Oceana Biomedicina Journal
Vol 1, No 2 (2018): Oceana Biomedicina Journal

Molecular Mechanism of Cholerae Toxin (ctx) in Causing Diarrhea

Praja, Rian Kusuma Arinta ( Udayana University )
Rosalina, Reny ( Institut Ilmu Kesehatan Bhakti Wiyata Kediri, East Java Indonesia )



Article Info

Publish Date
30 Jul 2018

Abstract

Vibrio cholerae is one of the pathogenic bacteria transmitted through contaminated food, especially seafood and contaminated beverages. V. cholerae produces cholerae toxin (ctx) which is encoded by the ctx gene located within its chromosome. This toxin has been recognized as one of the toxins responsible for cholera outbreaks. The mechanism of ctx gene expression is induced by environmental signals such as pH, osmolarity, temperature, bile, amino acids, and CO2. These signals will be a positive transcriptional factor to the ToxR gene that regulates the biogenesis of cholerae toxin. After cholerae toxin has been successfully expressed, V. cholerae uses a type II secretion (T2S) pathway to deliver cholerae toxin to the extracellular environment. Cholerae toxin consists of A and B subunits. The B subunit plays a role in attaching to the receptor Manosialosyl Ganglioside (GM1 ganglioside) and the A subunit plays a role in catalyzing ADP-ribosylation of Gs (stimulatory) proteins and turning them into active condition. The Gs proteins will convert the inactive adenilate cyclase (AC) into active AC. The increase of AC activity will increase the cyclic adenosine 3'5'-monophosphate (cAMP) concentration along the cell membrane. The cAMP then causes the active secretion of sodium (Na+), chloride (Cl-), potassium (K+), bicarbonate (HCO3-), and water (H2O) out of the cell into the intestinal lumen, resulting in large fluid losses and electrolyte imbalances. Keywords: Vibrio cholerae, cholerae toxin (ctx), ToxR gene, type II secretion (T2S), GM1 ganglioside, adenilate cyclase.

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Journal Info

Abbrev

journal

Publisher

Subject

Biochemistry, Genetics & Molecular Biology Immunology & microbiology Medicine & Pharmacology Public Health

Description

Hyperbaric medicine, marine medicine other than hyperbaric, on ships, boats and harbor health, maritime and coastal health, medicolegal aspects and medicolegal related to ships, ports and districts / maritime / coastal communities and fishermen, epidemiological aspects of diseases, disabilities and ...