Grb2:Sos2:p-Y-Irs1 mediated nucleotide exchange of p21 Ras (IRS)

Stable Identifier
Reaction [transition]
Rattus norvegicus
SVG |   | PPTX  | SBGN
Grb2:Sos2:p-Y-Irs1 mediated nucleotide exchange of p21 Ras (IRS)

SOS promotes the formation of GTP-bound RAS, thus activating this protein. RAS activation results in activation of the protein kinases RAF1, B-Raf, and MAP-ERK kinase kinase (MEKK), and the catalytic subunit of PI3K, as well as of a series of RALGEFs. The activation cycle of RAS GTPases is regulated by their interaction with specific guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). GEFs promote activation by inducing the release of GDP, whereas GAPs inactivate RAS-like proteins by stimulating their intrinsic GTPase activity. NGF-induced RAS activation via SHC-GRB2-SOS is maximal at 2 min but it is no longer detected after 5 min. Therefore, the transient activation of RAS obtained through SHC-GRB2-SOS is insufficient for the prolonged activation of ERKs found in NGF-treated cells.

Literature References
PubMed ID Title Journal Year
8316835 The function of GRB2 in linking the insulin receptor to Ras signaling pathways.

Skolnik, EY, Batzer, A, Li, N, Lee, CH, Lowenstein, E, Mohammadi, M, Margolis, B, Schlessinger, J

Science 1993
Catalyst Activity
Catalyst Activity
Ras guanyl-nucleotide exchange factor activity of Grb2:Sos2:p-Y-Irs1 [cytosol]
Physical Entity
Orthologous Events