Friedman D L, Ken R
Department of Molecular Biology, Vanderbilt University, Nashville, Tennessee 37235.
J Biol Chem. 1988 Jan 25;263(3):1103-6.
The in vivo effect of insulin upon the incorporation of 32Pi into nuclear proteins was investigated in quiescent baby hamster kidney fibroblasts (BHK-21). Insulin has previously been shown to be mitogenic in these cells (Richman, R. A., Johnson, R. A., and Friedman, D. L. (1981) Proc. Soc. Exp. Biol. Med. 168, 196-203). Incorporation into two proteins (Mr = 62,000 and 72,000) in the 0.4 M salt-resistant nuclear fraction was enhanced 2-6-fold by insulin. The effect of insulin (20 nM) was observable within 5 min of treatment, reached a maximum at 15 min, and continued for at least 90 min. The half-maximal effect of insulin was obtained at a concentration of approximately 1 nM. Analysis of nuclear matrix preparations indicated that the two insulin-sensitive proteins were prominent nuclear matrix proteins and suggested that they were lamins A and C. This was confirmed by immunostaining with lamin antibodies and by two-dimensional electrophoresis. These studies indicate that insulin rapidly stimulates the incorporation of phosphate into nuclear lamins A and C in quiescent BHK-21 fibroblasts.
在静止的幼仓鼠肾成纤维细胞（BHK-21）中研究了胰岛素对32Pi掺入核蛋白的体内效应。先前已证明胰岛素在这些细胞中具有促有丝分裂作用（Richman，R. A.，Johnson，R. A.，和Friedman，D. L.（1981年）《实验生物学与医学学会会刊》168，196 - 203）。胰岛素使0.4 M耐盐核组分中的两种蛋白（分子量分别为62,000和72,000）的掺入量增加了2至6倍。胰岛素（20 nM）的作用在处理后5分钟内即可观察到，15分钟时达到最大值，并持续至少90分钟。胰岛素的半最大效应在浓度约为1 nM时获得。对核基质制剂的分析表明，这两种对胰岛素敏感的蛋白是突出的核基质蛋白，提示它们是核纤层蛋白A和C。用核纤层蛋白抗体进行免疫染色和二维电泳证实了这一点。这些研究表明，胰岛素在静止的BHK-21成纤维细胞中迅速刺激磷酸盐掺入核纤层蛋白A和C。
