MAT2B: Methionine Adenosyltransferase 2B
A regulatory subunit of methionine adenosyltransferase, involved in methionine metabolism and linked to liver disease and cancer.
Gene Information Card
| Symbol | MAT2B |
|---|---|
| Full Name | methionine adenosyltransferase 2B |
| Gene Type | protein-coding |
| Chromosomal Location | 5q34 |
| NCBI Gene ID | 27430 ncbi.nlm.nih.gov/gene/27430 |
| Ensembl ID | ENSG00000113522 |
| UniProt ID | Q9NZL9 |
| OMIM ID | 605583 |
| HGNC ID | 6904 |
| Aliases | MAT II beta, Nbla02991, SDR23E1, MGC1387 |
Description
MAT2B encodes the beta regulatory subunit of methionine adenosyltransferase (MAT) II, which catalyzes the synthesis of S-adenosylmethionine (SAMe) from methionine and ATP. This subunit modulates the catalytic activity of the alpha subunit (MAT2A) and is involved in methionine metabolism, cell proliferation, and differentiation. MAT2B is overexpressed in various cancers, particularly hepatocellular carcinoma, and is implicated in liver disease.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hepatocellular carcinoma | Overexpression of MAT2B promotes cell proliferation and inhibits apoptosis via SAMe-dependent and independent pathways. | PMID: 15601830; NCBI Gene |
| Liver cirrhosis | Altered MAT2B expression contributes to disrupted methionine metabolism and hepatic fibrosis. | PMID: 15601830 |
| Colorectal cancer | MAT2B upregulation associated with poor prognosis and increased tumor growth. | COSMIC; PMID: 23431147 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Kidney | 8.3 | Low |
| Testis | 6.1 | Low |
| Pancreas | 5.4 | Low |
| Lung | 4.2 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 15.2 | Hepatocellular carcinoma cell line |
| HEK293 | 9.8 | Embryonic kidney cells |
| HeLa | 7.1 | Cervical cancer cells |
| A549 | 5.6 | Lung carcinoma cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G | missense | 0.01% | p.Met1Val; potential loss of start codon |
| c.214C>T | missense | 0.02% | p.Arg72Cys; unknown significance |
| c.487G>A | missense | 0.005% | p.Gly163Ser; reported in COSMIC |
Mutation functional classification
Loss of Function (LOF)
Mutations disrupting the start codon or critical residues may reduce MAT2B protein levels or impair regulatory function.
Gain of Function (GOF)
Not well characterized; overexpression in cancer suggests potential gain-of-function via increased SAMe synthesis.
Dominant Negative (DN)
No dominant-negative mutations reported for MAT2B.
View complete mutation data：
Gene Ontology (GO)
| • methionine adenosyltransferase activity (GO:0004478) | • S-adenosylmethionine biosynthetic process (GO:0006556) |
| • cytoplasm (GO:0005737) | • cytosol (GO:0005829) |
Pathways
• Methionine metabolism (KEGG: hsa00270)
• S-adenosylmethionine (SAMe) cycle
Protein Summary
MAT2B is a 334-amino acid protein (UniProt Q9NZL9) that functions as a regulatory subunit of methionine adenosyltransferase II. It forms a hetero-oligomeric complex with the catalytic MAT2A subunit, enhancing its stability and modulating its activity. The protein contains a short-chain dehydrogenase/reductase (SDR) domain, though its enzymatic role is unclear. MAT2B is predominantly cytosolic and highly expressed in liver and kidney.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MAT2B Knockout HEK293 Cell Line | EDJ-KQ2894 | Human | 27430 | Details Get a Quote |
| MAT2B Knockout A-549 Cell Line | EDJ-KQ23967 | Human | 27430 | Details Get a Quote |
| MAT2B Knockout HCT 116 Cell Line | EDJ-KQ23968 | Human | 27430 | Details Get a Quote |
| MAT2B Knockout HeLa Cell Line | EDJ-KQ23969 | Human | 27430 | Details Get a Quote |
