Calmodulin-dependent kinase I regulates adrenal cell expression of aldosterone synthase.

Aldosterone synthase (CYP11B2) is expressed in the adrenal glomerulosa and controls the capacity of the adrenal glomerulosa to produce aldosterone. Herein, human NCI-H295R (H295R) adrenocortical cells were used to define the calcium-dependent mechanisms regulating CYP11B2 gene transcription using reporter constructs containing CYP11B2 gene 5'-flanking DNA. Treatment of H295R cells with calcium/calmodulin-dependent protein kinase (CaMK) inhibitor (KN93) or calmodulin inhibitor (calmidazolium) blocked angiotensin II and potassium (K(+)) stimulation of CYP11B2 reporter gene expression.