Autoinhibition of Sos by intramolecular interactions

Sos proteins function as activators of Ras signaling by catalyzing guanine nucleotide exchange on Ras. Sos regulation was initially thought to be accomplished primarily through its growth factor-dependent recruitment to the plasma membrane. More recent data has indicated that while membrane association is an indispensable means of Sos regulation, additional mechanisms involving intramolecular interactions function to control Sos activity towards Ras. This review will examine the experimental evidence for Sos intramolecular interactions and their contribution to Sos regulation.