ALG5 / YPL227C Overview

Standard Name
ALG5 1
Systematic Name
Feature Type
ORF , Verified
UDP-glucose:dolichyl-phosphate glucosyltransferase; involved in asparagine-linked glycosylation in the endoplasmic reticulum; human ortholog ALG5 can partially complement yeast alg5 mutant 2 4
Name Description
Asparagine-Linked Glycosylation 3
Comparative Info
Sequence Details


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


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)
3009 +/- 587
Half-life (hr)


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 ALG5 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.

Dolichyl-phosphate beta-glucosyltransferase involved in synthesis of oligosaccharide chains for N-linked protein glycosylation; integral to endoplasmic reticulum membrane

View computational annotations

Molecular Function

Manually Curated

Biological Process

Manually Curated

Cellular Component

Manually Curated


Phenotype Details


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.

Non-essential gene; null mutant displays heat sensitivity and under-glycosylation of secreted proteins; in large-scale studies, null mutant shows reduced competitive fitness and desiccation resistance, rounded cell shape, and altered resistance to a variety of chemicals
Disease Details


Disease Annotations consist of three mandatory components: a gene product, a term from the Disease Ontology (DO) controlled vocabulary and an evidence code. SGD provides manually curated DO Annotations derived from the literature. Click "Disease Details" to view all Disease information and evidence for this locus as well as diseases it shares with other genes.

Yeast ALG5 is homologous to human ALG5, and has been used to study congenital disorder of glycosylation type I
Interaction Details


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.

440 total interactions for 256 unique genes

Physical Interactions

  • Affinity Capture-MS: 6
  • Affinity Capture-RNA: 1
  • Co-localization: 1
  • PCA: 36

Genetic Interactions

  • Dosage Rescue: 1
  • Negative Genetic: 292
  • Phenotypic Enhancement: 8
  • Phenotypic Suppression: 29
  • Positive Genetic: 49
  • Synthetic Growth Defect: 7
  • Synthetic Lethality: 9
  • Synthetic Rescue: 1
Regulation Details


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.

ALG5 encodes a dolichyl-phosphate beta-glucosyltransferase (Dol-P-Glc synthase) that transfers glucose (Glc) from UDP-Glc to dolichyl-phosphate (Dol-P). The product of this reaction, Dol-P-Glc, is utilized during the first stage of N-linked glycosylation of proteins in the endoplasmic reticulum (ER) - the assembly of the lipid-linked oligosaccharide (LLO). The LLO then serves as a donor in the second stage - the transfer of the assembled 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) molecules. The last three reactions, catalyzed by glucosyltransferases Alg6p, Alg8p and Alg10p, require Dol-P-Glc as a donor of Glc and, therefore, depend on the Alg5p activity. The reaction catalyzed by Alg5p takes place on the cytosolic side of the ER membrane and the product, Dol-P-Glc, has to be translocated to the lumenal side, where the late steps of the LLO assembly are known to occur, but the protein(s) responsible for this translocation have not been identified. The assembled LLO 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 ALG enzymes involved. 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 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 Details


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


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.