INVESTIGATION OF MOLECULAR EVENTS DURING CELL CYCLE PROGRESSION

尽管在确定机制方面已经取得了很大进展 对细胞周期蛋白/细胞周期蛋白依赖性蛋白激酶活性的调节，几乎没有 已知这些蛋白激酶复合体的底物。尽管如此，它 被认为可能有助于底物的选择性 对于不同的络合物，导致了例如 G1/S事件的Cln2/Cdc28与G2/M事件的Clb2/Cdc28 (请注意，CDC28蛋白激酶催化亚基与 这两种情况)。为了批判性地审视这一想法，并按顺序 开始阐明细胞周期蛋白依赖性的作用机制 在触发不同的细胞周期转变中，有必要 鉴定和鉴定这些蛋白的磷酸化底物 复合体，以确定是否有任何或全部只是专门 被单独的细胞周期蛋白/镉28复合体磷酸化，并确定 这些磷酸化事件对细胞的功能影响 周期控制。我们正在设计的实验将利用我们的 新开发的MS方法，以帮助识别这些 潜在重要的磷酸化底物。

Although much progress has been made in determining the mechanisms of regulation of cyclin/cyclin dependent kinase activation, little is known about substrates for these protein kinase complexes. Still, it is considered likely that cyclins contribute to substrate selectivity for the different complexes, resulting in the specificity of e.g. Cln2/Cdc28 for Gl/S events vs. that of Clb2/Cdc28 for G2/M events (note that the Cdc28 protein kinase catalytic subunit is the same in both cases). In order to examine this idea critically, and in order to begin to elucidate the mechanisms of action of cyclin-dependent kinases in triggering diverse cell cycle transitions, it is necessary to identify and characterize phosphorylation substrates of these complexes, to determine if any or all are only specifically phosphorylated by individual cyclin/Cdc28 complexes, and to determine the functional consequences of these phosphorylation events for cell cycle control. We are designing experiments that will utilize our newly developed MS approaches to assist in the identification of these potentially important phosphorylation substrates.