Expression and purification of functional human glycogen synthase-1:glycogenin-1 complex in insect cells

Hunter, R. W., Zeqiraj, E., Morrice, N., Sicheri, F. and Sakamoto, K. (2015) Expression and purification of functional human glycogen synthase-1:glycogenin-1 complex in insect cells. Protein Expression and Purification, 108, pp. 23-29. (doi: 10.1016/j.pep.2014.12.007) (PMID:25527037) (PMCID:PMC4370744)

Abstract

We report the successful expression and purification of functional human muscle glycogen synthase (GYS1) in complex with human glycogenin-1 (GN1). Stoichiometric GYS1:GN1 complex was produced by co-expression of GYS1 and GN1 using a bicistronic pFastBac™-Dual expression vector, followed by affinity purification and subsequent size-exclusion chromatography. Mass spectrometry analysis identified that GYS1 is phosphorylated at several well-characterised and uncharacterised Ser/Thr residues. Biochemical analysis, including activity ratio (in the absence relative to that in the presence of glucose-6-phosphate) measurement, covalently attached phosphate estimation as well as phosphatase treatment, revealed that recombinant GYS1 is substantially more heavily phosphorylated than would be observed in intact human or rodent muscle tissues. A large quantity of highly-pure stoichiometric GYS1:GN1 complex will be useful to study its structural and biochemical properties in the future, which would reveal mechanistic insights into its functional role in glycogen biosynthesis.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Morrice, Dr Nicholas
• Authors: Hunter, R. W., Zeqiraj, E., Morrice, N., Sicheri, F., and Sakamoto, K.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Protein Expression and Purification
• Publisher: Elsevier
• ISSN: 1046-5928
• ISSN (Online): 1096-0279
• Copyright Holders: Copyright © 2015 The Authors
• First Published: First published in Protein Expression and Purification 108:23-29
• Publisher Policy: Reproduced under a Creative Commons License