PKCδ associated with membranes from IC2 cells expressing D814Y Kit is phosphorylated on tyrosine. IC2 cells expressing WT or D814Y Kit were stimulated with 100 ng/mL murine SCF for 15 minutes at room temperature prior to isolation of membranes. (A) Membrane protein (600 μg) from IC2 cells expressing WT or D814Y Kit was immunoprecipitated with an antibody specific for PKCδ, resolved by SDS-PAGE, transferred to immobilon-P, and immunoblotted with an antibody for phosphotyrosine. Membrane proteins immunoprecipitated with normal rabbit IgG were used as a negative control. (B) The immunoblots were subsequently stripped and reprobed with an antibody specific for PKCδ. These data are representative of results from 4 independent experiments. IB indicates immunoblot.