Calcium-dependent increase in tyrosine kinase activity stimulated by angiotensin II.
Calcium-dependent increase in tyrosine kinase activity stimulated by angiotensin II.
复制标题
血管紧张素 II 刺激钙依赖性酪氨酸激酶活性增加。
DOI：
10.1073/pnas.89.18.8837
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发表时间：
1992
影响因子：
11.1
通讯作者：
Earp,HS
中科院分区：
文献类型：
--
作者：
Huckle,WR;Dy,RC;Earp,HS
许多激素和神经递质的细胞效应，包括血管活性剂血管紧张素II（AngII）和[Arg 8]加压素，部分介导的蛋白丝氨酸苏氨酸激酶激活的细胞溶质Ca 2+浓度的增加。在这项研究中，我们测试了Ca（2+）动员剂激活细胞酪氨酸激酶的能力。用AngII处理完整的GN 4肝上皮细胞迅速（小于或等于15秒）增加酪氨酸激酶活性，所述酪氨酸激酶活性在未分级的细胞裂解物中或在来自洗涤剂溶解的细胞的抗磷酸酪氨酸免疫复合物中测量。增加磷酸化的外源性底物聚（Glu 80 Tyr 20）（3- 4倍以上的控制）的免疫沉淀激酶密切关注的时间和剂量依赖性的外观酪氨酸磷蛋白在完整的细胞。AngII的这种作用被毒胡萝卜素（一种升高Ca（2+）的肿瘤促进剂）模拟。AngII而不是表皮生长因子增加酪氨酸激酶活性的能力在加载有Ca 2+螯合剂双-（O-氨基苯氧基）-乙烷-N，N，N ′，N ′-四乙酸的细胞中被阻断。通过酪氨酸磷酸酶处理的免疫沉淀蛋白的去磷酸化伴随着体外激酶活性的60-70%的损失，表明AngII敏感性激酶在完整细胞中被磷酸化激活。这些发现证明了两个广泛存在的信号通路之间的联系，酪氨酸激酶和Ca 2+第二信使系统，并建议在血管紧张素II和[Arg 8]加压素的内分泌作用的Ca（2+）激活的酪氨酸激酶的可能参与。
The cellular effects of numerous hormones and neurotransmitters, including the vasoactive agents angiotensin II (AngII) and [Arg8]vasopressin, are mediated in part by protein-serine threonine kinases activated by increase of cytosolic Ca2+ concentration. In this study, we have tested the ability of Ca(2+)-mobilizing agents to activate cellular tyrosine kinases. Treatment of intact GN4 liver epithelial cells with AngII rapidly (less than or equal to 15 sec) increased tyrosine kinase activity measured either in unfractionated cell lysates or in anti-phosphotyrosine immune complexes from detergent-solubilized cells. Increased phosphorylation of the exogenous substrate poly(Glu80Tyr20) (3- to 4-fold over control) by immunoprecipitated kinases closely paralleled the time- and dose-dependence of the appearance of tyrosine phosphoproteins in intact cells. This effect of AngII was mimicked by thapsigargin, a Ca(2+)-elevating tumor promoter. The ability of AngII, but not epidermal growth factor, to increase tyrosine kinase activity was blocked in cells loaded with the Ca2+ chelator bis-(O-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid. Dephosphorylation of immunoprecipitated proteins by tyrosine phosphatase treatment was accompanied by a 60-70% loss in in vitro kinase activity, suggesting that the AngII-sensitive kinase(s) are activated by phosphorylation in intact cells. These findings demonstrate a link between two widely occurring signaling pathways, the tyrosine kinases and the Ca2+ second-messenger system, and suggest the possible involvement of Ca(2+)-activated tyrosine kinases in the endocrine actions of AngII and [Arg8]vasopressin.