Phosphorylation of the cAMP-dependent protein kinase (PKA) regulatory subunit modulates PKA-AKAP interaction, substrate phosphorylation, and calcium signaling in cardiac cells.

ABSTRACT: Subcellular compartmentalization of the cAMP-dependent protein kinase (PKA) by protein kinase A-anchoring proteins (AKAPs) facilitates local protein phosphorylation. However, little is known about how PKA targeting to AKAPs is regulated in the intact cell. PKA binds to an amphipathic helical region of AKAPs via an N-terminal domain of the regulatory subunit. In vitro studies showed that autophosphorylation of type II regulatory subunit (RII) can alter its affinity for AKAPs and the catalytic subunit (PKA(cat)). We now investigate whether phosphorylation of serine 96 on RII regulates PKA targeting to AKAPs, downstream substrate phosphorylation and calcium cycling in primary cultured cardiomyocytes. We demonstrated that, whereas there is basal phosphorylation of RII subunits, persistent maxi

SUBMITTER: Manni S 

PROVIDER: S-EPMC2527120 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature