Cyclic AMP-specific 3',5'-cyclic phosphodiesterase 4B (PDE4B)

Cyclic AMP-specific 3',5'-cyclic phosphodiesterase 4B (PDE4B) is an enzyme that specifically hydrolyzes cAMP, a second messenger involved in cellular signaling cascades, and regulates cAMP concentrations within cells[5]. PDE4B belongs to the phosphodiesterase family, subfamily PDE4, and is one of four PDE4 isoforms (A–D), encoded by the *PDE4B* gene on chromosome 1p31.3. PDE4B exists in several alternatively spliced isoforms, with variable regulatory (Upstream Conserved Regions 1 and 2, UCR1/2) and catalytic domains, and forms functional dimers[2][3]. Its activity is crucial in modulating inflammatory responses and neuronal signaling. Altered PDE4B function has been implicated in neuropsychiatric conditions, inflammatory diseases, and cognitive processes, making it a validated drug target for selective PDE4 inhibitors such as crisaborole and rolipram[5][7]. PDE4B’s enzymatic activity is regulated by phosphorylation (PKA, ERK) and dimerization, with differential effects by isoform[3][7]. Selectivity for PDE4B over other PDE4 subtypes remains a focus to improve therapeutic indices and minimize adverse effects.

Other names

cAMP-specific phosphodiesterase 4BPhosphodiesterase 4BPDE4B1–5 (referring to isoforms)cAMP phosphodiesterase3',5'-cyclic-AMP phosphodiesterase

Competitive inhibition of cAMP hydrolytic activity. This leads to an increase in intracellular cAMP levels, resulting in reduced inflammation and modulation of neuronal signaling.