title: Guanylyl cyclase C receptor: regulation of catalytic activity by ATP.
abstract: Guanylyl cyclase C (GCC), a member of the family of membrane bound guanylyl cyclases is the receptor for the heat-stable enterotoxin (ST) peptides and the guanylin family of endogenous peptides. GCC is activated upon ligand binding to increase intracellular cGMP levels, which in turn activates other downstream signalling events in the cell. GCC is also activated in vitro by nonionic detergents. We have used the T84 cell line as a model system to investigate the regulation of GCC activity by ATP. Ligand-stimulated GCC activity is potentiated in the presence of ATP, whereas detergent-stimulated activity is inhibited. The potentiation of GCC activity by ATP is dependent on the presence of Mg2+ ions, and is probably brought about by a direct binding of Mg-ATP to GCC. The protein kinase-like domain of GCC, which has earlier been shown to play a critical role in the regulation of GCC activity, may be a possible site for the binding of Mg-ATP to GCC.
authors.affiliation: Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India.
authors.forename: R
authors.initials: R
authors.lastname: Bhandari
authors.forename: K
authors.initials: K
authors.lastname: Suguna
authors.forename: S S
authors.initials: SS
authors.lastname: Visweswariah
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000595:Amino Acid Sequence; D002460:Cell Line; D002462:Cell Membrane; D003106:Colon / Q000166:cytology; D004768:Enterotoxins / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled; D018000:Receptors, Peptide / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D004768:Enterotoxins; D018000:Receptors, Peptide; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D006162:Guanylate Cyclase; D000074261:Receptors, Enterotoxin; D050705:Receptors, Guanylate Cyclase-Coupled