Purification of a factor capable of stimulating the guanine nucleotide exchange reaction of ras proteins and its effect on ras-related small molecular mass G proteins.
Purification of a factor capable of stimulating the guanine nucleotide exchange reaction of ras proteins and its effect on ras-related small molecular mass G proteins.
复制标题
能够刺激ras蛋白鸟嘌呤核苷酸交换反应的因子的纯化及其对ras相关小分子质量G蛋白的影响。
DOI：
10.1073/pnas.87.20.8008
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发表时间：
1990
影响因子：
11.1
通讯作者：
Kamata,T
中科院分区：
文献类型：
--
作者：
Huang,YK;Kung,HF;Kamata,T
We have previously identified a membrane factor capable of stimulating guanine nucleotide exchange activity for ras p21 proteins. The ras guanine nucleotide exchange factor (rGEF) was purified from bovine brain to near homogeneity by successive chromatographies on DE52 DEAE-cellulose, Sepharose 6B, hydroxylapatite, and FPLC phenyl-Superose resins. SDS/polyacrylamide gel electrophoresis of the purified rGEF showed a single major protein with a molecular mass of 35 kDa. rGEF increased the exchange rate of GDP in normal [Gly12]p21 or oncogenic [Val12]p21 up to 30- to 40-fold under physiological concentrations of Mg2+. Since the factor was free from GDP/GTP binding activity and nonspecific GDP hydrolytic activity, we propose that rGEF may regulate GDP/GTP exchange reaction of ras proteins in response to external growth signals. Moreover, rGEF enhanced the dissociation of bound GDP from some of ras-like G proteins, R-ras, rap1-A, rab1-B, and rho proteins, raising the possibility that rGEF may affect the activities of these proteins.
