Antonicelli F, Omri B, Breton M F, Rothhut B, Russo-Marie F, Pavlovic-Hournac M, Haye B
Laboratoire de Biochimie, UFR Sciences, Reims, France.
FEBS Lett. 1989 Dec 4;258(2):346-50. doi: 10.1016/0014-5793(89)81690-4.
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.
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。
