Glycogenin-2 (GYG2)

Glycogenin-2 is a self-glucosylating enzyme primarily expressed in the liver, encoded by the GYG2 gene. It initiates *de novo* glycogen biosynthesis by catalyzing the covalent attachment of the first few glucose units (from UDP-glucose) to itself, creating a short α(1,4)-linked glucosyl chain that serves as a primer for glycogen synthase and glycogen branching enzyme[1][3][4]. The primary physiological role of glycogenin-2 is in the liver, where it helps initiate and regulate the size and structure of glycogen particles, contributing to glucose homeostasis in mammals[1][7]. Unlike its paralog glycogenin-1 (GYG1), which is expressed mainly in muscle, GYG2 is largely restricted to hepatic and cardiac tissue. Studies in humans show that deletion or loss of GYG2 does not severely impair glycogen synthesis or glucose release from the liver, indicating redundancy with glycogenin-1 and suggesting that its absence is generally compensated[5]. No drugs are known to specifically target glycogenin-2, and its deficiency has not been conclusively linked to a defined metabolic or glycogen storage disorder[5][1].

Other names

Glycogenin-2GYG2GN-2GN2glycogenin glucosyltransferasepriming glucosyltransferaseUDP-glucose:glycogenin glucosyltransferase

Not applicable (no drugs are known to directly target glycogenin-2 clinically as of current knowledge)