Kinase activation of regulatory domain mutations in ABL. Immunoprecipitated ABL proteins expressing patient SH3-SH2 domain mutations alone or together with the ABL-activating PP (P223E/P230E) mutations were assayed for activity by in vitro kinase assays with an optimal substrate peptide. The graphs show catalytic activity relative to ABL for 4 experiments (from 2 independent transfections) done in duplicate (mean ± SD). Representative immunoblots showing equal Abl protein levels (top panel) and degree of Abl autophosphorylation (bottom panel) are shown below the bar graphs. Note that, in the left panel, 2 lanes with unrelated samples were cropped between lanes 8 and 9 (indicated by dashed line).