Hansson A, Thorén M
Department of Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
Growth Regul. 1995 Jun;5(2):92-100.
A peak of cytosolic myelin basic protein kinase activity was observed at 2-5 min after addition of 10 nM insulin-like growth factor-I (IGF-I) to Swiss 3T3 fibroblasts. Analysis of the induced kinase activity by chromatography, immunodetection and in situ kinase assay suggests that this represents a 1.8- to 3.5-fold increase in the activity of p42 mitogen-activated protein kinase. Addition of insulin at 10 nM also resulted in an increased kinase activity in these respects, however, only to approximately 60% of that induced by IGF-I. A similar quantitative relation between the effects of insulin and IGF-I was found for induction of lipid and glycogen synthesis from [14C- (U)]-D-glucose. However, incorporation of 3H-L-leucine into protein was stimulated to the same extent by the two agents. The effect of 10 nM insulin on proliferation, measured as tetrazolium dye reduction, was only 18% of that induced by 10 nM IGF-I. The obtained data suggest that cytosolic mitogen-activated protein kinase activation may constitute a signalling pathway for glucose metabolism, and especially glycogen synthesis, induced by peptides of the insulin superfamily.
在向瑞士3T3成纤维细胞添加10 nM胰岛素样生长因子-I（IGF-I）后2 - 5分钟观察到胞质髓鞘碱性蛋白激酶活性达到峰值。通过色谱分析、免疫检测和原位激酶测定对诱导的激酶活性进行分析表明，这代表p42丝裂原活化蛋白激酶的活性增加了1.8至3.5倍。添加10 nM胰岛素在这些方面也导致激酶活性增加，然而，仅达到IGF-I诱导活性的约60%。在从[14C -（U）]-D-葡萄糖诱导脂质和糖原合成方面，发现胰岛素和IGF-I的作用之间存在类似的定量关系。然而，两种试剂对3H-L-亮氨酸掺入蛋白质的刺激程度相同。以四唑盐染料还原法测量，10 nM胰岛素对增殖的影响仅为10 nM IGF-I诱导影响的18%。所获得的数据表明，胞质丝裂原活化蛋白激酶的激活可能构成胰岛素超家族肽诱导的葡萄糖代谢，特别是糖原合成的信号通路。
