switch-associated protein 70 (SWAP-70, SWAP70, KIAA0640, HSPC321)

Function: 1) PIP3-dependent guanine nucleotide exchange factor 2) transduces signals from tyrosine kinase receptors to RAC (RAS-independent) 3) mediates signaling of membrane ruffling 4) regulates actin cytoskeleton as an effector or adapter protein in response to agonist stimulated PIP2 production & cell protrusion 5) component of SWAP complex 6) Tyr-phosphorylated Structure: - contains 1 PH domain - PH domain is essential for PIP3 binding Compartment: - cytoplasm, cell membrane, nucleus - in resting B-cells, localized mainly in cytoplasm, upon activation, recruited to plasma membrane, then translocates to the nucleus - in activated, class-switching B-cells, associated with membrane IgG but not IgM - localized to loose actin filament arrays located behind actively extending lamellipodia Expression: - expressed only in mature B-cells including those associated with mucosa-associated tissue & bronchus-associated tissue - widely expressed - abundant in spleen, & fairly abundant in kidney, lung & liver - also found in monocytes & macrophages

General

guanine nucleotide exchange factor (GDP/GTP dissociation stimulator, guanine nucleotide-releasing factor/protein, GNEF, GNDS, GDS) phosphoprotein

Properties

SIZE: MW = 69 kD entity length = 585 aa COMPARTMENT: cytoplasm cell nucleus MOTIF: PH domain {210-306} MOTIF: lysine-rich region {291-294} MOTIF: lysine residue (SEVERAL) coiled coil {316-539}

Database Correlations

OMIM 604762 UniProt Q9UH65 Pfam PF00169

References

UniProt :accession Q9UH65