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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

Human proteins containing this domain

GUCA2A; GUCA2B;

Structure

Structure

This peptide has two topogies,[5] both isoforms are shown below:

File:PDB 1uya EBI.jpg
Structure of the A-form of human uroguanylin.[5]
File:PDB 1uyb EBI.jpg
Structure of the B-form of human uroguanylin.[5]
References

References

  1. 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.
  2. 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.
  3. 3.0 3.1 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.
  4. 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.
  5. 5.0 5.1 5.2 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.
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