JMJD2D (KDM4D) is a histone demethylase located in the nucleus that specifically demethylates Lysine 9 of Histone H3, thereby playing a central role in the histone code. JMJD2D (KDM4D) demethylates both di- and trimethylated histone H3 Lys 9, while it has no activity on monomethylated residues. The demethylation reaction of the Lys residue generates formaldehyde and succinate as a by product. In addition, JMJD2D forms a complex with the ligand-bound form of the Androgen Receptor (AR) and, through this interaction, activates AR expression. Overexpression of AR is associated with prostate cancer, suggesting that, via its ability to upregulate AR, JMJD2D (KDM4D) may be involved in carcinogenesis.
