SOS1（SOS Ras/Rac guanine nucleotide exchange factor 1），癌症关联基因，基因ID：6654，该基因编码一种蛋白质，它是ras蛋白的鸟嘌呤核苷酸交换因子，ras蛋白是结合鸟嘌呤核苷酸并参与信号转导途径的膜蛋白。gtp结合激活和gtp水解失活ras蛋白。这个基因的产物可能通过促进gtp与gdp的交换来调节ras蛋白。该基因突变与牙龈纤维瘤病1和努南综合征4型相关。[由RefSeq提供，2008年7月]This gene encodes a protein that is a guanine nucleotide exchange factor for RAS proteins， membrane proteins that bind guanine nucleotides and participate in signal transduction pathways. GTP binding activates and GTP hydrolysis inactivates RAS proteins. The product of this gene may regulate RAS proteins by facilitating the exchange of GTP for GDP. Mutations in this gene are associated with gingival fibromatosis 1 and Noonan syndrome type 4. [provided by RefSeq， Jul 2008]。