Deguchi M, Hata Y, Takeuchi M, Ide N, Hirao K, Yao I, Irie M, Toyoda A, Takai Y
Takai Biotimer Project, ERATO, Japan Science and Technology Corporation, c/o JCR Pharmaceuticals Co. Ltd., 2-2-10 Murotani, Nishi-ku, Kobe 651-2241, Japan.
J Biol Chem. 1998 Oct 9;273(41):26269-72. doi: 10.1074/jbc.273.41.26269.
PSD-95/SAP90 is a synaptic membrane-associated guanylate kinase with three PDZ, one SH3, and one guanylate kinase (GK) domain. PSD-95/SAP90 binds various proteins through the PDZ domains and organizes synaptic junctions. PSD-95/SAP90 also interacts with the postsynaptic density (PSD) fraction-enriched protein, named SAPAP (also called GKAP and DAP), through the GK domain. SAPAP is Triton X-100-insoluble and recruits PSD-95/SAP90 into the Triton X-100-insoluble fraction in the transfected cells, suggesting that SAPAP may fix PSD-95/SAP90 to the PSD. Here we report a novel protein interacting with the GK domain of PSD-95/SAP90, BEGAIN. BEGAIN is specifically expressed in brain and enriched in the PSD fraction. BEGAIN is Triton X-100-soluble in the transfected cells but is recruited to the Triton X-100-insoluble fraction by SAPAP when coexpressed with PSD-95/SAP90. BEGAIN may be a novel PSD component associated with the core complex of PSD-95/SAP90 and SAPAP.
PSD - 95/SAP90是一种与突触膜相关的鸟苷酸激酶，具有三个PDZ结构域、一个SH3结构域和一个鸟苷酸激酶（GK）结构域。PSD - 95/SAP90通过PDZ结构域结合多种蛋白质并组织突触连接。PSD - 95/SAP90还通过GK结构域与富含突触后致密区（PSD）组分的蛋白质SAPAP（也称为GKAP和DAP）相互作用。SAPAP不溶于Triton X - 100，并将PSD - 95/SAP90募集到转染细胞中不溶于Triton X - 100的组分中，这表明SAPAP可能将PSD - 95/SAP90固定到PSD上。在此我们报告一种与PSD - 95/SAP90的GK结构域相互作用的新型蛋白质BEGAIN。BEGAIN在脑中特异性表达并在PSD组分中富集。BEGAIN在转染细胞中可溶于Triton X - 100，但与PSD - 95/SAP90共表达时会被SAPAP募集到不溶于Triton X - 100的组分中。BEGAIN可能是一种与PSD - 95/SAP90和SAPAP的核心复合物相关的新型PSD组分。
