Small (72-residue) multi-pass ER-membrane regulatory subunit of the fission-yeast dolichol-phosphate-mannose synthase complex (dpm1-dpm2-dpm3). By homology with mammalian DPM2, it stabilises the dpm3 anchor subunit and enhances the catalytic activity of dpm1, which transfers mannose from GDP-mannose to dolichyl phosphate. The DPM2 subunit is absent from budding yeast, whose Dol-P-Man synthase is a single anchored polypeptide.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005737 cytoplasm | HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ... | TOO GENERAL | Summary: ORFeome-wide YFP screen reported a cytoplasmic signal. dpm2 is a multi-pass ER membrane protein; ER is within the cytoplasm, so the term is not wrong but is uninformative. Reason: ER membrane is the informative location. Supporting Evidence: PMID:16823372 Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein. file:SCHPO/dpm2/dpm2-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane {ECO:0000250}; |
| GO:0005783 endoplasmic reticulum | HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ... | ACCEPT | Summary: ORFeome YFP localisation to the ER, consistent with dpm2 being an ER-membrane subunit of DPM synthase. Supporting Evidence: PMID:16823372 Next, we determined the localization of 4,431 proteins, corresponding to approximately 90% of the fission yeast proteome, by tagging each ORF with the yellow fluorescent protein. |
| GO:0005783 endoplasmic reticulum | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA (PTN000385888) with human DPM2 and Arabidopsis homologs; ER residence is conserved across the DPM2 family. Supporting Evidence: file:SCHPO/dpm2/dpm2-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane {ECO:0000250}; |
| GO:0005789 endoplasmic reticulum membrane | IEA GO_REF:0000120 | ACCEPT | Summary: Combined IEA (InterPro IPR009914 DPM2 family, UniProt SubCell SL-0097); ER membrane is the core location for this multi-pass subunit. Supporting Evidence: file:SCHPO/dpm2/dpm2-uniprot.txt SUBCELLULAR LOCATION: Endoplasmic reticulum membrane {ECO:0000250}; |
| GO:0006488 dolichol-linked oligosaccharide biosynthetic process | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA (PTN000385888). As a subunit needed for full DPM synthase activity, dpm2 contributes to supplying Dol-P-Man for LLO assembly; consistent with the human DPM2 review. Supporting Evidence: PMID:10835346 DPM synthase activity was 10 times higher in the presence of DPM2, indicating that DPM2 also plays a role in the enzymatic reaction. PMID:18387370 The sugar transfer from dolichol-phosphate-sugars occurs exclusively on the luminal side of the endoplasmic reticulum and is utilized in all four glycosylation pathways. |
| GO:0008047 enzyme activator activity | ISO GO_REF:0000024 | ACCEPT | Summary: ISO from human DPM2 (O94777), which raises DPM synthase activity about tenfold. Matches the PomBase GO-CAM (dpm2 positively regulates dpm1) and the module annoton. Supporting Evidence: PMID:10835346 DPM synthase activity was 10 times higher in the presence of DPM2, indicating that DPM2 also plays a role in the enzymatic reaction. file:SCHPO/dpm2/dpm2-uniprot.txt FUNCTION: Regulates the biosynthesis of dolichol phosphate-mannose. |
| GO:0030234 enzyme regulator activity | IBA GO_REF:0000033 | TOO GENERAL | Summary: PAINT IBA for enzyme regulator activity; correct parent of the more specific GO:0008047 (also annotated). Supporting Evidence: PMID:10835346 DPM synthase activity was 10 times higher in the presence of DPM2, indicating that DPM2 also plays a role in the enzymatic reaction. |
| GO:0030234 enzyme regulator activity | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO (IPR009914) enzyme regulator activity; correct, less specific than GO:0008047. Supporting Evidence: file:SCHPO/dpm2/dpm2-uniprot.txt FUNCTION: Regulates the biosynthesis of dolichol phosphate-mannose. |
| GO:0033185 dolichol-phosphate-mannose synthase complex | IBA GO_REF:0000033 | ACCEPT | Summary: PAINT IBA for membership of the DPM synthase complex; S. pombe has all three subunits. Supporting Evidence: PMID:10835346 Schizosaccharomyces pombe has proteins that resemble three human subunits file:SCHPO/dpm2/dpm2-uniprot.txt SUBUNIT: Composed of three subunits; dpm1, dpm2 and dpm3. |
| GO:0033185 dolichol-phosphate-mannose synthase complex | ISO GO_REF:0000024 | ACCEPT | Summary: ISO from human DPM2, subunit of the DPM1/DPM2/DPM3 complex. Supporting Evidence: PMID:10835346 Therefore, DPM2 stabilizes DPM3 and DPM3 stabilizes DPM1. file:SCHPO/dpm2/dpm2-uniprot.txt SUBUNIT: Composed of three subunits; dpm1, dpm2 and dpm3. |
| GO:0180047 dolichol phosphate mannose biosynthetic process | IEA GO_REF:0000002 | ACCEPT | Summary: InterPro2GO (IPR009914) dolichol phosphate mannose biosynthetic process; dpm2 is a regulatory subunit of the enzyme that makes Dol-P-Man. Supporting Evidence: file:SCHPO/dpm2/dpm2-uniprot.txt FUNCTION: Regulates the biosynthesis of dolichol phosphate-mannose. |
| GO:0180047 dolichol phosphate mannose biosynthetic process | TAS PMID:18387370 Dolichol-phosphate mannose synthase: structure, function and... | ACCEPT | Summary: TAS from the Maeda & Kinoshita review of DPM synthase (mammalian complex). Not S. pombe data but an appropriate review-based statement for a conserved subunit. Supporting Evidence: PMID:18387370 we focus on the biosynthesis of dolichol-phosphate-mannose, and particularly on the mammalian enzyme complex involved in the reaction PMID:10835346 DPM synthase activity was 10 times higher in the presence of DPM2, indicating that DPM2 also plays a role in the enzymatic reaction. |
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Download this section (compressed HTML)Q: Is S. pombe dpm2 essential, and does it activate dpm1 directly (e.g. by improving dolichyl-phosphate binding) or only by stabilising dpm3?
Experiment: Measure Dol-P-Man synthase activity and dpm1/dpm3 levels in S. pombe dpm2 deletion or depletion strains.
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