Recombinant human KMT1A / SUV39H1 protein

Specifications

Form

Liquid

General info

Function

Histone methyltransferase that specifically trimethylates 'Lys-9' of histone H3 using monomethylated H3 'Lys-9' as substrate. Also weakly methylates histone H1 (in vitro). H3 'Lys-9' trimethylation represents a specific tag for epigenetic transcriptional repression by recruiting HP1 (CBX1, CBX3 and/or CBX5) proteins to methylated histones. Mainly functions in heterochromatin regions, thereby playing a central role in the establishment of constitutive heterochromatin at pericentric and telomere regions. H3 'Lys-9' trimethylation is also required to direct DNA methylation at pericentric repeats. SUV39H1 is targeted to histone H3 via its interaction with RB1 and is involved in many processes, such as repression of MYOD1-stimulated differentiation, regulation of the control switch for exiting the cell cycle and entering differentiation, repression by the PML-RARA fusion protein, BMP-induced repression, repression of switch recombination to IgA and regulation of telomere length. Component of the eNoSC (energy-dependent nucleolar silencing) complex, a complex that mediates silencing of rDNA in response to intracellular energy status and acts by recruiting histone-modifying enzymes. The eNoSC complex is able to sense the energy status of cell : upon glucose starvation, elevation of NAD(+)/NADP(+) ratio activates SIRT1, leading to histone H3 deacetylation followed by dimethylation of H3 at 'Lys-9' (H3K9me2) by SUV39H1 and the formation of silent chromatin in the rDNA locus. Recruited by the large PER complex to the E-box elements of the circadian target genes such as PER2 itself or PER1, contributes to the conversion of local chromatin to a heterochromatin-like repressive state through H3 'Lys-9' trimethylation.. (Microbial infection) Plays a role in defense against mycobacterial infections. Methylates M.tuberculosis HupB on 'Lys-140', probably methylates HupB of M.bovis also. Methylation has an inhibitory effect on mycobacterial growth in the host. Macrophages expressing about 60% SUV39H1 are slightly more susceptible to M.bovis or M.tuberculosis infection. Chaetocin (an inhibitor of this enzyme) increases macrophage survival of M.tuberculosis. This protein inhibits biofilm formation by M.tuberculosis via 'Lys-140' trimethylation.

Sequence similarities

Belongs to the class V-like SAM-binding methyltransferase superfamily. Histone-lysine methyltransferase family. Suvar3-9 subfamily.

Post-translational modifications

Phosphorylated on serine residues, and to a lesser degree, on threonine residues. The phosphorylated form is stabilized by SBF1 and is less active in its transcriptional repressor function.. Ubiquitinated by the DCX(DCAF13) E3 ubiquitin ligase complex, leading to its degradation.. Acetylated at Lys-266, leading to inhibition of enzyme activity. SIRT1-mediated deacetylation relieves this inhibition.. (Microbial infection) A higher molecular weight form is also seen in M.bovis infected cells.

Subcellular localisation

Nucleus