GYG1 Human

Glycogenin-1 is a crucial enzyme involved in the biosynthesis of glycogen, a multi-branched polysaccharide that serves as a primary means of glucose storage in animal cells. This enzyme is capable of self-glucosylation, forming an oligosaccharide primer that acts as a substrate for glycogen synthase .

Glycogenin-1 belongs to the glycosyltransferase 8 family and is known for its self-glycosylation ability. This process involves the transfer of glucose residues from UDP-glucose to itself, forming an alpha-1,4-glycan of around 10 residues attached to the tyrosine residue at position 195 . The enzyme operates through an inter-subunit mechanism, which is essential for initiating glycogen synthesis .

In humans, Glycogenin-1 is encoded by the GYG1 gene located on chromosome 3 (3q24). The enzyme is predominantly expressed in skeletal muscle tissues, including the biceps brachii, deltoid muscle, and glutes . It is also found in other tissues such as the liver, where it plays a role in maintaining glucose homeostasis .

Recombinant human Glycogenin-1 is produced using Escherichia coli as an expression system. The protein is purified using conventional chromatography techniques, achieving a purity level of over 90% suitable for SDS-PAGE . This recombinant form retains the enzyme’s biological activity, making it valuable for research and therapeutic applications.

Glycogenin-1 is essential for glycogen metabolism regulation. In the liver, glycogen serves to maintain glucose levels between meals by generating glucose through glycogenolysis. In skeletal muscles, glycogen provides a readily available energy source during physical activity .

Mutations in the GYG1 gene can lead to glycogen storage diseases, which are characterized by abnormal glycogen accumulation in tissues. Understanding the function and regulation of Glycogenin-1 is crucial for developing therapeutic strategies for these conditions .