在猪甲状腺细胞培养物的胞质溶胶中鉴定出四种脂皮质素蛋白以及蛋白激酶C对脂皮质素I的磷酸化作用。

Identification of four lipocortin proteins and phosphorylation of lipocortin I by protein kinase C in cytosols of porcine thyroid cell cultures.

作者信息

Antonicelli F, Omri B, Breton M F, Rothhut B, Russo-Marie F, Pavlovic-Hournac M, Haye B

机构信息

Laboratoire de Biochimie, UFR Sciences, Reims, France.

出版信息

FEBS Lett. 1989 Dec 4;258(2):346-50. doi: 10.1016/0014-5793(89)81690-4.

DOI:10.1016/0014-5793(89)81690-4

PMID:2532154

Abstract

Four proteins of the lipocortin family, lipocortin I (35 kDa), lipocortin II (36 kDa), lipocortin V (32 kDa) and lipocortin VI (67-70 kDa), were identified in the cytosols of 2-day-old cultures of thyroid cells. Only lipocortin I was phosphorylated in vitro in fully differentiated, thyroid stimulating hormone-treated cells (0.1 mU/ml). Protein kinase C was the only kinase activity which phosphorylated lipocortin I. Phosphorylation shifted its pI from 6.9 to 6.6. The in vitro phosphorylation of lipocortin I was impaired in cultures exposed for 2 days to phorbol ester (10(-7) M), although it was present in both the cytosol and the particulate fraction of these cells.

摘要

在甲状腺细胞2日龄培养物的胞质溶胶中鉴定出脂皮质素家族的四种蛋白质，即脂皮质素I（35 kDa）、脂皮质素II（36 kDa）、脂皮质素V（32 kDa）和脂皮质素VI（67 - 70 kDa）。在完全分化的、经促甲状腺激素处理的细胞（0.1 mU/ml）中，仅脂皮质素I在体外被磷酸化。蛋白激酶C是唯一能使脂皮质素I磷酸化的激酶活性。磷酸化使其等电点从6.9变为6.6。尽管在暴露于佛波酯（10⁻⁷ M）2天的培养物中，脂皮质素I存在于这些细胞的胞质溶胶和颗粒部分，但它的体外磷酸化受到损害。