FIGURE 3.

Dasatinib and imatinib can inhibit phosphorylation of PKCδ at Tyr-64 and Tyr-155. A and D, ParC5 cells were left untreated or treated with 5 mm H₂O₂ for 10 min with or without pretreatment with 20 nm dasatinib (A) or 1 μm imatinib (D) for 30 min. Whole cell lysates were resolved using SDS-PAGE and analyzed for PKCδ pY64, pY155, and pY311. Inhibition of c-Src and c-Abl was determined by probing for their respective activation sites pY416 (c-Src) and pY412 (c-Abl). Blots were stripped and probed for total PKCδ, total c-Src, total c-Abl, and actin. B and C, 293T cells were transfected with either wild type c-Src (B), wild type c-Abl (C), or the gatekeeper mutation for c-Src T341I (B) or c-Abl T315I (C). Transfected cells were treated as in A. Whole cell lysates were resolved using SDS-PAGE and analyzed for PKCδ pY64, pY155, and pY311. For B and C, an asterisk denotes the band representing PKCδ pY155. Blots were stripped and probed for total PKCδ, total c-Src, total c-Abl, and actin. For D, an asterisk distinguishes the band representing c-Abl pY412 from a lower background band.