nRap GEP: A novel neural GDP/GTP exchange protein for Rap1 small G protein that interacts with synaptic scaffolding molecule (S-SCAM)
nRap GEP: A novel neural GDP/GTP exchange protein for Rap1 small G protein that interacts with synaptic scaffolding molecule (S-SCAM)
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DOI：
10.1006/bbrc.1999.1619
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发表时间：
1999-11-11
影响因子：
3.1
通讯作者：
Takai, Y
中科院分区：
文献类型：
--
作者：
Ohtsuka, T;Hata, Y;Takai, Y
突触支架分子（S-SCAM）具有六个PDZ结构域，通过其与N-甲基-D-天冬氨酸受体和神经连接素在突触连接处相互作用。我们在这里分离到一种新的S-SCAM结合蛋白。该蛋白具有一个PDZ、一个Ras缔合、一个Ras GDP/GTP交换蛋白（Ras GEP）结构域和一个用于结合PDZ结构域的C-末端共有基序。我们将其命名为nRap GEP（neural Rap GEP）。此外，nRap GEP具有不完全的环AMP（cAMP）结合（CAB）结构域。除了Epac/cAMP-GEFI具有完整的CAB和Ras GEP结构域，但缺乏其他两个结构域和C-末端基序外，nRap GEP的结构域组织与Epac/cAMP-guanine nucleotide exchange factor（GEF）I相似。nRap GEP对Rap 1具有GEP活性，但不结合cAMP，nRap GEP在大鼠脑中特异性表达。免疫组织化学分析显示nRap GEP和S-SCAM定位于小脑的突触区。这些结果表明nRap GEP是一种新的神经Rap 1特异性GEP，与S-SCAM相关。(C)北京：科学出版社.
Synaptic scaffolding molecule (S-SCAM) has six PDZ domains through which it interacts with N-methyl-D-aspartate receptors and neuroligin at synaptic junctions. We isolated here a novel S-SCAM-binding protein. This protein has one PDZ, one Ras association, one Ras GDP/GTP exchange protein (Ras GEP) domain, and one C-terminal consensus motif for binding to PDZ domains. We named it nRap GEP (neural Rap GEP). nRap GEP moreover has an incomplete cyclic AMP (cAMP)-binding (CAB) domain. The domain organization of nRap GEP is similar to that of Epac/cAMP-guanine nucleotide exchange factor (GEF) I, except that Epac/cAMP-GEFI has complete CAB and Ras GEP domains but lacks the other two domains and the C-terminal motif. nRap GEP showed GEP activity for Rap1 but did not bind cAMP, nRap GEP was specifically expressed in rat brain. Immunohistochemical analysis revealed that nRap GEP and S-SCAM were localized at synaptic areas of the cerebellum. These results suggest that nRap GEP is a novel neural Rap1-specific GEP which is associated with S-SCAM. (C) 1999 Academic Press.