RUI: Mechanism of Action of the ras p21

Ras蛋白是鸟嘌呤核苷酸结合蛋白， 对细胞信号传导至关重要。 虽然 ras的细胞和突变形式的作用机制 蛋白p21尚未完全描述，显微注射 任何一种形式都可以使非洲爪蟾卵母细胞进行减数分裂细胞 师. 由于ras蛋白已被发现增加 多磷脂酰肌醇周转，ras可能通过 该途径的细胞内信使，蛋白激酶C和 1，4，5-三磷酸肌醇（IP 3）。 由于IP 3已被发现， 在卵母细胞和其他细胞类型中释放细胞内钙， 这表明，RAS的至少某些行为可能是由于 增加细胞内钙。 虽然其他实验室 专注于蛋白激酶C途径，该实验室 ras蛋白可以在细胞内释放 钙 建议进行实验，以直接确定是否 ras蛋白增加细胞内钙， 细胞或突变形式的ras诱导两种反应（减数分裂 细胞分裂和细胞内pH值的增加）， 钙增加。 拟议的研究将研究一种 蛋白，即“ras”蛋白，在信号转导中起重要作用。 跨细胞膜的转导。 ras显微注射 蛋白质进入青蛙卵诱导细胞分裂。 各种 有证据表明，RAS效应可能涉及到 细胞内游离钙水平。 这项研究将 确定ras蛋白本身是否从 细胞内储存或影响细胞内钙水平 不那么直接。 结果将有助于更好地 了解细胞信号转导的机制。

Ras proteins are guanine nucleotide-binding proteins which are central to cellular signal transduction. Although the mechanism(s) of action of cellular and mutant forms of the ras protein p21 have not been fully described, microinjection of either form can cause Xenopus oocytes to undergo meiotic cell division. Since ras protein has been found to increase polyphosphatidylinositol turnover, ras may act through the intracellular messengers of this pathway, protein kinase C and inositol 1,4,5-trisphosphate (IP3). Since IP3 has been found to release intracellular calcium in oocytes and other cell types, this suggests that at least some actions of ras may be due to increased intracellular calcium. While other laboratories have concentrated on the protein kinase C pathway, this laboratory has indirect evidence that ras protein can release intracellular calcium. Experiments are proposed to establish directly whether ras protein increases intracellular calcium and whether the cellular or mutant forms of ras induce two responses (meiotic cell division and an increase in intracellular pH) through the calcium increase. The proposed research will examine the mechanism of action of a protein, the "ras" protein, that is important in signal transduction across the cell membrane. Microinjection of ras proteins into frog eggs induces cell division. A variety of evidence suggests that ras effects may involve changes in the level of intracellular free calcium. This research will determine whether the ras protein itself releases calcium from intracellular stores or affects intracellular calcium levels less directly. The results will contribute to a better understanding of the mechanisms of cellular signal transduction.