BIPHASIC AND SYNERGISTIC ACTIVATION OF P44(MAPK) (ERK1) BY GROWTH-FACTORS - CORRELATION BETWEEN LATE PHASE ACTIVATION AND MITOGENICITY
BIPHASIC AND SYNERGISTIC ACTIVATION OF P44(MAPK) (ERK1) BY GROWTH-FACTORS - CORRELATION BETWEEN LATE PHASE ACTIVATION AND MITOGENICITY
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DOI：
10.1210/me.6.5.845
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发表时间：
1992-05-01
影响因子：
--
通讯作者：
POUYSSEGUR, J
中科院分区：
文献类型：
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作者：
MELOCHE, S;SEUWEN, K;POUYSSEGUR, J
我们用特异性抗血清检测了生长因子刺激的仓鼠成纤维细胞中p44丝裂原活化蛋白激酶（p44 mapk）的磷酸化和蛋白激酶活性。p44 mapk的活性受受体酪氨酸激酶和G蛋白偶联受体的刺激。详细的动力学研究表明，α-凝血酶诱导CCL 39细胞中p44 mapk的激活呈双相：快速相出现在5-10 min，随后是晚期和持续相，4 h后仍然升高。30秒后用水蛭素灭活α-凝血酶，阻止DNA合成，并没有改变早期p44 mapk反应，但完全消除了晚期。用百日咳毒素预处理细胞，其抑制超过95%的α-凝血酶诱导的有丝分裂原性，导致晚期活性的完全丧失，而早期峰值部分减弱。用碱性成纤维细胞生长因子处理CCL 39细胞也诱导p44 mapk的强烈激活。5-羟色胺本身不是促分裂剂，对晚期p44 mapk活性没有影响，但与碱性成纤维细胞生长因子协同诱导晚期激酶反应和DNA合成。p44 mapk的早期和晚期激活都伴随着该酶的酪氨酸磷酸化。总之，结果表明，有一个非常密切的相关性之间的能力的生长因子诱导晚期和持续的p44 mapk激活和它的促有丝分裂的潜力。因此，我们认为持续的p44 mapk激活是生长因子诱导的细胞周期进程的一个必要事件。
We have examined the phosphorylation and protein kinase activity of p44 mitogen-activated protein kinase (p44mapk) in growth factor-stimulated hamster fibroblasts using a specific antiserum. The activity of p44mapk WaS stimulated both by receptor tyrosine kinases and G protein-coupled receptors. Detailed kinetics revealed that alpha-thrombin induces a biphasic activation of p44mapk in CCL39 cells: a rapid phase appearing at 5-10 min was followed by a late and sustained phase still elevated after 4 h. Inactivation of alpha-thrombin with hirudin after 30 sec, which prevented DNA synthesis, did not alter the early p44mapk response but completely abolished the late phase. Pretreatment of the cells with pertussis toxin, which inhibits by more than 95% alpha-thrombin-induced mitogenicity, resulted in the complete loss of late phase activity, while the early peak was partially attenuated. Treatment of CCL39 cells with basic fibroblast growth factor also induced a strong activation of p44mapk. Serotonin, which is not a mitogen by its own, had no effect on late phase p44mapk activity, but synergized with basic fibroblast growth factor to induce late kinase response and DNA synthesis. Both early and late phase activation of p44mapk were accompanied by tyrosine phosphorylation of the enzyme. Together, the results indicate that there is a very close correlation between the ability of a growth factor to induce late and sustained p44mapk activation and its mitogenic potential. Therefore, we propose that sustained p44mapk activation is an obligatory event for growth factor-induced cell cycle progression.