Serine/threonine-protein kinase PLK1 (UniProt: P53350; also known as EC: 2.7.11.21, Polo-like kinase 1, PLK-1, Serine/threonine-protein kinase 13, STPK13) is encoded by the PLK1 (also known as PLK) gene (Gene ID: 5347) in human. PLK-1 is a serine/threonine-protein kinase that performs several important functions throughout M phase of the cell cycle, including the regulation of centrosome maturation and spindle assembly, the removal of cohesins from chromosome arms, the inactivation of anaphase-promoting complex/cyclosome (APC/C) inhibitors, and the regulation of mitotic exit and cytokinesis. It is shown to express in placenta and colon and its activity is enhanced by growth promoting agents. PLK-1 is activated by phosphorylation at Thr210 by aurora kinase A. It accumulates to a maximum during the G2 and M phases and declines to a nearly undetectable levels following mitosis and throughout G1 phase. However, it begins to accumulate again during the S phase of cell cycle. The kinase domain of PLK-1 is localized to amino acids 53-305 with activation loop in the region of amino acids 194-221. PLK-1 contains 2 POLO box domains (aa 417-480 and 515-584), which act as phosphopeptide-binding module that recognize and bind serine-phosphothreonine/ phosphoserine]-(proline/X) motifs. PLK-1 recognizes and binds docking proteins that are already phosphorylated on these motifs, and then phosphorylates them. Defects in PLK1 gene are associated with some cancers, such as gastric, thyroid or B-cell lymphomas. Expression is shown to be higher in tumor tissues with a poor prognosis, suggesting its role in malignant transformations and carcinogenesis.，官网链接：https://www.sigmaaldrich.cn/product/mm/abe2619 默克 科研、开发、生产。 作为生命科学行业的全球领先供应商，我们致力于为科研、生物技术开发和生产，以及制药药物疗法开发和生产提供各类解决方案和服务。

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