Protein kinase C mediates cholinergically regulated protein phosphorylation in a Cl(-)-secreting epithelium.
Protein kinase C mediates cholinergically regulated protein phosphorylation in a Cl(-)-secreting epithelium.
复制标题
蛋白激酶 C 介导 Cl(-) 分泌上皮细胞中胆碱能调节的蛋白质磷酸化。
DOI：
10.1152/ajpcell.1990.258.2.c227
复制
发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Cohn,JA
中科院分区：
文献类型：
--
作者：
Cohn,JA
T84细胞单层被用来研究上皮细胞中蛋白磷酸化的胆碱能调节。当T84细胞单层用32 Pi标记并用卡巴胆碱刺激时，六种蛋白质表现出改变的磷酸化。最显著的反应是p83标记的五倍增加，p83是一种Mr为83，000的酸性蛋白质。p83标记的增加与激动剂作用的开始、激动剂效力和阿托品的拮抗作用有关，与刺激分泌平行。然而，p83和分泌反应的不同之处在于p83反应更持久。当T84细胞组分与[γ-32 P]ATP孵育时，Ca 2（+）-磷脂刺激p83标记。当T84细胞提取物与纯化的蛋白激酶C一起孵育时以及当完整细胞暴露于佛波醇肉豆蔻酸乙酸酯时，也会发生p83的磷酸化。p83在与腺苷3 '，5'-环一磷酸（cAMP）孵育的细胞组分中或在用通过cAMP起作用的激动剂刺激的单层中不变得磷酸化。因此卡巴胆碱刺激T84细胞中蛋白激酶C的内源性底物的磷酸化。这种磷酸化反应的持续时间表明蛋白激酶C可能介导对卡巴胆碱的持续反应，可能起到限制刺激分泌的持续时间的作用。
T84 cell monolayers were used to study the cholinergic regulation of protein phosphorylation in epithelial cells. When T84 cell monolayers are labeled with 32Pi and stimulated with carbachol, six proteins exhibit altered phosphorylation. The most prominent response is a fivefold increase in labeling of p83, an acidic protein of Mr 83,000. Increasing labeling of p83 parallels stimulated secretion with respect to the onset of agonist action, agonist potency, and antagonism by atropine. However, the p83 and secretory responses differ in that the p83 response is more sustained. When T84 cell fractions are incubated with [gamma-32P]ATP, Ca2(+)-phospholipid stimulates p83 labeling. Phosphorylation of p83 also occurs when a T84 cell extract is incubated with purified protein kinase C and when intact cells are exposed to phorbol myristate acetate. p83 does not become phosphorylated in cell fractions incubated with adenosine 3',5'-cyclic monophosphate (cAMP) or in monolayers stimulated with agonists acting via cAMP. Thus carbachol stimulates the phosphorylation of an endogenous substrate for protein kinase C in T84 cells. The duration of this phosphorylation response suggests that protein kinase C may mediate a sustained response to carbachol, possibly acting to limit the duration of stimulated secretion.