Ganglioside GM1 (primary receptor for heat-labile enterotoxin) (GM1 (or "GM1 ganglioside"))

The so-called "heat-labile enterotoxin receptor" is not a protein receptor but refers primarily to the ganglioside GM1, a type of glycosphingolipid abundant in lipid rafts of mammalian intestinal epithelial cells. The B subunit of heat-labile enterotoxin (LT-B) produced by certain enterotoxigenic Escherichia coli (ETEC) binds to GM1 on the host cell membrane, enabling delivery of the enzymatically active A subunit (LT-A) into the cell. The A subunit then catalyzes ADP-ribosylation of the Gsα subunit of adenylate cyclase, increasing intracellular cAMP and resulting in dysregulated electrolyte and water secretion in the gut. This mechanism underlies the clinical syndrome of infectious secretory diarrhea. There are no drugs directly targeting GM1 to block enterotoxin binding, but derivatives of LT-B are being explored as vaccine adjuvants due to their immunomodulatory properties.

Other names

Heat-labile enterotoxin receptor (descriptive, not a unique molecule)GM1 ganglioside receptorMonosialotetrahexosylganglioside receptorGlycosphingolipid receptor for heat-labile enterotoxin

Binding of the B subunit of heat-labile enterotoxin (LT-B) to GM1 on host epithelial cell membranes allows entry of the catalytic A subunit of the toxin, which then activates adenylate cyclase, raising cAMP and leading to electrolyte secretion and diarrhea