Guanylin

Guanylin is a peptide composed of 15 amino acids, secreted by goblet cells located in the colon. It functions as an agonist for the guanylyl cyclase receptor GC-C, playing a role in regulating the transport of electrolytes and water in both intestinal and renal epithelia.
de Sauvage et al. 1992 Proceedings of the National Academy of Sciences of the United States of America 89(19): 9089-93
Sciaky et al. 1994 Genomics 24 (3): 583-7