GO:0033185 dolichol-phosphate-mannose synthase complex: Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0033185 describes the dolichol-phosphate-mannose synthase complex, a three-subunit endoplasmic reticulum enzyme that produces dolichol-phosphate-mannose (DPM), the mannose donor for N-linked and O-linked glycosylation.
• The complex contains a catalytic subunit (DPM1), a regulatory subunit (DPM2), and a stabilizing subunit (DPM3) in humans and several other metazoa [1,5,6].
• DPM1 is tethered to and stabilized on the endoplasmic reticulum membrane by DPM3, while DPM2 controls subcellular localization, DPM1 stability, and dolichol-phosphate binding [5,6].
• Loss of DPM synthase function impairs glycosylation of proteins such as alpha-dystroglycan and desmosomal components, linking the complex to muscular dystrophy, skin disorders, and brain disease [3,4,8].
• A genome-wide CRISPR-Cas9 screen identified the DPM synthase complex as a host dependency factor for dengue virus infection.
• The complex is a tractable target for knockout, point-mutation, knock-in, and overexpression cell models to dissect glycosylation biology and host-pathogen interactions [2,3,5].
Description
The dolichol-phosphate-mannose synthase complex (GO:0033185) is a protein complex that possesses dolichyl-phosphate beta-D-mannosyltransferase activity and is responsible for synthesizing dolichol-phosphate-mannose (DPM), a key mannose donor in eukaryotic glycosylation. In humans and several other metazoa, the complex is composed of three subunits: the catalytic subunit DPM1, the regulatory subunit DPM2, and the stabilizing subunit DPM3 [1,5,6]. This complex is anchored in the endoplasmic reticulum membrane and provides mannose for the assembly of lipid-linked oligosaccharides and for O-mannosylation of proteins such as alpha-dystroglycan [1,4].
dolichol-phosphate-mannose synthase complex At A Glance
| GO ID | GO:0033185 |
|---|---|
| GO term | dolichol-phosphate-mannose synthase complex |
| Ontology | cellular_component |
| Synonym | dolichyl-phosphate beta-D-mannosyltransferase complex; DPM synthase complex |
| Major function | Synthesis of dolichol-phosphate-mannose (DPM), the mannose donor for N-linked and O-linked glycosylation |
| Subunits | DPM1 (catalytic), DPM2 (regulatory), DPM3 (stabilizing) [1,5,6] |
| Subcellular location | Endoplasmic reticulum membrane [5,6] |
| Enzymatic activity | Dolichyl-phosphate beta-D-mannosyltransferase activity |
What Is GO:0033185?
The dolichol-phosphate-mannose synthase complex is a protein complex that catalyzes the transfer of mannose from GDP-mannose to dolichol phosphate, forming dolichol-phosphate-mannose. According to the QuickGO definition, it contains a catalytic subunit, a regulatory subunit, and a third subunit that stabilizes the complex; in human and several other metazoa these subunits are named DPM1, DPM2, and DPM3, respectively [1,5,6].
Why Is dolichol-phosphate-mannose synthase complex Important in Cell Biology?
The dolichol-phosphate-mannose synthase complex is essential because it generates dolichol-phosphate-mannose, the obligate mannose donor for multiple glycosylation pathways in the endoplasmic reticulum. Defects in this complex cause hypoglycosylation of proteins, leading to muscular dystrophy, skin fragility, and brain disease in humans and model organisms [3,4,8]. Moreover, the complex has been identified as a host dependency factor for dengue virus, highlighting its relevance in infectious disease research.
• Provides dolichol-phosphate-mannose for N-linked glycosylation and O-mannosylation.
• DPM1, DPM2, and DPM3 form a three-subunit complex with distinct catalytic, regulatory, and stabilizing roles [1,5,6].
• DPM3 tethers and stabilizes DPM1 on the endoplasmic reticulum membrane.
• DPM2 regulates DPM1 localization, stability, and dolichol-phosphate binding.
• Loss of DPM synthase function causes dystrophic muscle with hypoglycosylated alpha-dystroglycan in zebrafish.
• DPM1 modulates desmosomal adhesion and epidermal differentiation through SERPINB5.
• A recurrent homozygous missense DPM3 variant leads to muscle and brain disease.
• The complex is a host dependency factor for dengue virus infection.
• Ethanol exposure impairs N-linked glycosylation, involving DPM synthase-related steps.
• The complex is a target for CRISPR knockout, point-mutation, knock-in, and overexpression studies [2,3,5].
What Happens During dolichol-phosphate-mannose synthase complex?
Substrate binding and catalysis
In simple terms: The enzyme grabs mannose from GDP-mannose and attaches it to dolichol phosphate.
The catalytic subunit DPM1 transfers mannose from GDP-mannose to dolichol phosphate, forming dolichol-phosphate-mannose (DPM). This reaction occurs at the cytoplasmic face of the endoplasmic reticulum membrane and requires the regulatory subunit DPM2 for correct subcellular localization and stabilization of DPM1.
Complex assembly and stabilization
In simple terms: Three proteins come together so the enzyme works properly and stays in place.
DPM1 is tethered to and stabilized on the endoplasmic reticulum membrane by DPM3. DPM2 regulates the biosynthesis of dolichol-phosphate-mannose by ensuring correct subcellular localization and stabilization of DPM1 and by binding dolichol phosphate. Together, DPM1, DPM2, and DPM3 form the functional DPM synthase complex.
DPM utilization in glycosylation
In simple terms: The mannose tag made by the complex is used to build sugar chains on proteins.
Dolichol-phosphate-mannose produced by the complex serves as the mannose donor for N-linked glycosylation and O-mannosylation of proteins such as alpha-dystroglycan [1,4]. Depletion of DPM synthase in zebrafish leads to dystrophic muscle with hypoglycosylated alpha-dystroglycan, demonstrating the importance of DPM for muscle integrity.
Regulation by subunit availability
In simple terms: The amount of each subunit controls how active the complex is.
DPM2 regulates DPM1 stability and dolichol-phosphate binding, and DPM3 stabilizes DPM1 on the membrane [5,6]. Ethanol-induced impairment in the biosynthesis of N-linked glycosylation further indicates that environmental factors can affect this pathway.
Key Genes Involved in GO:0033185 dolichol-phosphate-mannose synthase complex
The following genes and proteins are the core components and regulators of the dolichol-phosphate-mannose synthase complex and its glycosylation output.
| Gene | Major Role | Research Relevance |
|---|---|---|
| DPM1 | Catalytic subunit; transfers mannose from GDP-mannose to dolichol phosphate | Target for knockout and point-mutation studies of glycosylation and epidermal differentiation |
| DPM2 | Regulatory subunit; controls DPM1 localization, stability, and dolichol-phosphate binding | Key for understanding complex assembly and DPM biosynthesis regulation |
| DPM3 | Stabilizing subunit; tethers and stabilizes DPM1 on the ER membrane | Mutations cause muscle and brain disease; target for knock-in disease models |
| DPM1 (zebrafish ortholog) | Catalytic subunit in zebrafish | Model for dystrophic muscle and hypoglycosylated alpha-dystroglycan |
| SERPINB5 | Effector downstream of DPM1 in desmosomal adhesion and epidermal differentiation | Readout for DPM1-dependent skin biology |
| Alpha-dystroglycan | Glycosylated substrate requiring DPM-derived mannose | Biomarker for DPM synthase deficiency in muscle |
| GDP-mannose | Mannose donor substrate for DPM1 | Metabolic input for DPM synthesis assays |
| Dolichol phosphate | Acceptor substrate for DPM1 | Substrate for enzymatic activity measurements |
| Dengue virus dependency factors | Host factors identified with DPM synthase in CRISPR screen | Target for antiviral host-directed strategies |
| Desmosomal proteins | Affected by DPM1 loss in epidermis | Readouts for cell adhesion studies |
| N-linked glycosylation machinery | Uses DPM as mannose donor | Pathway context for glycosylation research |
| O-mannosylation machinery | Uses DPM for O-mannosyl glycans | Pathway context for muscular dystrophy research |
| ER membrane proteins | Anchor and stabilize the complex [5,6] | Study of membrane protein complex assembly [5,6] |
| Ethanol metabolism | Impairs N-linked glycosylation biosynthesis | Environmental modifier of glycosylation |
| DPM3 mutant variants | Cause muscle and brain disease | Disease modeling with knock-in alleles |
How Is dolichol-phosphate-mannose synthase complex Regulated?
The dolichol-phosphate-mannose synthase complex is regulated at the level of subunit availability and stability. DPM2 regulates the biosynthesis of dolichol-phosphate-mannose by controlling correct subcellular localization and stabilization of DPM1 and by binding dolichol phosphate. DPM3 tethers and stabilizes DPM1 on the endoplasmic reticulum membrane. Ethanol exposure impairs the biosynthesis of N-linked glycosylation, indicating that environmental factors can modulate this pathway.
dolichol-phosphate-mannose synthase complex and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| DPM3 | Muscle and brain disease | Knock-in of recurrent missense variant in cell lines or zebrafish |
| DPM1 | Epidermal differentiation and desmosomal adhesion defects | Knockout keratinocytes and skin equivalents |
| DPM1 (zebrafish) | Dystrophic muscle with hypoglycosylated alpha-dystroglycan | Zebrafish knockout or knockdown |
| DPM synthase complex | Dengue virus host dependency | CRISPR knockout in permissive cell lines followed by infection |
| DPM2 | Regulation of DPM biosynthesis | Knockout and rescue with DPM2 variants |
Muscular dystrophy and hypoglycosylation
Depletion of dolichol-phosphate-mannose synthase in zebrafish leads to dystrophic muscle with hypoglycosylated alpha-dystroglycan, linking the complex to muscular dystrophy. A recurrent homozygous missense DPM3 variant leads to muscle and brain disease, further supporting the role of DPM synthase in neuromuscular pathology.
Skin and epidermal differentiation disorders
DPM1 modulates desmosomal adhesion and epidermal differentiation through SERPINB5, indicating that DPM synthase function is required for skin integrity. Loss of DPM1 impairs desmosomal adhesion, which may contribute to epidermal fragility.
Viral infection
A genome-wide CRISPR-Cas9 screen identified the dolichol-phosphate-mannose synthase complex as a host dependency factor for dengue virus infection, highlighting its role in viral entry or replication.
From dolichol-phosphate-mannose synthase complex-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of DPM1 impair glycosylation and epidermal differentiation? | DPM1 knockout cell line |
| Does a DPM3 missense variant cause muscle and brain disease? | DPM3 knock-in cell or animal model |
| Is the DPM synthase complex required for dengue virus infection? | CRISPR knockout in permissive cells followed by infection |
| How does DPM2 regulate DPM1 localization and stability? | DPM2 knockout with tagged DPM1 rescue |
| Does DPM3 stabilize DPM1 on the ER membrane? | DPM3 knockout with tagged DPM1 knock-in |
| Can overexpression of DPM subunits increase DPM synthesis? | DPM1/DPM2/DPM3 overexpression cell lines |
How to Study the dolichol-phosphate-mannose synthase complex Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR-Cas9 knockout screen | Host dependency factors | Identify DPM synthase as required for dengue virus infection |
| Glycosylation immunoblotting | Glycosylation status of alpha-dystroglycan | Assess DPM synthase depletion in zebrafish |
| Fluorescence microscopy | Subcellular localization of DPM subunits | Study DPM2 and DPM3 function [5,6] |
| Protein stability assays | DPM1 stability | Test DPM3-mediated stabilization |
| Enzymatic activity assay | Dolichyl-phosphate beta-D-mannosyltransferase activity | Measure DPM synthesis |
| Knock-in disease modeling | Mutant DPM3 function | Model muscle and brain disease |
| Epidermal differentiation assays | Desmosomal adhesion and differentiation | Study DPM1 in skin |
| Ethanol treatment assays | N-linked glycosylation biosynthesis | Investigate environmental impairment |
CRISPR-Cas9 knockout screens
Genome-wide CRISPR-Cas9 screens can identify host dependency factors, as demonstrated by the identification of the DPM synthase complex as required for dengue virus infection.
Glycosylation analysis
Analysis of alpha-dystroglycan glycosylation in zebrafish and cell models reveals hypoglycosylation upon DPM synthase depletion. N-linked glycosylation biosynthesis can be assessed in ethanol-treated cells.
Subcellular localization and stability assays
Tagged DPM1, DPM2, and DPM3 constructs can be used to monitor endoplasmic reticulum localization and protein stability, as shown for DPM2 and DPM3 [5,6].
Disease variant modeling
Knock-in of patient-derived DPM3 missense variants allows study of muscle and brain disease mechanisms. DPM1 knockout models can be used to study desmosomal adhesion and epidermal differentiation.
How CRISPR Can Be Used to Study GO:0033185 dolichol-phosphate-mannose synthase complex
Knockout
CRISPR knockout of DPM1, DPM2, or DPM3 can abolish DPM synthase function, leading to hypoglycosylation and providing models for muscular dystrophy and skin disorders [3,4]. Knockout of the complex in permissive cells reduces dengue virus infection, confirming its role as a host dependency factor.
Point Mutation
Point mutations in DPM3, such as the recurrent homozygous missense variant, can be introduced to model muscle and brain disease and to dissect subunit-specific functions.
Knock-in
Knock-in of tagged DPM1, DPM2, or DPM3 allows monitoring of complex assembly, localization, and stability in the endoplasmic reticulum membrane [5,6].
Overexpression
Overexpression of DPM1, DPM2, and DPM3 can increase DPM synthesis and glycosylation capacity, providing tools to study pathway saturation and rescue phenotypes.
How EDITGENE Supports dolichol-phosphate-mannose synthase complex Research
Researchers studying dolichol-phosphate-mannose synthase complex-related genes often need to determine whether a candidate gene is causally involved in glycosylation, disease, or host-pathogen interactions. EDITGENE provides CRISPR-based cell models and screening services to enable these studies.
Contact EDITGENE today to design your custom CRISPR model for dolichol-phosphate-mannose synthase complex research.
Frequently Asked Questions About dolichol-phosphate-mannose synthase complex
What is the dolichol-phosphate-mannose synthase complex?
It is a three-subunit endoplasmic reticulum enzyme complex that synthesizes dolichol-phosphate-mannose, the mannose donor for glycosylation.
What genes are involved in the dolichol-phosphate-mannose synthase complex?
The core genes are DPM1 (catalytic), DPM2 (regulatory), and DPM3 (stabilizing) [1,5,6].
What is GO:0033185?
GO:0033185 is the Gene Ontology cellular component term for the dolichol-phosphate-mannose synthase complex.
What does DPM1 do in the complex?
DPM1 is the catalytic subunit that transfers mannose from GDP-mannose to dolichol phosphate.
How does DPM3 stabilize DPM1?
DPM3 tethers and stabilizes DPM1 on the endoplasmic reticulum membrane.
What is the role of DPM2?
DPM2 regulates DPM biosynthesis by controlling DPM1 localization and stability and by binding dolichol phosphate.
What diseases are linked to DPM synthase defects?
Mutations cause muscular dystrophy, skin disorders, and brain disease, and the complex is a dengue virus host dependency factor [2,3,4,8].
How can I study the DPM synthase complex with CRISPR?
Use knockout, point-mutation, knock-in, or overexpression models to dissect subunit function and glycosylation outcomes [2,3,5,8].
Is the DPM synthase complex involved in viral infection?
Yes, a genome-wide CRISPR screen identified it as a host dependency factor for dengue virus.
What experimental models are available for DPM synthase research?
Zebrafish, knockout cell lines, knock-in disease variants, and overexpression systems are commonly used [1,3,4,8].
Conclusion
The dolichol-phosphate-mannose synthase complex (GO:0033185) is a central enzyme in eukaryotic glycosylation, composed of DPM1, DPM2, and DPM3 [1,5,6]. Its dysfunction causes muscular dystrophy, skin disorders, and brain disease, and it serves as a host dependency factor for dengue virus [2,3,4,8]. CRISPR-based knockout, point-mutation, knock-in, and overexpression models provide powerful tools to dissect its biology and therapeutic potential [2,3,5,8].
References
- 1. Maeda Y et al.. 2008. Dolichol-phosphate mannose synthase: structure, function and regulation.. Biochim Biophys Acta 1780(6):861-8 PMID: 18387370
- 2. Labeau A et al.. 2020. A Genome-Wide CRISPR-Cas9 Screen Identifies the Dolichol-Phosphate Mannose Synthase Complex as a Host Dependency Factor for Dengue Virus Infection.. J Virol 94(7) PMID: 31915280
- 3. Rathod M et al.. 2024. DPM1 modulates desmosomal adhesion and epidermal differentiation through SERPINB5.. J Cell Biol 223(4) PMID: 38477878
- 4. Marchese M et al.. 2016. Dolichol-phosphate mannose synthase depletion in zebrafish leads to dystrophic muscle with hypoglycosylated α-dystroglycan.. Biochem Biophys Res Commun 477(1):137-143 PMID: 27291147
- 5. Ashida H et al.. 2006. DPM1, the catalytic subunit of dolichol-phosphate mannose synthase, is tethered to and stabilized on the endoplasmic reticulum membrane by DPM3.. J Biol Chem 281(2):896-904 PMID: 16280320
- 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 PMID: 9724629
- 7. Welti M et al.. 2014. Ethanol-induced impairment in the biosynthesis of N-linked glycosylation.. J Cell Biochem 115(4):754-62 PMID: 24243557
- 8. Nagy S et al.. 2022. A recurrent homozygous missense DPM3 variant leads to muscle and brain disease.. Clin Genet 102(6):530-536 PMID: 35932216
