Extracellular signal-regulated kinase and the small GTP-binding protein, Rac, contribute to the effects of transforming growth factor-beta 1 on gene expression
Extracellular signal-regulated kinase and the small GTP-binding protein, Rac, contribute to the effects of transforming growth factor-beta 1 on gene expression
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DOI：
10.1074/jbc.271.28.16567
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发表时间：
1996-07-12
影响因子：
4.8
通讯作者：
Goldberg, HJ
中科院分区：
文献类型：
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作者：
Mucsi, I;Skorecki, KL;Goldberg, HJ
由转化生长因子-β(转化生长因子-β)向细胞核传递信号的激酶和调节蛋白的特性还不是很好。为了研究细胞外信号调节激酶(ERK)通路在这一过程中的作用，我们将转化生长因子-β反应的荧光素酶报告基因和表达载体瞬时导入NIH3T3成纤维细胞，以阻断这一信号转导通路。丝裂原活化蛋白(MAP)激酶磷酸酶-1和显性负MAP/ERK激酶1突变体分别将转化生长因子-β1对纤溶酶原激活物抑制物-1(PAI-1)启动子活性的刺激作用从11.5倍降低到4倍和4.9倍。I型胶原促进剂也观察到了类似的结果。转化生长因子-β1使ERK1活性在5min和3h分别增加4.5倍和3.1倍，而Jun激酶和p38活性不受影响。共转染小G蛋白的显性负性突变体Rac，而不是显性负性Ras、Cdc42或Rho突变体，可将转化生长因子-β1对PAI-1启动子的影响减少约一半。为了支持Rac在转化生长因子-β信号转导中的作用，NIH3T3细胞暴露于转化生长因子-β1 3min后，与Pac的GTP结合增加了3.7倍。这些结果表明，转化生长因子-β1部分通过ERK和RAC调节NIH3T3细胞的基因表达。
The kinases and regulatory proteins that convey signals initiated by transforming growth factor-beta (TGF-beta) to the nucleus are poorly characterized. To study the role of the extracellular signal-regulated kinase (ERK) pathway in this process, we transiently transfected NIH 3T3 fibroblasts with TGF-beta-responsive luciferase re porter genes and expression vectors designed to interrupt this kinase cascade. Mitogen-activated protein (MAP) kinase phosphatase-1 and a dominant negative MAP/ERK kinase 1 mutant reduced stimulation of plasminogen activator inhibitor-1 (PAI-1) promoter activity by TGF-beta 1 from 11.5 to 4-fold and 4.9-fold, respectively. Similar results were observed with the type I collagen promoters. TGF-beta 1 increased ERK1 activity 4.5 fold at 5 min and 3.1-fold at 3 h, while Jun kinase and p38 activity were not affected. Cotransfection of a dominant negative mutant of the small G protein, Rac, but not dominant negative Ras, Cdc42, or Rho mutants, reduced the effects of TGF-beta 1 on the PAI-1 promoter by approximately half. In support of a role for Rac in signaling by TGF-beta, GTP binding to Pac was increased 3.7-fold following exposure of NIH 3T3 cells to TGF-beta 1 for 3 min. These findings indicate that TGF-beta 1 modulates gene expression partly through ERK and Rac in NIH 3T3 cells.