EHSH1/intersectin, a protein that contains EH and SH3 domains and binds to dynamin and SNAP-25 -: A protein connection between exocytosis and endocytosis?

作     者：Okamoto, M Schoch, S Südhof, TC 

作者机构：Univ Texas SW Med Ctr Howard Hughes Med Inst Ctr Basic Neurosci Dallas TX 75235 USA Univ Texas SW Med Ctr Dept Mol Genet Dallas TX 75235 USA 

出 版 物：《JOURNAL OF BIOLOGICAL CHEMISTRY》 (生物化学杂志)

年 卷 期：1999年第274卷第26期

页      面：18446-18454页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

主　　题：衔接蛋白质类 膜泡运输 氨基酸序列 载体蛋白质类/化学 载体蛋白质类/代谢 果蝇属 果蝇蛋白质类 动力蛋白质类 胞吞作用 胞吐作用 GTP磷酸水解酶类/代谢 基因文库 膜蛋白质类 分子序列数据 神经组织蛋白质类/代谢 蛋白质结合 突触体相关蛋白质25 爪蟾属 src同源域 动物 人类 小鼠 大鼠 

摘      要：In yeast two-hybrid screens for proteins that bind to SNAP-25 and may be involved in exocytosis, we isolated a protein called EHSH1 (for ER domain/SH3 domain-containing protein). Cloning of full-length cDNAs revealed that EHSH1 is composed of an N-terminal region with two EH domains, a central region that is enriched in lysine, leucine, glutamate, arginine, and glutamine (KLERQ domain), and a C-terminal region comprised of five SH3 domains. The third SH3 domain is alternatively spliced, Data bank searches demonstrated that EHSH1 is very similar to Xenopus and human intersectins and to human SH3P17. In addition, we identified expressed sequence tags that encode a second isoform of EHSH1, called EHSH2. EHSH1 is abundantly expressed in brain and at lower levels in all other tissues tested. In binding studies, we found that the central KLERQ domain of EHSH1 binds to recombinant or native brain SNAP-25 and SNAP-23, The C-terminal SH3 domains, by contrast, quantitatively interact with dynamin, a protein involved in endocytosis. Dynamin strongly binds to the alternatively spliced central SH3 domain (SH3C) and the two C-terminal SH3 domains (SH3D and SH3E) but not to the N-terminal SH3 domains (SH3A and SH3B), Immunoprecipitations confirmed that both dynamin and SNAP-25 are complexed to EHSH1 in brain, Our data suggest that EHSH1/intersectin may be a novel adaptor protein that couples endocytic membrane traffic to exocytosis. The ability of multiple SH3 domains in EHSH1 to bind to dynamin suggests that EHSH1 can cluster several dynamin molecules in a manner that is regulated by alternative splicing.