Histone-lysine N-methyltransferase SETDB1 (SETDB1)

Histone-lysine N-methyltransferase SETDB1 (SETDB1) is an evolutionarily conserved epigenetic enzyme that catalyzes the di- and tri-methylation of lysine 9 on histone H3 (H3K9) in euchromatin regions, leading to transcriptional silencing and heterochromatin formation via recruitment of proteins such as heterochromatin protein 1 (HP1). Structurally, SETDB1 contains a bifurcated SET domain, methyl-CpG-binding domain (MBD), and multiple Tudor domains that mediate chromatin association and protein-protein interactions. SETDB1 is crucial for regulation of development, immune responses, and maintenance of genomic stability, and its amplification or dysregulation is strongly associated with tumorigenesis, immune evasion, and resistance to immunotherapy. Although it represents an attractive therapeutic target in oncology and immunomodulation, pharmacological blockade remains challenging due to drug design difficulties and risks of epigenetic toxicity

Other names

ERG-associated protein with SET domainESETKIAA0067KMT1EH3-K9-HMTase 4KG1TTDRD21Histone H3-K9 methyltransferase 4Lysine N-methyltransferase 1Etudor domain containing 21

Most SETDB1-inhibiting drugs would be expected to block the methylation of H3K9, derepressing silenced genes including tumor suppressors, immune genes, and retroelements, or interfering with interaction partners (e.g., KRAB-ZFP, KAP1, hAM)