The cholinergic gene locus is coordinately regulated by protein kinase A II in PC12 cells

The vesicular acetylcholine transporter (VAChT) gene and the choline acetyltransferase (ChAT) gene comprise the cholinergic gene locus. We have studied the coordinate regulation of these genes by cyclic AMP-dependent protein kinase (PKA) in the rat pheochromocytoma cell line PC12 and PC12 PKA-deficient mutants. Both ChAT and VAChT mRNA increased approximately fourfold after treatment of PC12 cells with dibutyryl cyclic AMP (dbcAMP). ChAT and PKA activity were also increased by dbcAMP. The basal levels of ChAT and VAChT mRNAs in the PKA-deficient cell lines were both about six times lower than in wild-type PC12 cells, and were induced less than twofold by addition of dbcAMP. H-89 and H-9, specific inhibitors for PKA, reduced ChAT and VAChT mRNA levels to approximately one-third that of untreated cells and ChAT activity to approximately one-fourth that of untreated PC12 cells. Activation of PKA type II, but not PKA type I, increased ChAT activity approximately threefold. Analysis of reporter gene constructs indicates that PKA affects gene transcription at an upstream site in the cholinergic gene locus. These results demonstrate that the expression of the ChAT and VAChT genes is regulated coordinately at the transcriptional level, and a signaling pathway specifically involving PKA II plays an important role in this process.