What is cholera toxin B subunit?
What is cholera toxin B subunit?
Cholera toxin B subunit (CT-B) attaches to cells by binding to ganglioside GM1, making it a powerful tool for retrograde labeling of neurons. When used in neuronal tracing applications, CT-B is typically introduced by pressure injection or by iontophoretic injection into neural tissue.
How many B subunits are in cholera toxin?
The major virulence factor is cholera toxin (CT), which consists of two subunits: the A subunit (CTA) and the B subunit (CTB).
Does cholera toxin stimulate Gs subunit?
Cholera toxin, by acting as a classical A-B type toxin, leads to ADP-ribosylation of G protein, and constitutive activation of AC, thereby giving rise to increased levels of cyclic AMP within the host cell (Fig.
How is cholera toxin produced?
Cholera toxin (CT) is a bacterial protein toxin produced by Vibrio cholerae, which binds to cellular membranes with high affinity. The B subunit (CTB) binds to the monosialoganglioside GM1 that is clustered in membrane microdomains on the plasma membrane of different cell types, including neurons.
How does cholera toxin B work?
Cholera toxin acts by the following mechanism: First, the B subunit ring of the cholera toxin binds to GM1 gangliosides on the surface of target cells. If a cell lacks GM1 the toxin most likely binds to other types of glycans, such as Lewis Y and Lewis X, attached to proteins instead of lipids.
Which organ is affected by cholera toxin?
A bacterium called Vibrio cholerae causes cholera infection. The deadly effects of the disease are the result of a toxin the bacteria produces in the small intestine. The toxin causes the body to secrete enormous amounts of water, leading to diarrhea and a rapid loss of fluids and salts (electrolytes).
Is cholera toxin pore forming?
Besides CT and TCP, V. cholerae generates several additional secreted proteins that possess well characterized cytotoxic activity in vitro (16, 17). This cytotoxic factor is a pore-forming toxin that causes vacuolization or cell lysis and necrosis, depending on the cell type and toxin concentration (21–25).
What does cholera toxin activate?
Abstract. Cholera diarrhoea is due to the action of a toxin that acts on all animal cells by stimulating the enzyme adenylate cyclase, which catalyses the production oc cyclic AMP from ATP.
Where is cholera toxin found?
GM1 gangliosides are found in lipid rafts on the cell surface.
How is cholera activated?
Cholera diarrhoea is due to the action of a toxin that acts on all animal cells by stimulating the enzyme adenylate cyclase, which catalyses the production oc cyclic AMP from ATP. The stimulation of adenylate cyclase depends on the presence of NAD and other co-factors present in the cell sap.
Why does cholera toxin cause diarrhea?