| 1998 |
DPM2, an 84-amino acid ER membrane protein, forms a complex with DPM1 that is essential for ER localization and stable expression of DPM1; DPM2 also enhances binding of dolichol phosphate (a substrate) to the synthase complex. DPM1 alone is catalytically sufficient when artificially tethered to the ER via a fusion protein. |
Expression cloning in Lec15 mutant CHO cells, co-immunoprecipitation, fusion-protein complementation assay, subcellular fractionation |
The EMBO journal |
High |
9724629
|
| 2000 |
Human DPM synthase is a heterotrimer of DPM1 (catalytic), DPM2 (regulatory), and DPM3 (structural stabilizer). DPM3 associates with DPM1 via its C-terminal domain and with DPM2 via its N-terminal portion; DPM2 stabilizes DPM3, and DPM3 in turn stabilizes DPM1. Overexpression of DPM3 in DPM2-null (Lec15) cells restores DPM biosynthesis with increased DPM1 levels. DPM2 also contributes to enzymatic activity (~10-fold enhancement). |
Genetic complementation in Lec15 cells, co-purification, overexpression, DPM synthase activity assays |
The EMBO journal |
High |
10835346
|
| 2000 |
Mutations in DPM1 (point mutation R92G / C274G, and a 13-bp deletion) cause ~95% deficiency in dolichol-phosphate-mannose (Dol-P-Man) synthase activity in patient fibroblasts, with an ~6-fold elevated apparent Km for GDP-mannose, leading to production of a truncated Man5 dolichol-linked oligosaccharide precursor instead of the normal Man9 form. Addition of exogenous mannose corrected the truncation. |
Metabolic labeling with [3H]mannose, microsomal enzyme activity assay (Km determination), Sanger sequencing, mannose supplementation rescue |
The Journal of clinical investigation |
High |
10642597
|
| 1990 |
The S. cerevisiae DPM1 gene product (Dol-P-Man synthase) is the catalytic enzyme responsible for synthesis and membrane translocation of dolichol-phosphate-mannose, which donates mannose residues for N-linked glycosylation. S. cerevisiae DPM1 complemented a glycosylation-defective CHO cell line (B4-2-1), restoring Dol-P-Man synthase activity and correct oligosaccharide assembly. Indirect immunofluorescence showed reticular (ER) localization of the DPM1 protein. |
Stable transfection complementation, FACS lectin-binding analysis, enzymatic activity assay in cell lysates, HPLC of lipid-linked oligosaccharides, endoglycosidase H sensitivity assay, indirect immunofluorescence |
Molecular and cellular biology |
High |
2201896
|
| 2005 |
DPM3 tethers DPM1 to the ER membrane via a coiled-coil domain near DPM3's C-terminus; this tethering is critical for DPM synthase activity. In the absence of DPM3, DPM1 is rapidly degraded by the proteasome. Free DPM1 associates strongly with CHIP (C-terminus of Hsc70-interacting protein), a chaperone-dependent E3 ubiquitin ligase, indicating DPM1 is ubiquitinated by CHIP when not incorporated into the complex. |
Generation of DPM3-deficient CHO2.38 cells, microsomal DPM synthase activity assay, domain-deletion mutagenesis of DPM3, proteasome inhibitor treatment, co-immunoprecipitation with CHIP |
The Journal of biological chemistry |
High |
16280320
|
| 2006 |
An intronic DPM1 mutation (g.IVS4-5T>A) causes exon skipping and a shortened transcript, reducing DPM1 mRNA expression by >90% (via a nonsense-mediated mRNA decay-independent mechanism), resulting in only residual Dol-P-Man synthase activity and accumulation of the immature Dol-PP-GlcNAc2Man5 species. Loss of DPM1 expression also secondarily reduces DPM2 expression. |
RT-PCR, Sanger sequencing, Dol-P-Man synthase activity assay in patient fibroblasts, lipid-linked oligosaccharide analysis, mRNA quantification |
Pediatric research |
Medium |
16641202
|
| 2013 |
A DPM1 missense mutation (p.Gly152Val) reduces DPM1 binding to DPM3 without decreasing the enzyme's affinity for substrate, suggesting Gly152 is important for DPM3 interaction rather than catalysis. Overall DPM1 enzyme activity in patient fibroblasts was reduced by ~80%. |
DPM1 enzyme activity assay in patient fibroblasts, transfection of tagged wild-type and mutant DPM1 constructs, co-immunoprecipitation with DPM3 |
Molecular genetics and metabolism |
Medium |
23856421
|
| 2022 |
In a Drosophila CRISPR screen, inhibition of Dpm1 (the DPM1 ortholog) rescued cell survival and glycoprotein levels under DPAGT1 inhibition and alleviated ER stress in two in vivo models, demonstrating a genetic epistatic relationship where reduced Dpm1 activity suppresses consequences of deficient upstream N-glycosylation initiation. A novel interaction between fructose/glycolytic metabolism and ER stress was also identified in this context. |
Genome-wide CRISPR knockout screen in Drosophila cells, in vivo genetic epistasis in Drosophila models, glycoprotein level measurement, metabolic analysis |
PLoS genetics |
Medium |
36166480
|
| 2024 |
Deletion of DPM1 in human keratinocytes impairs desmosomal adhesion, disrupts localization of desmoplakin and desmoglein-2, and causes cytoskeletal organization defects. Proteomic analysis identified SERPINB5 as a DPM1-dependent interaction partner of desmoplakin; mechanistically, SERPINB5 reduces desmoplakin phosphorylation at serine 176, which is required for strong intercellular adhesion. |
CRISPR knockout of DPM1 in keratinocytes, 3D organotypic epidermis model, immunofluorescence localization, mass spectrometry-based proteomics, co-immunoprecipitation, phosphorylation analysis |
The Journal of cell biology |
Medium |
38477878
|
| 2026 |
DPM1 was identified as a direct regulator of IRE1α expression and activity via a BioID proximity screen. DPM1 ablation in colorectal cancer cells reduces protein glycosylation, leading to chronic IRE1 activation, which in turn enhances cytotoxic T cell-mediated immunosurveillance. IRE1 inhibition or knockout reverses this immune phenotype. |
BioID proximity labeling screen, DPM1 knockout, IRE1 activity assays, IRE1 inhibition/KO epistasis, T cell cytotoxicity assays |
Nature communications |
Medium |
42230629
|