Methionine adenosyltransferase 1A (MAT1A)

Methionine adenosyltransferase 1A (MAT1A) is a liver-specific enzyme that catalyzes the formation of S-adenosylmethionine (SAMe) from methionine and ATP, a critical reaction providing the cell’s principal methyl donor for a wide range of biological methylation reactions, including DNA, RNA, protein, and lipid methylation[2][3][4]. MAT1A is predominantly expressed in adult liver and found as homotetrameric (MAT I) or homodimeric (MAT III) complexes[2][3]. It has crucial roles in liver function and mitochondrial health, beyond SAMe synthesis—it regulates gene expression directly and modulates protein abundance, e.g., downregulating mitochondrial CYP2E1 via methylation and proteasomal degradation, thereby affecting mitochondrial membrane potential and reactive oxygen species production[1]. Loss of MAT1A expression or enzyme activity is strongly linked to various liver diseases (alcoholic hepatitis, NAFLD, cirrhosis, hepatocellular carcinoma), and germline defects cause inherited hypermethioninemia syndromes[1][2][3]. MAT1A is an established biomarker and potential therapeutic target for diseases involving disrupted cellular methylation and liver dysfunction.

Other names

S-adenosylmethionine synthase isoform type-1AMS1MATA1AdoMet synthase 1MAT 1MAT-I/IIISAMSSAMS1Methionine adenosyltransferase IMethionine adenosyltransferase I/IIIS-adenosylmethionine synthetaseadoMet synthase 1adoMet synthetase 1methionine adenosyltransferase Ialpha

Modulation of S-adenosylmethionine synthesis; Maintenance of methylation-dependent cellular homeostasis; Regulation of expression and stability of methylation-sensitive proteins (e.g., CYP2E1)