PREX2 - phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 2 Gene

中文名称：磷脂酰肌醇-3,4,5-三磷酸依赖性 Rac 交换因子 2

种属: Homo sapiens

同用名: DEP.2; DEPDC2; P-REX2; PPP1R129

关于 PREX2

功能概要

该基因编码的蛋白属于磷脂酰肌醇 3,4,5-三磷酸 (PIP3) 依赖性 Rac 交换器 (PREX) 家族，是 Rac 家族小 G 蛋白的 Dbl 型鸟嘌呤核苷酸交换因子。这种蛋白质的结构域包括催化弥漫性 B 细胞淋巴瘤同源性和 pleckstrin 同源性 (DPHH) 结构域、两个散乱的 EGL-10 和 pleckstrin 同源性 (DEP) 结构域、两个 PDZ 结构域和一个 C 末端肌醇多磷酸盐-4 在其中一种亚型中发现的磷酸酶 (IP4P) 结构域。这种蛋白质促进 Rac1 上 GDP 与 GTP 的交换，从而允许 GTP 结合的 Rac1 激活下游效应器。研究还表明，该蛋白的 pleckstrin 同源结构域与磷酸酶和张力蛋白同源物 (PTEN) 基因产物相互作用，抑制 PTEN 磷酸酶活性，从而激活磷酸肌醇 3 激酶 (PI3K) 信号通路。相反，PTEN 基因产物也被证明可以抑制这种蛋白质的 GEF 活性。该基因在胰岛素信号通路中发挥作用，在某些癌症中已观察到该基因的突变或过度表达。[RefSeq 提供，2016 年 4 月]

The protein encoded by this gene belongs to the phosphatidylinositol 3,4,5-trisphosphate (PIP3)-dependent Rac exchanger (PREX) family, which are Dbl-type guanine-nucleotide exchange factors for Rac family small G proteins. Structural domains of this protein include the catalytic diffuse B-cell lymphoma homology and pleckstrin homology (DHPH) domain, two disheveled, EGL-10, and pleckstrin homology (DEP) domains, two PDZ domains, and a C-terminal inositol polyphosphate-4 Phosphatase (IP4P) domain that is found in one of the isoforms. This protein facilitates the exchange of GDP for GTP on Rac1, allowing the GTP-bound Rac1 to activate downstream effectors. Studies also show that the pleckstrin homology domain of this protein interacts with the Phosphatase and tensin homolog (PTEN) gene product to inhibit PTEN Phosphatase activity, thus activating the phosphoinositide-3 kinase (PI3K) signaling pathway. Conversely, the PTEN gene product has also been shown to inhibit the GEF activity of this protein. This gene plays a role in insulin-signaling pathways, and either mutations or overexpression of this gene have been observed in some cancers. [provided by RefSeq, Apr 2016]