Characterization of the slow-growth phenotype of S. cerevisiae Whip/Mgs1 Sgs1 double deletion mutants.
RecQ DNA helicases from many organisms have been indicated to function in the maintenance of genomic stability. In human cells, mutation in the WRN helicase, a RecQ-like DNA helicase, results in the Werner syndrome (WS), a genetic disorder characterized by genomic instability and premature ageing. Similarly, mutation in SGS1, the RECQ homologue in budding yeast, results in genomic instability and accelerated ageing. We previously demonstrated that mouse WRN interacts physically with a novel, highly conserved protein that we named WHIP, and that in budding yeast cells, simultaneous deletion of WHIP/MGS1 and SGS1 results in slow growth and shortened life span. Here we show by using genetic analysis in Saccharomyces cerevisiae that mgs1Delta sgs1Delta cells have increased rates of terminal G2/M arrest, and show elevated rates of spontaneous sister chromatid recombination (SCR) and rDNA array recombination. Finally, we report that complementation of the synthetic relationship between SGS1 and WHIP/MGS1 requires both the helicase and Top3-binding activities of Sgs1, as well as the ATPase activity of Mgs1. Our results suggest that Whip/Mgs1 is implicated in DNA metabolism, and is required for normal growth and cell cycle progression in the absence of Sgs1.
Branzei
Dana
D
Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba-ku, Sendai, Miyagi, Japan. dana@mail2.pharm.tohoku.ac.jp
Seki
Masayuki
M
Onoda
Fumitoshi
F
Yagi
Hideki
H
Kawabe
Yoh-ichi
Y
Enomoto
Takemi
T
D000251:Adenosine Triphosphatases / Q000235:genetics*; D002453:Cell Cycle; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D004265:DNA Helicases / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D017353:Gene Deletion; D008938:Mitosis / Q000502:physiology*; D016296:Mutagenesis; D010641:Phenotype; D051721:Rad52 DNA Repair and Recombination Protein; D053484:RecQ Helicases; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion; D012854:Sister Chromatid Exchange / Q000235:genetics*
D004275:DNA, Ribosomal; D004268:DNA-Binding Proteins; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; C506739:MGS1 protein, S cerevisiae; C090472:SGS1 protein, S cerevisiae; D004265:DNA Helicases; D053484:RecQ Helicases