PP1 Inhibitor-2: Proteins and Enzymes

Protein Phosphatase 1 Inhibitor-2 (PP1 Inhibitor-2), also called PP1 regulatory subunit 2 (PP1R2), I2, and IPP2, binds to PP1 through an RVxF consensus sequence. The complex inactivates PP1, preventing it from dephosphorylating substrates such as glycogen phosphorylase. Unlike PP1 Inhibitor-1, the binding of PP1 Inhibitor-2 is Protein Kinase A phosphorylation-independent. Dissociation of the PP1 Inhibitor-2 complex is enhanced by phosphorylation at T72 by GSK-3, ERK, or CDK. Overexpression of PP1 Inhibitor-2 in mouse heart improves cardiac function without changing organ size.