Ziman M, Johnson D I
Department of Microbiology and Molecular Genetics, University of Vermont, Burlington 05401.
Yeast. 1994 Apr;10(4):463-74. doi: 10.1002/yea.320100405.
Cdc24p and Cdc42p are involved in the control of cell polarity during the Saccharomyces cerevisiae cell cycle. Cdc42p is a member of the Ras superfamily of GTPases and Cdc24p displays limited amino-acid sequence similarity with the Dbl proto-oncoprotein, which acts to stimulate guanine-nucleotide exchange on human Cdc42p. We have performed several genetic experiments to test whether Cdc24p and Cdc42p interact within the cell. First, overexpression of Cdc24p suppressed the dominant-negative cdc42D118A allele. Second, overexpression of wild-type CDC24 and CDC42 genes together was a lethal event resulting in a morphological phenotype of large, round, unbudded cells, indicating a loss of cell polarity. Third, a cdc24ts cdc42ts double mutant exhibited a synthetic-lethal phenotype at the semi-permissive temperature of 30 degrees C. These data suggest that Cdc24p and Cdc42p interact within the cell and that Cdc24p may be involved in the regulation of Cdc42p activity.
Cdc24p和Cdc42p参与酿酒酵母细胞周期中细胞极性的控制。Cdc42p是GTP酶Ras超家族的成员，Cdc24p与Dbl原癌蛋白的氨基酸序列相似性有限，Dbl原癌蛋白可刺激人Cdc42p上的鸟嘌呤核苷酸交换。我们进行了多项遗传学实验，以测试Cdc24p和Cdc42p在细胞内是否相互作用。首先，Cdc24p的过表达抑制了显性负性cdc42D118A等位基因。其次，野生型CDC24和CDC42基因一起过表达是一个致死事件，导致出现大的、圆形的、未出芽细胞的形态学表型，表明细胞极性丧失。第三，cdc24ts cdc42ts双突变体在30摄氏度的半允许温度下表现出合成致死表型。这些数据表明Cdc24p和Cdc42p在细胞内相互作用，并且Cdc24p可能参与Cdc42p活性的调节。
