Figure 4.

The activation loop in p300 is not involved in MAML1-dependent p300 autoacetylation. (A) 293 cells were transfected with MAML1, p300 and p300Δloop and the lysates from the cells were subjected to SDS–PAGE. MAML1, p300 and the acetylation of p300, were visualized in western blotting with antibodies recognizing MAML1, p300, acetylated lysines or acetylated Lys1499 in p300. (B) The p300Δloop protein function as a more potent coactivator of MAML1. 293 cells were cotransfected with a luciferase reporter containing five Gal4-binding sites and vectors expressing Gal4-MAML1, p300 or p300Δloop.