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外文期刊>The biochemical journal
>Platelet-derived growth factor activation of mitogen-activated protein kinase depends on the sequential activation of phosphatidylcholine-specific phospholipase C, protein kinase C-ζ and Raf-1
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Platelet-derived growth factor activation of mitogen-activated protein kinase depends on the sequential activation of phosphatidylcholine-specific phospholipase C, protein kinase C-ζ and Raf-1
pThe mechanism of Raf-1 activation by platelet-derived growth factor (PDGF) is poorly defined. We previously reported that, in Rat-1 fibroblasts, PDGF activates a phosphatidylcholine-specific phospholipase C (PC-PLC) and that the product, diacylglycerol, somehow activates protein kinase C-ζ (PKC-ζ). Both PC-PLC and PKC-ζ activities were required for PDGF activation of mitogen-activated protein kinase (MAPK). Now we report that MAPK activation by exogenous PC-PLC depends on Raf-1 activation. PKC-ζ co-immunoprecipitates with, phoshorylates and activates Raf-1, suggesting that in the PDGF- and PC-PLC-activated MAPK pathway, PKC-ζ operates in a signalling complex as a direct activator of Raf-1./p
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机译:>血小板衍生生长因子(PDGF)激活Raf-1的机制尚不清楚。我们先前曾报道过,在Rat-1成纤维细胞中,PDGF激活了磷脂酰胆碱特异性磷脂酶C(PC-PLC),而产物二酰基甘油则以某种方式激活了蛋白激酶C-ζ(PKC-ζ)。 PDGF激活有丝分裂原激活的蛋白激酶(MAPK)需要PC-PLC和PKC-ζ活性。现在,我们报告外源PC-PLC激活MAPK取决于Raf-1激活。 PKC-ζ与Raf-1共沉淀,磷酸化并激活Raf-1,这表明在PDGF和PC-PLC激活的MAPK途径中,PKC-ζ在信号复合物中作为Raf-1的直接激活剂起作用。 p >
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