Guanylin
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[2][3]. Upon receptor binding, guanylin increases the intracellular concentration of cGMP, induces chloride secretion and decreases intestinal fluid absorption, ultimately causing diarrhoea[4]. The peptide stimulates the enzyme through the same receptor binding region as the heat-stable enterotoxins[3].
Human proteins containing this domain
GUCA2A; GUCA2B;
Structure
This peptide has two topogies,[5] both isoforms are shown below:
References
- ^ PDB 1O8R; Lauber T, Neudecker P, Rösch P, Marx UC (June 2003). "Solution structure of human proguanylin: the role of a hormone prosequence". J. Biol. Chem. 278 (26): 24118–24. doi:10.1074/jbc.M300370200. PMID 12707255.
- ^ Sciaky D, Kosiba JL, Cohen MB (1994). "Genomic sequence of the murine guanylin gene". Genomics 24 (3): 583–587. doi:10.1006/geno.1994.1670. PMID 7713512.
- ^ a b Goeddel DV, Kuang WJ, Henzel W, Keshav S, Gillett N, de Sauvage FJ (1992). "Precursor structure, expression, and tissue distribution of human guanylin". Proc. Natl. Acad. Sci. U.S.A. 89 (19): 9089–9093. doi:10.1073/pnas.89.19.9089. PMC 50070. PMID 1409606. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=50070.
- ^ Smith CE, Currie MG, Fok KF, Kato J, Moore RJ, Hamra FK, Duffin KL (1992). "Guanylin: an endogenous activator of intestinal guanylate cyclase". Proc. Natl. Acad. Sci. U.S.A. 89 (3): 947–951. doi:10.1073/pnas.89.3.947. PMC 48362. PMID 1346555. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=48362.
- ^ a b c Marx UC, Klodt J, Meyer M, et al. (September 1998). "One peptide, two topologies: structure and interconversion dynamics of human uroguanylin isomers". J. Pept. Res. 52 (3): 229–40. doi:10.1111/j.1399-3011.1998.tb01480.x. PMID 9774236.
External links