This family consists of the eukaryotic glycogen synthase proteins GYS1, GYS2 and GYS3 [1,2]. Glycogen synthase (GS) is the enzyme responsible for the synthesis of -1,4-linked glucose chains in glycogen. It is the rate limiting enzyme in the synthesis of the polysaccharide, and its activity is highly regulated through phosphorylation at multiple sites and also by allosteric effectors, mainly glucose 6-phosphate (G6P) [3].

1: Two glycogen synthase isoforms in Saccharomyces cerevisiae are coded by distinct genes that are differentially controlled. Farkas I, Hardy TA, Goebl MG, Roach PJ; J Biol Chem 1991;266:15602-15607. PMID:1908457

2: Mutations in the liver glycogen synthase gene in children with hypoglycemia due to glycogen storage disease type 0. Orho M, Bosshard NU, Buist NR, Gitzelmann R, Aynsley-Green A, Blumel P, Gannon MC, Nuttall FQ, Groop LC; J Clin Invest 1998;102:507-515. PMID:9691087

3: Intracellular distribution of glycogen synthase and glycogen in primary cultured rat hepatocytes. Garcia-Rocha M, Roca A, De La Iglesia N, Baba O, Fernandez-Novell JM, Ferrer JC, Guinovart JJ; Biochem J 2001;357:17-24. PMID:11415431