Suppressor Of Variegation 3-9 Homolog 1 (SUV39H1)

SUV39H1 contains a chromodomain that is located close to the N terminus, a cysteine-rich region, an adjacent C-terminal SET domain that is followed at the very C-terminal tail by 3 conserved cysteine residues, and a putative nuclear localization signal. SUV39H1 shares 95% amino acid sequence identity with mouse Suv39h1, 42% identity with Drosophila Su(var)3-9, and 38% identity with S. pombe CLR4, another Su(var)3-9 ortholog. Immunoblot analysis of protein extracts from human cell lines detected an approximately 48-kD endogenous SUV39H1 protein, a mass that corresponds with the mass calculated from the SUV39H1 cDNA. Immunodetection of endogenous SUV39H1 protein revealed enriched distribution at heterochromatic foci during interphase and centromere-specific localization during metaphase.