Dci (CG13890; also PEC1/PECI) is a Drosophila melanogaster dodecenoyl-CoA delta-isomerase (delta(3),delta(2)-enoyl-CoA isomerase, EC 5.3.3.8), an auxiliary enzyme of unsaturated fatty acid beta-oxidation. It converts (3Z)- or (3E)-enoyl-CoA intermediates - which arise when a double bond of an unsaturated fatty acid reaches the 3,4-position during chain shortening and cannot be handled by the core enoyl-CoA hydratase - into the (2E)-enoyl-CoA that re-enters the standard beta-oxidation spiral. By gene name and sequence Dci corresponds to the peroxisomal-type isomerase (human ECI2 / PECI class) and UniProt annotates it as peroxisomal; Drosophila additionally has a cluster of mitochondrial enoyl-CoA delta-isomerase 1 paralogs (CG4592/CG4594/CG4598) that are the more likely carriers of the mitochondrial ECI1 role. Dci has also been recovered as a hit in a genetic screen for susceptibility to intestinal Vibrio cholerae (Gram-negative) infection.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005782 peroxisomal matrix | IBA GO_REF:0000033 | ACCEPT | Summary: Phylogenetically inferred peroxisomal matrix localization, the specific compartment for the peroxisomal-type (PECI/ECI2-class) enoyl-CoA isomerase that Dci represents. Reason: The specific, core location of Dci; consistent with its UniProt peroxisomal assignment and the peroxisome annotations below. |
| GO:0004165 delta(3)-delta(2)-enoyl-CoA isomerase activity | IBA GO_REF:0000033 | ACCEPT | Summary: Phylogenetically inferred delta(3),delta(2)-enoyl-CoA isomerase activity (EC 5.3.3.8) - the defining molecular function of Dci and the auxiliary isomerase step of unsaturated fatty acid beta-oxidation. Reason: Core molecular function of Dci, concordant with the EC/UniProt name and the ISS/IEA evidence. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt Dodecenoyl-CoA delta-isomerase |
| GO:0006635 fatty acid beta-oxidation | IBA GO_REF:0000033 | ACCEPT | Summary: Phylogenetically inferred participation in fatty acid beta-oxidation - specifically the auxiliary isomerase step that allows unsaturated fatty acids to be fully degraded. Reason: Core biological process for Dci as an auxiliary enzyme of (unsaturated) fatty acid beta-oxidation. |
| GO:0004165 delta(3)-delta(2)-enoyl-CoA isomerase activity | IEA GO_REF:0000120 | ACCEPT | Summary: Electronic assignment of the EC 5.3.3.8 delta(3),delta(2)-enoyl-CoA isomerase activity, duplicating the core molecular-function call. Reason: Core molecular function of Dci. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt Dodecenoyl-CoA delta-isomerase |
| GO:0005777 peroxisome | IEA GO_REF:0000120 | ACCEPT | Summary: Electronic peroxisome localization, consistent with the UniProt peroxisomal assignment for the PECI/ECI2-class isomerase. Reason: Peroxisome is the core compartment for Dci; the peroxisomal matrix is the more specific term. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt SUBCELLULAR LOCATION: Peroxisome |
| GO:0005739 mitochondrion | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Orthology-based mitochondrion localization. Dci is by name and UniProt a peroxisomal (PECI/ECI2-class) isomerase; the mitochondrial enoyl-CoA delta-isomerase 1 role in Drosophila is more likely carried by the CG4592/CG4594/CG4598 paralog cluster. This ISS call may reflect cross-transfer from those mitochondrial paralogs. Reason: Uncertain/secondary; Dci's core compartment is the peroxisome. Retained as non-core pending direct evidence of a mitochondrial pool (the mitochondrial ECI1 role is likely a paralog's). |
| GO:0005777 peroxisome | ISS GO_REF:0000024 | ACCEPT | Summary: Orthology-based peroxisome localization, concordant with the core peroxisomal compartment. Reason: Peroxisome is the core compartment for Dci. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt SUBCELLULAR LOCATION: Peroxisome |
| GO:0004165 delta(3)-delta(2)-enoyl-CoA isomerase activity | ISS GO_REF:0000024 | ACCEPT | Summary: Orthology-based delta(3),delta(2)-enoyl-CoA isomerase activity, duplicating the core molecular-function call. Reason: Core molecular function of Dci. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt Dodecenoyl-CoA delta-isomerase |
| GO:0005777 peroxisome | ISM PMID:22758915 An inventory of peroxisomal proteins and pathways in Drosoph... | ACCEPT | Summary: Sequence-model (targeting-signal) prediction of peroxisomal localization from the Drosophila peroxisomal-proteome inventory, consistent with the UniProt peroxisomal assignment. Reason: Peroxisome is the core compartment; the prediction agrees with the UniProt and orthology evidence. Supporting Evidence: PMID:22758915 The subcellular localization of five of these predicted peroxisomal proteins was confirmed. |
| GO:0050829 defense response to Gram-negative bacterium | IMP PMID:19046341 Genetic analysis of Drosophila melanogaster susceptibility t... | KEEP AS NON CORE | Summary: Mutant-phenotype annotation from a genetic screen for Drosophila susceptibility to intestinal Vibrio cholerae (a Gram-negative pathogen) infection, in which Dci was recovered as a hit. This is an organism-level phenotype indirect to Dci's enzymatic role in lipid metabolism. Reason: A genuine experimental phenotype but peripheral/indirect to the core isomerase function; likely reflects the metabolic contribution of fatty-acid oxidation to the infection response rather than a dedicated immune role. Retained per the curator's IMP assignment. |
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Download this section (compressed HTML)Q: Is Drosophila Dci exclusively peroxisomal (as UniProt indicates), or does it also contribute a mitochondrial delta(3),delta(2)-enoyl-CoA isomerase pool, and is the mitochondrial ECI1 role instead carried by the CG4592/CG4594/CG4598 paralog cluster?
Experiment: Tagged-protein localization and organelle fractionation of Dci versus the CG4592/CG4594/CG4598 mitochondrial enoyl-CoA delta-isomerase paralogs to assign the mitochondrial versus peroxisomal isomerase steps of unsaturated fatty acid beta-oxidation in the fly.
Hypothesis: Dci provides the peroxisomal delta(3),delta(2)-enoyl-CoA isomerase activity while the CG459x paralogs provide the mitochondrial activity required for the mitochondrial unsaturated-FAO cassette.
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