Lambert Que T, Reuther Gary W
H. Lee Moffitt Cancer Center and Research Institute, University of South Florida, Tampa, Florida, USA.
Methods Enzymol. 2006;407:82-98. doi: 10.1016/S0076-6879(05)07008-4.
Ras guanine nucleotide releasing proteins (RasGRPs) function as guanine nucleotide exchange factors for Ras proteins. Thus, RasGRPs are direct activators of Ras proteins and contribute an important role in various cell-signaling pathways that are regulated by the activation state of Ras proteins. RasGRPs are regulated by the second messengers diacylglycerol and intracellular calcium and are also known as CalDAG-GEFs or calcium and diacylglycerol-regulated guanine nucleotide exchange factors. RasGRPs couple signaling events that generate these second messengers in the cell into activation of signaling pathways that are regulated by Ras. RasGRPs, therefore, increase the repertoire of extracellular stimuli that lead to activation of Ras. Analyzing the regulation of RasGRP activity should continue to play an important role in understanding the mechanisms by which signal transduction pathways use RasGRP proteins to activate Ras proteins in cells.
Ras鸟嘌呤核苷酸释放蛋白（RasGRPs）作为Ras蛋白的鸟嘌呤核苷酸交换因子发挥作用。因此，RasGRPs是Ras蛋白的直接激活剂，并在由Ras蛋白激活状态调节的各种细胞信号通路中发挥重要作用。RasGRPs受第二信使二酰基甘油和细胞内钙的调节，也被称为CalDAG-GEFs或钙和二酰基甘油调节的鸟嘌呤核苷酸交换因子。RasGRPs将在细胞中产生这些第二信使的信号事件与由Ras调节的信号通路的激活联系起来。因此，RasGRPs增加了导致Ras激活的细胞外刺激的种类。分析RasGRP活性的调节在理解信号转导通路利用RasGRP蛋白在细胞中激活Ras蛋白的机制方面应继续发挥重要作用。
