Regulation anf Function of Clp 1p Protein Phosphatase

Clp 1p 蛋白磷酸酶的调节和功能

• 批准号: 6802835
• 负责人: DANNEL MCCOLLUM
• 金额: $ 27.14万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-19 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6802835
• 关键词: cell cycle; cell growth regulation; cell nucleus; cyclin dependent kinase; enzyme activity; fungal proteins; gene mutation; genetic screening; molecular cloning; phenotype; phosphoprotein phosphatase; phosphorylation; protein localization; protein protein interaction; protein transport; site directed mutagenesis

DESCRIPTION (provided by applicant): Cyclin dependent kinases (Cdks) are the key regulators of cell cycle transitions in eukaryotic cells. Precise coordination of each cell cycle step with the others is essential for cells to correctly transmit an intact genome to each daughter cell. Failure to do so can lead to polyploidy, genomic instability and cancer. Recently work has shown that the Cdc 14-family of protein phosphatases may be important regulators of Cdk activity and play a crucial role in coordinating late mitotic events to maintain genomic stability. We have found that the fission yeast S. pombe Cdc 14 ortholog Clp 1p functions to block further rounds of cell cycle progression if cytokinesis is delayed. Clp 1p carries out this function by regulating Cdk activity and a conserved signaling pathway termed the SIN. Deletion of clp1 makes cells unable to restrain cell cycle progression if cytokinesis is delayed resulting in polyploid cells. The long-term goal of this project is to understand how Clp1p regulates Cdk activity, and how Clp1p is regulated to ensure that mitosis is properly coordinated with cytokinesis. My specific aims are: (1) To determine how release of Clp1p from the nucleus in early mitosis is regulated and how in late mitosis the SIN functions to keep Clp1p out of the nucleus, as well as the significance of this regulation for Clp1p function. (2) To characterize the role of Clp1p phosphorylation in regulating Clp1p activity and/or localization by (A) determining the effect of phosphorylation of on Clp1p phosphatase activity, (B) mapping and mutagenesis of Clp1p phosphorylation sites followed by characterization of the phenotype of Clp1p phosphorylation site mutants. (3) To identify (A) Clp1p interacting protein(s) at different cell cycle stages, as well as (B) Clp1p regulated processes using biochemical and genetic analysis. (4) To test the model that Clp1p regulates Cdk activity by antagonizing a self-activating mechanism by which Cdk1p promotes its own activity by phosphorylating and activating its activator Cdc25p and inhibiting its inhibitor Wee 1p.

描述（由申请人提供）：细胞周期蛋白依赖性激酶（CDK）是真核细胞中细胞周期转变的关键调节剂。每个细胞周期步骤与其他细胞的精确配位对于细胞正确将完整的基因组正确传递到每个子细胞是必不可少的。不这样做会导致多倍体，基因组不稳定性和癌症。最近的工作表明，蛋白质磷酸酶的CDC 14户家庭可能是CDK活性的重要调节剂，并且在协调晚期有丝分裂事件以维持基因组稳定性方面起着至关重要的作用。我们发现，如果细胞因子延迟，裂变酵母菌S. pombe CDC 14直系同源物CLP 1P功能可以阻止细胞周期的进一步回合。 CLP 1P通过调节CDK活性和称为SIN的保守信号通路来执行此功能。 CLP1的缺失使细胞无法抑制细胞周期的进展，如果延迟导致多倍体细胞。该项目的长期目标是了解CLP1P如何调节CDK活性，以及​​如何调节CLP1P，以确保有丝分裂与细胞因子合适。我的具体目的是：（1）确定如何调控Clp1p从细胞核中释放，以及如何在晚期有丝分裂中释放sin功能以使Clp1p脱离细胞核，以及该调节对CLP1P功能的重要性。 （2）通过（a）确定Clp1p磷酸酶活性对Clp1p磷酸酶活性的磷酸化对CLP1P磷酸化位点的映射和诱变的作用，表征CLP1P磷酸化在调节CLP1P活性和/或定位中的作用。 （3）在不同的细胞周期阶段鉴定（a）CLP1P相互作用的蛋白质，以及（b）CLP1P使用生化和遗传分析调节的过程。 （4）测试CLP1P通过拮抗自动激活机制来调节CDK活性的模型，CDK1P通过磷酸化和激活其激活剂CDC25P并抑制其抑制剂WEE 1P来促进其自身的活性。