Adenylate cyclase in membrane fractions of RIN-A2-cells: studies with forskolin, NaF, GppNHp and NEM.
In crude membrane fractions of rat pancreatic islets and of RIN-A2-cells, forskolin and NaF stimulated adenylate cyclase activity. Basal and stimulated enzyme activity was approximately 3 to 6 fold higher in membranes of RIN-A2-cells than in membranes of islet cells. In RIN-A2-cells GppNHp and NEM inhibited forskolin-stimulated enzyme activity. The inhibitory effect of GppNHp could be reduced by NEM. It is suggested that the adenylate cyclase system of RIN-A2-cells contains inhibitory and stimulatory N-proteins and that there are critical thiols related to Ni, Ns and/or the catalytic unit. Thus, membrane fractions of RIN-A2-cells may be an appropriate model for studies on the adenylate cyclase system of insulin-producing cells.
Trier
J K
JK
Department of Pharmacology, University of Tübingen, Federal Republic of Germany.
Kühn
M
M
Ammon
H P
HP
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology*; D005033:Ethylmaleimide / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology*; D051381:Rats; D012969:Sodium Fluoride / Q000494:pharmacology*
D005576:Colforsin; D006165:Guanylyl Imidodiphosphate; D006160:Guanosine Triphosphate; D012969:Sodium Fluoride; D000262:Adenylyl Cyclases; D005033:Ethylmaleimide