ATF-2 and p300 cooperate in the activation of transcription of the c-jun gene during the differentiation of F9 cells. We show here that a repressor of AP-1, JDP2 (Jun dimerization protein 2), inhibits the transactivation of the c-jun gene by ATF-2 and p300, by recruitment of a histone deacetylase complex, thereby repressing the retinoic acid (RA)-induced transcription of the c-jun gene and inhibiting the RA-mediated differentiation of F9 cells. Furthermore, JDP2/HDAC complex was replaced by p300 complex on the DRE (differentiation response element) of the c-jun promoter within 24 h after the start of exposure of cells to RA, with an accompanying change in the histone-acetylation status of the chromatin, indicating that the initiation of transcription of the c-jun gene was controled by sequential action of HDAC(s) and HAT(s) on c-jun promoter.