Based on limited published evidence, PPP1R3E encodes a glycogen-targeting regulatory subunit of protein phosphatase 1 (PP1) involved in glycogen metabolism. It binds glycogen and directs PP1 to dephosphorylate and activate glycogen synthase, promoting glycogen synthesis 1. PPP1R3E expression is insulin-regulated and downregulated in diabetes, with species-specific tissue distribution differences between humans and rodents 1. Recent genetic studies identified PPP1R3E as a candidate autosomal recessive gene in Parkinson's disease families 2, though the mechanistic relationship between PPP1R3E dysfunction and neurodegeneration remains unclear.