Glycogenin-1 (GYG1)
The protein contains 350 amino acids for an estimated molecular weight of 39384 Da.
Self-glucosylates, via an inter-subunit mechanism, to form an oligosaccharide primer that serves as substrate for glycogen synthase. (updated: April 1, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
Biological Process
Carbohydrate metabolic process
Glucose metabolic process
Glycogen biosynthetic process
Glycogen catabolic process
Neutrophil degranulation
Pathogenesis
Small molecule metabolic process
The reference OMIM entry for this protein is 603942
Glycogenin 1; gyg1
DESCRIPTION
The GYG1 gene encodes glycogenin-1, a glycosyltransferase (EC 2.4.1.186) that catalyzes 2 autoglucosylation reactions using UDP-glucose as the donor substrate during the initiation of glycogen synthesis. GYG1 is expressed in skeletal and heart muscle. During initiation, the covalent attachment of a glucose residue to glycogenin is followed by elongation to form an oligosaccharide chain (summary by Viskupic et al., 1992 and Nilsson et al., 2012).CLONING
Viskupic et al. (1992) isolated cDNAs encoding glycogenin from rabbit muscle, rat, and cow. Recombinant mammalian glycogenin was enzymatically active and capable of self-glucosylation. After incubation with UDP-glucose, the recombinant protein was able to serve as a substrate for glycogen synthase, leading to the production of high M(r) polysaccharide. Barbetti et al. (1996) identified a human glycogenin cDNA. The predicted 333-amino acid human protein shares 93% identity with rabbit muscle glycogenin. Northern blot analysis revealed that the 2.4-kb glycogenin mRNA was expressed prominently in human skeletal muscle and heart, and to a lesser extent in several other tissues. Imagawa et al. (2014) noted that GYG1 is not expressed in liver or brain, tissues in which GYG2 (300198) is highly expressed.MAPPING
By FISH, Barbetti et al. (1996) mapped the GYG1 gene to chromosome 3q25.1. Using somatic cell hybrid analysis, they confirmed the chromosome 3 localization and also identified intronless glycogenin-related sequences on chromosomes 12 and 13. By FISH, Lomako et al. (1996) mapped the GYG1 gene to chromosome 3q24.MOLECULAR GENETICS
- Glycogen Storage Disease XV In a 27-year-old man with muscle weakness and cardiac arrhythmias associated with glycogen depletion, here designated glycogen storage disease XV (GSD15; 613507), Moslemi et al. (2010) identified compound heterozygosity for a nonsense (603942.0001) and a missense (603942.0002) mutation in the GYG1 gene. Western blotting demonstrated the presence of unglucosylated glycogenin-1 in the patient's skeletal and cardiac muscle. - Polyglucosan Body Myopathy 2 In 7 unrelated patients with polyglucosan body myopathy-2 (PGBM2; 616199), Malfatti et al. (2014) identified homozygous or compound heterozygous mutations in the GYG1 gene (see, e.g., 603942.0003-603942.0007). The most common mutation was a splice site mutation (603942.0003), found in the homozygous or compound heterozygous state in 4 patients. Segregation analysis of the mutations in families was not reported. Unlike the patient reported by Moslemi et al. (2010), none of the 7 patients with PGBM2 had evidence of cardiac involvement. Some patients had absence of GYG1 protein in skeletal muscle tissue, whereas others had reduced levels of the protein with some residual function. Analysis of glycogenin-1 in skeletal muscle of 1 patient who had a deletion of the C terminus of GYG1 (603942.0004) indicated that the protein was autoglucosylated, but that elongation of the glycogen polymer was impaired. These findings suggested that the C terminus of GYG1 is important for glycogen synthase (GYS1; 138570) activity. ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 603942 was added.