Phosphodiesterase 4A (PDE4A) and Phosphodiesterase 4B (PDE4B) (PDE4A, PDE4B)

Phosphodiesterase 4A and 4B are members of the PDE4 enzyme subfamily, which hydrolyze intracellular cAMP to 5'-AMP, acting as key regulators of cellular signaling in neurons, immune cells, and other tissues. These enzymes are encoded by separate genes and have multiple isoforms defined by alternative splicing and post-translational modifications. PDE4A is primarily membrane-associated and localized to the brain, especially in regions associated with learning and memory, while PDE4B is broadly expressed and implicated in inflammatory signaling. Selective inhibition of PDE4A/B increases cAMP, modulating various physiological processes and providing therapeutic effects in neurodegenerative, psychiatric, and inflammatory diseases. Isoform-specific localization and function are determined by distinct N-terminal sequences and post-translational modifications, which further control subcellular compartmentalization and signaling specificity.

Other names

PDE4APDE4BcAMP-specific phosphodiesterase 4AcAMP-specific phosphodiesterase 4BcAMP PDE4A/B

Inhibition of cAMP breakdown, leading to increased cAMP signaling in target tissues. Regulation of cAMP-dependent protein kinase A (PKA) and downstream transcription factors (e.g., CREB).