SOS1

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]

Full Name

SOS Ras/Rac Guanine Nucleotide Exchange Factor 1

Function

Promotes the exchange of Ras-bound GDP by GTP (PubMed:8493579).
Probably by promoting Ras activation, regulates phosphorylation of MAP kinase MAPK3 in response to EGF (PubMed:17339331).
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).

Biological Process

Biological Process axon guidanceTAS:Reactome
Biological Process B cell homeostasisIEA:Ensembl
Biological Process blood vessel morphogenesisIEA:Ensembl
Biological Process cardiac atrium morphogenesisIEA:Ensembl
Biological Process cytokine-mediated signaling pathwayTAS:Reactome
Biological Process epidermal growth factor receptor signaling pathwayTAS:Reactome
Biological Process eyelid development in camera-type eyeIEA:Ensembl
Biological Process Fc-epsilon receptor signaling pathwayTAS:Reactome
Biological Process fibroblast growth factor receptor signaling pathwayIEA:Ensembl
Biological Process hair follicle developmentIEA:Ensembl
Biological Process heart trabecula morphogenesisIEA:Ensembl
Biological Process leukocyte migrationTAS:Reactome
Biological Process midbrain morphogenesisIEA:Ensembl
Biological Process multicellular organism growthIEA:Ensembl
Biological Process neurotrophin TRK receptor signaling pathwayIEA:Ensembl
Biological Process pericardium morphogenesisIEA:Ensembl
Biological Process positive regulation of epidermal growth factor receptor signaling pathwayIEA:Ensembl
Biological Process positive regulation of GTPase activityManual Assertion Based On ExperimentIBA:GO_Central
Biological Process positive regulation of small GTPase mediated signal transductionIEA:Ensembl
Biological Process Ras protein signal transductionManual Assertion Based On ExperimentIDA:ComplexPortal
Biological Process regulation of cell population proliferationManual Assertion Based On ExperimentIDA:ComplexPortal
Biological Process regulation of MAP kinase activityManual Assertion Based On ExperimentIDA:ComplexPortal
Biological Process regulation of pro-B cell differentiationIEA:Ensembl
Biological Process regulation of T cell differentiation in thymusIEA:Ensembl
Biological Process regulation of T cell proliferationIEA:Ensembl
Biological Process regulation of transcription by RNA polymerase IIManual Assertion Based On ExperimentIDA:ComplexPortal
Biological Process roof of mouth developmentIEA:Ensembl
Biological Process signal transduction1 PublicationNAS:ProtInc
Biological Process vitellogenesisIEA:Ensembl

Cellular Location

cytoplasm
cytosol
GTPase complex
neuronal cell body
plasma membrane
postsynaptic density

Involvement in disease

Fibromatosis, gingival, 1 (GINGF1):
A form of hereditary gingival fibromatosis, a rare condition characterized by a slow, progressive overgrowth of the gingiva. The excess gingival tissue can cover part of or the entire crown, and can result in diastemas, teeth displacement, or retention of primary or impacted teeth. GINGF1 is usually transmitted as an autosomal dominant trait, although sporadic cases are common.
Noonan syndrome 4 (NS4):
A form of Noonan syndrome, a disease characterized by short stature, facial dysmorphic features such as hypertelorism, a downward eyeslant and low-set posteriorly rotated ears, and a high incidence of congenital heart defects and hypertrophic cardiomyopathy. Other features can include a short neck with webbing or redundancy of skin, deafness, motor delay, variable intellectual deficits, multiple skeletal defects, cryptorchidism, and bleeding diathesis. Individuals with Noonan syndrome are at risk of juvenile myelomonocytic leukemia, a myeloproliferative disorder characterized by excessive production of myelomonocytic cells. Some patients with NS4 have polyarticular villonodular synovitis.

PTM

Phosphorylation at Ser-1134 and Ser-1161 by RPS6KA3 create YWHAB and YWHAE binding sites and which contribute to the negative regulation of EGF-induced MAPK1/3 phosphorylation.