Activation of a novel pathway involving Mms1 and Rad59 in sgs1 cells.
Unequal sister chromatid recombination (uSCR) is elevated in budding yeast sgs1 mutants, which lack a homolog of the human BLM gene that causes Bloom syndrome. Examination of the mechanism responsible for elevated uSCR in sgs1 mutants showed that mutation of RAD51 also resulted in hyper-uSCR. Data from this study show that defects in the Rad51-Sgs1-dependent and Sgs1-dependent lesion-bypass pathways activate Rad59-Rad1- and Rad59-dependent pathways, respectively, resulting in uSCR. Moreover, the elevation of uSCR in sgs1 and rad51 mutants was dependent on MMS1, which encodes one of the components of the Mms22 module. Lastly, a putative role of Mms1 in the elevation of uSCR and a possible mechanism by which uSCR is elevated as a result of defective Sgs1 and Rad51 are discussed.
Ui
Ayako
A
Molecular Cell Biology Laboratory, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
Seki
Masayuki
M
Ogiwara
Hideaki
H
Lai
Mong Sing
MS
Yamamoto
Kazuo
K
Tada
Shusuke
S
Enomoto
Takemi
T
D004249:DNA Damage / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000502:physiology*; D051721:Rad52 DNA Repair and Recombination Protein; D053484:RecQ Helicases / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D012854:Sister Chromatid Exchange / Q000502:physiology*
D004268:DNA-Binding Proteins; C497197:RAD52 protein, S cerevisiae; C400213:RAD59 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; C090472:SGS1 protein, S cerevisiae; D053484:RecQ Helicases