ALTERED TYROSINE-527 PHOSPHORYLATION AND MITOTIC ACTIVATION OF P60C-SRC
ALTERED TYROSINE-527 PHOSPHORYLATION AND MITOTIC ACTIVATION OF P60C-SRC
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DOI：
10.1038/349172a0
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发表时间：
1991-01-10
期刊：
影响因子：
64.8
通讯作者：
SHALLOWAY, D
中科院分区：
文献类型：
--
作者：
BAGRODIA, S;CHACKALAPARAMPIL, I;SHALLOWAY, D
p60 c-src（c-src基因的蛋白质）的酪氨酸激酶活性在有丝分裂期间增加1、2;这可能在启动细胞周期的这一阶段期间发生的至少一些细胞变化中是重要的。 尽管有证据表明p60 c-src在有丝分裂过程中在几个位点被磷酸化，但体外磷酸化并不增加其激酶活性2，3。 我们现在报告，这种激酶活性的p60 c-src突变体与残基酪氨酸527改变为苯丙氨酸不改变在细胞周期中，这表明该残基的磷酸化状态的变化可能是负责在有丝分裂的p60 c-src的激活。 虽然在Tyr 527的磷酸化的变化不能检测到与野生型蛋白质，我们发现，磷酸化在Tyr 527的突变体与激酶活性降低有丝分裂过程中减少了三倍。 在这些结果的基础上，我们认为，在有丝分裂的p60 c-src的激活的结果从酪氨酸527磷酸化减少，和p60 c-src可能是或可能激活酪氨酸527磷酸化的激酶。
The tyrosine kinase activity of p60c-src, the protein of the c-src gene, increase during mitosis 1,2; this may be important in initiating at least some of the cellular changes that occur during this phase of the cell cycle. Although there is evidence that p60c-src is phosphorylated at several sites during mitosis, phosphorylation in vitro does not increase its kinase activity 2,3. We now report that this kinase activity of a p60c-src mutant with residue tyrosine 527 changed to phenylanine does not change during the cell cycle, suggesting that changes in the phosphorylation state of this residue may be responsible for the activation of p60c-src at mitosis. Although changes in phosphorylation at Tyr527 cannot be detected with the wild-type protein we find that phosphorylation at Tyr527 of a mutant with reduced kinase activity decreased threefold during mitosis. On the basis of these results we suggest that activation of p60c-src at mitosis results from decreased phosphorylation on Tyr 527, and that p60c-src may be or may activate the kinase that phosphorylates Tyr 527.