Cyclic guanosine monophosphate-dependent protein kinase type I (PKG I)

Cyclic guanosine monophosphate-dependent protein kinase type I (PKG I, also known as PRKG1) is a serine/threonine-specific protein kinase activated by cyclic GMP (cGMP)[1][2][8]. It acts as a central mediator of the nitric oxide (NO)/cGMP pathway, phosphorylating multiple protein targets involved in vascular smooth muscle relaxation, inhibition of platelet aggregation, and regulation of cellular phenotype in various tissues[1][2][3][4][8]. PRKG1 exists mainly as two isoforms (PKG Iα and PKG Iβ), localized predominantly in the cytoplasm, and plays key roles in cardiovascular homeostasis, modulation of cell proliferation, and neurophysiological processes[1][2][3][8]. Disruption of PKG I activity is implicated in cardiovascular diseases, while pharmacological modulation is of interest for treating hypertension, heart failure, and erectile dysfunction[4][7][8].

Other names

cGMP-dependent protein kinase type IProtein kinase G type IPRKG1cGKIPKG1cGMP-dependent protein kinase 1

Inhibition of PKG blocks downstream cGMP signaling and smooth muscle relaxation (typically with selective inhibitors) Activation of PKG induces phosphorylation of target proteins, reducing intracellular calcium and promoting smooth muscle relaxation (activation with cGMP analogs or NO donors) Modulation of PKG activity can alter platelet function and vascular tone