Histone methyltransferase that specifically monomethylates 'Lys-4' of histone H3 (  ). H3 'Lys-4' methylation represents a specific tag for epigenetic transcriptional activation ( ). Plays a central role in the transcriptional activation of genes such as collagenase or insulin (, ). Recruited by IPF1/PDX-1 to the insulin promoter, leading to activate transcription . Has also methyltransferase activity toward non-histone proteins such as CGAS, p53/TP53, TAF10, and possibly TAF7 by recognizing and binding the [KR]-[STA]-K in substrate proteins ( , ). Monomethylates 'Lys-189' of TAF10, leading to increase the affinity of TAF10 for RNA polymerase II (, ). Monomethylates 'Lys-372' of p53/TP53, stabilizing p53/TP53 and increasing p53/TP53-mediated transcriptional activation ( ). Monomethylates 'Lys-491' of CGAS, promoting interaction between SGF29 and CGAS (By similarity).
Subcellular locations: Nucleus, Chromosome
Widely expressed. Expressed in pancreatic islets.