Glycogenin is dispensible in mice liver glycogen synthesis

Abstract

Glycogen is a polysaccharide molecule that stores glucose in animals, fungi, and E.coli. Glycogen biosynthesis starts on an oligosaccharide chain primed by glycogenin, elongated by glycogen synthase and branched via glycogen branching enzyme. Traditionally, glycogenin is believed to be essential for glycogen synthesis and structure formation. However, a recent study on glycogenin knockout mice found that glycogen formation still occurs in skeletal muscle, liver, cardiac muscle, and brain. The study also revealed structural and physiological results that contradict the expected role of glycogenin in linking β particles into α particles. This research aims to explore glycogenin's function in the liver through proteomic investigation on Gyg KO mice and targeted glycogen structure characterization and selected metabolites biochemical quantification. The results suggest glycogenin is dispensible for liver tissue. There is only minor metabolism change in Gyg KO mice liver.