Evidence of meiotic crossover control in Saccharomyces cerevisiae through Mec1-mediated phosphorylation of replication protein A
Evidence of meiotic crossover control in Saccharomyces cerevisiae through Mec1-mediated phosphorylation of replication protein A
复制标题
DOI：
10.1534/genetics.105.047845
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发表时间：
2006-01-01
期刊：
影响因子：
3.3
通讯作者：
Brush, GS
中科院分区：
文献类型：
--
作者：
Bartrand, AJ;Iyasu, D;Brush, GS
复制蛋白A(Replica Protein A，RPA)是真核生物中主要的单链DNA结合蛋白，对DNA的复制、修复和重组至关重要。在发芽酵母的有丝分裂和减数分裂过程中，RPA在需要Mec1蛋白激酶的反应中被磷酸化，Mec1蛋白激酶是一种中央检查点调节因子，也是人类ATR的同源物。通过质谱学和定点突变，我们现在已经在RPA异源三聚体的中间亚基中鉴定出一个丝氨酸残基，它在体内和体外都是Mecl磷酸化的靶点。含有由丝氨酸突变为天冬氨酸而产生的拟磷酸型RPA的细胞，在特定的遗传间隔内，减数分裂交叉的模式发生了显着的变化。这些结果提示了MECL的一种新功能，它通过RPA作用于局部控制相互重组。
Replication protein A (RPA) is the major single-stranded DNA-binding protein in eukaryotes, essential for DNA replication, repair, and recombination. During mitosis and meiosis in budding yeast, RPA becomes phosphorylated in reactions that require the Mec1 protein kinase, a central checkpoint regulator and homolog of human ATR. Through mass spectrometry and site-directed mutagenesis, we have now identified a single serine residue in the middle subunit of the RPA heterotrimer that is targeted for phosphorylation by Mecl both in vivo and in vitro. Cells containing a phosphomimetic version of RPA generated by mutation of this serine to aspartate exhibit a significant alteration in the pattern of meiotic crossovers for specific genetic intervals. These results suggest a new function of Mecl that operates through RPA to locally control reciprocal recombination.