GSY2/YLR258W Summary Help

Standard Name GSY2 1
Systematic Name YLR258W
Feature Type ORF, Verified
Description Glycogen synthase; expression induced by glucose limitation, nitrogen starvation, heat shock, and stationary phase; activity regulated by cAMP-dependent, Snf1p and Pho85p kinases as well as by the Gac1p-Glc7p phosphatase; GSY2 has a paralog, GSY1, that arose from the whole genome duplication; relocalizes from cytoplasm to plasma membrane upon DNA replication stress (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and see Summary Paragraph)
Name Description Glycogen SYnthase 1
Chromosomal Location
ChrXII:660716 to 662833 | ORF Map | GBrowse
Gene Ontology Annotations All GSY2 GO evidence and references
  View Computational GO annotations for GSY2
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 14 genes
Classical genetics
Large-scale survey
106 total interaction(s) for 72 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 28
  • Affinity Capture-RNA: 5
  • Affinity Capture-Western: 3
  • Biochemical Activity: 10
  • Co-crystal Structure: 1
  • Co-purification: 1
  • PCA: 6
  • Protein-peptide: 1
  • Reconstituted Complex: 12
  • Two-hybrid: 13

Genetic Interactions
  • Dosage Growth Defect: 3
  • Dosage Lethality: 1
  • Negative Genetic: 11
  • Phenotypic Suppression: 2
  • Positive Genetic: 4
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 1
  • Synthetic Rescue: 2

Expression Summary
Length (a.a.) 705
Molecular Weight (Da) 80,078
Isoelectric Point (pI) 6.32
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXII:660716 to 662833 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..2118 660716..662833 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000004248

Glycogen, a branched polymer of glucose, is a storage molecule whose accumulation is under rigorous nutritional control in many cells (11). In S. cerevisiae, glycogen biosynthesis involves three processes: nucleation, elongation, and ramification, or branching (12). GLG1 and GLG2 encode self-glucosylating glycogenin glucosyltransferases (EC: involved in glycogen nucleation (11). Both Glg1p and Glg2p are able to use UDP-glucose to produce a short alpha (1,4)-glucosyl chain covalently attached to an internal tyrosine residue (13). Glycogen synthase (EC:, Gsy1p and Gsy2p) is then able to extend the linear alpha (1,4)-chains of glycogen by catalyzing the formation of alpha (1,4)-glucosidic bonds from UDP-glucose at the non-reducing ends (1). Branches can be added into the glycogen molecule by Glc3p, the glycogen branching enzyme (EC: in S. cerevisiae (14). No enzyme that releases the glycogen chain from Glg1p or Glg2p has been identified (12).

GSY2 encodes the majority (approximately 90%) of the glycogen synthase activity in S. cerevisiae (1). GSY2 mRNA begins to accumulate when approximately 50% of the environmental glucose is gone, and peaks when environmental glucose is exhausted, similar to other glycogen metabolism genes (2). GSY2 is also induced by nitrogen starvation, environmental stresses, and stationary phase (7). Transcription of GSY2 is under complex regulation, with positive regulation by Snf1p, and by Msn2p/Msn4p through stress response elements (STREs), and negative regulation by Pho85p, and by cAMP-dependent protein kinase activity by both STRE-dependent and -independent mechanisms (15). Gys2p activity is also regulated at the protein level through the actions of protein kinases and protein phosphatases. The Pcl8p and Pcl10p cyclins direct Pho85p phosphorylation of Gsy2p, which decreases Gsy2p activity (5), and the Gac1p-Glc7p phosphatase dephosphorylates Gsy2p, which increases Gsy2p activity (8). GSY2 shows similarity to human glycogen synthase genes GYS1 and GYS2 (4).

Last updated: 2005-08-30 Contact SGD

References cited on this page View Complete Literature Guide for GSY2
1) Farkas I, et al.  (1991) Two glycogen synthase isoforms in Saccharomyces cerevisiae are coded by distinct genes that are differentially controlled. J Biol Chem 266(24):15602-7
2) Parrou JL, et al.  (1999) Dynamic responses of reserve carbohydrate metabolism under carbon and nitrogen limitations in Saccharomyces cerevisiae. Yeast 15(3):191-203
3) Hardy TA, et al.  (1994) Interactions between cAMP-dependent and SNF1 protein kinases in the control of glycogen accumulation in Saccharomyces cerevisiae. J Biol Chem 269(45):27907-13
4) Hardy TA and Roach PJ  (1993) Control of yeast glycogen synthase-2 by COOH-terminal phosphorylation. J Biol Chem 268(32):23799-805
5) Huang D, et al.  (1998) Cyclin partners determine Pho85 protein kinase substrate specificity in vitro and in vivo: control of glycogen biosynthesis by Pcl8 and Pcl10. Mol Cell Biol 18(6):3289-99
6) Peng ZY, et al.  (1990) Purification and characterization of glycogen synthase from a glycogen-deficient strain of Saccharomyces cerevisiae. J Biol Chem 265(23):13871-7
7) Ni HT and LaPorte DC  (1995) Response of a yeast glycogen synthase gene to stress. Mol Microbiol 16(6):1197-205
8) Wu X, et al.  (2001) Characterization of Gac1p, a regulatory subunit of protein phosphatase type I involved in glycogen accumulation in Saccharomyces cerevisiae. Mol Genet Genomics 265(4):622-35
9) Byrne KP and Wolfe KH  (2005) The Yeast Gene Order Browser: combining curated homology and syntenic context reveals gene fate in polyploid species. Genome Res 15(10):1456-61
10) Tkach JM, et al.  (2012) Dissecting DNA damage response pathways by analysing protein localization and abundance changes during DNA replication stress. Nat Cell Biol 14(9):966-76
11) Cheng C, et al.  (1995) Requirement of the self-glucosylating initiator proteins Glg1p and Glg2p for glycogen accumulation in Saccharomyces cerevisiae. Mol Cell Biol 15(12):6632-40
12) Francois J and Parrou JL  (2001) Reserve carbohydrates metabolism in the yeast Saccharomyces cerevisiae. FEMS Microbiol Rev 25(1):125-45
13) Mu J, et al.  (1996) Initiation of glycogen synthesis in yeast. Requirement of multiple tyrosine residues for function of the self-glucosylating Glg proteins in vivo. J Biol Chem 271(43):26554-60
14) Thon VJ, et al.  (1992) Coordinate regulation of glycogen metabolism in the yeast Saccharomyces cerevisiae. Induction of glycogen branching enzyme. J Biol Chem 267(21):15224-8
15) Enjalbert B, et al.  (2004) Combinatorial control by the protein kinases PKA, PHO85 and SNF1 of transcriptional induction of the Saccharomyces cerevisiae GSY2 gene at the diauxic shift. Mol Genet Genomics 271(6):697-708