Legend: HEK293 cells were transfected with either empty expression vector (pSR ) or pSRa-Vav2 driving expression of human Vav2. Indicated antibodies (SHD or DPH) were used to immunoprecipitate Vav2 from 300 ug protein lysates. Immunoprecipitated activity was identified by immunoblot of complexes using either DPH (upper gel) or SHD (lower gel) antisera at (1:10000). Immunoprecipitation of Endogenous/Exogenous Vav2 from HEK 283 (75 u g lysate per lane). Top gel - i.p. Ab: DPH or SHD preimmune serum (2.5 l/300 g lysate). DPH or SHD alpha Vav2 antiserum (2.5 l/300 g lysate). Western Blot Ab: DPH anti Vav2 1:10000. Bottom Gel - i.p. Ab DPH or SHD preimmune sera (2.5 l/300 g lysate). DPH or SHD anti Vav2 antisera (2.5 l/300 g lysate). Western blot Ab - SHD anti Vav2 antibody 1:10000.