Protein phosphatase 1 regulatory subunit 3A (PPP1R3A)

Protein phosphatase 1 regulatory subunit 3A (PPP1R3A) is a muscle-specific regulatory subunit of protein phosphatase 1 (PP1) that targets PP1 to glycogen particles in skeletal muscle and heart, enabling dephosphorylation of key enzymes involved in glycogen metabolism such as glycogen synthase and glycogen phosphorylase kinase. PPP1R3A binds both to the PP1 catalytic subunit and to glycogen, forming part of a heterodimeric complex central to glycogen synthesis and degradation. By integrating signaling pathways including those mediated by insulin and adrenaline, PPP1R3A critically modulates energy homeostasis, with genetic variants or altered expression implicated in diseases like type 2 diabetes, obesity, and cardiac arrhythmias. Recent evidence also identifies PPP1R3A as a modulator of calcium handling complexes important for cardiac function, contributing to arrhythmogenic susceptibility when its function is impaired.

Other names

GMPP1GPPP1R3RG1protein phosphatase 1 glycogen-associated regulatory subunitprotein phosphatase type-1 glycogen targeting subunitglycogen-associated regulatory subunit of protein phosphatase-1protein phosphatase 1 regulatory subunit GMglycogen and sarcoplasmic reticulum binding subunit, skeletal muscleserine/threonine-specific protein phosphatase skeletal muscle glycogen targeting subunit

Drugs would act by modulating glycogen metabolism or influencing PP1 targeting/activity via PPP1R3A’s regulatory impact (no direct drugs currently listed)