Hart M J, Maru Y, Leonard D, Witte O N, Evans T, Cerione R A
Department of Biochemistry, Cell, and Molecular Biology, Cornell University, Ithaca, NY 14853.
Science. 1992 Oct 30;258(5083):812-5. doi: 10.1126/science.1439791.
Members of the family of Ras-related guanosine triphosphate (GTP) binding proteins appear to take part in the regulation of a number of biological processes, including cell growth and differentiation. Three different classes of proteins that regulate the GTP binding and GTP hydrolytic activities of the Ras family members have been identified. These different regulatory proteins inhibit guanosine diphosphate (GDP) dissociation (designated as GDIs), stimulate GDP dissociation and GDP-GTP exchange (designated as GDSs), or stimulate GTP hydrolysis (designated as GAPs). In the case of the Ras-like protein CDC42Hs, which is the human homolog of a Saccharomyces cerevisiae cell division cycle protein, the GDI protein also inhibited both the intrinsic and GAP-stimulated hydrolysis of GTP. These findings establish an additional role for the GDI protein--namely, as a guanosine triphosphatase (GTPase) inhibitory protein for a Ras-like GTP binding protein.
Ras相关鸟苷三磷酸（GTP）结合蛋白家族的成员似乎参与了包括细胞生长和分化在内的许多生物学过程的调节。已鉴定出三类不同的蛋白质，它们调节Ras家族成员的GTP结合和GTP水解活性。这些不同的调节蛋白抑制鸟苷二磷酸（GDP）解离（称为GDIs），刺激GDP解离和GDP-GTP交换（称为GDSs），或刺激GTP水解（称为GAPs）。就Ras样蛋白CDC42Hs而言，它是酿酒酵母细胞分裂周期蛋白的人类同源物，GDI蛋白也抑制GTP的内在水解和GAP刺激的水解。这些发现确立了GDI蛋白的另一个作用——即作为一种针对Ras样GTP结合蛋白的鸟苷三磷酸酶（GTPase）抑制蛋白。
