MGAT3: Mannosyl (Alpha-1,3-)-Glycoprotein Beta-1,4-N-Acetylglucosaminyltransferase
Key enzyme in the biosynthesis of hybrid and complex N-glycans, involved in cell adhesion and cancer progression.
Gene Information Card
| Symbol | MGAT3 |
|---|---|
| Full Name | Mannosyl (Alpha-1,3-)-Glycoprotein Beta-1,4-N-Acetylglucosaminyltransferase |
| Gene Type | protein-coding |
| Chromosomal Location | 22q13.1 |
| NCBI Gene ID | 4248 ncbi.nlm.nih.gov/gene/4248 |
| Ensembl ID | ENSG00000128272 |
| UniProt ID | Q09327 |
| OMIM ID | 604034 |
| HGNC ID | 7046 |
| Aliases | GNT-III, GNT3, GnT-III |
Description
The MGAT3 gene encodes beta-1,4-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase (GnT-III), a Golgi enzyme that catalyzes the addition of a bisecting N-acetylglucosamine (GlcNAc) residue to the core mannose of N-glycans. This modification alters glycan conformation and modulates the function of glycoproteins involved in cell adhesion, migration, and signaling. MGAT3 expression is frequently altered in cancer and inflammatory diseases.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hepatocellular carcinoma | Reduced MGAT3 expression leads to altered N-glycosylation of E-cadherin, promoting cell migration and invasion. | PMID: 23454750 |
| Colorectal cancer | Loss of bisecting GlcNAc due to MGAT3 downregulation correlates with increased metastasis and poor prognosis. | PMID: 25670082 |
| Breast cancer | MGAT3 overexpression suppresses tumor growth by modifying EGFR glycosylation and signaling. | PMID: 21145416 |
| Rheumatoid arthritis | MGAT3 expression is upregulated in synovial fibroblasts, affecting integrin-mediated adhesion. | PMID: 17374726 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 5.2 | Medium |
| Kidney | 3.8 | Low |
| Brain | 2.1 | Low |
| Placenta | 6.7 | Medium |
| Lung | 1.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 4.9 | Hepatocellular carcinoma cell line |
| MCF7 | 3.2 | Breast cancer cell line |
| A549 | 1.8 | Lung carcinoma cell line |
| HEK293 | 2.5 | Embryonic kidney cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Loss of start codon; likely loss of function |
| c.104C>T (p.Pro35Leu) | Missense | <0.01% | Unknown functional effect |
| c.682G>A (p.Gly228Arg) | Missense | <0.01% | Reported in COSMIC; potential impact on enzyme activity |
Mutation functional classification
Loss of Function (LOF)
Mutations that abolish start codon or disrupt catalytic domain are predicted to reduce or eliminate GnT-III activity, leading to altered N-glycan profiles.
Gain of Function (GOF)
No documented gain-of-function mutations in MGAT3.
Dominant Negative (DN)
No evidence of dominant-negative effects for MGAT3 mutations.
View complete mutation data：
Gene Ontology (GO)
| • acetylglucosaminyltransferase activity (GO:0008375) | • Golgi apparatus (GO:0005794) |
| • protein N-linked glycosylation (GO:0006487) | • glycosyltransferase activity (GO:0016757) |
Pathways
• N-Glycan biosynthesis (KEGG: hsa00510)
• Biosynthesis of N-glycan antennae (Reactome: R-HSA-975578)
Protein Summary
GnT-III is a type II transmembrane glycoprotein localized to the Golgi apparatus. It transfers N-acetylglucosamine from UDP-GlcNAc to the beta-linked mannose of the N-glycan core, creating a bisecting GlcNAc structure. This modification inhibits further processing by other glycosyltransferases, thereby regulating the branching and complexity of N-glycans. GnT-III plays a critical role in cell-cell adhesion, receptor signaling, and cancer metastasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MGAT3 Knockout HEK293 Cell Line | EDJ-KQ5207 | Human | 4248 | Details Get a Quote |
| MGAT3 Knockout HeLa Cell Line | EDJ-KQ53869 | Human | 4248 | Details Get a Quote |
| MGAT3 Knockout A-549 Cell Line | EDJ-KQ62357 | Human | 4248 | Details Get a Quote |
| MGAT3 Knockout HCT 116 Cell Line | EDJ-KQ70827 | Human | 4248 | Details Get a Quote |
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