Site‐specific regulation of the GEF Cdc24p by the scaffold protein Far1p during yeast mating
Site‐specific regulation of the GEF Cdc24p by the scaffold protein Far1p during yeast mating
复制标题
酵母交配过程中支架蛋白 Far1p 对 GEF Cdc24p 的位点特异性调节
作者：
P. Wiget;Y. Shimada;Anne‐Christine Butty;E. Bi;M. Peter
通过异源三聚体G蛋白的受体介导的细胞极化在多种生物体中诱导细胞骨架重排。在酵母中，Far1p通过将活化的Gβγ连接到鸟嘌呤核苷酸交换因子（GEF）Cdc24 p（其激活Rho型GTdR Cdc42 p）来使细胞生长朝向交配伴侣。在这里，我们研究了Far1p在体内Cdc24p调控中的作用。使用交配细胞的延时显微镜和Far1p的人工膜靶向，我们表明Far1p是必要的，足以将Cdc24p招募到质膜上。野生型Far1 p含有PH样结构域，这是其体内膜定位所需的。有趣的是，膜靶向Far1p的表达导致毒性，最有可能是通过在细胞皮层均匀激活Cdc42p。全长Far1p在体内作为Cdc24p激活剂的能力需要其与Cdc24p和Gβγ相互作用。我们的研究结果表明，Gβγ不仅将Far1p靶向到正确的位点，而且还可能触发Far1p的构象变化，这是其在体内激活Cdc24 p的能力所必需的。
Receptor‐mediated cell polarization via heterotrimeric G‐proteins induces cytoskeletal rearrangements in a variety of organisms. In yeast, Far1p is required for orienting cell growth towards the mating partner by linking activated Gβγ to the guanine‐nucleotide exchange factor (GEF) Cdc24p, which activates the Rho‐type GTPase Cdc42p. Here we investigated the role of Far1p in the regulation of Cdc24p in vivo. Using time‐lapse microscopy of mating cells and artificial membrane targeting of Far1p, we show that Far1p is necessary and sufficient to recruit Cdc24p to the plasma membrane. Wild‐type Far1p contains a PH‐like domain, which is required for its membrane localization in vivo. Interestingly, expression of membrane‐targeted Far1p causes toxicity, most likely by activating Cdc42p uniformly at the cell cortex. The ability of full‐length Far1p to function as an activator of Cdc24p in vivo requires its interaction with Cdc24p and Gβγ. Our results imply that Gβγ not only targets Far1p to the correct site but may also trigger a conformational change in Far1p that is required for its ability to activate Cdc24p in vivo.
影响因子：
56.9
作者：
Butty, AC;Pryciak, PM;Peter, M
通讯作者：
Peter, M
鉴定酿酒酵母中正常信息素诱导的细胞极化所需的基因。
影响因子：
3.3
作者：
Chenevert,J;Valtz,N;Herskowitz,I
通讯作者：
Herskowitz,I