MAT1

MAT1 is a gene symbol designation that has been applied to several distinct genetic elements in different organisms. Because of this, MAT1 does not refer to a single gene or protein. The meaning of MAT1 depends on the lineage and context.

In many fungi and related organisms, the MAT1 locus is the mating-type region that governs sexual compatibility and development. It typically exists in alternative alleles, such as MAT1-1 and MAT1-2, which encode transcription factors that regulate pheromone signaling, meiosis, and other aspects of mating. The MAT locus is species-specific in structure and regulation, but its general function is to determine mating identity and to ensure that sexual reproduction occurs between compatible partners.

In humans and other vertebrates, the closest commonly studied gene with a similar designation is MAT1A, encoding the catalytic subunit of methionine adenosyltransferase I. This enzyme catalyzes the synthesis of S-adenosylmethionine, a universal methyl donor used in methylation reactions and other metabolic processes. MAT1A expression is primarily hepatic, whereas a paralog, MAT2A, has broader tissue expression and is regulated differently. Dysregulation of MAT1A and related genes has been linked to liver disease and hepatocellular carcinoma.

Because MAT1 is used for multiple, unrelated purposes, readers should consult organism- and gene-specific sources to determine the precise entity referred to by MAT1 in a given context.