BAF53 interacts with p53 and functions in p53-mediated p21-gene transcription.

BAF53, a component of chromatin remodelling and histone acetyltransferase complexes, has been shown to be essential for cell survival in human cells and plays roles in p53-mediated gene transcription. However, the mechanism concerned in the process needs to be further explored. In this study, we show that BAF53 is involved in the repression of p53-dependent p21-gene transcription by interacting with p53 both in vivo and in vitro. Through electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation analyses, we demonstrate that BAF53 can reduce the p53-binding ability to p21 promoter. By western-blot experiments, we find that BAF53 can decrease p53-Lys382 acetylation, which may be partially responsible for the repression of p53-binding ability. Furthermore, BAF53 represses p21-promoter activity in a BRG1-independent manner. These data contribute to elucidating the molecular mechanisms of BAF53 in regulating p53-mediated gene transcription.