Cholera toxin acts by which mechanism?
Ans. a. Overactivates adenylate cyclase (cAMP) by permanently activating GsCholera toxin binds and activates Gs, resulting in very high levels of intracellular cAMP. This rise in cAMP opens luminal Cl- channels, causing a massive secretory diarrhea.TOXINS WITH A-B ADP-RIBOSYL TRANSFERASE ACTIVITYToxin ADP-Ribosylated Host ProteinEffect on Host CellPseudomonas Exotoxin SExotoxin A UnknowneEF-2Inhibits translocation during protein synthesisDiphtheria toxin eEF-2Inhibits translocation during protein synthesisE. coliHeat-labile toxin (LT)Heat-stable toxin (ST)G-protein (GS)Increases cAMP in intestinal epithelium causing diarrheaIncreases cGMP in, which decreases the resorption of NaCI and H20 in gutCholera toxin G-protein (GS)Increases cAMP in intestinal epithelium causing diarrheaPertussis toxin G-protein (Gi)Increases cAMP causing edema, lymphocytosis and increased insulin secretionEdema toxin Mimics the adenylate cyclase enzyme (Increases cAMP)Shiga toxin (ST) Inactivate 60S ribosome by removing adenine from rRNA
Overactivates adenylate cyclase (cAMP) by permanently activating Gs
Mimics the adenylate cyclase enzyme (cAMP)
Overactivates guanylate cyclase (cGMP)
Inactivate elongation factor (EF-2)
Bacteria