The Phospho-PKAR2(S99) antibody detects the regulatory subunit RIIβ (PRKAR2B) of protein kinase A (PKA) when phosphorylated at serine 99. PKA, a central mediator of cAMP signaling, consists of two regulatory (R) and two catalytic (C) subunits. The R subunits (R1α, R1β, R2α, R2β) inhibit C subunits until cAMP binding triggers dissociation, enabling C subunits to phosphorylate downstream targets. RIIβ contains two cAMP-binding domains and a hinge region where phosphorylation occurs. S99 phosphorylation in the hinge region is linked to RIIβ stability, subcellular localization, and interactions with A-kinase anchoring proteins (AKAPs), which spatially regulate PKA activity.
This antibody is widely used to study cAMP/PKA signaling dynamics in metabolic regulation, cardiac function, and neurological processes. Aberrant PKA activity is implicated in metabolic disorders, cardiovascular diseases, and cancers. Phosphorylation at S99 may influence RIIβ degradation via the ubiquitin-proteasome system, impacting PKA signaling duration. Researchers employ the Phospho-PKAR2(S99) antibody in techniques like Western blotting, immunofluorescence, or immunohistochemistry to assess RIIβ activation states in cell/tissue models, particularly in obesity, diabetes, or tumorigenesis studies. Its specificity for the phosphorylated form makes it valuable for dissecting context-dependent cAMP/PKA pathway regulation.