Genetic characterization of a possible role of Phe382 (F382) as a functional gatekeeper controlling imatinib mesylate binding.

(A) Schematic representation of the interaction between the A-loop and the β3-αC-loop mediated by H-bonds between Arg386 (R386) and Asp276/Glu279 (D276/E279). (B) Cos7 cells were transfected with 1 μg pApuro, Bcr-Ablwt, Bcr-AblTyr393Phe, or Bcr-AblAsp276Ser/Glu279Ser. Activity of the various Bcr-Abl mutants was assessed by means of phospho-Abl and phosphotyrosine antibodies. (C) Phospho-Abl and Abl immunoblots of lysates from Cos7 cells transfected with either pApuro, Bcr-Ablwt, Bcr-AblTyr393Phe, or Bcr-AblAsp276Ser/Glu279Ser. Cells were either left untreated or incubated with the indicated concentrations of imatinib mesylate. (D) Proliferation (top panel) and survival (bottom panel) of 32D cells expressing either Bcr-Ablwt, Bcr-AblTyr393Phe, or Bcr-AblAsp276Ser/Glu279Ser grown in the presence of the indicated concentrations of imatinib mesylate. Data are shown as means ± SD.