The insulin receptor substrate IRSp53 links postsynaptic shank1 to the small G-protein cdc42
The insulin receptor substrate IRSp53 links postsynaptic shank1 to the small G-protein cdc42
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DOI：
10.1006/mcne.2002.1201
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发表时间：
2002-12-01
影响因子：
3.5
通讯作者：
Kreienkamp, HJ
中科院分区：
文献类型：
--
作者：
Soltau, M;Richter, D;Kreienkamp, HJ
多结构域shank/ProSAP/SSTRIP蛋白是哺乳动物大脑谷氨酸能突触的主要支架蛋白；shank1/SSTRIP在海马神经元中的表达诱导树突棘的形态学改变，提示shank1参与突触的形成和突触结构的活动依赖性改变。利用酵母双杂交筛选中shank1富含脯氨酸的部分区域，我们确定了胰岛素受体底物IRSp53作为相互作用伙伴。覆盖分析证实了shank1中富含脯氨酸的序列（残基911-940）与IRSp53的SH3结构域之间存在强相互作用。当在HEK细胞中共表达时，shank1与细胞内结构中的IRSp53共定位，阻止了IRSp53在缺乏shank1的情况下靶向到由IRSp53表达诱导的丝状足。IRSp53也与活化形式的小g蛋白cdc42结合。有趣的是，IRSp53以小g蛋白调控的方式与转染的HEK细胞中的shank1共沉淀。因此，IRSp53构成了cdc42调控的shank1配体，这可能为小g蛋白介导的突触后复合物结构作用提供了分子基础。
The multidomain shank/ProSAP/SSTRIP proteins are major scaffold proteins in glutamatergic synapses in the mammalian brain; expression of shank1/SSTRIP in hippocampal neurons induces morphological changes in dendritic spines, suggesting that shank1 is involved in synapse formation and activity-dependent changes of synaptic structure. Using part of the proline-rich region of shank1 in a yeast two hybrid screen, we identified the insulin receptor substrate IRSp53 as an interaction partner. Overlay assays verified a strong interaction between a proline-rich sequence (residues 911-940) in shank1 and the SH3 domain of IRSp53. When coexpressed in HEK cells, shank1 colocalizes with IRSp53 in intracellular structures, preventing targeting of IRSp53 to filopodia which are induced by IRSp53 expression in the absence of shank1. IRSp53 also binds to the activated form of the small G-protein cdc42. Interestingly, IRSp53 coprecipitates with shank1 from transfected HEK cells in a small G-protein-regulated manner. Thus, IRSp53 constitutes a cdc42-regulated ligand for shank1 which may provide a molecular basis for small G-protein mediated effects on the structure of the postsynaptic complex.