PRKACG/PKAc gamma

The gamma catalytic subunit of PKA, encoded by PRKACG, is the most divergent of the three autosomal C-subunit genes and shows the narrowest tissue distribution, with highest expression in testis and appreciable levels in brain. Like Ca and Cb, it is packaged into the regulatory-catalytic holoenzyme and liberated by cAMP, but its distinct N-terminal sequence influences subcellular localization and interaction with AKAP anchoring proteins. Cg phosphorylates serine/threonine in consensus PKA motifs and has been implicated in sperm function and neuronal cAMP signaling. Because of its restricted expression, PRKACG provides a means to dissect isoform-specific contributions of PKA catalytic subunits in germ cells and brain tissue.