syk kinase activation by a src kinase-initiated activation loop phosphorylation chain reaction
syk kinase activation by a src kinase-initiated activation loop phosphorylation chain reaction
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DOI：
10.1073/pnas.94.5.1919
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发表时间：
1997-03-04
影响因子：
11.1
通讯作者：
Scharenberg, AM
中科院分区：
文献类型：
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作者：
ElHillal, O;Kurosaki, T;Scharenberg, AM
syk酪氨酸激酶的激活几乎是在许多类型的抗原受体（包括Fc受体）参与后立即发生的，但syk被激活的机制目前尚不清楚。在这里，我们证明Fc受体诱导的syk激活是由于src家族激酶和其他活化的syk分子磷酸化syk激活环的结果。这表明syk的激活是src激酶启动的激活环磷酸化链反应的结果，这种类型的激活机制预测syk的激活将表现为指数动力学，这为其在微弱的抗原受体刺激下快速而强劲的激活提供了潜在的解释。我们提出类似的机制可能负责产生其他细胞质酪氨酸激酶的快速激活，例如布鲁顿酪氨酸激酶/tec家族的酪氨酸激酶。
Activation of the syk tyrosine kinase occurs almost immediately following engagement of many types of antigen receptors, including Fc receptors, but the mechanism through which syk is activated is currently unclear, Here we demonstrate that Fc receptor-induced syk activation occurs as the result of phosphorylation of the syk activation loop by both src family kinases and other molecules of activated syk, suggesting that syk activation occurs as the result of a src kinase-initiated activation loop phosphorylation chain reaction, This type of activation mechanism predicts that syk activation would exhibit exponential kinetics, providing a potential explanation for its rapid and robust activation by even a weak antigen receptor stimuli. We propose that a similar mechanism may be responsible for generating rapid activation of other cytoplasmic tyrosine kinases, such as those of the Bruton tyrosine kinase/tec family, as well.