Fig. 3. Coexpression of ELMO1 is not required for DOCK180-mediated Rac activation in LR73 cells. (A) LR73 cells were transfected with a control plasmid or with the indicated amounts of plasmids coding for Flag-DOCK180 and Myc-ELMO1. GTP loading of Rac was measured by the PBD pull-down assay, and the precipitated Rac was analyzed by immunoblotting with anti-Rac antibodies. Expression levels of Rac, Flag-DOCK180 and Myc-ELMO1 were analyzed by anti-Rac, anti-Flag and anti-Myc immunoblotting, respectively, in total cell lysates. (B) LR73 cells were transfected with a control plasmid or with the indicated amounts of plasmids coding for Flag-DOCK180 with or without cotransfection of 1 µg of ELMO1-GFP. GTP loading of Rac was measured by the PBD pull-down assay, and the precipitated Rac was analyzed by immunoblotting with anti-Rac antibodies. Expression levels of Rac, Flag-DOCK180 and ELMO1-GFP were analyzed by anti-Rac, anti-Flag and anti-GFP immunoblotting, respectively, in total cell lysates.