Mérida I, Varela I, Alvarez J F, Cabrero C, Mato J M
FEBS Lett. 1986 Feb 17;196(2):274-8. doi: 10.1016/0014-5793(86)80262-9.
Addition of vasopressin (1 microM) to isolated rat hepatocytes prelabeled with [32P]phosphate was accompanied by a 250% increase in the phosphorylation of phospholipid methyltransferase. Vasopressin-stimulated phospholipid methyltransferase phosphorylation was time- and dose-dependent. 32P-labeled phospholipid methyltransferase was recovered by immunoprecipitation and SDS-polyacrylamide gel electrophoresis. After electrophoresis, phospholipid methyltransferase was electroeluted from the polyacrylamide gel and subjected to tryptic digestion or HCl hydrolysis. Analysis of 32P-labeled peptides reveals only one site of phosphorylation and the analysis of [32P]phosphoamino acids indicates that phosphoserine is the only labeled amino acid.
向预先用[32P]磷酸盐标记的离体大鼠肝细胞中添加血管加压素（1微摩尔），伴随着磷脂甲基转移酶磷酸化增加250%。血管加压素刺激的磷脂甲基转移酶磷酸化具有时间和剂量依赖性。通过免疫沉淀和SDS-聚丙烯酰胺凝胶电泳回收32P标记的磷脂甲基转移酶。电泳后，从聚丙烯酰胺凝胶中电洗脱磷脂甲基转移酶，并进行胰蛋白酶消化或盐酸水解。对32P标记肽的分析仅揭示了一个磷酸化位点，而对[32P]磷酸氨基酸的分析表明，磷酸丝氨酸是唯一被标记的氨基酸。
