GALNT9: Polypeptide N-Acetylgalactosaminyltransferase 9
A member of the UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase family involved in mucin-type O-glycosylation.
Gene Information Card
| Symbol | GALNT9 |
|---|---|
| Full Name | Polypeptide N-acetylgalactosaminyltransferase 9 |
| Gene Type | Protein coding |
| Chromosomal Location | 12q24.33 |
| NCBI Gene ID | 50614 ncbi.nlm.nih.gov/gene/50614 |
| Ensembl ID | ENSG00000182870 |
| UniProt ID | Q6L8Q7 |
| OMIM ID | 608251 |
| HGNC ID | 4127 |
| Aliases | GALNAC-T9, GalNAc-T9, pp-GalNAc-T9 |
Description
GALNT9 encodes a member of the UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-T) family. These enzymes catalyze the initial step of mucin-type O-linked glycosylation, transferring N-acetylgalactosamine (GalNAc) to serine or threonine residues on target proteins. GALNT9 is specifically expressed in the brain and testis and is involved in the regulation of protein function through O-glycosylation.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (various types) | Altered O-glycosylation patterns; GALNT9 expression changes may affect tumor progression and metastasis. | COSMIC database reports mutations in multiple cancer types; expression changes observed in breast, colorectal, and lung cancers. |
| Intellectual disability | Potential role in neurodevelopment; rare variants reported in patients with developmental delay. | ClinVar entries for missense variants of uncertain significance. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Testis | 8.3 | Medium |
| Thyroid | 3.1 | Low |
| Adrenal gland | 2.0 | Low |
| Liver | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 15.2 | High expression; neuronal origin |
| U-87 MG (glioblastoma) | 10.8 | Moderate expression |
| MCF7 (breast cancer) | 2.1 | Low expression |
| HEK293 (embryonic kidney) | 1.3 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1015C>T (p.Arg339Cys) | Missense | 0.01% (gnomAD) | Uncertain significance; may affect catalytic activity |
| c.1342G>A (p.Gly448Ser) | Missense | 0.005% (gnomAD) | Uncertain significance; reported in ClinVar |
| c.1720_1721insA (p.Thr574AsnfsTer5) | Frameshift | Rare | Loss of function; truncation of C-terminal domain |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations predicted to truncate the protein, likely abolishing enzymatic activity.
Gain of Function (GOF)
No evidence for gain-of-function mutations in GALNT9.
Dominant Negative (DN)
No known dominant-negative effects reported.
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 (Reactome: R-HSA-913709)
• O-linked glycosylation of mucins (KEGG: hsa00512)
Protein Summary
GALNT9 is a type II transmembrane protein localized to the Golgi apparatus. It catalyzes the transfer of GalNAc to serine/threonine residues, initiating mucin-type O-glycosylation. The protein contains a catalytic domain and a lectin domain that may facilitate substrate recognition. It is predominantly expressed in brain and testis, suggesting specialized roles in neuronal and reproductive tissues.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GALNT9 Knockout HEK293 Cell Line | EDJ-KQ10782 | Human | 50614 | Details Get a Quote |
| GALNT9 Knockout HeLa Cell Line | EDJ-KQ56172 | Human | 50614 | Details Get a Quote |
| GALNT9 Knockout A-549 Cell Line | EDJ-KQ64662 | Human | 50614 | Details Get a Quote |
| GALNT9 Knockout HCT 116 Cell Line | EDJ-KQ73111 | Human | 50614 | Details Get a Quote |
