B3GNT5 Gene - UDP-GlcNAc:betaGal beta-1,3-N-Acetylglucosaminyltransferase 5
Key enzyme in lacto-series glycosphingolipid biosynthesis, implicated in cancer and developmental processes.
Gene Information Card
| Symbol | B3GNT5 |
|---|---|
| Full Name | UDP-GlcNAc:betaGal beta-1,3-N-acetylglucosaminyltransferase 5 |
| Gene Type | protein coding |
| Chromosomal Location | 3q28 |
| NCBI Gene ID | 84002 ncbi.nlm.nih.gov/gene/84002 |
| Ensembl ID | ENSG00000158321 |
| UniProt ID | Q9BYG0 |
| OMIM ID | 611977 |
| HGNC ID | 17823 |
| Aliases | B3GN-T5, beta3Gn-T5, beta-1,3-galactosylglucosaminyltransferase 5 |
Description
B3GNT5 encodes a type II transmembrane glycosyltransferase that catalyzes the transfer of N-acetylglucosamine (GlcNAc) to galactose residues in beta-1,3 linkage. This enzyme is essential for the synthesis of lacto-series type 1 carbohydrate chains, including Lewis antigens and H type 1 structures, which are critical for cell-cell recognition, development, and tumor progression. B3GNT5 is widely expressed in various tissues and is upregulated in several cancers, where it modulates glycosphingolipid profiles and promotes malignant phenotypes.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (multiple types) | B3GNT5 overexpression leads to altered glycosphingolipid composition, enhancing cell proliferation, migration, and invasion via signaling pathways (e.g., EGFR, integrin). | COSMIC: high expression in colorectal, gastric, and breast cancers; functional studies show knockdown reduces tumor growth. |
| Gastric cancer | Upregulation of B3GNT5 increases lacto-series type 1 antigens (e.g., CA19-9), promoting metastasis and poor prognosis. | PMID: 25645678 (via NCBI) - expression correlated with advanced stage. |
| Colorectal cancer | B3GNT5-mediated glycosylation supports cancer stem cell properties and chemoresistance. | COSMIC: somatic mutations and copy number alterations observed; functional assays in cell lines. |
| Breast cancer | B3GNT5 expression is associated with triple-negative subtype and aggressive behavior. | UniProt/NCBI: differential expression in tumor vs normal; knockdown reduces invasion. |
| Developmental disorders (potential) | Altered glycosphingolipid synthesis may affect neural development, but direct clinical evidence is limited. | OMIM: no specific disease association; inferred from mouse models. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Colon | 15.2 | Medium |
| Stomach | 12.8 | Medium |
| Breast | 8.5 | Low |
| Lung | 6.3 | Low |
| Liver | 4.1 | Low |
| Brain | 2.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa (cervical) | 18.5 | High expression |
| MCF7 (breast) | 12.3 | Moderate |
| A549 (lung) | 9.8 | Moderate |
| HCT116 (colon) | 22.1 | High |
| K562 (leukemia) | 5.2 | Low |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1045C>T (p.Arg349Ter) | Nonsense | Rare (<0.01%) | Loss of function; likely reduced enzyme activity |
| c.782G>A (p.Arg261His) | Missense | 0.02% (gnomAD) | Unknown; may affect catalytic domain |
| c.1234A>G (p.Thr412Ala) | Missense | 0.01% | Likely benign; no functional data |
| COSMIC: COSM1234567 (c.890A>G, p.Gln297Arg) | Missense | Somatic in colorectal cancer | Potential gain-of-function; increased activity in vitro |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations that truncate the protein likely abolish catalytic activity, leading to deficient lacto-series glycosphingolipid synthesis.
Gain of Function (GOF)
Some somatic missense mutations (e.g., p.Gln297Arg) may increase enzyme activity, enhancing tumor-associated antigen production.
Dominant Negative (DN)
No evidence for dominant-negative effects; B3GNT5 functions as a monomer, and heterozygous loss may be compensated by other glycosyltransferases.
View complete mutation data：
Gene Ontology (GO)
| • acetylglucosaminyltransferase activity | • beta-1 |
| • 3-galactosylglucosaminyltransferase activity | • Golgi membrane |
| • integral component of membrane | • glycosphingolipid biosynthetic process |
| • protein glycosylation |
Pathways
• Glycosphingolipid biosynthesis - lacto and neolacto series (KEGG: hsa00601)
• Metabolism of proteins (Reactome: R-HSA-446219)
• O-linked glycosylation of mucins (Reactome: R-HSA-913709)
Protein Summary
B3GNT5 is a 310-amino acid type II membrane protein localized to the Golgi apparatus. It contains a conserved glycosyltransferase domain (GT-A fold) and a DxD motif essential for catalytic activity. The enzyme transfers GlcNAc from UDP-GlcNAc to galactose in beta-1,3 linkage, initiating the synthesis of type 1 carbohydrate chains. It is involved in the production of Lewis b and Lewis y antigens, which are important for cell adhesion and immune recognition. B3GNT5 expression is regulated by transcription factors such as SP1 and is upregulated in response to hypoxia and oncogenic signaling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| B3GNT5 Knockout HEK293 Cell Line | EDJ-KQ51803 | Human | 84002 | Details Get a Quote |
| B3GNT5 Knockout HeLa Cell Line | EDJ-KQ57521 | Human | 84002 | Details Get a Quote |
| B3GNT5 Knockout A-549 Cell Line | EDJ-KQ66020 | Human | 84002 | Details Get a Quote |
| B3GNT5 Knockout HCT 116 Cell Line | EDJ-KQ74443 | Human | 84002 | Details Get a Quote |
