DPM1/YPR183W Summary Help

Standard Name DPM1 1
Systematic Name YPR183W
Alias SED3
Feature Type ORF, Verified
Description Dolichol phosphate mannose (Dol-P-Man) synthase of the ER membrane; catalyzes the formation of Dol-P-Man from Dol-P and GDP-Man; required for glycosyl phosphatidylinositol membrane anchoring, O mannosylation, and protein glycosylation (1, 2, 3, 4 and see Summary Paragraph)
Name Description Dolichol Phosphate Mannose synthase 1
Chromosomal Location
ChrXVI:900755 to 901558 | ORF Map | GBrowse
Gene Ontology Annotations All DPM1 GO evidence and references
  View Computational GO annotations for DPM1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 7 genes
Classical genetics
reduction of function
Large-scale survey
reduction of function
111 total interaction(s) for 75 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 20
  • Affinity Capture-RNA: 4
  • Affinity Capture-Western: 3
  • Co-fractionation: 2
  • Co-localization: 2
  • Co-purification: 1
  • PCA: 6
  • Reconstituted Complex: 1
  • Two-hybrid: 3

Genetic Interactions
  • Dosage Rescue: 2
  • Negative Genetic: 52
  • Phenotypic Suppression: 2
  • Positive Genetic: 4
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 4
  • Synthetic Rescue: 3

Expression Summary
Length (a.a.) 267
Molecular Weight (Da) 30,362
Isoelectric Point (pI) 7.97
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXVI:900755 to 901558 | ORF Map | GBrowse
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..804 900755..901558 2011-02-03 1996-07-31
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 SGDIDS000006387

DPM1 encodes the gene for dolichyl phosphate mannose (Dol-P-Man) synthase (EC (2, 1) which adds a mannose moiety to dolichyl phosphate on the cytosolic side of the endoplasmic reticulum (ER); then the sugar moiety flips into the lumen of the ER, where Dol-P-Man serves as a source of mannose for three types of protein modifications: N-linked glycosylation, O-linked glycosylation, and synthesis of glycosyl phosphatidylinositol (GPI) anchors. A similar reaction is catalyzed by Alg5p, which adds glucose to Dol-P, but Alg5p participates only in N-linked glycosylation.

Deletion of DPM1 is lethal (1), but conditional mutants accumulate lipid-linked oligosaccharides (LLO's) with five mannose residues (2) which are added to LLO's on the exterior of the ER by several proteins, including Alg1p, Alg2p, and Alg7p. Mutants lacking Dpm1p also fail to initiate O-mannosylation of proteins, and they accumulate unmannosylated phosphatidylinositol which is not incorporated into proteins (2). Similar phenotypes are also observed in mutants lacking Sec53p or Sec59p which catalyze reactions upstream of Dol-P-Man synthesis.

Human Dpm1p also has Dol-P-Man synthase activity, but lacks lacks a C-terminal hydrophobic domain that allows localization to the ER membrane (5). Fully active ER-bound human Dol-P-Man synthase is a complex of three proteins: Dpm1p (OMIM), Dpm2p (OMIM), and Dpm3p (OMIM) (6, 7, 8). Mutations in DPM1 are associated with the congenital disorder of glycosylation CDG-Ie (OMIM).

Last updated: 2005-07-01 Contact SGD

References cited on this page View Complete Literature Guide for DPM1
1) Orlean P, et al.  (1988) Cloning and sequencing of the yeast gene for dolichol phosphate mannose synthase, an essential protein. J Biol Chem 263(33):17499-507
2) Orlean P  (1990) Dolichol phosphate mannose synthase is required in vivo for glycosyl phosphatidylinositol membrane anchoring, O mannosylation, and N glycosylation of protein in Saccharomyces cerevisiae. Mol Cell Biol 10(11):5796-805
3) Albright CF, et al.  (1989) A 13-amino acid peptide in three yeast glycosyltransferases may be involved in dolichol recognition. Proc Natl Acad Sci U S A 86(19):7366-9
4) Haselbeck A  (1989) Purification of GDP mannose:dolichyl-phosphate O-beta-D-mannosyltransferase from Saccharomyces cerevisiae. Eur J Biochem 181(3):663-8
5) Colussi PA, et al.  (1997) Human and Saccharomyces cerevisiae dolichol phosphate mannose synthases represent two classes of the enzyme, but both function in Schizosaccharomyces pombe. Proc Natl Acad Sci U S A 94(15):7873-8
6) Maeda Y, et al.  (1998) DPM2 regulates biosynthesis of dolichol phosphate-mannose in mammalian cells: correct subcellular localization and stabilization of DPM1, and binding of dolichol phosphate. EMBO J 17(17):4920-9
7) Tomita S, et al.  (1998) A homologue of Saccharomyces cerevisiae Dpm1p is not sufficient for synthesis of dolichol-phosphate-mannose in mammalian cells. J Biol Chem 273(15):9249-54
8) Maeda Y, et al.  (2000) Human dolichol-phosphate-mannose synthase consists of three subunits, DPM1, DPM2 and DPM3. EMBO J 19(11):2475-82