ALG7 / YBR243C Overview
- Standard Name
- Systematic Name
- SGD ID
- Feature Type
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
- Name Description
- Asparagine-Linked Glycosylation
- Comparative Info
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.
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.)
- Mol. Weight (Da)
- Isoelectric Point
- Median Abundance (molecules/cell)
- 599 +/- 480
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.
Gene Ontology Details
GO Annotations consist of four mandatory components: a gene product, a term from one of the three
Gene Ontology (GO) controlled vocabularies
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.
- 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
- Manually Curated
- Manually Curated
- Manually Curated
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.
- 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
- reduction of function
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
- Affinity Capture-RNA: 2
- Affinity Capture-Western: 6
- Co-fractionation: 1
- PCA: 5
- Two-hybrid: 2
- 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
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.
- 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.
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.
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.
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.