DNA-methyltransferase 1, DNA-methyltransferase 3A, and DNA-methyltransferase 3B (DNMT1, DNMT3A, DNMT3B)

DNA (cytosine-5)-methyltransferase 1, DNA (cytosine-5)-methyltransferase 3A, and DNA (cytosine-5)-methyltransferase 3B (abbreviated as DNMT1, DNMT3A, and DNMT3B) are enzymes responsible for catalyzing the transfer of a methyl group to the 5-position of cytosine residues in DNA, primarily at CpG sites[3][4][5]. DNMT1 is primarily responsible for maintenance methylation during DNA replication, ensuring faithful propagation of epigenetic signals[3]. DNMT3A and DNMT3B are primarily responsible for de novo methylation during development and in specific contexts, establishing new methylation marks[2][4]. Aberrant activity or expression of these enzymes can contribute to disease, including various cancers, by altering normal gene expression programs[1][2]. Several therapeutic agents seek to inhibit their function or correct pathogenic methylation patterns.

Other names

DNMT1DNMT3ADNMT3BDNA methyltransferase 1/3a/3bMaintenance methyltransferaseDe novo methyltransferase

Covalent inhibition of DNA methyltransferase activity: Nucleoside analogs (like 5-azacytidine and decitabine) incorporate into DNA/RNA and trap DNMTs covalently, leading to DNA hypomethylation and reactivation of silenced genes[2].