Guanylin
Encyclopedia
Guanylin is a 15 amino acid
polypeptide that is secreted by goblet cells in the colon
. Guanylin acts as an agonist of the guanylyl cyclase receptor GC-C and regulates electrolyte
and water
transport in intestinal and renal epithelia. Upon receptor binding, guanylin increases the intracellular concentration of cGMP
, induces chloride secretion and decreases intestinal fluid absorption, ultimately causing diarrhoea. The peptide stimulates the enzyme through the same receptor binding
region as the heat-stable enterotoxin
s.
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
polypeptide that is secreted by goblet cells in the colon
Colon (anatomy)
The colon is the last part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body, and is the site in which flora-aided fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a...
. Guanylin acts as an agonist of the guanylyl cyclase receptor GC-C and regulates electrolyte
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....
and water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
transport in intestinal and renal epithelia. Upon receptor binding, guanylin increases the intracellular concentration of cGMP
Cyclic guanosine monophosphate
Cyclic guanosine monophosphate is a cyclic nucleotide derived from guanosine triphosphate . cGMP acts as a second messenger much like cyclic AMP...
, induces chloride secretion and decreases intestinal fluid absorption, ultimately causing diarrhoea. The peptide stimulates the enzyme through the same receptor binding
region as the heat-stable enterotoxin
Heat-stable enterotoxin
Heat-stable enterotoxins are secretory peptides produced by some bacterial strains, such as enterotoxigenic Escherichia coli which are in general toxic to animals.These peptides keep their 3D structure and remain active at temperatures as high as 100oC....
s.