Heat-labile enterotoxin A subunit (eltA)

Heat-labile enterotoxin A subunit is the enzymatically active component of the AB5-type toxin produced by *E. coli*. Upon delivery to host cells by the B subunit pentamer, the A subunit catalyzes ADP-ribosylation of the Gsα protein, locking adenylate cyclase in its active state. This produces a massive increase in intracellular cAMP, ultimately driving the chloride and water secretion that results in severe diarrhea. The A subunit also modulates host immune signaling and plays a role in pathogen adherence and immune evasion by altering epithelial cell responses. It is both a critical virulence factor and a target for vaccine/adjuvant intervention[2][4][5][6].

Other names

LT-AeltAE. coli heat-labile enterotoxin catalytic subunitEnterotoxin A chainADP-ribosylating toxin A subunit

ADP-ribosylation of Gsα subunit of host adenylate cyclase, leading to constitutive activation and increased cAMP production. This results in electrolyte and water secretion from intestinal cells and diarrhea. It also causes suppression of host innate immunity and mucin alteration (immunomodulation).