Suhandynata Raymond T, Wan Lihong, Zhou Huilin, Hollingsworth Nancy M
Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, 11794-5215, United States of America.
Ludwig Institute for Cancer Research, University of California San Diego, La Jolla, California, 92093, United States of America.
PLoS One. 2016 May 23;11(5):e0155931. doi: 10.1371/journal.pone.0155931. eCollection 2016.
Meiotic recombination plays a key role in sexual reproduction as it generates crossovers that, in combination with sister chromatid cohesion, physically connect homologous chromosomes, thereby promoting their proper segregation at the first meiotic division. Meiotic recombination is initiated by programmed double strand breaks (DSBs) catalyzed by the evolutionarily conserved, topoisomerase-like protein Spo11. Repair of these DSBs is highly regulated to create crossovers between homologs that are distributed throughout the genome. This repair requires the presence of the mitotic recombinase, Rad51, as well as the strand exchange activity of the meiosis-specific recombinase, Dmc1. A key regulator of meiotic DSB repair in Saccharomyces cerevisiae is the meiosis-specific kinase Mek1, which promotes interhomolog strand invasion and is required for the meiotic recombination checkpoint and the crossover/noncrossover decision. Understanding how Mek1 regulates meiotic recombination requires the identification of its substrates. Towards that end, an unbiased phosphoproteomic approach utilizing Stable Isotope Labeling by Amino Acids in Cells (SILAC) was utilized to generate a list of potential Mek1 substrates, as well as proteins containing consensus phosphorylation sites for cyclin-dependent kinase, the checkpoint kinases, Mec1/Tel1, and the polo-like kinase, Cdc5. These experiments represent the first global phosphoproteomic dataset for proteins in meiotic budding yeast.
减数分裂重组在有性生殖中起着关键作用，因为它产生交叉，这些交叉与姐妹染色单体黏连相结合，物理上连接同源染色体，从而促进它们在第一次减数分裂时的正确分离。减数分裂重组由进化上保守的拓扑异构酶样蛋白Spo11催化的程序性双链断裂（DSB）引发。这些DSB的修复受到高度调控，以在整个基因组中分布的同源物之间产生交叉。这种修复需要有丝分裂重组酶Rad51的存在，以及减数分裂特异性重组酶Dmc1的链交换活性。酿酒酵母中减数分裂DSB修复的关键调节因子是减数分裂特异性激酶Mek1，它促进同源链入侵，并且是减数分裂重组检查点和交叉/非交叉决定所必需的。了解Mek1如何调节减数分裂重组需要鉴定其底物。为此，利用细胞中氨基酸稳定同位素标记（SILAC）的无偏磷酸化蛋白质组学方法来生成潜在的Mek1底物列表，以及含有细胞周期蛋白依赖性激酶、检查点激酶Mec1/Tel1和polo样激酶Cdc5的共有磷酸化位点的蛋白质列表。这些实验代表了减数分裂芽殖酵母中蛋白质的首个全局磷酸化蛋白质组数据集。
