Phosphorylation status of the D835 mutants.

Cos7 cells were transfected with D835 mutant cDNA. Mutants were immunoprecipitated and probed with antiphosphotyrosine antibody. All mutants were constitutively tyrosine phosphorylated without FL stimulation. Because of the higher amounts of the loading samples, the phosphorylated band of wild-type FLT3 looks relatively high.