of this chapter is to highlight our current understanding of how DNA repair pathways affect sensitivity to Top2 poisons. It is hoped that some of these concepts will lead to new approaches for the clinical application of Top2 targeting agents. In addition to the clinical importance of Top2 targeting agents, these drugs have served as model compounds to study cellular responses to DNA damage. Unlike ionizing radiation or alkylating agents, many Top2 targeting drugs are highly specific,
    DNA Topoisomerases and Cancer, 1st edited by Y. Pommier, 01/2012: chapter 18: pages 381-407; Springer., ISBN: 978-1-4614-0323-4
  • Source
    • "Our functional analyses of a comprehensive histone point mutant library showed 90 MMS-sensitive mutants (Matsubara et al. 2007; Sakamoto et al. 2009). As most HR mutants show MMS sensitivity (Ajimura et al. 1993), these MMS-sensitive histone point mutants are potentially defective in one or more types of HR. Among these, H2A-S128A (see Introduction ) and H3-K56A (in this study) mutant cells are defective in HR. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Eukaryotic chromatin is regulated by chromatin factors such as histone modification enzymes, chromatin remodeling complexes and histone chaperones in a variety of DNA-dependent reactions. Among these reactions, transcription in the chromatin context is well studied. On the other hand, how other DNA-dependent reactions, including postreplicative homologous recombination, are regulated in the chromatin context remains elusive. Here, histone H3 Lys56 acetylation, mediated by the histone acetyltransferase Rtt109 and the histone chaperone Cia1/Asf1, is shown to be required for postreplicative sister chromatid recombination. This recombination did not occur in the cia1/asf1-V94R mutant, which lacks histone binding and histone chaperone activities and which cannot promote the histone acetyltransferase activity of Rtt109. A defect in another histone chaperone, CAF-1, led to an increase in acetylated H3-K56 (H3-K56-Ac)-dependent postreplicative recombination. Some DNA lesions recognized by the putative ubiquitin ligase complex Rtt101-Mms1-Mms22, which is reported to act downstream of the H3-K56-Ac signaling pathway, seem to be increased in CAF-1 defective cells. Taken together, these data provide the framework for a postreplicative recombination mechanism controlled by histone modifiers and histone chaperones in multiple ways.
    Genes to Cells 09/2010; 15(9):945-58. DOI:10.1111/j.1365-2443.2010.01435.x · 2.86 Impact Factor
  • Source
    • "To determine whether the difference between C × C and C × P recombination is specific to rad52-Y66A, we tested another hyper-recombination mutant from the RAD52 epistasis group. Compared to a wild-type strain, spontaneous C × C recombination in an mre11Δ mutant is induced eight-to ten-fold [16]. This recombination rate is not increased further by the presence of the rad52-Y66A mutation (Table 1). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Spontaneous mitotic recombination is a potential source of genetic changes such as loss of heterozygosity and chromosome translocations, which may lead to genetic disease. In this study we have used a rad52 hyper-recombination mutant, rad52-Y66A, to investigate the process of spontaneous heteroallelic recombination in the yeast Saccharomyces cerevisiae. We find that spontaneous recombination has different genetic requirements, depending on whether the recombination event occurs between chromosomes or between chromosome and plasmid sequences. The hyper-recombination phenotype of the rad52-Y66A mutation is epistatic with deletion of MRE11, which is required for establishment of DNA damage-induced cohesion. Moreover, single-cell analysis of strains expressing YFP-tagged Rad52-Y66A reveals a close to wild-type frequency of focus formation, but with foci lasting 6 times longer. This result suggests that spontaneous DNA lesions that require recombinational repair occur at the same frequency in wild-type and rad52-Y66A cells, but that the recombination process is slow in rad52-Y66A cells. Taken together, we propose that the slow recombinational DNA repair in the rad52-Y66A mutant leads to a by-pass of the window-of-opportunity for sister chromatid recombination normally promoted by MRE11-dependent damage-induced cohesion thereby causing a shift towards interchromosomal recombination.
    DNA repair 11/2009; 9(1):23-32. DOI:10.1016/j.dnarep.2009.10.001 · 3.36 Impact Factor
Show more


Available from