DNMT3L

DNMT3L, or DNA methyltransferase 3 like, is a protein that plays a crucial role in epigenetics, particularly in the establishment of DNA methylation patterns. It is a regulatory protein that lacks intrinsic catalytic activity, meaning it cannot directly add methyl groups to DNA itself. Instead, DNMT3L interacts with and stimulates the activity of DNA methyltransferases (DNMTs), specifically DNMT3A and DNMT3B. These DNMTs are responsible for de novo methylation, the process of establishing new methylation marks on DNA, which is essential for processes like embryonic development and silencing of transposable elements.

The expression of DNMT3L is particularly high during gametogenesis and early embryogenesis. In germ cells, it is critical for reprogramming the DNA methylation landscape, setting up appropriate methylation patterns for sperm and egg. During early embryonic development, it assists DNMT3A and DNMT3B in methylating the genome, which is vital for cell differentiation and maintaining genomic stability. Mutations or dysregulation of DNMT3L have been linked to various developmental abnormalities and diseases, including certain types of cancer and developmental disorders. Its interaction with DNMTs and its role in establishing methylation patterns make DNMT3L a key player in the complex epigenetic machinery that governs gene expression and cellular identity.