Secretin receptors in the neuroglioma hybrid cell line NG108-15. Characterization and regulation of their expression.
Secretin receptors in membranes from the neuroblastoma-glioma hybrid cell line NG108-15 were investigated by 125I-secretin binding and adenylate cyclase activation. On both parameters the corresponding relative potencies of parent peptides were, respectively: secretin greater than helodermin greater than peptide histidine isoleucinamide = vasoactive intestinal peptide. With secretin analogs and secretin fragments, the order of potency for binding was: secretin = [Val5]secretin greater than [Ala2]secretin = [Ala11]secretin greater than [Ala4, Val5] secretin greater than [Ala4]secretin greater than [D-Phe4] secretin greater than [D-Phe2]secretin = secretin (2-27) greater than secretin (3-27) greater than secretin (7-27). Also, on adenylate cyclase, [D-Phe4]secretin, [D-Phe2]secretin, secretin (2-27) and secretin (3-27) were partial agonists while secretin (7-27) was ineffective. The differentiating agent N6,2'-O-dibutyryladenosine 3',5'-monophosphate (1 mM) increased the density of secretin receptors and secretin-stimulated adenylate cyclase activity after a lag period of 4 h. After incubation for 24 h, receptor number and enzyme activity were increased 4- and 3-fold, respectively. These effects were inhibited totally by 1 microgram/ml cycloheximide and halved by 5 micrograms/ml actinomycin D. They were mimicked by 1 mM sodium butyrate but were not reproduced by either 8-bromoadenosine 3',5'-monophosphate or the phosphodiesterase inhibitor rac-4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone.
Gossen
D
D
Department of Biochemistry and Nutrition, Medical School, Université Libre de Bruxelles, Belgium.
Tastenoy
M
M
Robberecht
P
P
Christophe
J
J
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002087:Butyrates / Q000494:pharmacology; D020148:Butyric Acid; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004789:Enzyme Activation; D006822:Hybrid Cells; D007700:Kinetics; D051379:Mice; D009457:Neuroglia / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D051381:Rats; D043562:Receptors, G-Protein-Coupled; D011964:Receptors, Gastrointestinal Hormone / Q000378:metabolism*; D012633:Secretin / Q000378:metabolism*
D002087:Butyrates; D043562:Receptors, G-Protein-Coupled; D011964:Receptors, Gastrointestinal Hormone; C029937:secretin receptor; D020148:Butyric Acid; D012633:Secretin; D003994:Bucladesine; D000262:Adenylyl Cyclases