Effect of growth hormone on protein phosphorylation in isolated rat hepatocytes.
Effect of growth hormone on protein phosphorylation in isolated rat hepatocytes.
复制标题
生长激素对离体大鼠肝细胞蛋白质磷酸化的影响。
DOI:
10.1021/bi00377a009
复制
发表时间:
1987
期刊:
影响因子:
2.9
通讯作者:
Donner,DB
中科院分区:
文献类型:
--
作者:
Yamada,K;Lipson,KE;Marino,MW;Donner,DB
Revised Manuscript Received October 20, 1986 abstract: Hepatocytes from male rats were incubated with [32P] P; for 40 min at 37 C, thereby equilibrating the cellular ATP pool with 32P. Subsequent exposure to bovine growth hormone for 10 additional min did not change the specific activity of cellular [t-32P] ATP. Two-dimensional gel electrophoresis or chromatofocusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to fractionate phosphoproteins solubilizedfrom control or hormone-stimulated cells. Stimulation of hepatocytes with 5 nM growth hormone for 10 min at 37 C affected the phosphorylation of a number of proteins including an Mr 46000 species of p/4.7 whose phosphorylation was augmented (2.65±0.50)-fold. A significant fraction of the maximal effect of growth hormone on phosphorylation of the MT 46 000 species was elicited by 1-5% receptor occupancy. Bovine growth hormone, which binds to somatogenic receptors with great specificity, or recombinant human growth hormone, which is not contaminated with other hormones, affected phosphorylation of hepatic proteins similarly. The Mr 46 000phosphoprotein was isolated in a fraction enriched in cytosol after centrifugation of cellular homogenates. Phosphorylation of the Mx 46 000 phos-phoprotein was also increased (1.75±0.35)-fold and (2.15±0.50)-fold by insulin and glucagon, respectively. These observations are consistent with the possibilitythat selective changes in the phosphorylation state of cellular proteins may mediate growth hormone actions in cells. e first step leading to growth hormone action is binding to receptors, which have been identified in a number of dif-ferent cells and membranes (Kelly et al., 1974; Lesniak et al.,