Human prk is a conserved protein serine/threonine kinase involved in regulating M phase functions
Human prk is a conserved protein serine/threonine kinase involved in regulating M phase functions
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DOI：
10.1074/jbc.272.45.28646
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发表时间：
1997-11-07
影响因子：
4.8
通讯作者：
Dai, W
中科院分区：
文献类型：
--
作者：
Bin, OY;Pan, HQ;Dai, W
人prk编码一种新的丝氨酸/苏氨酸激酶，能够在体外强烈磷酸化酪蛋白而不是组蛋白HL。在肺成纤维细胞的细胞周期的不同阶段期间，PRK表达在不同水平上受到严格调节。Prk激酶活性在有丝分裂、G（1）和G（1）/S期间相对较低，在细胞周期的晚期S和G（2）阶段达到峰值。通过杆状病毒载体系统表达的重组人Prk能够磷酸化Cdc 25 C，Cdc 25 C是G（2）/M转换的正调节剂。人prk与酿酒酵母CDC 5和黑腹果蝇波罗具有显著的序列同源性，两者都是有丝分裂和减数分裂所必需的。全长prk基因转录本极大地增强了甾体酮诱导的非洲爪蟾卵母细胞减数分裂成熟。另一方面，反义prk转录本能显著延迟和降低卵母细胞的成熟率。在ii型CDC 5突变株中表达。酿酒酵母，人Prk，但不是缺失突变蛋白，完全拯救了芽殖酵母的温度敏感表型。总之，prk可能代表一种新的蛋白激酶，在调节哺乳动物细胞有丝分裂的发生和/或进展中起重要作用。
Human prk encodes a novel protein serine/threonine kinase capable of strongly phosphorylating casein but not histone HL in vitro. prk expression is tightly regulated at various levels during different stages of the cell cycle in lung fibroblasts. The Prk kinase activity is relatively low during mitosis, G(1), and G(1)/S, and peaks during late S and G(2) stages of the cell cycle. Recombinant human Prk expressed through the baculoviral vector system is capable of phosphorylating Cdc25C, a positive regulator for the G(2)/M transition. Human prk shares significant sequence homology with Saccharomyces cerevisiae CDC5 and Drosophila melanogaster polo, both of which are essential for mitosis and meiosis. Full-length prk, transcripts greatly potentiate progesterone-induced meiotic maturation of Xenopus laevis oocytes. Oh the other hand, antisense prk transcripts significantly delay and reduce the rate of oocyte maturation. When expressed in ii CDC5 mutant strain of S. cerevisiae, human Prk, but not a deletional mutant protein, fully rescues the temperature-sensitive phenotype of the budding yeast. Taken together, prk may represent a new protein kinase, playing an important role in regulating the onset and/or progression of mitosis' in mammalian cells.