MAT1A: Methionine Adenosyltransferase 1A
Key enzyme in methionine metabolism and liver function
Gene Information Card
| Symbol | MAT1A |
|---|---|
| Full Name | Methionine Adenosyltransferase 1A |
| Gene Type | Protein coding |
| Chromosomal Location | 10q22.3 |
| NCBI Gene ID | 4143 ncbi.nlm.nih.gov/gene/4143 |
| Ensembl ID | ENSG00000151224 |
| UniProt ID | Q00266 |
| OMIM ID | 610550 |
| HGNC ID | 6903 |
| Aliases | MAT, MATA1, SAMS1, MATI, MATII |
Description
The MAT1A gene encodes the catalytic subunit of methionine adenosyltransferase (MAT), which catalyzes the formation of S-adenosylmethionine (SAMe) from methionine and ATP. SAMe is a key methyl donor in numerous methylation reactions and is essential for liver health, polyamine synthesis, and transsulfuration pathways. MAT1A is predominantly expressed in adult liver, and its deficiency leads to hypermethioninemia and increased risk of liver injury.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hypermethioninemia due to MAT1A deficiency | Loss-of-function mutations in MAT1A reduce MAT activity, causing accumulation of methionine in blood and urine. | OMIM #250850; ClinVar |
| Hepatocellular carcinoma | Downregulation or epigenetic silencing of MAT1A in liver tumors reduces SAMe levels, promoting cell proliferation and dedifferentiation. | NCBI Gene; COSMIC |
| Liver cirrhosis | Reduced MAT1A expression correlates with decreased SAMe and increased oxidative stress in fibrotic liver. | UniProt; PubMed studies |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 89.2 | High |
| Pancreas | 1.5 | Low |
| Kidney | 0.8 | Low |
| Brain | 0.3 | Not detected |
| Heart | 0.2 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 112.5 | Hepatocellular carcinoma cell line |
| Huh7 | 95.3 | Hepatoma cell line |
| HEK293 | 0.4 | Embryonic kidney cells; low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.791G>A (p.Arg264His) | Missense | Common in hypermethioninemia | Reduces MAT activity by ~80% |
| c.1069G>A (p.Gly357Arg) | Missense | Rare | Loss of catalytic function |
| c.1135C>T (p.Arg379Cys) | Missense | Reported in liver cancer | Dominant-negative effect on MAT activity |
Mutation functional classification
Loss of Function (LOF)
Most MAT1A mutations (e.g., p.Arg264His, p.Gly357Arg) reduce or abolish enzymatic activity, leading to hypermethioninemia.
Gain of Function (GOF)
No known gain-of-function mutations reported in MAT1A.
Dominant Negative (DN)
p.Arg379Cys is proposed to exert a dominant-negative effect, interfering with wild-type MAT1A function in heterozygous state.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Methionine metabolism (KEGG: hsa00270)
• S-adenosylmethionine (SAMe) cycle
• Transsulfuration pathway
Protein Summary
MAT1A encodes the alpha 1 catalytic subunit of methionine adenosyltransferase, a homotetrameric enzyme that converts methionine and ATP to S-adenosylmethionine (SAMe). The protein is 395 amino acids long and is primarily expressed in adult liver. It plays a critical role in methylation, polyamine synthesis, and antioxidant defense. Mutations cause hypermethioninemia, and reduced expression is linked to liver carcinogenesis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MAT1A Knockout HEK293 Cell Line | EDJ-KQ5181 | Human | 4143 | Details Get a Quote |
| MAT1A Knockout HCT 116 Cell Line | EDJ-KQ26935 | Human | 4143 | Details Get a Quote |
| MAT1A Knockout HeLa Cell Line | EDJ-KQ53842 | Human | 4143 | Details Get a Quote |
| MAT1A Knockout A-549 Cell Line | EDJ-KQ62328 | Human | 4143 | Details Get a Quote |
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