Protein phosphatase 1 regulatory subunit 3C (PPP1R3C)

Protein phosphatase 1 regulatory subunit 3C is a regulatory protein that serves as a targeting subunit for protein phosphatase 1 (PP1), anchoring the enzyme to glycogen particles and regulating its activity in glycogen metabolism[1][5]. It enhances glycogen biosynthesis by activating glycogen synthase and reducing the activity of glycogen phosphorylase, thereby limiting glycogen breakdown[1][3][5]. DNA hypermethylation of PPP1R3C is associated with colorectal cancer[3]. PPP1R3C interacts with laforin, a phosphatase involved in Lafora disease[3]. Overexpression results in marked increases in both basal and insulin-stimulated glycogen synthesis[1][3][5]. The protein belongs to the family of carbohydrate binding module-containing, PP1 regulatory subunits[4]. No drugs directly targeting PPP1R3C are listed in major databases as of mid-2024. Disease associations include cancer (colorectal, prostate), epilepsy, and glycogen storage disorders. Mechanistically, modulation of PPP1R3C could impact glucose homeostasis and PP1-related signaling. Biomarker status is indicated for some cancers (e.g., DNA methylation status in colorectal cancer). Safety concerns would mirror those typical for metabolic regulators, including risk of hypoglycemia and widespread cellular effects due to PP1 activity modulation[3][5].

Other names

Protein phosphatase 1 regulatory subunit 3CPPP1R3CPPP1R5PTGProtein targeting to glycogenPP1 subunit R5Phosphatase 1 regulatory inhibitor subunit 5

Not drug-targeted in current clinical practice; mechanistically, drugs would target its regulatory effect on glycogen synthase/phosphorylase, potentially influencing glycogen metabolism indirectly