Watson P, Davis K, Didmon M, Broad P, Davey J
Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
Mol Microbiol. 1999 Aug;33(3):623-34. doi: 10.1046/j.1365-2958.1999.01510.x.
The rate and extent of a cell's response to an extracellular stimulus is influenced by regulators that act on the intracellular signalling machinery. Although not directly involved in propagating the intracellular signal, regulators control the activity of the proteins that transmit the signals. To understand this aspect of cell signalling, we have studied the pheromone response pathway in the fission yeast Schizosaccharomyces pombe, a relatively simple signalling system in a genetically tractable organism. We demonstrate this approach by investigating the role of Rgs1, a member of the Regulator of G protein Signalling (RGS) family of proteins. The rgs1 gene was identified through the Sz. pombe genome sequencing project (accession number Q09777) and recognized as having similarity to RGS proteins [Tesmer et al. (1997) Cell 89: 251-261], but this is the first report concerning the activity of the protein. Strains lacking rgs1 (Deltargs1) are hypersensitive to pheromone stimulation and unable to conjugate with a mating partner. Inhibition of mating occurs at a relative late stage in the process as Deltargs1 strains exhibit pheromone-dependent transcription and form shmoos. Expression of SST2 (an RGS protein that regulates pheromone signalling in the budding yeast Saccharomyces cerevisiae) overcomes the hypersensitivity of the Deltargs1 strains but fails to rescue their mating defect.
细胞对细胞外刺激的反应速率和程度受作用于细胞内信号传导机制的调节因子影响。尽管这些调节因子不直接参与细胞内信号的传播，但它们控制着传递信号的蛋白质的活性。为了理解细胞信号传导的这一方面，我们研究了裂殖酵母粟酒裂殖酵母中的信息素反应途径，这是一种在遗传上易于处理的生物体中的相对简单的信号系统。我们通过研究G蛋白信号调节因子（RGS）家族蛋白成员Rgs1的作用来证明这种方法。rgs1基因是通过粟酒裂殖酵母基因组测序项目（登录号Q09777）鉴定出来的，并被认为与RGS蛋白具有相似性[特斯默等人（1997年）《细胞》89卷：251 - 261页]，但这是关于该蛋白活性的首次报道。缺乏rgs1的菌株（Δrgs1）对信息素刺激高度敏感，并且无法与交配伙伴接合。交配抑制发生在这个过程的相对后期，因为Δrgs1菌株表现出信息素依赖性转录并形成接合突起。SST2（一种调节芽殖酵母酿酒酵母中信息素信号传导的RGS蛋白）的表达克服了Δrgs1菌株的高度敏感性，但未能挽救它们的交配缺陷。
