Protein phosphatase 1 regulatory subunit 17, also known as G-substrate, is a substrate for cGMP-dependent protein kinase (PKG) and is primarily located in cerebellar Purkinje cells []. G-substrate phosphorylated by PKG inhibits the catalytic subunit of both protein phosphatase-1 and -2A [, ]. G-substrate regulates cerebellum-dependent long-term memory and it acts as a neuroprotectant in the ventral tegmental area and retina [].
