PKA catalytic subunits dissociate from regulatory subunits to regulate neuronal functions.

Protein kinase A (PKA) is the major effector of the second messenger cAMP and plays a critical role in numerous cell biology processes. The function and specificity of PKA rely on spatial compartmentalization. However, the precise subcellular distribution and dynamics of activated PKA remain debated. Textbooks illustrate that upon activation PKA catalytic subunits dissociate from regulatory subunits. However, some recent work has proposed that PKA catalytic subunits remain associated with regulatory subunits following physiological activation. The present study tests these two models in the context of neuronal function. The results support the classical model of PKA activation. A clarified model of PKA action will contribute to the understanding of how the specificity of PKA phosphorylation may be achieved.