Regulation of a calcium-dependent tyrosine kinase in vascular smooth muscle cells by angiotensin II and platelet-derived growth factor - Dependence on calcium and the actin cytoskeleton
Regulation of a calcium-dependent tyrosine kinase in vascular smooth muscle cells by angiotensin II and platelet-derived growth factor - Dependence on calcium and the actin cytoskeleton
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DOI：
10.1074/jbc.273.3.1711
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发表时间：
1998-01-16
影响因子：
4.8
通讯作者：
Graves, LM
中科院分区：
文献类型：
--
作者：
Brinson, AE;Harding, T;Graves, LM
一种新的，p125（FAK）同源物，CADTK，已被检测到在神经，上皮，或造血细胞，但不是在成纤维细胞。我们现在证明了CADTK在间充质细胞，大鼠主动脉平滑肌细胞（RSMC）中的表达。血管紧张素II（Ang II）或血小板衍生生长因子（PDGF-BB和PDGF-AA）显着刺激CADTK酪氨酸磷酸化在RSMC：但不影响p125（FAK）磷酸化。PDGF依赖的CADTK酪氨酸磷酸化比Ang II更慢且更长，这与这些激动剂对胞浆钙（[Ca 2 +]（i））信号传导的差异效应密切相关。细胞内钙离子螯合剂抑制血管紧张素II和PDGF对CADTK的快速和持续激活。细胞外钙螯合抑制PDGF刺激的CADTK酪氨酸磷酸化的增加，以及持续（但不是早期）激活的Ang II，相反，p125（FAK）酪氨酸磷酸化是最大的静止，贴壁RSMC和EGTA孵育不受影响。蛋白激酶C活性的耗竭部分抑制了Ang II和PDGF诱导的CADTK酪氨酸磷酸化。另外的结果证实了CADTK和细胞骨架之间的关系，第一，桩蛋白的酪氨酸磷酸化与CADTK的激活相关，这种增加被EGTA抑制，第二，细胞松弛素D阻断PDGF或Ang II刺激的CADTK的酪氨酸磷酸化，表明细胞骨架在激动剂依赖性CADTK激活中的作用。第三，CADTK定位的免疫荧光分析表明肌动蛋白样细胞骨架染色延伸到焦点接触，这些结果表明，在间充质细胞中，CADTK是本地化和激活的肌动蛋白细胞因子依赖的机制，钙和蛋白激酶C依赖的方式独立于p125（FAK）的调节机制。
A novel, p125(FAK) homologue, CADTK, has been detected in neural, epithelial, or hematopoietic cells but not in fibroblasts. We now demonstrate CADTK expression in a mesenchymal cell, rat aortic smooth muscle cells (RSMC). Angiotensin II (Ang II) or platelet-derived growth factor (PDGF-BB and PDGF-AA) markedly stimulated CADTK tyrosine phosphorylation in RSMC: but did not affect p125(FAK) phosphorylation. The PDGF-dependent CADTK tyrosine phosphorylation was slower and more prolonged than that of Ang II, correlating well with the differential effects of these agonists on cytosolic calcium ([Ca2+](i)) signaling. An intracellular calcium chelator inhibited both the rapid and sustained activation of CADTK by Ang II and PDGF. Extracellular calcium chelation inhibited the PDGF-stimulated increase in CADTK tyrosine phosphorylation as well as the sustained (but not the early) activation by Ang II, In contrast, p125(FAK) tyrosine phosphorylation was maximal in quiescent, adherent RSMC and was not affected by incubation with EGTA. Depletion of protein kinase C activity partially inhibited both the Ang II- and PDGF-induced CADTK tyrosine phosphorylation. Additional results confirm a relation between CADTK and the cytoskeleton, First, the tyrosine phosphorylation of paxillin correlated with activation of CADTK; this increase was inhibited by EGTA, Second, cytochalasin D blocked the PDGF- or Ang II stimulated tyrosine phosphorylation of CADTK, suggesting a role for the cytoskeleton in agonist-dependent CADTK activation. Third, immunofluorescence analysis of CADTK localization demonstrated actin-like cytoskeleton staining extending into focal contacts, These results suggest that in mesenchymal cells, CADTK is localized to and activated by an actin cytoskeleton-dependent mechanism; a mechanism that is regulated in a calcium and protein kinase C-dependent manner independently of p125(FAK).