Pokemon Decreases The Transcriptional Activity Of Rar Alpha In The Absence Of Ligand

Pokemon is a transcriptional repressor that belongs to the POZ and Kruppel (POK) protein family. In this study, we investigated the potential interaction between Pokemon and retinoic acid receptor alpha (RAR alpha) and determined the role of Pokemon in regulation of RAR alpha transcriptional activity in the absence of ligand. We found that Pokemon could directly interact with RAR alpha. Moreover, we demonstrated that Pokemon could decrease the transcriptional activity of RAR alpha in the absence of ligand. Furthermore, we showed that Pokemon could repress the transcriptional activity of RAR alpha by increasing the recruitment of nuclear receptor co-repressor (NCoR) and silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) to the retinoic acid response element (RARE) element. Taken together, these data suggest that Pokemon is a novel partner of RAR alpha that acts as a co-repressor to regulate RAR alpha transcriptional activity in the absence of ligand.