ALG12/YNR030W Summary Help

Standard Name ALG12 1
Systematic Name YNR030W
Alias ECM39 2
Feature Type ORF, Verified
Description Alpha-1,6-mannosyltransferase localized to the ER; responsible for the addition of the alpha-1,6 mannose to dolichol-linked Man7GlcNAc2, acts in the dolichol pathway for N-glycosylation (1, 3, 4 and see Summary Paragraph)
Name Description Asparagine-Linked Glycosylation 5
Chromosomal Location
ChrXIV:678799 to 680454 | ORF Map | GBrowse
Gene Ontology Annotations All ALG12 GO evidence and references
  View Computational GO annotations for ALG12
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Regulators 4 genes
Classical genetics
Large-scale survey
168 total interaction(s) for 79 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 2
  • Affinity Capture-RNA: 4
  • Co-purification: 1
  • PCA: 1
  • Protein-RNA: 1
  • Two-hybrid: 2

Genetic Interactions
  • Negative Genetic: 89
  • Phenotypic Enhancement: 8
  • Phenotypic Suppression: 41
  • Positive Genetic: 15
  • Synthetic Growth Defect: 1
  • Synthetic Lethality: 1
  • Synthetic Rescue: 2

Expression Summary
Length (a.a.) 551
Molecular Weight (Da) 62,672
Isoelectric Point (pI) 7.09
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXIV:678799 to 680454 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1997-01-28
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1656 678799..680454 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 SGDIDS000005313

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 6, 7).

ALG12 is an alpha 1,6 mannosyltransferase that catalyzes the addition of the eighth mannose moiety in the lumen of the endoplasmic reticulum (4). The seventh and ninth mannoses are both added by Alg9p. Mutants accumulate lipid-linked oligosaccharides (LLO's) with seven mannose moieties (4).

Human ALG12 (OMIM) complements deletion of yeast ALG12 (8) and has been found to be mutated in the congenital disorder of glycosylation CDG-1g (OMIM) (8, 9).

Last updated: 2005-07-01 Contact SGD

References cited on this page View Complete Literature Guide for ALG12
1) Jakob CA, et al.  (1998) Degradation of misfolded endoplasmic reticulum glycoproteins in Saccharomyces cerevisiae is determined by a specific oligosaccharide structure. J Cell Biol 142(5):1223-33
2) Lussier M, et al.  (1997) Large scale identification of genes involved in cell surface biosynthesis and architecture in Saccharomyces cerevisiae. Genetics 147(2):435-50
3) Grimme SJ, et al.  (2001) The essential Smp3 protein is required for addition of the side-branching fourth mannose during assembly of yeast glycosylphosphatidylinositols. J Biol Chem 276(29):27731-9
4) Burda P, et al.  (1999) Ordered assembly of the asymmetrically branched lipid-linked oligosaccharide in the endoplasmic reticulum is ensured by the substrate specificity of the individual glycosyltransferases. Glycobiology 9(6):617-25
5) Huffaker TC and Robbins PW  (1982) Temperature-sensitive yeast mutants deficient in asparagine-linked glycosylation. J Biol Chem 257(6):3203-10
6) Herscovics A and Orlean P  (1993) Glycoprotein biosynthesis in yeast. FASEB J 7(6):540-50
7) Burda P and Aebi M  (1999) The dolichol pathway of N-linked glycosylation. Biochim Biophys Acta 1426(2):239-57
8) Grubenmann CE, et al.  (2002) ALG12 mannosyltransferase defect in congenital disorder of glycosylation type lg. Hum Mol Genet 11(19):2331-9
9) Chantret I, et al.  (2002) Congenital disorders of glycosylation type Ig is defined by a deficiency in dolichyl-P-mannose:Man7GlcNAc2-PP-dolichyl mannosyltransferase. J Biol Chem 277(28):25815-22