KDM4A Recombinant Protein

This gene is a member of the Jumonji domain 2 (JMJD2) family and encodes a protein containing a JmjN domain, a JmjC domain, a JD2H domain, two TUDOR domains, and two PHD-type zinc fingers. This nuclear protein functions as a trimethylation-specific demethylase, converting specific trimethylated histone residues to the dimethylated form, and as a transcriptional repressor. [provided by RefSeq, Apr 2009]

Function: Histone demethylase that specifically demethylates 'Lys-9' and 'Lys-36' residues of histone H3, thereby playing a central role in histone code. Does not demethylate histone H3 'Lys-4', H3 'Lys-27' nor H4 'Lys-20'. Demethylates trimethylated H3 'Lys-9' and H3 'Lys-36' residue, while it has no activity on mono- and dimethylated residues. Demethylation of Lys residue generates formaldehyde and succinate. Participates in transcriptional repression of ASCL2 and E2F-responsive promoters via the recruitment of histone deacetylases and NCOR1, respectively. Ref.5 Ref.6 Ref.12Isoform 2: Crucial for muscle differentiation, promotes transcriptional activation of the Myog gene by directing the removal of repressive chromatin marks at its promoter. Lacks the N-terminal demethylase domain. Ref.5 Ref.6 Ref.12

Cofactor: Binds 1 Fe2+ ion per subunit. Ref.6

Subunit structure: Interacts with histone deacetylase proteins HDAC1, HDAC2 and HDAC3. Interacts with RB and NCOR1. Interacts with HTLV-1 Tax protein. Ref.4 Ref.5

Subcellular location: Nucleus Ref.4 Ref.5.

Tissue specificity: Ubiquitous. Ref.4

Domain: The 2 Tudor domains recognize and bind methylated histone H3 'Lys-4' residue (H3K4me). Double Tudor domain has an interdigitated structure and the unusual fold is required for its ability to bind methylated histone tails. Trimethylated H3 'Lys-4' (H3K4me3) is bound in a cage of 3 aromatic residues, 2 of which are from the Tudor domain 2, while the binding specificity is determined by side-chain interactions involving residues from the Tudor domain 1. The Tudor domains are also able to bind trimethylated histone H3 'Lys-9' (H3K9me3), di- and trimethylated H4 'Lys-20' (H4K20me2 and H4K20me3). Has high affinity for H4K20me2, blocking recruitment of proteins such as TP53BP1. Ref.6 Ref.7 Ref.11 Ref.14

Post-translational modification: Ubiquitinated by RNF8 and RNF168 following DNA damage, leading to its degradation. Degradation promotes accessibility of H4K20me2 mark for DNA repair protein TP53BP1, which is then recruited. Ref.11

Sequence similarities: Belongs to the JHDM3 histone demethylase family.Contains 1 JmjC domain.Contains 1 JmjN domain.Contains 2 PHD-type zinc fingers.Contains 2 Tudor domains.

Sequence caution: The sequence BAA31652.2 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.