MGAT4A
Alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase A
Gene Information Card
| Symbol | MGAT4A |
|---|---|
| Full Name | Alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase A |
| Gene Type | protein-coding |
| Chromosomal Location | 2q11.2 |
| NCBI Gene ID | 11320 ncbi.nlm.nih.gov/gene/11320 |
| Ensembl ID | ENSG00000171094 |
| UniProt ID | Q9UM21 |
| OMIM ID | 604623 |
| HGNC ID | 7049 |
| Aliases | GNT-IV, GNT-IVA, GnT-4a, N-acetylglucosaminyltransferase IV-A |
Description
MGAT4A encodes a Golgi enzyme that catalyzes the transfer of N-acetylglucosamine from UDP-GlcNAc to the core mannose residues of N-glycans, forming the GlcNAcβ1-4Manα1-3 branch. This modification is critical for glycoprotein maturation, cell adhesion, and receptor signaling. Mutations in MGAT4A cause congenital disorder of glycosylation type Ij (CDG-Ij), characterized by multisystem developmental abnormalities.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital disorder of glycosylation type Ij (CDG-Ij) | Loss-of-function mutations impair N-glycan branching, leading to defective glycoprotein trafficking and function. | ClinVar, OMIM |
| Colorectal cancer | Altered MGAT4A expression affects E-cadherin glycosylation and cell adhesion, promoting metastasis. | COSMIC, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Kidney | 9.8 | Medium |
| Brain | 6.2 | Low |
| Placenta | 15.3 | High |
| Lung | 4.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 18.7 | High expression |
| HepG2 | 22.1 | High expression |
| HeLa | 7.5 | Medium expression |
| A549 | 3.2 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.103C>T (p.Arg35Ter) | Nonsense | <0.01% | Loss of function; associated with CDG-Ij |
| c.742G>A (p.Gly248Arg) | Missense | <0.01% | Impaired enzymatic activity; CDG-Ij |
| c.1265_1266del (p.Gln422ArgfsTer5) | Frameshift | <0.01% | Truncated protein; loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense, frameshift, and missense mutations that reduce or abolish GlcNAc transferase activity are associated with CDG-Ij.
Gain of Function (GOF)
Not reported in MGAT4A.
Dominant Negative (DN)
Not reported in MGAT4A.
View complete mutation data：
Gene Ontology (GO)
| • N-acetylglucosaminyltransferase activity (GO:0008375) | • Golgi membrane (GO:0000139) |
| • protein N-linked glycosylation (GO:0006487) | • transferring glycosyl groups (GO:0016757) |
Pathways
• N-glycan biosynthesis (KEGG: hsa00510)
• Metabolism of carbohydrates (Reactome: R-HSA-71387)
Protein Summary
MGAT4A encodes a 535-amino acid type II transmembrane protein localized to the Golgi apparatus. It functions as a homodimer and requires Mn2+ for activity. The enzyme adds a GlcNAc residue to the Manα1-3 arm of the N-glycan core, generating tri- and tetra-antennary structures. These branched glycans modulate glycoprotein half-life, receptor binding, and cell-cell interactions.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MGAT4A Knockout HEK293 Cell Line | EDJ-KQ7369 | Human | 11320 | Details Get a Quote |
| MGAT4A Knockout A-549 Cell Line | EDJ-KQ32485 | Human | 11320 | Details Get a Quote |
| MGAT4A Knockout HCT 116 Cell Line | EDJ-KQ32486 | Human | 11320 | Details Get a Quote |
| MGAT4A Knockout HeLa Cell Line | EDJ-KQ55630 | Human | 11320 | Details Get a Quote |
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