GYG1
Function
Glycogenin participates in the glycogen biosynthetic process along with glycogen synthase and glycogen branching enzyme. It catalyzes the formation of a short alpha (1,4)-glucosyl chain covalently attached via a glucose 1-O-tyrosyl linkage to internal tyrosine residues and these chains act as primers for the elongation reaction catalyzed by glycogen synthase.
Involvement in disease
Glycogen storage disease 15
GSD15
A metabolic disorder resulting in muscle weakness, associated with the glycogen depletion in skeletal muscle, and cardiac arrhythmia, associated with the accumulation of abnormal storage material in the heart. The skeletal muscle shows a marked predominance of slow-twitch, oxidative muscle fibers and mitochondrial proliferation.
None
The disease is caused by variants affecting the gene represented in this entry.
Polyglucosan body myopathy 2
PGBM2
A glycogen storage disease characterized by polyglucosan accumulation in muscle, and skeletal myopathy without cardiac involvement. Most patients manifest slowly progressive, hip girdle, shoulder girdle, and/or hand and leg muscle weakness. Polyglucosan contains abnormally long and poorly branched glucosyl chains and is variably resistant to digestion by alpha-amylase.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Glycan biosynthesis; glycogen biosynthesis.
Post-translational modifications
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.
Sequence Similarities
Belongs to the glycosyltransferase 8 family. Glycogenin subfamily.
Tissue Specificity
Highly expressed in skeletal muscle and heart, with lower levels in brain, lung, kidney and pancreas.
Cellular localization
- Cytoplasm
- Nucleus
- Localizes to glycogen granules (glycosomes) in the cytoplasm (By similarity). Cytosolic localization is dependent on the actin cytoskeleton (By similarity).
Alternative names
GYG, GYG1, Glycogenin-1, GN-1, GN1