Detergent-extraction of a regulatory subunit of brain adenylate cyclase and its sensitivity to calmodulin and forskolin.

The increase in activity of brain adenylate cyclase caused by nonionic detergent might be associated with the response of this enzyme to calcium and calmodulin. The loss of fluoride and guanyl 5'-yl imidodiphosphate stimulation of adenylate cyclase by the incubation of brain membranes with Lubrol PX may be regarded as a selective release of guanine nucleotide regulatory subunits. The regulatory subunit preactivated with guanyl 5'-yl imidodiphosphate was resistant to detergent extraction. The loss of the subunits from membranes did not change the sensitivity of the enzyme to calmodulin and forskolin.