Description: Toxin consisting of an A subunit (27 kDa) with five B subunits (approximately 12 kDa each) surrounding, which attach the toxin to ganglioside GM1 on the cell surface. The A subunit catalyzes ADP-ribosylation of the α-subunit of the stimulatory G protein (Gαs), reducing GTPase activity and activating the α-subunit. This activation of Gαs leads to an increase in the activity of adenylyl cyclase, resulting in increased levels of cAMP. Cholera toxin has also been reported to ADP-ribosylate tubulin. Shown to be a potent mucosal vaccine adjuvant, inducing T helper cell type 2 responses by inhibiting the production of interleukin-12.