protein phosphatase 1 regulatory subunit 3A; protein phosphatase 1 glycogen-associated regulatory subunit; protein phosphatase type-1 glycogen targeting subunit; RG1 (PPP1R3A, PP1G)

Function

• seems to act as a glycogen-targeting subunit for PP1
• role in glycogen synthesis but is not essential for insulin activation of glycogen synthase
• phosphorylation at Ser-46 by ISPK stimulates the dephosphorylation of glycogen synthase & phosphorylase kinase
• interacts with PPP1CC catalytic subunit of PP1, & associates with glycogen (putative)

Structure

• the CBM21 domain is known to be involved in the localization to glycogen & is characteristic of some regulatory subunit of phosphatase complexes
• contains 1 CBM21 (carbohydrate binding type-21) domain

Compartment

membrane

Alternative splicing

• named isoforms=2
• at least on isoform may be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay

Expression

skeletal muscle & heart

Pathology

• defects in PPP1R3A gene associated with susceptibility to diabetes mellitus 2

More general terms

• protein phosphatase-1 regulatory subunit
• phosphoprotein
• membrane protein

Additional terms

• diabetes mellitus type 2 (insulin-resistant)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5506
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5506
• OMIM: https://mirror.omim.org/entry/125853
• OMIM: https://mirror.omim.org/entry/600917
• UniProt: http://www.uniprot.org/uniprot/Q16821.html