RT Journal Article
SR Electronic
T1 Calmodulin activates adenylate cyclase from rat anterior pituitary.
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 743
OP 748
VO 32
IS 6
A1 D V Greenlee
A1 S Okada
YR 1987
UL http://molpharm.aspetjournals.org/content/32/6/743.abstract
AB Bovine brain calmodulin activated adenylate cyclase in calmodulin-deficient rat anterior pituitary membranes. This activation appeared to be specific by the following criteria: 1) calmodulin activation was Ca2+ dependent and responded biphasically to calcium, displaying activation at low and inhibition at higher concentrations; 2) calmidazolium, a potent calmodulin antagonist, inhibited calmodulin activation of adenylate cyclase; 3) activation of the enzyme occurred in a dose-dependent manner, at calmodulin concentrations normally found in most cells (1- to 20-microM range). However, this response was not saturated using calmodulin concentrations as high as 50 microM. The data suggest that endogenous calmodulin can be dissociated from normal anterior pituitary adenylate cyclase, that the enzyme can be subsequently stimulated by addition of micromolar concentrations of calmodulin, and that this enzyme appears to be at least 50-fold less sensitive to calmodulin than is the brain adenylate cyclase.