glycogenin-1; GN-1 (GYG1. GYG)

Function

• self-glucosylates, via an inter-subunit mechanism, to form an oligosaccharide primer that serves as substrate for glycogen synthase
• glycan biosynthesis; glycogen biosynthesis
• self-glycosylated by the transfer of glucose residues from UDP-glucose to itself, forming an alpha-1,4-glycan of around 10 residues attached to Tyr-195
• phosphorylated (putative)
• homodimer tightly complexed to the 86 kD catalytic subunit of glycogen synthase GYS1
• also see glycogenin

Cofactor:

• divalent metal ions required for self-glucosylation
• Mn+2 is the most effective

UDP-alpha-D-glucose + glycogenin = UDP + alpha-D-glucosylglycogenin

Structure

belongs to the glycogenin family

Alternative splicing

named isoforms=3

Pathology

• defects in GYG1 are the cause of glycogen storage disease 15

More general terms

• glycogenin

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=2992
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:2992
• OMIM: https://mirror.omim.org/entry/603942
• OMIM: https://mirror.omim.org/entry/613507
• UniProt: http://www.uniprot.org/uniprot/P46976.html