ALG7/YBR243C Summary Help

Standard Name ALG7 1
Systematic Name YBR243C
Alias TUR1
Feature Type ORF, Verified
Description UDP-N-acetyl-glucosamine-1-P transferase; transfers Glc-Nac-P from UDP-GlcNac to Dol-P in the ER in the first step of the dolichol pathway of protein asparagine-linked glycosylation; inhibited by tunicamycin (2, 3 and see Summary Paragraph)
Name Description Asparagine-Linked Glycosylation 4
Chromosomal Location
ChrII:706793 to 705447 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All ALG7 GO evidence and references
  View Computational GO annotations for ALG7
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 3 genes
Classical genetics
Large-scale survey
reduction of function
49 total interaction(s) for 43 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 1
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 6
  • Co-fractionation: 1
  • Co-purification: 1
  • PCA: 5
  • Two-hybrid: 1

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Lethality: 1
  • Dosage Rescue: 2
  • Negative Genetic: 12
  • Positive Genetic: 8
  • Synthetic Growth Defect: 1
  • Synthetic Lethality: 1
  • Synthetic Rescue: 7

Expression Summary
Length (a.a.) 448
Molecular Weight (Da) 50,367
Isoelectric Point (pI) 8.4
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrII:706793 to 705447 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1347 706793..705447 2011-02-03 1997-01-28
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 SGDIDS000000447

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).

ALG7 encodes the dolichyl-P-dependent N-acetylglucosamine-1-P transferase (GPT) that catalyzes the first step in the synthesis of lipid-linked oligosaccharides (LLO's): addition of the first N-acetylglucosamine to dolichyl phosphate on the cytosolic side of the endoplasmic reticulum (3, 7).

Alg7p is essential, and its activity is inhibited by tunicamycin (3, 8). Expression of ALG7 is cell-cycle regulated, in coordination with ALG1 and ALG2 (8, 9). Upon alpha factor arrest, mutants with diminished Alg7p activity show only transient downregulation of CLN1 and CLN2 mRNAs, and therefore these alg7 mutants resume their progression through the cell cycle (10). An interesting hypomorphic alg7 mutant lost mitochondrial DNA (11).

ALG7 is the most ancient and widely found of the ALG genes examined (12). An orthologous gene from an Archaeal species (Methanococcus voltae) complements the alg7 deletion (13). The human ortholog, DPAGT1 (OMIM), also complements a conditional deletion of ALG7 (14). Mutations in DPAGT1 cause the congenital disorder of glycosylation CDG-Ij (OMIM) (15).

Last updated: 2005-07-12 Contact SGD

References cited on this page View Complete Literature Guide for ALG7
1) Rine J, et al.  (1983) Targeted selection of recombinant clones through gene dosage effects. Proc Natl Acad Sci U S A 80(22):6750-4
2) Kukuruzinska MA and Lennon K  (1995) Diminished activity of the first N-glycosylation enzyme, dolichol-P-dependent N-acetylglucosamine-1-P transferase (GPT), gives rise to mutant phenotypes in yeast. Biochim Biophys Acta 1247(1):51-9
3) Barnes G, et al.  (1984) Asparagine-linked glycosylation in Saccharomyces cerevisiae: genetic analysis of an early step. Mol Cell Biol 4(11):2381-8
4) Huffaker TC and Robbins PW  (1982) Temperature-sensitive yeast mutants deficient in asparagine-linked glycosylation. J Biol Chem 257(6):3203-10
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) Kukuruzinska MA and Robbins PW  (1987) Protein glycosylation in yeast: transcript heterogeneity of the ALG7 gene. Proc Natl Acad Sci U S A 84(8):2145-9
8) Kukuruzinska MA and Lennon K  (1994) Growth-related coordinate regulation of the early N-glycosylation genes in yeast. Glycobiology 4(4):437-43
9) Pretel R, et al.  (1995) Expression of the first N-glycosylation gene in the dolichol pathway, ALG7, is regulated at two major control points in the G1 phase of the Saccharomyces cerevisiae cell cycle. Exp Cell Res 219(2):477-86
10) Lennon K, et al.  (1997) Deregulation of the first N-glycosylation gene, ALG7, perturbs the expression of G1 cyclins and cell cycle arrest in Saccharomyces cerevisiae. Biochem Biophys Res Commun 237(3):562-5
11) Mendelsohn RD, et al.  (2005) A hypomorphic allele of the first N-glycosylation gene, ALG7, causes mitochondrial defects in yeast. Biochim Biophys Acta 1723(1-3):33-44
12) Samuelson J, et al.  (2005) The diversity of dolichol-linked precursors to Asn-linked glycans likely results from secondary loss of sets of glycosyltransferases. Proc Natl Acad Sci U S A 102(5):1548-53
13) Shams-Eldin H, et al.  (2008) Identification of the archaeal alg7 gene homolog (encoding N-acetylglucosamine-1-phosphate transferase) of the N-linked glycosylation system by cross-domain complementation in Saccharomyces cerevisiae. J Bacteriol 190(6):2217-20
14) Eckert V, et al.  (1998) Cloning and functional expression of the human GlcNAc-1-P transferase, the enzyme for the committed step of the dolichol cycle, by heterologous complementation in Saccharomyces cerevisiae. Glycobiology 8(1):77-85
15) Wu X, et al.  (2003) Deficiency of UDP-GlcNAc:Dolichol Phosphate N-Acetylglucosamine-1 Phosphate Transferase (DPAGT1) causes a novel congenital disorder of Glycosylation Type Ij. Hum Mutat 22(2):144-50