Interaction of p130 with, and consequent inhibition of, the catalytic subunit of protein phosphatase 1α
Interaction of p130 with, and consequent inhibition of, the catalytic subunit of protein phosphatase 1α
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DOI：
10.1074/jbc.m009677200
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发表时间：
2001-05-25
影响因子：
4.8
通讯作者：
Hirata, M
中科院分区：
文献类型：
--
作者：
Yoshimura, K;Takeuchi, H;Hirata, M
蛋白质 p130 最初是从大鼠脑中分离出来的，是一种肌醇 1,4,5-三磷酸结合蛋白，其结构域组织与磷脂酶 C-delta1 相似，但缺乏磷脂酶 C 活性。对人脑 cDNA 文库进行酵母双杂交筛选，寻找编码与 p130 相互作用的蛋白质的克隆，现已鉴定出蛋白磷酸酶 1 α (PP1c α) 的催化亚基作为 p130 结合蛋白。 p130 和 PP1c α 之间的关联也在体外通过叠加测定、“下拉”测定和表面等离子共振分析得到证实。 p130 与 PP1c α 的相互作用导致后者催化活性以 p130 浓度依赖性方式受到抑制。对稳定表达 p130 的 COS-1 细胞以及含有 p130 和 PP1c α 抗体的小鼠脑提取物进行免疫沉淀和免疫印迹分析，也检测到 p130 和 PP1c α 复合物的存在。稳定表达 p130 的 COS-1 细胞中的糖原磷酸化酶活性（受 PP1c α 去磷酸化负调节）高于对照 COS-1 细胞。这些结果表明，除了在肌醇 1,4,5-三磷酸和 Ca2+ 信号传导中发挥作用外，p130 还可能通过与 PP1c α 相互作用来调节蛋白质去磷酸化。
The protein p130 was originally isolated from rat brain as an inositol 1,4,5-trisphosphate-binding protein with a domain organization similar to that of phospholipase C-delta1 but which lacks phospholipase C activity. Yeast two-hybrid screening of a human brain cDNA library for clones that encode proteins that interact with p130 has now led to the identification of the catalytic subunit of protein phosphatase 1 alpha (PP1c alpha) as a p130-binding protein. The association between p130 and PP1c alpha was also confirmed in vitro by an overlay assay, a "pull-down" assay, and surface plasmon resonance analysis. The interaction of p130 with PP1c alpha resulted in inhibition of the catalytic activity of the latter in a p130 concentration-dependent manner. Immunoprecipitation and immunoblot analysis of COS-1 cells that stably express p130 and of mouse brain extract with antibodies to p130 and to PP1c alpha also detected the presence of a complex of p130 and PP1c alpha, The activity of glycogen phosphorylase, which is negatively regulated by dephosphorylation by PP1c alpha, was higher in COS-1 cells that stably express p130 than in control COS-1 cells. These results suggest that, in addition to its role in inositol 1,4,5-trisphosphate and Ca2+ signaling, p130 might also contribute to regulation of protein dephosphorylation through its interaction with PP1c alpha.