文章基本信息

标题：Role of calpain-mediated p53 truncation in semaphorin 3A-induced axonal growth regulation
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作者：Qingyu Qin ; Guanghong Liao ; Michel Baudry 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：31
页码：13883-13887
DOI：10.1073/pnas.1008652107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Neurite outgrowth represents a critical stage in the correct development of neuronal circuitries, and is dependent on the complex regulation of actin filament and microtubule dynamics by intrinsic as well as extrinsic signals. Previous studies have implicated the tumor suppressor factor, p53, in the regulation of axonal outgrowth through a nontranscriptional effect involving local regulation of the Rho kinase signaling pathway that controls these dynamics. In the present study, we first showed that semaphorin 3A-induced growth cone collapse in cultured hippocampal neurons was associated with the partial truncation of phosphorylated p53, and that both effects were prevented by calpain inhibition with either m-calpain-specific siRNA or inhibitors. We further determined that semaphorin 3A-mediated calpain activation and growth cone collapse were associated with m-calpain phosphorylation and prevented by inhibition of MAPK, ERK, or p38. In vitro studies confirmed that p53 and especially phosphorylated p53 were partially truncated by calpain. Thus, our results indicate that semaphorin 3A-mediated growth cone collapse is mediated in part by m-calpain activation, possibly through MAPK-mediated phosphorylation, and the resulting truncation of phosphorylated p53, leading to Rho kinase activation and cytoskeletal reorganization. They provide a pathway by which extrinsic signals regulate axonal growth through activation of m-calpain and p53 truncation.
关键词：ERK ; p38 MAPK ; phosphorylation ; Rho kinase ; hippocampus