Objective To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2(MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid(RA).Methods Neuronal differentiation of P19 cells was initiated with 4-day RA treatment.Immunofluorescence,real-time reverse transcription-polymerase chain reaction(RT-PCR) assay,and map2 promoter driven luciferase assay were performed to detect the expression and relative promoter activity of MAP2 in those RA-treated cells.Real-time PCR-based chromatin immunoprecipitation assay(ChIP) was carried out to reveal the specific recruitment of acetylated p53 onto its binding sites on map2 promoter.Results The expression of MAP2 was markedly increased in RA-induced P19 cells.The map2 mRNA increased 34-fold after 4 days of RA treatment and 730-fold 2 days after the treatment,compared with the cells without RA treatment(control).p53 was recruited to the promoter of map2 gene in acetylated form and thereby enhanced its promoter activity.p300/CBP associated factor(PCAF) was found induced in RA-treated cells and enriched in the nucleus,which might contribute to the acetylation of p53 in the regulation of map2 gene.Conclusions Acetylated p53 may participate in regulating the expression of map2 in RA-induced differentiation of P19 cells.PCAF is possibly involved in this process by mediating the acetylation of p53. Objective To investigate the regulatory mechanisms of acetylated p53 in the expression of microtubule-associated protein-2 (MAP2) in neuronal differentiation of P19 cells induced by all-trans retinoic acid (RA). Methods Neuronal differentiation of P19 cells was initiated with 4- day RA treatment. Immunofluorescence, real-time reverse transcription-polymerase chain reaction (RT-PCR) assay, and map2 promoter driven luciferase assay were performed to detect the expression and relative promoter activity of MAP2 in those RA-treated cells. PCR-based chromatin immunoprecipitation assay (ChIP) was carried out to reveal the specific recruitment of acetylated p53 onto its binding sites on map2 promoter. Results The expression of MAP2 was markedly increased in RA-induced P19 cells. Map2 mRNA increased 34-fold after 4 days of RA treatment and 730-fold 2 days after the treatment, compared with the cells without RA treatment (control) .p53 was recruited to the promoter of map2 gene in acetylated form and thus enhanced its promoter activity. p300 / CBP associated factor (PCAF) was found to be induced in RA-treated cells and enriched in the nucleus, which might contribute to the acetylation of p53 in the regulation of map 2 gene. Conclusions Acetylated p53 may participate in regulating the expression of map 2 in RA-induced differentiation of P19 cells. PCAF is likely involved in this process by mediating the acetylation of p53.