The mouse gene encoding the GM2 activator protein (Gm2a): cDNA sequence, expression, and chromosome mapping

The GM2 activator protein forms a substrate-complex with GM2 ganglioside, which enables degradation of the ganglioside by beta-hexosaminidase A. Mutations in the human GM2 activator protein gene (GM2A) result in the GM2 gangliosidosis AB variant, a severe neurological disease. We have isolated and sequenced a mouse GM2 activator protein (Gm2a) cDNA with complete protein coding and 3' untranslated regions. Expression of the Gm2a transcript (approximately 2.3 kb) was apparent in all tissues examined and was most abundant in kidney and testis. The Gm2a gene was mapped to a region on mouse chromosome (Chr) 11 that is homologous with a segment of human chromosome 5 containing the orthologous human gene. In addition, a Gm2a-related sequence (Gm2a-rs1) was mapped to mouse Chr 5.