Reaction: SOS-mediated nucleotide exchange of RAS (mediated by GRB2:SOS1 in complex with phosphorylated SHC1 and p-EGFRvIII)
- in pathway: Constitutive Signaling by EGFRvIII
SOS1 is the guanine nucleotide exchange factor (GEF) for RAS. SOS1, recruited by GRB2 bound to p-SHC1:p-EGFRvIII mutant, is assumed to activate RAS nucleotide exchange from the inactive form (bound to GDP) to an active form (bound to GTP). Although this reaction has not been shown to occur directly for EGFRvIII cancer mutant, activation of RAF/MAP kinase cascade has been demonstrated in cells expressing EGFRvIII (Montgomery et al. 1995).
Reaction - small molecule participants:
GDP [cytosol]
GTP [cytosol]
Reactome.org reaction link: R-HSA-5637808
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Reaction input - small molecules:
GTP(4-)
Reaction output - small molecules:
GDP(3-)
Reactome.org link: R-HSA-5637808