SOS1

Promotes the exchange of Ras-bound GDP by GTP. Probably by promoting Ras activation, regulates phosphorylation of MAP kinase MAPK3/ERK1 in response to EGF. Catalytic component of a trimeric complex that participates in transduction of signals from Ras to Rac by promoting the Rac-specific guanine nucleotide exchange factor (GEF) activity (By similarity)..

Function from UniProtKB (Q07889), read 2026-09-23. CC BY 4.0.