C1GALT1: Core 1 Synthase, Glycoprotein-N-Acetylgalactosamine 3-Beta-Galactosyltransferase 1
Key enzyme in mucin-type O-glycosylation; implicated in IgA nephropathy, cancer, and thrombocytopenia.
Gene Information Card
| Symbol | C1GALT1 |
|---|---|
| Full Name | Core 1 Synthase, Glycoprotein-N-Acetylgalactosamine 3-Beta-Galactosyltransferase 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 7p21.3 |
| NCBI Gene ID | 56913 ncbi.nlm.nih.gov/gene/56913 |
| Ensembl ID | ENSG00000106384 |
| UniProt ID | Q9NS00 |
| OMIM ID | 610555 |
| HGNC ID | 17937 |
| Aliases | T-synthase, C1GALT, core 1 beta3-Gal-T, GalNAc alpha2,6-sialyltransferase |
Description
C1GALT1 encodes the core 1 beta1,3-galactosyltransferase (T-synthase), which transfers galactose from UDP-galactose to N-acetylgalactosamine (GalNAc) to form the core 1 O-glycan (T antigen). This enzyme is essential for normal mucin-type O-glycosylation. Loss of function leads to expression of the Tn antigen, a cancer-associated glycan. Mutations in C1GALT1 are linked to IgA nephropathy (Berger's disease) and altered immune responses.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| IgA nephropathy (Berger's disease) | Reduced C1GALT1 activity leads to undergalactosylated IgA1, which forms immune complexes and deposits in glomeruli. | OMIM 610555; multiple case-control studies |
| Colorectal cancer | Aberrant O-glycosylation due to C1GALT1 downregulation promotes tumor progression and metastasis. | COSMIC; PMID: 23431147 |
| Thrombocytopenia (rare) | Defective O-glycosylation on platelet glycoproteins affects platelet function. | ClinVar; PMID: 23934620 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Colon | 28.5 | High |
| Stomach | 22.1 | High |
| Small intestine | 19.8 | Medium |
| Kidney | 15.3 | Medium |
| Liver | 8.2 | Low |
| Brain | 3.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 35.2 | High expression |
| HeLa | 28.7 | High expression |
| HCT 116 | 42.1 | Very high expression |
| K562 | 12.4 | Moderate expression |
| HepG2 | 9.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.800G>A (p.Arg267Gln) | Missense | 0.02% (gnomAD) | Reduced enzyme activity; associated with IgA nephropathy |
| c.1042C>T (p.Arg348Trp) | Missense | <0.01% | Loss of function; Tn antigen exposure |
| c.1186C>T (p.Arg396Cys) | Missense | 0.005% | Impaired galactosyltransferase activity |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Arg267Gln, p.Arg348Trp) reduce or abolish galactosyltransferase activity, leading to Tn antigen accumulation.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • galactosyltransferase activity (GO:0008378) | • protein glycosylation (GO:0006486) |
| • Golgi apparatus (GO:0005794) | • transferase activity (GO:0016757) |
Pathways
• Mucin-type O-glycan biosynthesis (KEGG: hsa00512)
• O-linked glycosylation (Reactome: R-HSA-5173105)
Protein Summary
C1GALT1 (T-synthase) is a 363-amino acid type II transmembrane protein localized to the Golgi apparatus. It catalyzes the addition of galactose to GalNAc-Ser/Thr to form core 1 O-glycans (T antigen). The enzyme requires the molecular chaperone COSMC (C1GALT1C1) for proper folding and activity. Loss of C1GALT1 function results in expression of the truncated Tn antigen, a hallmark of many carcinomas and a driver of IgA nephropathy.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| C1GALT1 Knockout HEK293 Cell Line | EDJ-KQ3097 | Human | 56913 | Details Get a Quote |
| C1GALT1C1 Knockout HEK293 Cell Line | EDJ-KQ3969 | Human | 29071 | Details Get a Quote |
| C1GALT1C1L Knockout HEK293 Cell Line | EDJ-KQ12583 | Human | 728819 | Details Get a Quote |
| C1GALT1 Knockout A-549 Cell Line | EDJ-KQ24420 | Human | 56913 | Details Get a Quote |
| C1GALT1 Knockout HCT 116 Cell Line | EDJ-KQ24421 | Human | 56913 | Details Get a Quote |
| C1GALT1 Knockout HeLa Cell Line | EDJ-KQ24422 | Human | 56913 | Details Get a Quote |
| C1GALT1C1 Knockout A-549 Cell Line | EDJ-KQ26247 | Human | 29071 | Details Get a Quote |
| C1GALT1C1 Knockout HCT 116 Cell Line | EDJ-KQ26248 | Human | 29071 | Details Get a Quote |
| C1GALT1C1 Knockout HeLa Cell Line | EDJ-KQ26249 | Human | 29071 | Details Get a Quote |
| C1GALT1C1L Knockout HeLa Cell Line | EDJ-KQ40312 | Human | 728819 | Details Get a Quote |
| C1GALT1C1L Knockout A-549 Cell Line | EDJ-KQ41609 | Human | 728819 | Details Get a Quote |
| C1GALT1C1L Knockout HCT 116 Cell Line | EDJ-KQ77550 | Human | 728819 | Details Get a Quote |
