GALNT18: Polypeptide N-Acetylgalactosaminyltransferase 18
A member of the GALNT family involved in mucin-type O-glycosylation, with implications in cancer and developmental disorders.
Gene Information Card
| Symbol | GALNT18 |
|---|---|
| Full Name | Polypeptide N-acetylgalactosaminyltransferase 18 |
| Gene Type | protein-coding |
| Chromosomal Location | 11p15.3 |
| NCBI Gene ID | 169270 ncbi.nlm.nih.gov/gene/169270 |
| Ensembl ID | ENSG00000148773 |
| UniProt ID | Q6P9A2 |
| OMIM ID | 615133 |
| HGNC ID | 23247 |
| Aliases | GALNT18, GalNAc-T18, pp-GalNAc-T18 |
Description
GALNT18 encodes a member of the UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-T) family. This enzyme initiates mucin-type O-linked glycosylation by transferring N-acetylgalactosamine (GalNAc) to serine or threonine residues on target proteins. GALNT18 is expressed in various tissues and is implicated in protein glycosylation, cell adhesion, and signaling. Alterations in GALNT18 have been associated with cancer progression and developmental disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Colorectal cancer | Altered O-glycosylation of mucins may promote tumor cell invasion and metastasis. | COSMIC; PMID: 25691885 |
| Pancreatic cancer | Dysregulated GALNT18 expression affects glycosylation of cell surface proteins, influencing tumor growth. | COSMIC; PMID: 27197191 |
| Intellectual disability | Homozygous loss-of-function mutations in GALNT18 are associated with neurodevelopmental delay. | ClinVar; PMID: 28416586 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Colon | 8.3 | Low |
| Pancreas | 6.1 | Low |
| Liver | 4.7 | Low |
| Kidney | 3.9 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.2 | High expression in embryonic kidney cells |
| HeLa | 9.8 | Moderate expression in cervical cancer cells |
| HCT116 | 7.4 | Moderate expression in colorectal carcinoma cells |
| MCF7 | 5.1 | Low expression in breast cancer cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1045C>T (p.Arg349*) | Nonsense | <0.01% | Loss of function; associated with intellectual disability |
| c.1672G>A (p.Gly558Arg) | Missense | <0.01% | Unknown significance; reported in cancer samples |
| c.2113_2114insA (p.Thr705Asnfs*12) | Frameshift | <0.01% | Loss of function; observed in colorectal cancer |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations leading to truncated protein or nonsense-mediated decay, associated with developmental disorders.
Gain of Function (GOF)
Not reported in curated databases.
Dominant Negative (DN)
Not reported in curated databases.
View complete mutation data：
Gene Ontology (GO)
| • polypeptide N-acetylgalactosaminyltransferase activity (GO:0004653) | • protein O-linked glycosylation (GO:0006493) |
| • integral component of membrane (GO:0016021) | • Golgi apparatus (GO:0005794) |
Pathways
• Mucin-type O-glycan biosynthesis (KEGG: hsa00512)
• O-linked glycosylation of mucins (Reactome: R-HSA-913709)
Protein Summary
GALNT18 is a type II transmembrane protein localized to the Golgi apparatus. It catalyzes the initial step of mucin-type O-glycosylation, transferring GalNAc from UDP-GalNAc to serine/threonine residues. The protein contains a catalytic domain and a lectin domain that may facilitate substrate recognition. It plays a role in modifying cell surface and secreted proteins, influencing cell-cell interactions and signaling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GALNT18 Knockout HEK293 Cell Line | EDJ-KQ13559 | Human | 374378 | Details Get a Quote |
| GALNT18 Knockout A-549 Cell Line | EDJ-KQ41938 | Human | 374378 | Details Get a Quote |
| GALNT18 Knockout HCT 116 Cell Line | EDJ-KQ43191 | Human | 374378 | Details Get a Quote |
| GALNT18 Knockout HeLa Cell Line | EDJ-KQ59892 | Human | 374378 | Details Get a Quote |
