ALG8/YOR067C Summary Help

ALG8 BASIC INFORMATION

Standard Name ALG8 1
Systematic Name YOR067C
Alias YOR29-18
Feature Type ORF, Verified
Description Glucosyl transferase, involved in N-linked glycosylation; adds glucose to the dolichol-linked oligosaccharide precursor prior to transfer to protein during lipid-linked oligosaccharide biosynthesis; similar to Alg6p (1, 2 and see Summary Paragraph)
Name Description Asparagine-Linked Glycosylation 1, 2
GO Annotations All ALG8 GO evidence and references
    View Computational GO annotations for ALG8
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Pathways
Mutant Phenotype All ALG8 Phenotype details and references
Classical genetics
null
Large-scale survey
null
Interactions ALG8 All interactions details and references
87 total interaction(s) for 50 unique genes/features.
Physical Interactions
  • Two-hybrid: 1
Genetic Interactions
  • Phenotypic Enhancement: 49
  • Phenotypic Suppression: 17
  • Synthetic Growth Defect: 8
  • Synthetic Lethality: 11
  • Synthetic Rescue: 1
Sequence Information
ChrXV:453464 to 451731 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gbrowse
Last Update Coordinates: 2006-01-05 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates		 Chromosomal
Coordinates		 Most Recent Updates
Coordinates Sequence
CDS 1..1734 453464..451731 2006-01-05 1996-07-31
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | UniProtKB
Primary SGDIDS000005593

ALG8 RESOURCES

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SGD ORF mapGBrowse
SGD ORF map
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  • Localization Resources
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  • Functional Analysis

Click on histogram for expression summary
Expression Summary histogram

ADDITIONAL INFORMATION for ALG8

SUMMARY PARAGRAPH for ALG8

During N-linked glycosylation of proteins, oligosaccharide chains are assembled on the carrier molecule dolichyl pyrophosphate in the following order: 2 molecules of N-acetylglucosamine (GlcNAc), 9 molecules of mannose, and 3 molecules of glucose. These 14-residue oligosaccharide cores are then transferred to asparagine residues on nascent polypeptide chains in the endoplasmic reticulum (ER). As proteins progress through the Golgi apparatus, the oligosaccharide cores are modified by trimming and extension to generate a diverse array of glycosylated proteins (reviewed in 3, 4).

ALG8 encodes an ER-membrane-bound alpha 1,3 glucosyltransferase that catalyzes the addition of the second of three glucose moieties (2) to growing lipid-linked oligosaccharides (LLO's) in the lumen of the endoplasmic reticulum. The first and third glucose residues are added by Alg6p (a close homolog of Alg8p) and Die2p (also known as Alg10p), respectively. Mutants lacking Alg8p produce truncated LLO's with only one glucose residue (5) that are able to be transferred to proteins with reduced efficiency (2). Mutations in human ALG8 (OMIM) have been implicated in the congenital disorder of glycosylation CDG-Ih (OMIM) (6, 7).

Last updated: 2006-03-03

REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for ALG8]

1) Stagljar I, et al.  (1994) New phenotype of mutations deficient in glucosylation of the lipid-linked oligosaccharide: cloning of the ALG8 locus. Proc Natl Acad Sci U S A 91(13):5977-81
2) Runge KW and Robbins PW  (1986) A new yeast mutation in the glucosylation steps of the asparagine-linked glycosylation pathway. Formation of a novel asparagine-linked oligosaccharide containing two glucose residues. J Biol Chem 261(33):15582-90
3) Herscovics A and Orlean P  (1993) Glycoprotein biosynthesis in yeast. FASEB J 7(6):540-50
4) Burda P and Aebi M  (1999) The dolichol pathway of N-linked glycosylation. Biochim Biophys Acta 1426(2):239-57
5) Munoz MD, et al.  (1994) Glycosylation of yeast exoglucanase sequons in alg mutants deficient in the glucosylation steps of the lipid-linked oligosaccharide. Presence of glucotriose unit in Dol-PP-GlcNAc2Man9Glc3 influences both glycosylation efficiency and selection of N-linked sites. Biochim Biophys Acta 1201(3):361-6
6) Chantret I, et al.  (2003) A deficiency in dolichyl-P-glucose:Glc1Man9GlcNAc2-PP-dolichyl alpha3-glucosyltransferase defines a new subtype of congenital disorders of glycosylation. J Biol Chem 278(11):9962-71
7) Schollen E, et al.  (2004) Clinical and molecular features of three patients with congenital disorders of glycosylation type Ih (CDG-Ih) (ALG8 deficiency). J Med Genet 41(7):550-6