Sequence specific transcription factor, JDP2 interacts with histone and inhibits p300-mediated histone acetylation.

Jun dimerization protein 2 (JDP2) is a novel member of AP-1 family and acts as a general repressor of a variety of transcription. JDP2 is able to bind to specific sites in target gene such as c-jun by forming homodimer or heterodimers with a JudATF family member to counteract their transcriptional activity. Previously we showed that JDPZ inhibits the retinoic acid (RA) dependent transcription by recruiting a histone deacetylase 3 (HDAC3) complex to the promoter region of the target genes. We present here that JDPZ has an inhibitory activity of acetylation of all core histones mediated by histone acetyltransferase (HAT) both of p300 and PCAF in vitro. The studis of both histone-binding and HAT-inhibitory activity using a variety of recombinant JDP2(s) indicated that JDPZ might target histone itself through the histone-binding domain of JDP2, which is essential but not sufficient for the inhibition of acetylation. Therefore, our data suggested that HAT-inhibitory activity of JDPZ could in part explain the transcriptional repression of several target genes.