The guanine nucleotide exchange domain of C3G is involved in enhancement of cell adhesion. (A) Inducible expression of C3G or its mutant in 32D cells. A clone of 32D/EpoR-Wt cells transfected with pTet-C3G (32DE/Tet-C3G) or pTet-C3G-dSS (32DE/Tet-C3G-dSS), coding for C3G or its mutant lacking the guanine nucleotide exchange domain, respectively, was cultured for 24 hours with (+) or without (−) Tet, as indicated. TCL were extracted and subjected to anti-C3G immunoblotting. Positions of C3G and its mutant, C3G-dSS, are indicated. (B) 32DE/Tet-C3G and 32DE/Tet-C3G-dSS cells were cultured for 24 hours with (+) or without (−) Tet, as indicated, and subjected to the cell adhesion assay as described in Materials and Methods.