DNMT3AB

DNMT3AB is not an officially recognized gene symbol; in many sources the term is used informally to refer to the two de novo DNA methyltransferases DNMT3A and DNMT3B, or to the DNMT3 family as a group. In humans, DNMT3A and DNMT3B are responsible for establishing new DNA methylation patterns during development and in germ cells, complementing maintenance methylation carried out by DNMT1.

Function and mechanism

DNMT3A and DNMT3B catalyze the transfer of a methyl group from S-adenosylmethionine to cytosine bases, primarily at CpG dinucleotides, though de novo activity can occur in non-CpG contexts in embryonic stem cells. They contribute to genomic imprinting, X-chromosome inactivation, and silencing of transposable elements. The two enzymes share catalytic domains and a regulatory region that influences substrate preference and genomic targeting.

Regulation and interactions

DNMT3A and DNMT3B interact with DNMT3L, a regulatory factor that enhances their activity and guides them to chromatin through recognition of histone marks. Proper localization and activity also involve other factors such as UHRF1 during maintenance methylation, as well as chromatin context and developmentally regulated expression.

Clinical and biological significance

Mutations or dysregulation of DNMT3A are linked to hematologic malignancies such as acute myeloid leukemia, while alterations in DNMT3B can contribute to developmental disorders including ICF syndrome. Aberrant DNA methylation patterns involving these enzymes are implicated in various cancers and epigenetic diseases.

See also

DNA methyltransferase 3 (DNMT3A), DNMT3B, DNMT3L, epigenetic regulation.