3',5'-cyclic-AMP phosphodiesterase 4A

PDE4A Summary

PDE4A (3',5'-cyclic-AMP phosphodiesterase 4A) is a cAMP-hydrolyzing enzyme that catalyzes the breakdown of 3',5'-cyclic adenosine monophosphate (cAMP), a critical intracellular second messenger regulating diverse physiological processes (UniProt: P27815). The enzyme specifically and efficiently hydrolyzes cAMP but not cyclic GMP (cGMP), and its activity is independent of calcium and calmodulin modulation.

PDE4A belongs to the phosphodiesterase family of signaling proteins involved in cAMP-dependent cellular responses. The enzyme is broadly expressed across tissues where cAMP signaling plays a regulatory role in processes such as inflammation, neuronal function, and cell proliferation.

PDE4A shows decreased abundance in Alzheimer's disease brain tissue. Proteomics analysis of post-mortem AD brain versus age-matched controls detected PDE4A as downregulated with a mean log2 fold-change of −0.44 (Chaparral AD proteomics). This reduction may reflect compromised cAMP signaling capacity in AD pathology, though the modest magnitude of change and limited subcellular fraction data suggest further investigation is warranted to clarify the functional significance of this alteration.