Budding yeast Mph1 promotes sister chromatid interactions by a mechanism involving strand invasion
Budding yeast Mph1 promotes sister chromatid interactions by a mechanism involving strand invasion
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DOI：
10.1016/j.dnarep.2010.09.009
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发表时间：
2011-01-02
期刊：
影响因子：
3.8
通讯作者：
Kramer, Wilfried
中科院分区：
文献类型：
--
作者：
Ede, Christopher;Rudolph, Christian J.;Kramer, Wilfried
病变处复制叉的停滞是对基因组完整性和细胞活力的严重威胁。细胞已经开发出多种途径，允许继续合成，包括translesion合成，复制后修复和同源重组。我们已经设计了一个敏感的遗传系统检测酿酒酵母姐妹染色单体的相互作用。在KanMX 4模块中产生266 bp序列重复，并通过G418抗性菌落对回复进行评分。4-NQO诱导的和自发的回复都严格依赖于RAD 52。损伤诱导的回复也在很大程度上依赖于RAD 51。因此，大多数损伤诱导的事件需要链侵入步骤。诱导的回复没有受到影响，在rev 3突变体和rad 30突变体部分减少，表明参与的Pol eta。在缺乏Mph 1的细胞中，DNA解旋酶的FANCM家族的成员，其已经涉及到叉再激活的途径，涉及同源重组，损伤诱导的事件显着减少。连同自发突变表型的mph 1突变体，这些数据强烈表明，Mph 1有一个额外的功能，除了其先前描述的能力，破坏D-环的重组。我们建议，Mph 1促进D-环的形成。(C)2010爱思唯尔有限公司版权所有。
Stalling of replication forks at lesions is a serious threat to genomic integrity and cell viability. Cells have developed a variety of pathways that allow continuation of synthesis, including translesion synthesis, postreplication repair and homologous recombination. We have devised a sensitive genetic system for detection of sister chromatid interactions in Saccharomyces cerevisiae. A 266 bp sequence duplication in the KanMX4 module was generated and reversions were scored via G418 resistant colonies. Both 4-NQO induced and spontaneous reversions are strictly dependent on RAD52. Damage-induced reversions are also largely dependent on RAD51. Thus, most damage-induced events require a strand invasion step. Induced reversions were not affected in rev3 mutants and partially reduced in rad30 mutants indicating an involvement of Pol eta. In cells lacking Mph1, a member of the FANCM family of DNA helicases, that has been implicated in a pathway for fork reactivation involving homologous recombination, damage-induced events are significantly reduced. Together with the spontaneous mutator phenotype of mph1 mutants this data strongly suggest that Mph1 has an additional function in recombination besides its previously described ability to disrupt D-loops. We propose that Mph1 promotes D-loop formation. (C) 2010 Elsevier B.V. All rights reserved.