GSK-3调控GAPDH嵌入线粒体的作用和机制

项目名称： GSK-3调控GAPDH嵌入线粒体的作用和机制

项目编号： No.31200806

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 神经、认识与心理学

项目作者： 谢波

作者单位： 中山大学

项目金额： 23万元

中文摘要： GAPDH在神经退行性病变和神经元凋亡过程中发挥重要作用。我们发现： siRNA沉默GAPDH能保护性干预神经元凋亡的发生，但是GAPDH的促凋亡功能不依赖于表达上调和核或者线粒体转位。进一步实验表明，神经元凋亡时GAPDH嵌入（insertion）到线粒体膜上，提示这一"嵌入"与GAPDH的促凋亡作用密切相关。抑制GSK-3抑制了GAPDH嵌入线粒体；激酶反应实验显示GSK-3能直接磷酸化GAPDH；序列分析显示GAPDH的Thr235是GSK-3的潜在磷酸化位点。由此，我们提出假设：GSK-3磷酸化GAPDH的Thr235介导其嵌入线粒体并触发神经元凋亡。本项目拟采用位点突变和激酶分析等手段，旨在获得GSK-3磷酸化GAPDH Thr235介导其嵌入线粒体的可靠证据，揭示GAPDH的嵌入对线粒体损伤的作用及其机制，为确立GAPDH作为神经退行性疾病治疗新靶点提供科学依据。

中文关键词： GAPDH；凋亡；自噬；线粒体；一氧化氮合成酶

英文摘要： GAPDH plays an important role in neurodegeneration and neuronal apoptosis process. The present study demonstrates that siRNA knockdown of GAPDH protected neuron from apoptosis induced by activity deprivation. But GAPDH was neither upregulated nor translocated to nucleus or mitochondria during apoptosis. Furthermore, we found that GAPDH inserted into mitochondria during neuronal apoptosis, and the "insertion" was crucial for the pro-apoptotic function of GAPDH. Inhibition of pro-apoptotic kinase GSK-3 could block GAPDH insert into mitochondria; the in vitro kinase assay showed that GSK-3α/β could directly phosphorylate GAPDH and the Thr235 of GAPDH was a putative phosphorylation site of GSK-3. Based on the above findings, we put forward the hypothesis: GSK-3 mediates GAPDH insertion into mitochondria and neuronal apoptosis through phosphorylation of GAPDH at Thr235. In this project, we will use phosphorylation site mutation and in vitro kinase analysis to obtain the reliable evidence that GSK-3 phosphorylates of GAPDH at Thr235 to promote its insertion into mitochondria. This project will reveal the mechanism underlying GSK-3 regulation of GAPDH insertion into mitochondria which results in mitochondria dysfunction and provide the scientific basis for the establishment of GAPDH as a new treatment target of neurode

英文关键词： GAPDH；Apoptosis；Autophagy；Mitochondria；Nitric oxide synthase