Choleragen stimulates steroidogenesis and adenylate cyclase in cells lacking functional hormone receptors.
Choleragen stimulates steroid secretion and adenylate cyclase in three cell lines, adrenal tumor line (Y-1), a corticotropin-resistant mutant derived from Y-1 called OS-3, and a receptor-deficient Leydig tumor line (I-10). Sensitivity for half-maximal stimulation varies from 3 to 36 pM choleragen, the I-10 line being the most sensitive. Latency before the onset of steroidogenesis is longer in OS-3 and I-10 cells than in the Y-1 line. In both OS-3 and I-10 cells choleragen stimulates adenylate cyclase whether ITP or 5'-guanylylimidodiphosphate is the regulatory cofactor used. In addition to the responses of the receptor-deficient lines, choleragen does not, during its latency, block the response to corticotropin in Y-1 cells; corticotropin does not block binding of 125I-labeled choleragen to Y-1 cells; gangliosides do not interfere with the corticotropin-induced stimulation of Y-1 cells. We conclude that the corticotropin and choleragen receptors are different.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism / Q000494:pharmacology; D003994:Bucladesine / Q000494:pharmacology; D002460:Cell Line; D000242:Cyclic AMP / Q000494:pharmacology; D006150:Guanine Nucleotides / Q000494:pharmacology; D007292:Inosine Nucleotides / Q000494:pharmacology; D007700:Kinetics; D011956:Receptors, Cell Surface / Q000187:drug effects*; D013256:Steroids / Q000096:biosynthesis*; D014118:Toxins, Biological / Q000494:pharmacology*; D014734:Vibrio cholerae / Q000276:immunology
D006150:Guanine Nucleotides; D007292:Inosine Nucleotides; D011956:Receptors, Cell Surface; D013256:Steroids; D014118:Toxins, Biological; D003994:Bucladesine; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D000262:Adenylyl Cyclases