Lambert Alexandra A, Perron Marjorie P, Lavoie Elyse, Pallotta Dominick
Centre de Recherche sur la Structure, la Fonction et l'Ingénierie des Protéines (CREFSIP), Pavillon Charles-Eugène Marchand, Université Laval Québec, Canada.
FEMS Yeast Res. 2007 Sep;7(6):782-95. doi: 10.1111/j.1567-1364.2007.00239.x. Epub 2007 Apr 10.
We show that Arf3p, a member of the ADP ribosylation family, is involved in the organization of actin cables and cortical patches in Saccharomyces cerevisiae. Profilin-deficient cells (pfy1Delta) have severe growth defects and lack actin cables. Overexpression of ARF3 restores actin cables and corrects growth defects in these cells. Cells deficient for the cortical patch proteins Las17p and Vrp1p have growth defects and a random cortical patch distribution. Overexpression of ARF3 in las17Delta and in vrp1Delta cells partially corrects growth defects and restores the polarized distribution of cortical patches. The N-terminal glycine, a myristoylation site in Arf3p, is necessary for its suppressor activity. arf3Delta cells show a random budding pattern. Overexpression of BNI1, GEA2 or SYP1, three genes involved in actin cytoskeleton formation, restores the normal axial budding pattern of arf3Delta cells. BUD6 is a polarity gene and GEA2 is involved in retrograde transport and the organization of the actin cytoskeleton. We have identified genetic interactions between ARF3 and BUD6, and between ARF3 and GEA2. Both double mutant strains have actin cytoskeleton defects. Our results support a role for ARF3 in cell polarity and the organization of the actin cytoskeleton.
我们发现，ADP核糖基化家族成员Arf3p参与酿酒酵母中肌动蛋白电缆和皮质斑的组织。缺乏肌动蛋白单体结合蛋白的细胞（pfy1Delta）存在严重的生长缺陷且缺乏肌动蛋白电缆。ARF3的过表达可恢复肌动蛋白电缆并纠正这些细胞的生长缺陷。缺乏皮质斑蛋白Las17p和Vrp1p的细胞存在生长缺陷且皮质斑分布随机。在las17Delta和vrp1Delta细胞中过表达ARF3可部分纠正生长缺陷并恢复皮质斑的极化分布。Arf3p中的N端甘氨酸是一个肉豆蔻酰化位点，对其抑制活性是必需的。arf3Delta细胞表现出随机出芽模式。参与肌动蛋白细胞骨架形成的三个基因BNI1、GEA2或SYP1的过表达可恢复arf3Delta细胞的正常轴向出芽模式。BUD6是一个极性基因，GEA2参与逆行运输和肌动蛋白细胞骨架的组织。我们已经确定了ARF3与BUD6之间以及ARF3与GEA2之间的遗传相互作用。两种双突变菌株都存在肌动蛋白细胞骨架缺陷。我们的结果支持Arf3p在细胞极性和肌动蛋白细胞骨架组织中的作用。
