Marshall M S, Davis L J, Keys R D, Mosser S D, Hill W S, Scolnick E M, Gibbs J B
Department of Cancer Research, Merck Sharp and Dohme Research Laboratories, West Point, Pennsylvania 19486.
Mol Cell Biol. 1991 Aug;11(8):3997-4004. doi: 10.1128/mcb.11.8.3997-4004.1991.
The Krev-1 gene has been shown to suppress ras-mediated transformation in vitro. Both ras and Krev-1 proteins have identical effector domains (ras residues 32 to 40), which are required for biological activity and for the interaction of Ras p21 with Ras GTPase-activating protein (GAP). In this study, five amino acid residues flanking the ras effector domain, which are not conserved with the Krev-1 protein, were shown to be required for normal protein-protein interactions and biological activity. The substitution of Krev-1 p21 residues 26, 27, 30, 31, and 45 with the corresponding amino acid residues from Ras p21 resulted in a Krev-1 protein which had ras function in both mammalian and yeast biological assays. Replacement of these residues in Ras p21 with the corresponding Krev-1 p21 amino acids resulted in ras proteins which were impaired biologically or reduced in their affinity for in vitro GAP binding. Evaluation of these mutant ras proteins have implications for Ras p21-GAP interactions in vivo.
Krev-1基因已被证明在体外可抑制ras介导的细胞转化。ras蛋白和Krev-1蛋白具有相同的效应结构域（ras的32至40位残基），这对于生物活性以及Ras p21与Ras GTP酶激活蛋白（GAP）的相互作用是必需的。在本研究中，ras效应结构域两侧的五个氨基酸残基，它们与Krev-1蛋白不保守，被证明是正常蛋白质-蛋白质相互作用和生物活性所必需的。用Ras p21的相应氨基酸残基替换Krev-1 p21的26、27、30、31和45位残基，产生了一种在哺乳动物和酵母生物学测定中均具有ras功能的Krev-1蛋白。用相应的Krev-1 p21氨基酸替换Ras p21中的这些残基，导致ras蛋白的生物学功能受损或其对体外GAP结合的亲和力降低。对这些突变型ras蛋白的评估对体内Ras p21-GAP相互作用具有重要意义。
