SOS1, also known as son of sevenless homolog 1, is a Ras and Rac guanine nucleotide exchange factor. This protein is composed of several important domains. The CDC25 and REM domains provide the catalytic activity of SOS1 towards Ras and the histone fold DH/PH (Dbl homology and Pleckstrin homology) domains function, in tandem, to stimulate GTP/GDP exchange for Rac. Also, binding of GTP activates Ras proteins, and subsequent hydrolysis of the bound GTP to GDP and phosphate inactivates signaling by these proteins. GTP binding can be catalyzed by guanine nucleotide exchange factors for RAS, and GTP hydrolysis can be accelerated by GTPase-activating proteins (GAPs). Source: Recombinant protein corresponding to aa564-1049 from human SOS1, fused to His-Tag at C-terminal, expressed in Insect Cell. Molecular Weight: ~58kD (495aa) ~50-70kD (SDS-PAGE under reducing conditions.) AA Sequence: ADPEEQMRLP SADVYRFAEP DSEENIIFEE NMQPKAGIPI IKAGTVIKLI ERLTYHMYAD PNFVRTFLTT YRSFCKPQEL LSLIIERFEI PEPEPTEADR IAIENGDQPL SAELKRFRKE YIQPVQLRVL NVCRHWVEHH FYDFERDAYL LQRMEEFIGT VRGKAMKKWV ESITKIIQRK KIARDNGPGH NITFQSSPPT VEWHISRPGH IETFDLLTLH PIEIARQLTL LESDLYRAVQ PSELVGSVWT KEDKEINSPN LLKMIRHTTN LTLWFEKCIV ETENLEERVA VVSRIIEILQ VFQELNNFNG VLEVVSAMNS SPVYRLDHTF EQIPSRQKKI LEEAHELSED HYKKYLAKLR SINPPCVPFF GIYLTNILKT EEGNPEVLKR HGKELINFSK RRKVAEITGE IQQYQNQPYC LRVESDIKRF FENLNPMGNS MEKEFTDYLF NKSLEIEPRN PKPLPRFPKK YSYPLKSPGV RPSNPRPGTH HHHHH Endotoxin: <1EU/1ug (LAL) Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 12 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
