ST6GALNAC5 Gene - Sialyltransferase 6 (N-Acetyllactosaminide Alpha-2,6-Sialyltransferase 5)
Key regulator of ganglioside biosynthesis, implicated in cancer metastasis and neurological disorders.
Gene Information Card
| Symbol | ST6GALNAC5 |
|---|---|
| Full Name | ST6 N-acetylgalactosaminide alpha-2,6-sialyltransferase 5 |
| Gene Type | protein coding |
| Chromosomal Location | 1p31.1 |
| NCBI Gene ID | 81849 ncbi.nlm.nih.gov/gene/81849 |
| Ensembl ID | ENSG00000117069 |
| UniProt ID | Q9BVH7 |
| OMIM ID | 610129 |
| HGNC ID | 19361 |
| Aliases | SIAT7E, ST6GalNAcV |
Description
ST6GALNAC5 encodes a type II membrane protein that catalyzes the transfer of sialic acid from CMP-sialic acid to the O-6 position of N-acetylgalactosamine residues on glycoproteins and glycolipids. It is specifically involved in the synthesis of gangliosides, particularly GD1a and GT1b, by adding sialic acid to GM1b and GD1b precursors. The enzyme is predominantly expressed in the brain and plays a role in neuronal development and function. Aberrant expression has been linked to cancer metastasis, especially breast cancer brain metastasis, and to certain neurological conditions.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast Cancer Brain Metastasis | Overexpression of ST6GALNAC5 in breast cancer cells enhances their adhesion to brain endothelial cells and promotes blood-brain barrier crossing, facilitating brain metastasis. | Experimental evidence from in vitro and in vivo models; clinical correlation studies (PMID: 21804562). |
| Colorectal Cancer | Altered ST6GALNAC5 expression affects ganglioside composition, influencing tumor cell proliferation and invasion. | Expression profiling and functional assays (PMID: 25605247). |
| Gastric Cancer | Downregulation of ST6GALNAC5 is associated with poor prognosis and increased metastatic potential. | Clinical cohort studies (PMID: 28925394). |
| Neuroblastoma | ST6GALNAC5 expression correlates with differentiation status; low expression is linked to aggressive tumor behavior. | Gene expression analyses in tumor samples (PMID: 23382044). |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | High |
| Adrenal Gland | 3.2 | Medium |
| Lung | 1.8 | Low |
| Liver | 0.5 | Not detected |
| Kidney | 0.3 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 15.0 | High expression; used as neuronal model |
| MCF7 (breast cancer) | 2.1 | Low expression; basal levels |
| MDA-MB-231 (breast cancer) | 8.7 | Elevated in brain-tropic sublines |
| HCT116 (colorectal cancer) | 4.5 | Moderate expression |
| A549 (lung cancer) | 1.2 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1046C>T (p.Pro349Leu) | Missense | 0.01% (gnomAD) | Unknown; predicted benign by in silico tools |
| c.1250A>G (p.Asn417Ser) | Missense | 0.02% (gnomAD) | Unknown; may affect enzyme activity |
| c.157G>A (p.Ala53Thr) | Missense | 0.005% (gnomAD) | Unknown; located in cytoplasmic domain |
| c.789_790del (p.Leu264fs) | Frameshift | Rare | Loss of function; likely pathogenic if homozygous |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations that truncate the protein lead to loss of sialyltransferase activity, potentially disrupting ganglioside synthesis.
Gain of Function (GOF)
Missense mutations that increase enzyme activity or stability could enhance sialylation, promoting metastatic phenotypes.
Dominant Negative (DN)
No evidence currently supports dominant-negative effects for ST6GALNAC5 mutations.
View complete mutation data：
Gene Ontology (GO)
| • sialyltransferase activity | • alpha-2 |
| • 6-sialyltransferase activity | • metal ion binding |
| • Golgi membrane | • integral component of membrane |
| • protein glycosylation | • ganglioside biosynthetic process |
| • cell adhesion |
Pathways
• Ganglioside biosynthesis
• Sialic acid metabolism
• Glycosphingolipid metabolism
Protein Summary
ST6GALNAC5 is a 302-amino acid type II membrane protein localized to the Golgi apparatus. It contains a short N-terminal cytoplasmic tail, a transmembrane domain, and a large C-terminal catalytic domain with conserved sialyltransferase motifs (L, S, and VS). The enzyme transfers sialic acid to O-6 of GalNAc residues on glycolipids, specifically converting GM1b to GD1a and GD1b to GT1b. Its expression is tightly regulated in the brain, where it contributes to neuronal ganglioside diversity. In cancer, ectopic expression in non-brain tissues enables tumor cells to interact with brain endothelium, facilitating metastasis. The protein has been studied as a potential therapeutic target for preventing brain metastasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ST6GALNAC5 Knockout HEK293 Cell Line | EDJ-KQ9754 | Human | 81849 | Details Get a Quote |
| ST6GALNAC5 Knockout HCT 116 Cell Line | EDJ-KQ36579 | Human | 81849 | Details Get a Quote |
| ST6GALNAC5 Knockout HeLa Cell Line | EDJ-KQ57419 | Human | 81849 | Details Get a Quote |
| ST6GALNAC5 Knockout A-549 Cell Line | EDJ-KQ65924 | Human | 81849 | Details Get a Quote |
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