Interaction of 3BP2 with Vav family members. (A) A yeast 2-hybrid screen of a human lymphocyte library using LexA-3BP2 as bait was performed. Shown are the accession number of the different Vav cDNAs isolated during this screen, and the number of independent clones for each cDNA. (B) COS-1 cells were transiently transfected with expression plasmids encoding HA-tagged 3BP2, myc-tagged Vav1, myc-tagged Vav2, or combinations of these plasmids as indicated. Immunoprecipitates were prepared with anti-HA antibody and probed with anti-myc antibody. The membranes were then reprobed with anti-HA antibody to control 3BP2 protein expression. (C) A combination of HA-tagged 3BP2 and myc-tagged Vav3 were expressed in COS-1 cells and coimmunoprecipitations were performed.