Insulin-stimulated phosphorylation and insulin binding in canine renal basolateral membranes.
Insulin-stimulated phosphorylation and insulin binding in canine renal basolateral membranes.
复制标题
犬肾基底外侧膜中胰岛素刺激的磷酸化和胰岛素结合。
DOI：
10.1152/ajprenal.1984.247.3.f408
复制
发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Gavin3rd,JR
中科院分区：
文献类型：
--
作者：
Hammerman,MR;Gavin3rd,JR
为了表征胰岛素与肾近端肾小管细胞的相互作用，我们测量了从犬肾皮质分离的基底外侧膜和刷状缘膜中胰岛素刺激的磷酸化。胰岛素刺激了 92,000 Mr 蛋白带的特异性磷酸化，这可以在基底外侧膜十二烷基硫酸钠-聚丙烯酰胺凝胶的放射自显影照片上得到证实。随着时间的推移，92,000 Mr 带发生去磷酸化。胰岛素刺激的磷酸化具有浓度依赖性，在 10(-9) M 胰岛素下可清晰检测到，在 10(-6) M 下检测到最大。使用来自具有抗受体抗体的患者的血清对来自去污剂溶解的基底外侧膜的磷酸化 92,000 Mr 蛋白带进行免疫沉淀。在刷状缘膜中未检测到胰岛素刺激的磷酸化。胰岛素与膜的结合对天然激素具有高度特异性，并且基底外侧膜中的结合比刷状缘膜中的结合强几倍。这些观察结果与胰岛素刺激蛋白激酶的不对称分布以及近端肾小管细胞中的特定胰岛素结合位点一致。数据表明，胰岛素通过与特定的基底外侧膜受体结合以及这些受体的磷酸化对细胞产生生理作用。
To characterize the interaction of insulin with the renal proximal tubular cell, we measured insulin-stimulated phosphorylation in basolateral membranes and brush border membranes isolated from canine renal cortex. Insulin stimulated the specific phosphorylation of a 92,000 Mr protein band demonstrable on autoradiograms of sodium dodecyl sulfate-polyacrylamide gels of basolateral membranes. Dephosphorylation of the 92,000 Mr band occurred over time. Insulin-stimulated phosphorylation was concentration dependent, being clearly detectable at 10(-9) M insulin and maximal at 10(-6) M. The phosphorylated 92,000 Mr protein band from detergent-solubilized basolateral membranes was immunoprecipitated using serum from a patient with anti-receptor antibodies. No insulin-stimulated phosphorylation was detected in brush border membranes. Binding of insulin to membranes was highly specific for native hormone and was severalfold greater in basolateral membranes than in brush border membranes. These observations are consistent with the asymmetrical distribution of insulin-stimulated protein kinase as well as specific insulin binding sites in the proximal tubular cell. The data suggest that insulin exerts physiological effects on the cell through binding to specific basolateral membrane receptors and phosphorylation of those receptors.