Glycogenin-1 (GYG1)

Glycogenin-1 is a muscle-expressed enzyme classified as a glycosyltransferase, essential for glycogen biosynthesis by catalyzing autocatalytic addition of glucose residues to itself from UDP-glucose, forming a short oligosaccharide primer required for elongation by glycogen synthase and branching enzymes. It self-glucosylates—primarily on the Tyr-194 residue in humans—forming the core of growing glycogen particles, and remains covalently attached to the reducing end of glycogen molecules. The GYG1 gene encodes glycogenin-1; mutations in GYG1 cause muscle-specific glycogen storage disease type XV, which manifests as muscle glycogen depletion, mitochondrial proliferation, and can also lead to cardiomyopathy and arrhythmias. Glycogenin-1 is particularly important in muscle, while a related isoform, glycogenin-2, functions in the liver and heart. There are currently no specific drugs known to target glycogenin-1 directly in therapy; its main significance is in inherited metabolic disease and as a key regulator of muscle energy storage[1][3][4][5].

Other names

Glycogenin-1GYG1GYGGN-1GN1glycogenin glucosyltransferaseGSD15glycogeninglycogenin-1priming glucosyltransferaseUDP-glucose:glycogenin glucosyltransferase