Growth Hormone-Releasing Hormone Stimulates Mitogen-Activated Protein Kinase.
Growth Hormone-Releasing Hormone Stimulates Mitogen-Activated Protein Kinase.
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DOI：
10.1210/endo.141.6.7513
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发表时间：
2000-06
期刊：
影响因子：
4.8
通讯作者：
C. Pombo;J. Zalvide;B. Gaylinn;C. Die Guez
中科院分区：
文献类型：
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作者：
C. Pombo;J. Zalvide;B. Gaylinn;C. Die Guez
gh释放激素（GHRH）可诱导生长缺陷细胞增殖。靶细胞中涉及腺苷酸环化酶/cAMP/蛋白激酶A通路的途径似乎对这种作用很重要，或者至少在一些生长发育不良的垂体腺瘤中是不受调节的。我们研究了GHRH是否也能刺激丝裂原活化蛋白激酶（MAP）。在垂体细胞和过表达GHRH受体的细胞系中，GHRH可以激活MAP激酶。虽然蛋白激酶A和蛋白激酶C都可以激活CHO细胞系中的MAP激酶，但在该系统中，GHRH激活MAP激酶似乎不需要蛋白激酶A和蛋白激酶C。然而，与受体偶联的G蛋白的βγ-亚基的隔离抑制了GHRH介导的MAP激酶激活。该途径还涉及p21ras和磷脂酰肌醇3-激酶，可能是磷脂酰肌醇3-激酶-γ。尽管有p21ras的参与，但蛋白激酶Raf-1并不高。
GH-releasing hormone (GHRH) can induce proliferation of somatotroph cells. The pathway involving adenylyl cyclase/cAMP/protein kinase A pathway in its target cells seems to be important for this action, or at least it is deregulated in some somatotroph pituitary adenomas. We studied in this work whether GHRH can also stimulate mitogen-activated protein (MAP) kinase. GHRH can activate MAP kinase both in pituitary cells and in a cell line overexpressing the GHRH receptor. Although both protein kinase A and protein kinase C could activate MAP kinase in the CHO cell line studied, neither protein kinase A nor protein kinase C appears to be required for GHRH activation of MAP kinase in this system. However, sequestration of the βγ-subunits of the G protein coupled to the receptor inhibits MAP kinase activation mediated by GHRH. This pathway also involves p21ras and a phosphatidylinositol 3-kinase, probably phosphatidylinositol 3-kinase-γ. Despite the involvement of p21ras, the protein kinase Raf-1 is not hyperp...