The Stimulation by the Adrenocorticotropic Hormone of the Phosphorylation of an Adrenal Mitochondrial Preparation

Summary

Mitochondria isolated from beef adrenal cortex slices which had been incubated with and without ACTH and with ACTH plus puromycin or cycloheximide were incubated with (γ-³²P)ATP in the presence of the detergent, Triton X-100. A phosphorylated peak, detected by gel electrophoresis, was increased by ACTH and sharply decreased if the inhibitors of protein synthesis were present along with the ACTH. The changes in the extent of phosphorylation are accompanied by corresponding changes in corticoid synthesis. The data suggests that ACTH causes the phosphorylation of a rapidly turning-over protein which stimulates the conversion of cholesterol to pregnenolone.