RSF1 orchestrates p53 transcriptional activity by coordinating p300 acetyltransferase and FACT complex

The transcriptional regulation of p53-dependent genes in response to DNA damage is critical for effective DNA repair and cell survival. We previously established that RSF1 (remodeling and spacing factor 1) is necessary for p53-dependent gene transcription in response to DNA strand breaks. Here, we further elucidate that the role of RSF1 in p53 regulation by demonstrating that its depletion results in a reduction in the acetylated-Lys(K)382 level of p53, which governs its transcriptional activity. RSF1 was co-precipitated with p300 acetyltransferase upon etoposide treatment. Chromatin immunoprecipitation assays on the upstream region of CDKN1A gene revealed reduced p300 and TBP accumulation, which were accompanied with low H3H27ac and H3K4me1 levels in RSF1 knockout cells. Moreover, RSF1 depletion led to a reduced accumulation of SSRP1 and SPT16, subunits of FACT complex at the promoter of CDKN1A gene. These findings suggest that RSF1 promotes p53-dependent p21 gene transcription by facilitating the accumulation of p300 acetyltransferase at the enhancer and FACT at the promoter region of CDKN1A gene, respectively.