Phosphoserine Dependant Assembly of Signaling complexes

描述(由申请人提供)： 磷酸丝氨酸/苏氨酸结合区在控制细胞增殖的多个方面起着关键作用，包括细胞周期进程和细胞对DNA损伤的反应。目前的pSer/pThr结合域包括14-3-3蛋白、FHA结构域、WW结构域、F-box蛋白的WD40重复序列、串联BRCT结构域和Polo-box结构域。我们实验室的长期目标是识别和表征这些结构域，重点是识别它们的生理配体，确定它们识别pSer/Thr基序的结构基础，并阐明它们在复杂的蛋白激酶信号网络中调控细胞周期的分子基础。在真核细胞周期的多个阶段，包括发生在M期的许多事件，以及在DNA损伤反应中，Polo样蛋白是必不可少的。尽管它们很重要，但关于Polo样激酶活性是如何调节的，以及它们的底物的身份，人们还知之甚少。在这项建议中，我们结合生化、结构和细胞生物学技术来确定不变的pSer/pThr结合Polo-box结构域在调节Polo样激酶的激活、底物选择和磷酸化方面的功能。在这个过程中，我们将确定许多新的Polo样激酶配体和底物，这些配体和底物可能负责这些激酶在细胞中发挥的多效性作用。由于Polo-like Kinase在许多类型的人类癌症中表达上调，并且由于它们的实验下调导致细胞增殖减少和肿瘤退化，我们的实验结果应该确定Polo-box结构域是否是设计新型抗癌药物的良好靶点。

DESCRIPTION (provided by applicant): Phosphoserine/threonine-binding domains play critical roles in controlling multiple aspects of cell proliferation, including cell cycle progression and the cellular response to DNA damage. The current list of pSer/pThr-binding domains includes 14-3-3 proteins, FHA domains, WW domains, WD40 repeats of F-box proteins, tandem BRCT domains and the Polo-box domains of Polo-like kinases. The long-term goal of our laboratory is to identify and characterize these domains with a focus on identifying their physiological ligands, determining the structural basis for their pSer/Thr-motif recognition, and elucidating the molecular basis for their functions in cell cycle control within complex protein kinase signaling networks. Polo-like kinases are essential during multiple stages of the eukaryotic cell cycle, including many of the events that occur during M-phase, as well as in the DNA damage response. Despite their importance, details about how Polo-like kinase activity is regulated, and the identity of their substrates are poorly understood. In this proposal we use a combination of biochemical, structural and cell biological techniques to determine the function of the invariant pSer/pThr-binding Polo-box domain in regulating the activation of, and the substrate selection and phosphorylation by Polo-like kinases. In the process, we will identify many new Polo-like kinase ligands and substrates that may be responsible for the pleiotropic role these kinases play in the cell. Since Polo-like kinases are upregulated in many types of human cancer, and since their experimental down-regulation results in decreased cell proliferation and tumor regression, the results of our experiments should determine whether the Polo-box domain is a good target for novel anti-cancer drug design.