Probably targets cAMP-dependent protein kinase (PKA) to the cellular membrane or cytoskeletal structures. The membrane-associated form reduces epithelial sodium channel (ENaC) activity, whereas the free cytoplasmic form may negatively regulate ENaC channel feedback inhibition by intracellular sodium. Binds cAMP-dependent protein kinase (PKA). Interacts with PRKCA; only the cytoplasmic form is capable of interacting with PRKCA. Additional isoforms seem to exist. Expressed in brain, heart, lung, pancreas and placenta. Truncated N-terminus.