FIG. 7.
Effect of DH mutations on the transforming activity of Dbl. cDNAs encoding the wild-type DH-PH domain module of Dbl (residues 498 to 825), the DH mutation-bearing DH-PH modules, and proto-Dbl were subcloned into the pZipneoGST vector and assayed for focus-forming activity in NIH 3T3 cells. Foci were quantified at 14 days posttransfection by Giemsa staining. WT, wild type. (A) Tissue culture dishes transfected with 0.1 μg of pZipneoGST-Dbl cDNA were visualized directly by a video camera. (B) Normalized focus-forming activities (103 foci/μg of DNA) of the DH mutants made in CR2 compared to those of wild-type Dbl, proto-Dbl, and the CR3 L640A mutant.