Rom1p and Rom2p are GDP/GTP exchange proteins (GEPs) for the Rho1p small GTP binding protein in Saccharomyces cerevisiae
Rom1p and Rom2p are GDP/GTP exchange proteins (GEPs) for the Rho1p small GTP binding protein in Saccharomyces cerevisiae
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DOI：
10.1002/j.1460-2075.1996.tb00573.x
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发表时间：
1996-05-01
期刊：
影响因子：
11.4
通讯作者：
Takai, Y
中科院分区：
文献类型：
--
作者：
Ozaki, K;Tanaka, K;Takai, Y
RNO1基因在酿酒酵母中编码哺乳动物RhoA小GTP结合蛋白的同源物。Rho1p定位于生长部位，是芽形成所必需的。从RHO1温度敏感显性负突变等位基因RHO1 （G22S, D125N）中分离出多拷贝抑制子，命名为ROM （RHO1多拷贝抑制子）。发现Rom1p和Rom2p含有DH （Dbl同源）结构域和PH （pleckstrin同源）结构域，这两个结构域在Rho家族小GTP结合蛋白的GDP/GTP交换蛋白（GEPs）中都是保守的。ROM2的破坏导致温度敏感的生长表型，而ROM1和ROM2的破坏导致致命。δ δ rom1 δ rom2细胞的表型与δ δ rho1细胞相似，包括生长停滞，小芽和细胞裂解，并且δ δ rom2的温度敏感生长表型被rho1或RHO2过表达抑制，而CDC42不受抑制。含有Rom2p DH结构域的谷胱甘肽-s -转移酶（GST）融合蛋白表现出对Rho GDP解离抑制剂敏感的脂质修饰Rho1p特异性GDP/GTP交换活性，这些结果表明Rom1p和Rom2p是酵母中激活Rho1p的GEPs。
The RNO1 gene encodes a homolog of the mammalian RhoA small GTP binding protein in the yeast Saccharomyces cerevisiae. Rho1p is localized at the growth site and is required for bud formation. Multicopy suppressors of a temperature-sensitive, dominant negative mutant allele of RHO1, RHO1 (G22S, D125N), were isolated and named ROM (RHO1 multicopy suppressor). Rom1p and Rom2p were found to contain a DH (Dbl homologous) domain and a PH (pleckstrin homologous) domain, both of which are conserved among the GDP/GTP exchange proteins (GEPs) for the Rho family small GTP binding proteins, Disruption of ROM2 resulted in a temperature-sensitiv:e growth phenotype, whereas disruption of both ROM1 and ROM2 resulted in lethality. The phenotypes of Delta rom1 Delta rom2 cells were similar to those of Delta rho1 cells, including growth arrest with a small bud and cell lysis, Moreover, the temperature-sensitive growth phenotype of Delta rom2 was suppressed by overexpression of RHO1 or RHO2, but not of CDC42. The glutathione-S-transferase (GST) fusion protein containing the DH domain of Rom2p showed the lipid-modified Rho1p-specific GDP/GTP exchange activity which was sensitive to Rho GDP dissociation inhibitor, These results indicate that Rom1p and Rom2p are GEPs that activate Rho1p in S.cerevisiae.