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. Ubiquitous overexpression of Dci extends adult lifespan, increases tolerance of oxidative and starvation stress and is accompanied by nuclear accumulation of dFOXO and induction of dFOXO target genes.
| 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. No direct biochemical assay of fly Dci is cached; support is family membership: the record places Dci in PANTHER subfamily PTHR43684:SF1 (enoyl-CoA delta isomerase 2, the ECI2/PECI class) with an ECH_1 (crotonase-fold) Pfam domain, whose characterised members catalyse the delta(3),delta(2)-enoyl-CoA isomerase reaction. That, together with the PAINT phylogenetic placement behind this IBA, supports the activity by inheritance rather than by direct assay. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt PANTHER; PTHR43684:SF1; ENOYL-COA DELTA ISOMERASE 2; 1. file:DROME/Dci/Dci-uniprot.txt Pfam; PF00378; ECH_1; 1. |
| 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. Supported by family membership (PANTHER PTHR43684:SF1 enoyl-CoA delta isomerase 2 subfamily; ECH_1 crotonase-fold domain) rather than direct assay of the fly protein; consistent with the IBA row. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt PANTHER; PTHR43684:SF1; ENOYL-COA DELTA ISOMERASE 2; 1. file:DROME/Dci/Dci-uniprot.txt Pfam; PF00378; ECH_1; 1. |
| 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 (already carried by the IBA row). The UniProt location line rests only on ARBA, so support is instead: the Dci sequence ends in -AKL, a C-terminal PTS1 tripeptide (read from the SQ block of the cached UniProt record, which ends ...KNKAKL), and the Drosophila peroxisome inventory (PMID:22758915, abstract only) reports that fly matrix proteins are imported by the PTS1 system. Root organelle term kept per the organelle policy. Supporting Evidence: PMID:22758915 Drosophila appears to only utilize the peroxisome targeting signal type 1 system for matrix protein import |
| 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. Support is the C-terminal -AKL PTS1 tripeptide in the Dci sequence (read from the SQ block of the cached UniProt record, which ends ...KNKAKL) plus the report that Drosophila matrix proteins use the PTS1 import system (PMID:22758915, abstract only); the UniProt location line itself rests only on ARBA. Supporting Evidence: PMID:22758915 Drosophila appears to only utilize the peroxisome targeting signal type 1 system for matrix protein import |
| 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. Supported by family membership (PANTHER PTHR43684:SF1 enoyl-CoA delta isomerase 2 subfamily; ECH_1 crotonase-fold domain) consistent with the orthology transfer; no direct assay of the fly protein is cached. Supporting Evidence: file:DROME/Dci/Dci-uniprot.txt PANTHER; PTHR43684:SF1; ENOYL-COA DELTA ISOMERASE 2; 1. file:DROME/Dci/Dci-uniprot.txt Pfam; PF00378; ECH_1; 1. |
| 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.
Dodecenoyl-CoA delta-isomerase (Dci) encodes a putative peroxisomal enzyme that catalyzes the isomerization of 3-cis (3Z) and 3-trans (3E) double bonds into 2-trans (2E) in mono- and polyunsaturated enoyl-CoA thioesters in peroxisomal fatty acid beta-oxidation. When overexpressed, extends lifespan, enhances stress tolerance to oxidative and starvation stress and activates the product of foxo.
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