protein phosphatase 1 regulatory subunit 3B; protein phosphatase 1 regulatory subunit 4; R4; protein phosphatase 1 subunit GL; hepatic glycogen-targeting protein phosphatase 1 regulatory subunit GL (PPP1R3B, PPP1R4)

Function: - acts as a glycogen-targeting subunit for phosphatase PP1 - facilitates interaction of the PP1 with enzymes of glycogen metabolism & regulates its activity - suppresses the rate at which PP1 dephosphorylates (inactivates) glycogen phosphorylase & enhances the rate at which it activates glycogen synthase & therefore limits glycogen breakdown - activity is inhibited by PYGL, resulting in inhibition of glycogen synthase & glycogen phosphorylase phosphatase activities of PP1 - dramatically increases basal & insulin-stimulated glycogen synthesis upon overexpression in hepatocytes (putative) - interacts with glycogen, PPP1CC catalytic subunit of PP1 & PYGL - associates with glycogen particles - forms complexes with debranching enzyme, glycogen phosphorylase, glycogen synthase & phosphorylase kinase which is necessary for its regulation of PP1 activity (putative) Structure: - N-terminal region is required for binding to PP1, - central region is required for binding to glycogen - C-terminal region is required for binding to PYGL (putative) - contains 1 CBM21 domain (carbohydrate binding type-21) Expression: - moderately-highly expressed in liver - expressed moderately-predominantly in heart & skeletal muscle & myotubes - expressed moderately in liver. expressed weakly in placenta, lung & kidney

Properties

INHIBITS: phosphatase SIZE: entity length = 285 aa MW = 33 kD MOTIF: CBM21 {125-233}

Database Correlations

UniProt Q86XI6 Pfam PF03370 Entrez Gene 79660 Kegg hsa:7966

References

UniProt :accession Q86XI6