Recouery of Responsiueness to Acth and cAMP in a Protein Kinase-Defectiue Adrenal Cell Mutant Following Transfection with a Protein Kinase Gene

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Abstract
The cause and effect relationship between mutations in cAMP-dependent protein kinase activity and resistance of adrenocortical tumor cells to ACTH and cAMP was evaluated by transfection with cloned cDNAs encoding subunits of the mouse cAMP-dependent protein kinase. Protein kinase defective, Kin 8 adrenocortical tumor cells were transfected with pRev [an expression vector encoding the regulatory subunit of the type 1 cAMP-dependent protein kinase (R1)] or with pCαev [an expression vector encoding the catalytic subunit of cAMP-dependent protein kinase (c)]. The pCαev transformant recovered cAMP responsive protein kinase activity, whereas the pRev transformant recovered cAMP-binding activity, but did not recover cAMP responsive protein kinase activity. The pCαev transformant concomitantly recovered steroidogenic and morphologic responsiveness to ACTH- and 8-bromo-cAMP, whereas the pRev transformant remained resistant to these effects of the hormone and cyclic nucleotide. Since Kin 8 cells recovered their responsiveness to ACTH and 8-bromo-cAMP following