PKA-RII subunit phosphorylation precedes activation by cAMP and regulates activity termination.

ABSTRACT: Type II isoforms of cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA-II) contain a phosphorylatable epitope within the inhibitory domain of RII subunits (pRII) with still unclear function. In vitro, RII phosphorylation occurs in the absence of cAMP, whereas staining of cells with pRII-specific antibodies revealed a cAMP-dependent pattern. In sensory neurons, we found that increased pRII immunoreactivity reflects increased accessibility of the already phosphorylated RII epitope during cAMP-induced opening of the tetrameric RII₂:C₂ holoenzyme. Accordingly, induction of pRII by cAMP was sensitive to novel inhibitors of dissociation, whereas blocking catalytic activity was ineffective. Also in vitro, cAMP increased the binding of pRII antibodies to RI

SUBMITTER: Isensee J 

PROVIDER: S-EPMC5987717 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature