GBGT1 (Globoside Alpha-1,3-N-Acetylgalactosaminyltransferase 1)
Key enzyme in the synthesis of the Forssman glycolipid antigen, with implications in blood group determination and cancer biology.
Gene Information Card
| Symbol | GBGT1 |
|---|---|
| Full Name | Globoside Alpha-1,3-N-Acetylgalactosaminyltransferase 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 9q34.13 |
| NCBI Gene ID | 2760 ncbi.nlm.nih.gov/gene/2760 |
| Ensembl ID | ENSG00000148400 |
| UniProt ID | Q8N5D0 |
| OMIM ID | 606074 |
| HGNC ID | 19091 |
| Aliases | FS, Forssman glycolipid synthetase, Gb3/CtxB synthase |
Description
The GBGT1 gene encodes globoside alpha-1,3-N-acetylgalactosaminyltransferase 1, a glycosyltransferase enzyme that catalyzes the transfer of N-acetylgalactosamine to globotriaosylceramide (Gb3) to form globoside (Gb4) and the Forssman antigen. This enzyme is critical for the synthesis of certain glycosphingolipids on cell surfaces, influencing blood group antigenicity and cellular recognition. GBGT1 expression is normally restricted to certain tissues, but its aberrant expression has been observed in various cancers, where it contributes to tumor progression and immune evasion.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Forssman antigen expression in cancer | Aberrant GBGT1 expression leads to Forssman antigen synthesis on tumor cells, potentially altering immune recognition and promoting metastasis. | COSMIC; PubMed studies (e.g., 10.1002/ijc.2910550310) |
| Blood group-related incompatibility | Polymorphisms in GBGT1 can affect the expression of the Forssman antigen, which may be relevant in transfusion medicine and transplantation. | OMIM 606074; PubMed (e.g., 10.1111/j.1423-0410.2004.00593.x) |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Colon | 0.0 | Not detected |
| Kidney | 0.0 | Not detected |
| Liver | 0.0 | Not detected |
| Lung | 0.0 | Not detected |
| Spleen | 0.0 | Not detected |
| Testis | 0.0 | Not detected |
| Thyroid | 0.0 | Not detected |
| Prostate | 0.0 | Not detected |
| Breast | 0.0 | Not detected |
| Skin | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 0.0 | Not detected |
| MCF7 | 0.0 | Not detected |
| A549 | 0.0 | Not detected |
| HepG2 | 0.0 | Not detected |
| K562 | 0.0 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.887G>A (p.Arg296His) | Missense | Rare (MAF <0.01) | May affect enzyme activity; reported in ClinVar as variant of uncertain significance. |
| c.1042C>T (p.Arg348Ter) | Nonsense | Rare | Predicted to cause loss of function via nonsense-mediated decay; not clinically validated. |
Mutation functional classification
Loss of Function (LOF)
Loss-of-function mutations in GBGT1 are rare and may lead to absence of Forssman antigen, but no clear disease phenotype has been established in humans.
Gain of Function (GOF)
Gain-of-function is not well-documented; overexpression in cancer is likely due to transcriptional dysregulation rather than activating mutations.
Dominant Negative (DN)
No evidence for dominant-negative effects of GBGT1 mutations.
View complete mutation data：
Gene Ontology (GO)
| • N-acetylgalactosaminyltransferase activity | • glycosyltransferase activity |
| • metal ion binding | • Golgi membrane |
| • integral component of membrane | • carbohydrate metabolic process |
| • glycosphingolipid biosynthetic process |
Pathways
• Glycosphingolipid biosynthesis - globo and isoglobo series (KEGG: hsa00603)
• Metabolism of glycosphingolipids (Reactome: R-HSA-1660661)
Protein Summary
The GBGT1 protein is a type II membrane protein localized to the Golgi apparatus. It contains a conserved glycosyltransferase domain (GT-A fold) and requires divalent metal ions (e.g., Mn2+) for catalytic activity. The enzyme transfers N-acetylgalactosamine from UDP-GalNAc to globotriaosylceramide (Gb3) to produce globoside (Gb4), and also synthesizes the Forssman antigen from Gb4. Its expression is tightly regulated, and ectopic expression in tumors can lead to the appearance of the Forssman antigen, which is a potential target for cancer immunotherapy.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GBGT1 Knockout HEK293 Cell Line | EDJ-KQ51179 | Human | 26301 | Details Get a Quote |
| GBGT1 Knockout HeLa Cell Line | EDJ-KQ55929 | Human | 26301 | Details Get a Quote |
| GBGT1 Knockout A-549 Cell Line | EDJ-KQ64416 | Human | 26301 | Details Get a Quote |
| GBGT1 Knockout HCT 116 Cell Line | EDJ-KQ72870 | Human | 26301 | Details Get a Quote |
