Enables [phosphorylase] phosphatase activity and enzyme binding activity. Contributes to phosphoprotein phosphatase activity. Involved in regulation of glycogen biosynthetic process and regulation of glycogen catabolic process. Located in glycogen granule and intracellular membrane-bounded organelle. Orthologous to human PPP1R3C (protein phosphatase 1 regulatory subunit 3C). [provided by Alliance of Genome Resources, Apr 2022]