Jumonji/JARID2: Proteins and Enzymes

JARID2 (Jumonji/ARID domain-containing protein 2; also Jumonji [Japanese for "cruciform/cross"] and JMJ) is a 150-160 kDa member of the JMJ family of proteins. It is a nuclear complex coordinator that interacts with the G9a and GLP methyltransferases to repress gene transcription. JARID2 is expressed in mammalian embryonic neurons, megakaryocytes, hepatocytes and cardiomyocytes. Human JARID2 is 1246 amino acids (aa) in length. It contains an NLS (aa 1-131), a transcriptional repressor domain (aa 132-222), a DNA binding region (aa 558-709) and a nonfunctional histone demethylase domain (aa 916-1042). There are potential splice variants. One shows an alternative start site at Met173, another shows a deletion of aa 304-1151, and a third contains a 22 aa substitution for aa 1-60, coupled to a 50 aa substitution for aa 949-1246. Over aa 1-159, human JARID2 shares 96% aa identity with mouse JARID2.