PRKAR1B Gene: Function, Mutations, and Associated Diseases

PRKAR1B encodes the beta regulatory subunit of type I cAMP-dependent protein kinase (PKA). This subunit plays a critical role in regulating PKA activity by binding to the catalytic subunits and inhibiting their kinase activity in the absence of cAMP. Upon cAMP binding, the regulatory subunit dissociates, releasing active catalytic subunits that phosphorylate downstream targets. PRKAR1B is involved in various cellular processes including metabolism, gene transcription, cell proliferation, and differentiation. Mutations in PRKAR1B have been associated with neurodevelopmental disorders and certain cancers.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• cAMP/PKA signaling pathway

• G protein-coupled receptor signaling pathway

• Regulation of gene expression

• Wnt signaling pathway (crosstalk)

• MAPK signaling pathway (crosstalk)

PRKAR1B is a regulatory subunit of PKA, a tetrameric holoenzyme composed of two regulatory and two catalytic subunits. The protein contains an N-terminal dimerization/docking domain, a hinge region, and two cAMP-binding domains. In the absence of cAMP, PRKAR1B inhibits the catalytic subunits. Binding of cAMP to the regulatory subunits induces a conformational change that releases the catalytic subunits, enabling them to phosphorylate cytoplasmic and nuclear targets. PRKAR1B is highly expressed in the brain and testis, suggesting roles in neuronal signaling and spermatogenesis. Mutations in PRKAR1B can lead to dysregulated PKA activity, contributing to developmental disorders and cancer.