Phosphodiesterase terminates GPCR signaling by converting
Cyclic-nucleotide phosphodiesterases hydrolyze cAMP or cGMP to the corresponding inactive 5'-monophosphates, thereby terminating the second-messenger signal. Regulation of phosphodiesterase activity provides an important mechanism for controlling the duration and amplitude of cyclic-nucleotide signaling in cells. These enzymes are important pharmacological targets for modulating cyclic nucleotide levels. Careful
Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)