GM2A
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1G13, 1PU5, 1PUB, 1TJJ, 2AF9, 2AG2, 2AG4, 2AG9
Identifiers
Aliases	GM2A, GM2-AP, SAP-3, GM2 ganglioside activator, GM2AP, ganglioside GM2 activator
External IDs	OMIM: 613109 MGI: 95762 HomoloGene: 349 GeneCards: GM2A
Gene location (Human) Chr. Chromosome 5 (human)[1] Band 5q33.1 Start 151,212,150 bp[1] End 151,270,440 bp[1]
Gene location (Mouse) Chr. Chromosome 11 (mouse)[2] Band 11 B1.3|11 32.13 cM Start 54,988,941 bp[2] End 55,003,855 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in vulva human penis placenta cervix epithelium gums nipple inferior ganglion of vagus nerve monocyte periodontal fiber lymph node Top expressed in superior surface of tongue ascending aorta aortic valve gallbladder cumulus cell adrenal gland kidney blood subcutaneous adipose tissue proximal tubule More reference expression data BioGPS More reference expression data
Gene ontology Molecular function lipid transporter activity phospholipase activator activity beta-N-acetylgalactosaminidase activity beta-N-acetylhexosaminidase activity enzyme activator activity hydrolase activity sphingolipid activator protein activity Cellular component cytoplasm apical cortex lysosomal lumen mitochondrion potassium:proton exchanging ATPase complex cytoplasmic side of plasma membrane lysosome extracellular exosome extracellular region azurophil granule lumen basolateral plasma membrane apical plasma membrane Biological process positive regulation of hydrolase activity lipid transport glycosphingolipid metabolic process neuromuscular process controlling balance lipid metabolism lipid storage nervous system process learning or memory oligosaccharide catabolic process ganglioside metabolic process ganglioside catabolic process sphingolipid metabolic process neutrophil degranulation positive regulation of catalytic activity Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 2760 14667 Ensembl ENSG00000196743 ENSMUSG00000000594 UniProt P17900 Q60648 RefSeq (mRNA) NM_001167607 NM_000405 NM_010299 RefSeq (protein) NP_000396 NP_001161079 NP_034429 Location (UCSC) Chr 5: 151.21 – 151.27 Mb Chr 11: 54.99 – 55 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

GM2 ganglioside activator also known as GM2A is a protein which in humans is encoded by the GM2A gene.^[5][6]

Function

The protein encoded by this gene is a small glycolipid transport protein which acts as a substrate specific co-factor for the lysosomal enzyme β-hexosaminidase A. β-hexosaminidase A, together with GM2 ganglioside activator, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines.

GM2A is a lipid transfer protein that stimulates the enzymatic processing of gangliosides, and also T-cell activation through lipid presentation. This protein binds molecules of ganglioside GM2, extracts them from membranes, and presents them to beta-hexosaminidase A for cleavage of N-acetyl-D-galactosamine and conversion to GM3.

It was identified as a member of ML domain family of proteins involved in innate immunity and lipid metabolism in the SMART database. .

Regulation

In melanocytic cells GM2A gene expression may be regulated by MITF.^[7]

Clinical significance

Mutations in this gene, inherited in an autosomal recessive pattern, result in GM2-gangliosidosis, AB variant, a rare GM2 gangliosidosis that has symptoms and pathology identical with Tay–Sachs disease and Sandhoff disease.^[8]

GM2A mutations are rarely reported, and the cases that are observed often occur with consanguineous parents or in genetically isolated populations.^[9]

Because AB variant is so rarely diagnosed, even in infants, it is likely that most mutations of GM2A are fatal in the fetus in homozygotes and genetic compounds, and thus are never observed clinically.

See also

• Gangliosidosis
• Sandhoff disease
• Tay–Sachs disease
• Hexosaminidase
• GM1

References

Further reading