ALG7 / YBR243C Overview


Standard Name
ALG7 1
Systematic Name
YBR243C
SGD ID
SGD:S000000447
Aliases
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; human homolog DPAGT1 can complement yeast ALG7 mutant 2 3 5
Name Description
Asparagine-Linked Glycosylation 4
Comparative Info
Sequence Details

Sequence

The S. cerevisiae Reference Genome sequence is derived from laboratory strain S288C. Download DNA or protein sequence, view genomic context and coordinates. Click "Sequence Details" to view all sequence information for this locus, including that for other strains.


Protein Details

Protein

Basic sequence-derived (length, molecular weight, isoelectric point) and experimentally-determined (median abundance, median absolute deviation) protein information. Click "Protein Details" for further information about the protein such as half-life, abundance, domains, domains shared with other proteins, protein sequence retrieval for various strains, physico-chemical properties, protein modification sites, and external identifiers for the protein.


Length (a.a.)
448
Mol. Weight (Da)
50374.4
Isoelectric Point
8.51
Median Abundance (molecules/cell)
599 +/- 480

Alleles

Curated mutant alleles for the specified gene, listed alphabetically. Click on the allele name to open the allele page. Click "SGD search" to view all alleles in search results. Click "YeastMine" to view all alleles in YeastMine.


View all ALG7 alleles in SGD search | YeastMine

Gene Ontology Details

Gene Ontology

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code. SGD has manually curated and high-throughput GO Annotations, both derived from the literature, as well as computational, or predicted, annotations. Click "Gene Ontology Details" to view all GO information and evidence for this locus as well as biological processes it shares with other genes.


Summary
Dolichyl-P-dependent N-acetylglucosamine-1-P transferase (GPT) that catalyzes transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to dolichyl phosphate; involved in synthesis of oligosaccharide precursor for N-linked protein glycosylation; localized in endoplasmic reticulum

View computational annotations

Biological Process

Manually Curated

Cellular Component

Manually Curated

Pathways


Phenotype Details

Phenotype

Phenotype annotations for a gene are curated single mutant phenotypes that require an observable (e.g., "cell shape"), a qualifier (e.g., "abnormal"), a mutant type (e.g., null), strain background, and a reference. In addition, annotations are classified as classical genetics or high-throughput (e.g., large scale survey, systematic mutation set). Whenever possible, allele information and additional details are provided. Click "Phenotype Details" to view all phenotype annotations and evidence for this locus as well as phenotypes it shares with other genes.


Summary
Essential gene; activation blocks sporulation, increases resistance to GlcNAc phosphotransferase (GPT) inhibitor tunicamycin; reduced function mutants show decreased competitive fitness, decreased resistance to tunicamycin; repression causes loss of the mitochondrial genome, and decreased accumulation of dolichol-linked oligosaccharides; heterozygous diploid nulls are sensitive to tunicamycin
Interaction Details

Interaction

Interaction annotations are curated by BioGRID and include physical or genetic interactions observed between at least two genes. An interaction annotation is composed of the interaction type, name of the interactor, assay type (e.g., Two-Hybrid), annotation type (e.g., manual or high-throughput), and a reference, as well as other experimental details. Click "Interaction Details" to view all interaction annotations and evidence for this locus, including an interaction visualization.


57 total interactions for 51 unique genes

Physical Interactions

  • Affinity Capture-RNA: 2
  • Affinity Capture-Western: 6
  • Co-fractionation: 1
  • PCA: 5
  • Two-hybrid: 2

Genetic Interactions

  • Dosage Growth Defect: 1
  • Dosage Lethality: 1
  • Dosage Rescue: 7
  • Negative Genetic: 12
  • Phenotypic Enhancement: 2
  • Positive Genetic: 8
  • Synthetic Growth Defect: 1
  • Synthetic Lethality: 1
  • Synthetic Rescue: 8
Regulation Details

Regulation

The number of putative Regulators (genes that regulate it) and Targets (genes it regulates) for the given locus, based on experimental evidence. This evidence includes data generated through high-throughput techniques. Click "Regulation Details" to view all regulation annotations, shared GO enrichment among regulation Targets, and a regulator/target diagram for the locus.


Summary
ALG7 encodes a UDP-GlcNAc transferase involved in the first step of N-linked glycosylation of proteins in the endoplasmic reticulum (ER) - the assembly of the lipid-linked oligosaccharide (LLO), which then serves as a donor in the second step - the transfer of the oligosaccharide to asparagine residues of nascent polypeptides. The lipid component that anchors the LLO in the ER membrane is dolichol (Dol), a polyisoprenoid molecule composed in yeast of 15-16 isoprene units. The LLO assembly involves sequential additions of two N-acetylglucosamine (GlcNAc), nine mannose (Man), and three glucose (Glc) residues. Alg7p catalyzes the first step in this process, the addition of the GlcNAc moiety to Dol-PP. The subsequent steps involve the addition of the second GlcNAc molecule by the Alg13p-Alg14p complex, one Man molecule by Alg1p, two branching Man molecules by an alpha-1,3- and alpha-1,6-mannosyltransferase Alg2p, followed by two consecutive additions of Man by an alpha-1,2-mannosyltransferase Alg11p. All these steps take place on the cytoplasmic side of the ER membrane and the product, Dol-PP-GlcNAc2-Man5, is then flipped to the ER lumen by an unknown flippase. In the ER lumen, the oligosaccharide chain is elongated by four more Man residues, catalyzed by mannosyltransferases Alg3p, Alg12p and Alg9p, and three Glc residues, catalyzed by glucosyltransferases Alg6p, Alg8p and Alg10p. The final product delivers the 14 glycan molecule to the hetero-oligomeric oligosaccharyltransferase (Ost) complex (Ost1p, Ost2p, Ost3p, Ost4p, Ost5p, Ost6p, Stt3p, Swp1p, and Wbp1p), which transfers the entire oligosaccharide chain to asparagine side chains in polypeptides. The entire process that leads to the assembly of the LLO must be strictly ordered and the order appears to be ensured by high substrate specificities of all the participating ALG enzymes. The regulation of the activities appears to occur at the level of substrate availability, and the rate-limiting factor may be the amount of Dol-P on the cytoplasmic side of the ER membrane, which seems to be primarily affected by recycling of Dol-PP released by the Ost complex. The initial steps of protein N-glycosylation are remarkably conserved in evolution and most of the yeast genes involved in this process have their known homologs in humans, many of which are implicated in severe disorders such as the CDG syndrome (congenital disorders of glycosylation) as well as congenital muscular dystrophies.
Regulators
4
Targets
0
Expression Details

Expression

Expression data are derived from records contained in the Gene Expression Omnibus (GEO), and are first log2 transformed and normalized. Referenced datasets may contain one or more condition(s), and as a result there may be a greater number of conditions than datasets represented in a single clickable histogram bar. The histogram division at 0.0 separates the down-regulated (green) conditions and datasets from those that are up-regulated (red). Click "Expression Details" to view all expression annotations and details for this locus, including a visualization of genes that share a similar expression pattern.


Summary Paragraph

A summary of the locus, written by SGD Biocurators following a thorough review of the literature. Links to gene names and curated GO terms are included within the Summary Paragraphs.


Last Updated: 2005-07-01

Literature Details

Literature

All manually curated literature for the specified gene, organized into topics according to their relevance to the gene (Primary Literature, Additional Literature, or Review). Click "Literature Details" to view all literature information for this locus, including shared literature between genes.


Primary
16
Additional
31
Reviews
13

Resources