Interaction between glycogenin and glycogen synthase.
Glycogen synthase plays a key role in regulating glycogen metabolism. In a search for regulators of glycogen synthase, a yeast two-hybrid study was performed. Two glycogen synthase-interacting proteins were identified in human skeletal muscle, glycogenin-1, and nebulin. The interaction with glycogenin was found to be mediated by the region of glycogenin which contains the 33 COOH-terminal amino acid residues. The regions in glycogen synthase containing both NH2- and COOH-terminal phosphorylation sites are not involved in the interaction. The core segment of glycogen synthase from Glu21 to Gly503 does not bind COOH-terminal fragment of glycogenin. However, this region of glycogen synthase binds full-length glycogenin indicating that glycogenin contains at least one additional interacting site for glycogen synthase besides the COOH-terminus. We demonstrate that the COOH-terminal fragment of glycogenin can be used as an effective high affinity reagent for the purification of glycogen synthase from skeletal muscle and liver.
Skurat
Alexander V
AV
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202-5122, USA. askurat@iupui.edu
Dietrich
Amy D
AD
Roach
Peter J
PJ
D001665:Binding Sites; D005964:Glucosyltransferases / Q000737:chemistry* / Q000378:metabolism*; D006006:Glycogen Synthase / Q000737:chemistry* / Q000378:metabolism*; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D020798:Two-Hybrid System Techniques
D006023:Glycoproteins; C051887:glycogenin; D005964:Glucosyltransferases; D006006:Glycogen Synthase