ALG3/YBL082C Summary 
ALG3 BASIC INFORMATION
| Standard Name | ALG3 1 |
|---|---|
| Systematic Name | YBL082C |
| Alias | RHK1 2 |
| Feature Type | ORF, Verified |
| Description | Dolichol-P-Man dependent alpha(1-3) mannosyltransferase, involved in the synthesis of dolichol-linked oligosaccharide donor for N-linked glycosylation of proteins (2, 3, 4 and see Summary Paragraph) 
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| Name Description | Asparagine Linked Glycosylation 1 |
| GO Annotations | All ALG3 GO evidence and references |
|---|---|
| View Computational GO annotations for ALG3 | |
| Molecular Function | |
| Manually curated | |
| Biological Process | |
| Manually curated | |
| Cellular Component | |
| Manually curated |
| Pathways |
|---|
| Mutant Phenotype | All ALG3 Phenotype details and references |
|---|---|
| Classical genetics | |
| null |
|
| unspecified | |
| Large-scale survey | |
| null |
| Interactions | ALG3 All interactions details and references |
|---|---|
| 34 total interaction(s) for 20 unique genes/features. | |
| Physical Interactions |
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| Genetic Interactions |
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| External Links | All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | UniProtKB |
|---|
| Primary SGDID | S000000178 |
|---|
ALG3 RESOURCES
| SGD ORF map | GBrowse |
|---|---|
|
Click on histogram for expression summary
Expression Summary
ADDITIONAL INFORMATION for ALG3
SUMMARY PARAGRAPH for ALG3
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 5, 6).
Alg3p is an alpha 1,3 mannosyltransferase that catalyzes the addition of the sixth mannose moiety to the growing lipid-linked oligosaccharide (LLO) (3, 4). This is the first sugar added to the LLO in the lumen of the endoplasmic reticulum. The seventh mannose moiety is added by Alg9p. Disruption of ALG3 causes accumulation of lipid-linked oligosaccharides with five mannose residues (1, 3, 4).
The designation RHK1 indicates that mutants are resistant to the HM-1 killer toxin from the yeast Hansenula mrakii, possibly due to defective glycosylation of the toxin receptor (2).
Human ALG3 (OMIM) cDNA complements deletion of ALG3 in mutant yeast (7) and has been found to be mutated in the
Last updated: 2005-07-12
REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for ALG3]
| 1) | Huffaker TC and Robbins PW (1983) Yeast mutants deficient in protein glycosylation. Proc Natl Acad Sci U S A 80(24):7466-70 |
| 2) | Kimura T, et al. (1997) A novel yeast gene, RHK1, is involved in the synthesis of the cell wall receptor for the HM-1 killer toxin that inhibits beta-1,3-glucan synthesis. Mol Gen Genet 254(2):139-47 |
| 3) | Aebi M, et al. (1996) Cloning and characterization of the ALG3 gene of Saccharomyces cerevisiae. Glycobiology 6(4):439-44 |
| 4) | Sharma CB, et al. (2001) Biosynthesis of lipid-linked oligosaccharides in yeast: the ALG3 gene encodes the Dol-P-Man:Man5GlcNAc2-PP-Dol mannosyltransferase. Biol Chem 382(2):321-8 |
| 5) | Herscovics A and Orlean P (1993) Glycoprotein biosynthesis in yeast. FASEB J 7(6):540-50 |
| 6) | Burda P and Aebi M (1999) The dolichol pathway of N-linked glycosylation. Biochim Biophys Acta 1426(2):239-57 |
| 7) | Korner C, et al. (1999) Carbohydrate deficient glycoprotein syndrome type IV: deficiency of dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl mannosyltransferase. EMBO J 18(23):6816-22 |
