Stimulation of glycogen synthesis is one of the major physiological responses modulated by insulin.
The process occurs in the cytosol, and requires energy supplied by ATP and uridine triphosphate (UTP).
The synthesis of glycogen involves at least two distinguishable stages.
First by controlling the uptake and transport of glucose – the building block for the synthesis of glycogen molecule and secondly, by regulating the phosphorylation and activation states of enzymes involved in the synthesis and degradation of glycogen.
Most of the glycogen synthesis occurs through the lengthening of the polysaccharide chains of a preexisting glycogen molecule in which the reducing end of the glycogen is attached to the protein glycogenin. Glycogenin is a protein that attaches short chain of eight glucose molecules to the hydroxyl (-OH) group of a tyrosine residue on itself.
Glycogen synthase is responsible for making the α(1→4) linkages in glycogen. This enzyme only elongates already existing chains of glucose.
Synthesis of glycogen
