Methylation pathway enzyme (None for the generic term. Individual enzymes have their own abbreviations (e.g., DNMT1 for DNA methyltransferase 1, MTHFR for methylenetetrahydrofolate reductase))

The term "methylation pathway enzyme" refers collectively to several classes of enzymes that catalyze the transfer of a methyl group (-CH₃) onto substrates such as DNA, RNA, proteins (notably histones), small molecules including neurotransmitters and toxins. These reactions are central to cellular processes including gene regulation via epigenetic modification (DNA/histone/protein/RNA), detoxification pathways involving heavy metals or xenobiotics, synthesis/metabolism of amino acids and neurotransmitters. Key families include DNA methyltransferases, which add a methyl group primarily at CpG dinucleotides affecting gene silencing; histone lysine/arginine N-methyltransferases, which modify chromatin structure; metabolic cycle regulators like methionine synthase, methylenetetrahydrofolate reductase, and others involved in one-carbon metabolism essential for nucleotide biosynthesis and homocysteine recycling. Dysregulation or mutation within these pathways can contribute to diverse pathologies ranging from cancer through cardiovascular disease to psychiatric illness due to altered gene expression profiles or metabolite imbalances.

Other names

DNA methyltransferase (DNMT)Histone methyltransferaseMethionine synthase (MTR)Methylenetetrahydrofolate reductase (MTHFR)Catechol-O-methyltransferase (COMT)

Varies by target: - Inhibition of enzymatic activity to alter epigenetic marks or neurotransmitter levels. - Supplementing cofactors/substrates to restore normal function.