The protein kinase A regulatory subunit RIIβ (PKAR2 or PRKAR2B) is a critical component of the cAMP-dependent protein kinase (PKA) complex, which mediates cellular responses to cyclic AMP (cAMP) signaling. PKA exists as a tetrameric holoenzyme comprising two regulatory (R) subunits and two catalytic (C) subunits. The RIIβ subunit, encoded by the PRKAR2B gene, is one of four regulatory isoforms (RIα, RIβ, RIIα, RIIβ) that determine PKA localization, substrate specificity, and activation dynamics. RIIβ is highly expressed in adipose tissue, brain, and endocrine organs, where it plays a role in metabolic regulation, lipolysis, and neuronal signaling. Its expression is modulated by hormonal and nutritional cues, linking it to obesity, diabetes, and metabolic disorders.
Antibodies targeting PKAR2 are essential tools for studying PKA signaling dynamics, particularly in tissues where RIIβ dominates. They enable detection of protein expression, post-translational modifications, and interactions via techniques like Western blotting, immunohistochemistry, and co-immunoprecipitation. Research using PKAR2 antibodies has elucidated its involvement in adipocyte differentiation, neurotransmitter receptor trafficking, and tumorigenesis, as aberrant RIIβ expression is observed in certain cancers. Commercial antibodies are typically validated for specificity against conserved regions of RIIβ, distinguishing it from other regulatory subunits. Studies leveraging these reagents continue to advance understanding of cAMP-PKA pathways in disease mechanisms and therapeutic targeting.