GM2A Gene: GM2 Ganglioside Activator
Essential cofactor for beta-hexosaminidase A in GM2 ganglioside degradation; mutations cause Tay-Sachs disease AB variant.
Gene Information Card
| Symbol | GM2A |
|---|---|
| Full Name | GM2 ganglioside activator |
| Gene Type | Protein coding |
| Chromosomal Location | 5q33.1 |
| NCBI Gene ID | 2760 ncbi.nlm.nih.gov/gene/2760 |
| Ensembl ID | ENSG00000196743 |
| UniProt ID | P17900 |
| OMIM ID | 613109 |
| HGNC ID | 4367 |
| Aliases | SAP-3, GM2-AP, Sphingolipid activator protein 3 |
Description
The GM2A gene encodes the GM2 ganglioside activator (GM2AP), a small lipid-binding protein required for the degradation of GM2 ganglioside by beta-hexosaminidase A. GM2AP extracts GM2 from membranes and presents it to the enzyme. Loss-of-function mutations cause the AB variant of Tay-Sachs disease, a severe lysosomal storage disorder.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Tay-Sachs disease, AB variant | Loss of GM2AP function prevents GM2 ganglioside degradation, leading to neuronal accumulation | OMIM #272800; ClinVar pathogenic variants |
| GM2 gangliosidosis, AB variant | Same mechanism as above; allelic disorder | OMIM #272800 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Kidney | 8.3 | Medium |
| Liver | 6.1 | Low |
| Lung | 4.2 | Low |
| Heart | 3.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 15.2 | High expression |
| HeLa | 10.1 | Moderate expression |
| SH-SY5Y | 18.7 | Neuronal cell line, high expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.412C>T (p.Arg138*) | Nonsense | Rare | Loss of function; truncation |
| c.164G>A (p.Cys55Tyr) | Missense | Rare | Loss of function; disrupts disulfide bond |
| c.506_507del (p.Leu169Profs*10) | Frameshift | Rare | Loss of function; premature stop |
Mutation functional classification
Loss of Function (LOF)
Most GM2A mutations are loss-of-function, leading to GM2 ganglioside accumulation and Tay-Sachs AB variant.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported; disease is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • GM2 ganglioside binding | • sphingolipid activator activity |
| • lysosome | • lipid transport |
| • ganglioside catabolic process |
Pathways
• Glycosphingolipid metabolism (KEGG hsa00601)
• Sphingolipid signaling pathway (KEGG hsa04071)
• Lysosome (KEGG hsa04142)
Protein Summary
GM2 ganglioside activator (GM2AP) is a 193-amino-acid glycoprotein localized to lysosomes. It binds GM2 ganglioside and presents it to beta-hexosaminidase A for hydrolysis. The protein contains a saposin-like domain and is essential for normal ganglioside catabolism in neurons.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GM2A Knockout HEK293 Cell Line | EDJ-KQ4731 | Human | 2760 | Details Get a Quote |
| GM2A Knockout A-549 Cell Line | EDJ-KQ27471 | Human | 2760 | Details Get a Quote |
| GM2A Knockout HCT 116 Cell Line | EDJ-KQ27472 | Human | 2760 | Details Get a Quote |
| GM2A Knockout HeLa Cell Line | EDJ-KQ27473 | Human | 2760 | Details Get a Quote |
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