P107(WEE1) IS A DUAL-SPECIFICITY KINASE THAT PHOSPHORYLATES-P34(CDC2) ON TYROSINE-15
P107(WEE1) IS A DUAL-SPECIFICITY KINASE THAT PHOSPHORYLATES-P34(CDC2) ON TYROSINE-15
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DOI：
10.1073/pnas.89.7.2917
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发表时间：
1992-04-01
影响因子：
11.1
通讯作者：
PIWNICAWORMS, H
中科院分区：
文献类型：
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作者：
PARKER, LL;ATHERTONFESSLER, S;PIWNICAWORMS, H
p107 wee 1是一种蛋白激酶，在粟酒裂殖酵母中通过与p34 cdc 2相互作用而作为有丝分裂的剂量依赖性抑制剂发挥作用。 为了表征p107 wee 1的激酶活性，从过量生产的昆虫细胞中纯化其羧基末端催化结构域至均一。 通过凝胶过滤确定纯化蛋白质（p37 wee 1 KD）的表观分子量几乎等于37 kDa，与其为单体一致。 丝氨酸和酪氨酸激酶活性与p37 wee 1 KD共过滤，表明p107 wee 1是一种双特异性激酶。 在体外，p107 wee 1磷酸化p34 cdc 2的Tyr-15只有当p34 cdc 2与细胞周期蛋白复合。 无论是单体p34 cdc 2还是含有Tyr-15的肽都不能替代该测定中的p34 cdc 2/细胞周期蛋白复合物。 p107 wee 1对p34 cdc 2的磷酸化作用可抑制p34 cdc 2的组蛋白H-1激酶活性。 这些结果表明，p107 wee 1作为一个有丝分裂抑制剂的功能，直接磷酸化p34 cdc 2的Tyr-15和磷酸化的首选底物是p34 cdc 2/细胞周期蛋白复合物。
p107wee1 is a protein kinase that functions as a dose-dependent inhibitor of mitosis through its interactions with p34cdc2 in Schizosaccharomyces pombe. To characterize the kinase activity of p107wee1, its carboxyl-terminal catalytic domain was purified to homogeneity from overproducing insect cells. The apparent molecular mass of the purified protein (p37wee1 KD) was determined to be almost-equal-to 37 kDa by gel filtration, consistent with it being a monomer. Serine and tyrosine kinase activities cofiltered with p37wee1 KD, demonstrating that p107wee1 is a dual-specificity kinase. In vitro, p107wee1 phosphorylated p34cdc2 on Tyr-15 only when p34cdc2 was complexed with cyclin. Neither monomeric p34cdc2 nor a peptide containing Tyr-15 was able to substitute for the p34cdc2/cyclin complex in this assay. Furthermore, the phosphorylation of p34cdc2 by p107wee1 in vitro inhibited the histone H-1 kinase activity of p34cdc2. These results indicate that p107wee1 functions as a mitotic inhibitor by directly phosphorylating p34cdc2 on Tyr-15 and that the preferred substrate for phosphorylation is the p34cdc2/cyclin complex.