Development of Phosphodiesterase–Protein-Kinase Complexes as Novel Targets for Discovery of Inhibitors with Enhanced Specificity

Phosphodiesterases (PDEs) hydrolyze cyclic nucleotides to modulate multiple signaling events in cells. PDEs are recognized actively associate with nucleotide receptors (protein kinases, PKs) larger macromolecular assemblies referred as signalosomes. Complexation of PKs generates an expanded active site that enhances PDE activity. This facilitates signalosome-associated preferentially catalyze hydrolysis bound and aid signal termination. important drug targets, current strategies for inhibitor discovery based entirely on targeting conserved catalytic domains. often results inhibitors cross-reactivity amongst closely related attendant unwanted side effects. Here, our approach targeted PDE–PK complexes they would occur signalosomes, thereby offering greater specificity. Our developed fluorescence polarization assay was adapted identify block pockets one mode disrupt protein-protein interactions between a second mode. We tested this three different systems—cAMP-specific PDE8–PKAR, cGMP-specific PDE5–PKG, dual-specificity RegA–RD complexes—and ranked according their inhibition potency. Targeting offers biochemical tools describing the exquisite specificity networks