Methionine Adenosyltransferase (MAT) (甲硫氨酸腺苷转移酶)

Methionine adenosyltransferases (MATs), also known as S-Adenosylmethionine synthetase, are essential enzymes for life as they catalyzes the synthesis of one of the most important and pivotal biological molecules, S-adenosyl-methionine. S-adenosyl-methionine is the biological methyl donor required for a plethora of reactions within the cell.Mammalian systems express two genes, MAT1A and MAT2A, which encode for MATα1 and MATα2, the catalytic subunits of the MAT isoenzymes, respectively. A third gene MAT2B, encodes a regulatory subunit known as MATβ which controls the activity of MATα2. MAT1A, which is mainly expressed in hepatocytes, maintains the differentiated state of these cells, whilst MAT2A and MAT2B are expressed in extrahepatic tissues as well as non-parenchymal cells of the liver (e.g., hepatic stellate and Kupffer cells).