Controls the rhythmic contraction of enteric muscles probably by regulating G-protein coupled receptor aex-2-mediated calcium influx in GABAergic DVB neurons. Tetramer, composed of 2 regulatory (R) and 2 catalytic (C) subunits. In the presence of cAMP it dissociates into 2 active monomeric C subunits and an R dimer that binds four cAMP molecules. Expressed at a low level during embryogenesis. Expression increases sharply approximately four hours before hatching with levels peaking during the first larval stage. Levels then decrease as development progresses to adulthood. The pseudophosphorylation site binds to the substrate-binding region of the catalytic chain but is not phosphorylated. The physiological significance of phosphorylations by other kinases is unclear. Belongs to the cAMP-dependent kinase regulatory chain family.