HEXA

Also known as TSD, hexosaminidase subunit alpha

thumb|HEXA gene is located on the long (q) arm of Chromosome 15 (human)|chromosome 15 at position 24.1. Hexosaminidase A (alpha polypeptide), also known as HEXA, is an enzyme that in humans is encoded by the HEXA gene, located on the 15th chromosome.

Gene data

HEXA

Name: hexosaminidase subunit alpha
Type: protein-coding
Position: 72,340,924–72,376,420 (−)
Aliases: TSD
Ensembl: ENSG00000213614
RefSeq RNA: NM_000520.6, NM_001318825.2, NR_134869.3
RefSeq protein: NP_000511.2, NP_001305754.1

This gene encodes a member of the glycosyl hydrolase 20 family of proteins. The encoded preproprotein is proteolytically processed to generate the alpha subunit of the lysosomal enzyme beta-hexosaminidase. This enzyme, together with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Mutations in this gene lead to an accumulation of GM2 ganglioside in neurons, the underlying cause of neurodegenerative disorders termed the GM2 gangliosidoses, including Tay-Sachs disease (GM2-gangliosidosis type I). Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed. [provided by RefSeq, Jan 2016].

Gene Ontology

Biological process

Article

6 sections

Contents

Function
Gene mutations resulting in Tay–Sachs disease
Gene therapies for Tay-Sachs
References
Further reading
External links

Hexosaminidase A and the cofactor GM2 activator protein catalyze the degradation of the GM2 gangliosides and other molecules containing terminal N-acetyl hexosamines. Hexosaminidase A is a heterodimer composed of an alpha subunit (this protein) and a beta subunit. The alpha subunit polypeptide is encoded by the HEXA gene while the beta subunit is encoded by the HEXB gene. Gene mutations in the gene encoding the beta subunit (HEXB) often result in Sandhoff disease; whereas, mutations in the gene encoding the alpha subunit (HEXA, this gene) decrease the hydrolysis of GM2 gangliosides, which is the main cause of Tay–Sachs disease.