{"gene":"SLC25A17","run_date":"2026-06-10T07:46:32","timeline":{"discoveries":[{"year":1998,"finding":"HsPMP34 (SLC25A17) is a peroxisomal integral membrane protein with six membrane-spanning segments, belonging to the mitochondrial solute carrier family, as demonstrated by localization of a GFP fusion protein to peroxisomes (co-localizing with peroxisomal thiolase) in HepG2 cells and mouse fibroblasts; in PEX5 knockout fibroblasts lacking functional peroxisomes, the fluorescence pattern was altered, confirming peroxisomal targeting.","method":"Fluorescence microscopy of GFP fusion protein; co-localization with peroxisomal marker; expression in PEX5 knockout fibroblasts","journal":"European journal of biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization with functional context (peroxisome-dependency shown in PEX5 KO), single lab, two orthogonal methods","pmids":["9874197"],"is_preprint":false},{"year":2000,"finding":"PMP34 (SLC25A17) is an integral peroxisomal membrane protein whose N- and C-terminal domains face the cytosol. The loop between transmembrane segments 4 and 5, containing basic residues, is required for peroxisome targeting; alanine substitution of those basic residues abrogates targeting. Three hydrophobic transmembrane segments flanking this loop are essential for membrane integration into peroxisomes.","method":"Differential membrane permeabilization, immunofluorescence of epitope-tagged variants in HeLa and CHO-K1 cells, deletion mutagenesis and GFP fusion localization assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (topology mapping, mutagenesis, deletion variants) in a single rigorous study establishing a mechanistic topogenic signal","pmids":["11121399"],"is_preprint":false},{"year":2002,"finding":"PMP34 (SLC25A17) functions as a peroxisomal adenine nucleotide (ATP) transporter, demonstrated by: (1) rescue of defective medium-chain fatty acid oxidation in S. cerevisiae ANT1-disrupted cells (which lack the peroxisomal adenine nucleotide carrier) and (2) direct in vitro reconstitution of purified PMP34 in proteoliposomes showing adenine nucleotide transport activity.","method":"Yeast genetic complementation (ANT1 deletion rescue); protein purification, reconstitution in proteoliposomes, in vitro transport assay","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution plus genetic epistasis in yeast, two independent orthogonal methods","pmids":["12445829"],"is_preprint":false},{"year":2012,"finding":"SLC25A17 is a peroxisomal transporter for multiple free cofactors: CoA, FAD, FMN, and AMP (primary substrates), and to a lesser extent NAD+, PAP, and ADP. Recombinant SLC25A17 reconstituted in liposomes operates almost exclusively by counter-exchange, is saturable, and is inhibited by pyridoxal 5'-phosphate and other mitochondrial carrier inhibitors. Its primary physiological role is to import CoA, FAD, and NAD+ into peroxisomes in exchange for intraperoxisomally generated PAP, FMN, and AMP.","method":"Recombinant protein expression, purification, reconstitution into liposomes, transport kinetics and inhibitor studies in vitro","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — rigorous in vitro reconstitution with kinetic characterization and inhibitor profiling, establishing substrate specificity and transport mechanism","pmids":["22185573"],"is_preprint":false},{"year":2019,"finding":"In zebrafish, Slc25a17 acts as a peroxisomal CoA transporter in vivo; knockdown severely compromises peroxisome function and alters lipid composition. Injection of exogenous CoA, but not NAD+, rescued the defective swim bladder development caused by slc25a17 knockdown, establishing CoA transport as the primary in vivo function.","method":"Zebrafish morpholino knockdown, lipid composition analysis, CoA/NAD+ rescue injection","journal":"Journal of cellular physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo genetic knockdown with substrate-specific rescue, single lab, demonstrates CoA as primary functional substrate in vivo","pmids":["31187491"],"is_preprint":false},{"year":2020,"finding":"PMP34 (SLC25A17) is required for normal peroxisomal degradation of phytanic and pristanic acid in mice. Slc25a17 gene-trap knockout mice on dietary phytol showed hepatomegaly, liver inflammation, induction of peroxisomal enzymes, elevated hepatic triacylglycerols and cholesterylesters, and accumulation of phytanic and pristanic acid (as both free acids and CoA esters), partially mediated by PPARα. Other peroxisomal pathways (bile acid synthesis, VLCFA metabolism, plasmalogen levels) were unaffected, suggesting the role of PMP34 is specifically linked to branched-chain fatty acid CoA metabolism or SCPx-catalyzed thiolytic cleavage.","method":"Slc25a17 gene-trap knockout mouse model, dietary phytol challenge, lipid profiling (acyl-CoA esters, free fatty acids), bile acid analysis, peroxisomal enzyme assays, PPARα pathway analysis","journal":"Frontiers in cell and developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO mouse model with dietary challenge, multiple biochemical readouts establishing specific role in branched-chain fatty acid metabolism, single lab but multiple orthogonal assays","pmids":["32266253"],"is_preprint":false},{"year":2023,"finding":"SLC25A17 inactivation in mammalian cells (HEK-293, HeLa, SV40-MEFs) shifts the glutathione redox couple toward a more reductive state (lower GSSG/GSH), with variable effects on NADPH and NAD+/NADH. This phenotype was rescued by expression of Candida boidinii Pmp47 (a putative ortholog). The redox change was not due to alterations in peroxisomal antioxidant enzyme expression, catalase activity, H2O2 permeability, or mitochondrial fitness. DEHA treatment revealed kinetic disconnection between peroxisomal and cytosolic glutathione pools and highlighted impact on peroxisomal NADPH metabolism.","method":"CRISPR/genetic inactivation of SLC25A17, redox sensor measurements (GSSG/GSH, NADPH, NAD+/NADH) in multiple cell lines, rescue with CbPmp47 expression, pharmacological dissection with DEHA","journal":"Free radical biology & medicine","confidence":"High","confidence_rationale":"Tier 2 / Strong — defined cellular phenotype in three independent cell lines with rescue experiment and pharmacological dissection, establishing SLC25A17 as a regulator of peroxisomal redox homeostasis","pmids":["38159891"],"is_preprint":false},{"year":2025,"finding":"USF2 transcriptionally activates PEX3, and upregulated PEX3 interacts with SLC25A17 to stabilize/upregulate its protein levels, thereby activating JAK2/STAT3 signaling and promoting lipid accumulation in lung adenocarcinoma cells. JAK2 inhibitor AG490 eliminated the lipid-accumulation effect of SLC25A17 overexpression.","method":"Chromatin binding assay (USF2 binding to PEX3 promoter), co-immunoprecipitation (PEX3-SLC25A17 interaction), overexpression/knockdown, western blotting, JAK2 inhibitor treatment","journal":"Toxicology and applied pharmacology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — co-IP for PEX3-SLC25A17 interaction plus pharmacological rescue, single lab, establishes upstream regulation and downstream JAK2/STAT3 pathway link","pmids":["40885408"],"is_preprint":false},{"year":2026,"finding":"MARCH1 (an E3 ubiquitin ligase) directly ubiquitinates SLC25A17, promoting its degradation. Loss of SLC25A17 protein (via MARCH1-mediated ubiquitination) attenuates M2 macrophage polarization and cisplatin resistance in lung adenocarcinoma; re-expression of SLC25A17 reverses the sensitization to cisplatin induced by MARCH1 overexpression.","method":"Co-immunoprecipitation, ubiquitination assay, rescue overexpression experiment, flow cytometry, ELISA, western blotting","journal":"Integrative biology : quantitative biosciences from nano to macro","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP and ubiquitination assay with rescue experiment in single lab identifying MARCH1 as the E3 ligase writing ubiquitin on SLC25A17","pmids":["41758657"],"is_preprint":false}],"current_model":"SLC25A17 (PMP34) is a peroxisomal integral membrane protein belonging to the mitochondrial carrier family that functions as a counter-exchange transporter for multiple adenine-containing cofactors—primarily CoA, FAD, FMN, and AMP, and to a lesser extent NAD+, PAP, and ADP—importing CoA, FAD, and NAD+ into the peroxisomal matrix in exchange for intraperoxisomally generated metabolites; its N- and C-termini face the cytosol, and a basic loop between TM segments 4 and 5 with flanking hydrophobic segments constitutes the peroxisomal targeting/topogenic signal; in vivo, it is essential for peroxisomal degradation of branched-chain fatty acids (phytanic/pristanic acid) and for maintaining peroxisomal redox homeostasis (glutathione and NADPH pools); it is subject to regulation by PEX3-mediated stabilization and MARCH1-mediated ubiquitination and degradation."},"narrative":{"mechanistic_narrative":"SLC25A17 (PMP34) is a peroxisomal integral membrane carrier of the mitochondrial solute carrier family that supplies the peroxisomal matrix with adenine-containing cofactors required for its metabolic reactions [PMID:9874197, PMID:12445829]. Topologically it spans the membrane with both N- and C-termini facing the cytosol, and a basic loop between transmembrane segments 4 and 5, flanked by three essential hydrophobic segments, encodes its peroxisomal targeting and membrane-integration signal [PMID:11121399]. Reconstituted in liposomes, the protein operates almost exclusively by saturable counter-exchange, importing CoA, FAD, and NAD+ (with AMP, FMN, PAP, and ADP as additional substrates) in exchange for intraperoxisomally generated metabolites, and is blocked by pyridoxal 5'-phosphate and other mitochondrial-carrier inhibitors [PMID:22185573]. Its principal physiological cargo in vivo is CoA: zebrafish knockdown defects are rescued by CoA but not NAD+ [PMID:31187491], and knockout mice fail to degrade the branched-chain fatty acids phytanic and pristanic acid, accumulating their free acids and CoA esters in a partly PPARα-dependent manner [PMID:32266253]. SLC25A17 also maintains peroxisomal redox homeostasis, since its inactivation shifts the glutathione couple toward a reductive state and perturbs peroxisomal NADPH metabolism [PMID:38159891]. Its protein abundance is set by opposing post-translational inputs: PEX3 binds and stabilizes SLC25A17 to drive JAK2/STAT3 signaling and lipid accumulation [PMID:40885408], while the E3 ligase MARCH1 directly ubiquitinates it to promote degradation, influencing macrophage polarization and chemoresistance [PMID:41758657].","teleology":[{"year":1998,"claim":"Established that SLC25A17 is a bona fide peroxisomal membrane protein of the mitochondrial carrier family, raising the question of what it transports across the peroxisomal membrane.","evidence":"GFP fusion localization and co-localization with peroxisomal thiolase in HepG2 and fibroblasts, with altered pattern in PEX5-knockout cells","pmids":["9874197"],"confidence":"Medium","gaps":["No transport substrate identified","Membrane topology not yet resolved"]},{"year":2000,"claim":"Defined the protein's membrane topology and the topogenic signal directing it to peroxisomes, explaining how the carrier is correctly inserted and targeted.","evidence":"Differential permeabilization, epitope-tagged topology mapping, and deletion/alanine-substitution mutagenesis in HeLa and CHO-K1 cells","pmids":["11121399"],"confidence":"High","gaps":["Does not identify the import machinery recognizing the loop signal","Transport function still unknown"]},{"year":2002,"claim":"Provided the first direct functional evidence that SLC25A17 transports adenine nucleotides, addressing what the carrier actually moves.","evidence":"Complementation of yeast ANT1 deletion and in vitro transport assay of reconstituted purified PMP34 in proteoliposomes","pmids":["12445829"],"confidence":"High","gaps":["Full substrate range and exchange mechanism not yet defined","Physiological substrate in mammals not established"]},{"year":2012,"claim":"Expanded and refined the substrate spectrum and demonstrated a counter-exchange mechanism, defining how cofactors enter the peroxisome.","evidence":"Recombinant protein reconstitution into liposomes with transport kinetics and inhibitor profiling","pmids":["22185573"],"confidence":"High","gaps":["In vitro substrate preference not yet validated as the in vivo physiological function","Counter-exchange partners inside peroxisome inferred, not directly measured in cells"]},{"year":2019,"claim":"Identified CoA as the primary physiological cargo in a whole organism, resolving which substrate matters most in vivo.","evidence":"Zebrafish morpholino knockdown with lipid profiling and substrate-specific rescue (CoA but not NAD+)","pmids":["31187491"],"confidence":"Medium","gaps":["Morpholino knockdown subject to off-target effects","Does not exclude additional roles for FAD/NAD+ transport"]},{"year":2020,"claim":"Linked the carrier to a specific metabolic pathway, showing it is required for peroxisomal degradation of branched-chain fatty acids in mammals.","evidence":"Slc25a17 gene-trap knockout mice under dietary phytol with acyl-CoA, free fatty acid, bile acid, and PPARα pathway profiling","pmids":["32266253"],"confidence":"High","gaps":["Why other peroxisomal pathways (VLCFA, plasmalogens, bile acids) are spared is unexplained","Mechanistic coupling between CoA import and SCPx-catalyzed cleavage not directly demonstrated"]},{"year":2023,"claim":"Established a role in peroxisomal redox homeostasis, broadening the functional consequence of cofactor transport beyond fatty acid catabolism.","evidence":"CRISPR/genetic inactivation in three cell lines with redox sensor measurements, CbPmp47 rescue, and DEHA pharmacological dissection","pmids":["38159891"],"confidence":"High","gaps":["Variable NADPH/NAD+ effects not fully resolved","Direct mechanistic link between altered cofactor import and glutathione redox shift not pinpointed"]},{"year":2025,"claim":"Identified PEX3 as a stabilizer of SLC25A17 protein driving a JAK2/STAT3 lipid-accumulation axis, introducing upstream regulation and a disease-relevant signaling output.","evidence":"USF2 chromatin binding to PEX3 promoter, PEX3-SLC25A17 co-IP, overexpression/knockdown, and AG490 JAK2 inhibition in lung adenocarcinoma cells","pmids":["40885408"],"confidence":"Medium","gaps":["Single Co-IP for PEX3-SLC25A17 without reciprocal validation","Mechanism linking SLC25A17 transport activity to JAK2/STAT3 activation unclear"]},{"year":2026,"claim":"Identified MARCH1 as the E3 ligase that ubiquitinates and degrades SLC25A17, defining a post-translational control point with consequences for macrophage polarization and chemoresistance.","evidence":"Co-IP, in vitro ubiquitination assay, and rescue overexpression in lung adenocarcinoma with flow cytometry and ELISA readouts","pmids":["41758657"],"confidence":"Medium","gaps":["Ubiquitination site(s) on SLC25A17 not mapped","Relationship between MARCH1-mediated degradation and PEX3 stabilization not integrated"]},{"year":null,"claim":"How cofactor import by SLC25A17 is mechanistically coupled to specific peroxisomal pathways (branched-chain fatty acid catabolism, glutathione/NADPH redox) and how its abundance is balanced by PEX3 stabilization versus MARCH1 degradation in physiological versus tumor contexts remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of the transport cycle","Counter-exchange partners not directly measured inside peroxisomes","Interplay of opposing regulatory inputs on protein level not reconciled"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005215","term_label":"transporter activity","supporting_discovery_ids":[2,3,4]},{"term_id":"GO:0140104","term_label":"molecular carrier activity","supporting_discovery_ids":[3]}],"localization":[{"term_id":"GO:0005777","term_label":"peroxisome","supporting_discovery_ids":[0,1]}],"pathway":[{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[3,5]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[6]}],"complexes":[],"partners":["PEX3","MARCH1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O43808","full_name":"Peroxisomal membrane protein PMP34","aliases":["34 kDa peroxisomal membrane protein","Solute carrier family 25 member 17"],"length_aa":307,"mass_kda":34.6,"function":"Peroxisomal transporter for multiple cofactors like coenzyme A (CoA), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN) and nucleotide adenosine monophosphate (AMP), and to a lesser extent for nicotinamide adenine dinucleotide (NAD(+)), adenosine diphosphate (ADP) and adenosine 3',5'-diphosphate (PAP). May catalyze the transport of free CoA, FAD and NAD(+) from the cytosol into the peroxisomal matrix by a counter-exchange mechanism","subcellular_location":"Cytoplasm; Peroxisome membrane","url":"https://www.uniprot.org/uniprotkb/O43808/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SLC25A17","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000100372","cell_line_id":"CID000893","localizations":[{"compartment":"vesicles","grade":3}],"interactors":[{"gene":"ARID4B","stoichiometry":10.0},{"gene":"PTGFRN","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID000893","total_profiled":1310},"omim":[{"mim_id":"606795","title":"SOLUTE CARRIER FAMILY 25 (MITOCHONDRIAL CARRIER), MEMBER 17; SLC25A17","url":"https://www.omim.org/entry/606795"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Peroxisomes","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/SLC25A17"},"hgnc":{"alias_symbol":["PMP34"],"prev_symbol":[]},"alphafold":{"accession":"O43808","domains":[{"cath_id":"1.50.40.10","chopping":"8-300","consensus_level":"medium","plddt":87.5845,"start":8,"end":300}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O43808","model_url":"https://alphafold.ebi.ac.uk/files/AF-O43808-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O43808-F1-predicted_aligned_error_v6.png","plddt_mean":85.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SLC25A17","jax_strain_url":"https://www.jax.org/strain/search?query=SLC25A17"},"sequence":{"accession":"O43808","fasta_url":"https://rest.uniprot.org/uniprotkb/O43808.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O43808/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O43808"}},"corpus_meta":[{"pmid":"22185573","id":"PMC_22185573","title":"The human gene SLC25A17 encodes a peroxisomal transporter of coenzyme A, FAD and NAD+.","date":"2012","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/22185573","citation_count":129,"is_preprint":false},{"pmid":"12445829","id":"PMC_12445829","title":"Identification of human PMP34 as a peroxisomal ATP transporter.","date":"2002","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/12445829","citation_count":84,"is_preprint":false},{"pmid":"9874197","id":"PMC_9874197","title":"Identification and characterization of human PMP34, a protein closely related to the peroxisomal integral membrane protein PMP47 of Candida boidinii.","date":"1998","source":"European journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9874197","citation_count":54,"is_preprint":false},{"pmid":"11121399","id":"PMC_11121399","title":"Topogenesis of peroxisomal membrane protein requires a short, positively charged intervening-loop sequence and flanking hydrophobic segments. study using human membrane protein PMP34.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11121399","citation_count":51,"is_preprint":false},{"pmid":"32266253","id":"PMC_32266253","title":"Slc25a17 Gene Trapped Mice: PMP34 Plays a Role in the Peroxisomal Degradation of Phytanic and Pristanic Acid.","date":"2020","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/32266253","citation_count":22,"is_preprint":false},{"pmid":"31187491","id":"PMC_31187491","title":"Slc25a17 acts as a peroxisomal coenzyme A transporter and regulates multiorgan development in zebrafish.","date":"2019","source":"Journal of cellular physiology","url":"https://pubmed.ncbi.nlm.nih.gov/31187491","citation_count":21,"is_preprint":false},{"pmid":"38402166","id":"PMC_38402166","title":"SLC25A17 inhibits autophagy to promote triple-negative breast cancer tumorigenesis by ROS-mediated JAK2/STAT3 signaling pathway.","date":"2024","source":"Cancer cell international","url":"https://pubmed.ncbi.nlm.nih.gov/38402166","citation_count":18,"is_preprint":false},{"pmid":"34939235","id":"PMC_34939235","title":"Role of solute carrier transporters SLC25A17 and SLC27A6 in acquired resistance to enzalutamide in castration-resistant prostate cancer.","date":"2021","source":"Molecular carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/34939235","citation_count":14,"is_preprint":false},{"pmid":"38159891","id":"PMC_38159891","title":"The solute carrier SLC25A17 sustains peroxisomal redox homeostasis in diverse mammalian cell lines.","date":"2023","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/38159891","citation_count":4,"is_preprint":false},{"pmid":"40885408","id":"PMC_40885408","title":"USF2 regulates the JAK2/STAT3 pathway through PEX3-mediated SLC25A17 upregulation to affect lipid metabolism and promote the progression of lung adenocarcinoma.","date":"2025","source":"Toxicology and applied pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/40885408","citation_count":3,"is_preprint":false},{"pmid":"41758657","id":"PMC_41758657","title":"MARCH1 attenuates lung adenocarcinoma by blocking macrophage M2 polarization and cisplatin resistance through reducing SLC25A17 stability.","date":"2026","source":"Integrative biology : quantitative biosciences from nano to macro","url":"https://pubmed.ncbi.nlm.nih.gov/41758657","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8035,"output_tokens":2877,"usd":0.03363,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10252,"output_tokens":3152,"usd":0.06503,"stage2_stop_reason":"end_turn"},"total_usd":0.09866,"stage1_batch_id":"msgbatch_013LWZZT6MWaqB9qyTSeQBmU","stage2_batch_id":"msgbatch_0194ZzQaTGNpruoNJBbEMbt3","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1998,\n      \"finding\": \"HsPMP34 (SLC25A17) is a peroxisomal integral membrane protein with six membrane-spanning segments, belonging to the mitochondrial solute carrier family, as demonstrated by localization of a GFP fusion protein to peroxisomes (co-localizing with peroxisomal thiolase) in HepG2 cells and mouse fibroblasts; in PEX5 knockout fibroblasts lacking functional peroxisomes, the fluorescence pattern was altered, confirming peroxisomal targeting.\",\n      \"method\": \"Fluorescence microscopy of GFP fusion protein; co-localization with peroxisomal marker; expression in PEX5 knockout fibroblasts\",\n      \"journal\": \"European journal of biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization with functional context (peroxisome-dependency shown in PEX5 KO), single lab, two orthogonal methods\",\n      \"pmids\": [\"9874197\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"PMP34 (SLC25A17) is an integral peroxisomal membrane protein whose N- and C-terminal domains face the cytosol. The loop between transmembrane segments 4 and 5, containing basic residues, is required for peroxisome targeting; alanine substitution of those basic residues abrogates targeting. Three hydrophobic transmembrane segments flanking this loop are essential for membrane integration into peroxisomes.\",\n      \"method\": \"Differential membrane permeabilization, immunofluorescence of epitope-tagged variants in HeLa and CHO-K1 cells, deletion mutagenesis and GFP fusion localization assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (topology mapping, mutagenesis, deletion variants) in a single rigorous study establishing a mechanistic topogenic signal\",\n      \"pmids\": [\"11121399\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"PMP34 (SLC25A17) functions as a peroxisomal adenine nucleotide (ATP) transporter, demonstrated by: (1) rescue of defective medium-chain fatty acid oxidation in S. cerevisiae ANT1-disrupted cells (which lack the peroxisomal adenine nucleotide carrier) and (2) direct in vitro reconstitution of purified PMP34 in proteoliposomes showing adenine nucleotide transport activity.\",\n      \"method\": \"Yeast genetic complementation (ANT1 deletion rescue); protein purification, reconstitution in proteoliposomes, in vitro transport assay\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution plus genetic epistasis in yeast, two independent orthogonal methods\",\n      \"pmids\": [\"12445829\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"SLC25A17 is a peroxisomal transporter for multiple free cofactors: CoA, FAD, FMN, and AMP (primary substrates), and to a lesser extent NAD+, PAP, and ADP. Recombinant SLC25A17 reconstituted in liposomes operates almost exclusively by counter-exchange, is saturable, and is inhibited by pyridoxal 5'-phosphate and other mitochondrial carrier inhibitors. Its primary physiological role is to import CoA, FAD, and NAD+ into peroxisomes in exchange for intraperoxisomally generated PAP, FMN, and AMP.\",\n      \"method\": \"Recombinant protein expression, purification, reconstitution into liposomes, transport kinetics and inhibitor studies in vitro\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — rigorous in vitro reconstitution with kinetic characterization and inhibitor profiling, establishing substrate specificity and transport mechanism\",\n      \"pmids\": [\"22185573\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In zebrafish, Slc25a17 acts as a peroxisomal CoA transporter in vivo; knockdown severely compromises peroxisome function and alters lipid composition. Injection of exogenous CoA, but not NAD+, rescued the defective swim bladder development caused by slc25a17 knockdown, establishing CoA transport as the primary in vivo function.\",\n      \"method\": \"Zebrafish morpholino knockdown, lipid composition analysis, CoA/NAD+ rescue injection\",\n      \"journal\": \"Journal of cellular physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo genetic knockdown with substrate-specific rescue, single lab, demonstrates CoA as primary functional substrate in vivo\",\n      \"pmids\": [\"31187491\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"PMP34 (SLC25A17) is required for normal peroxisomal degradation of phytanic and pristanic acid in mice. Slc25a17 gene-trap knockout mice on dietary phytol showed hepatomegaly, liver inflammation, induction of peroxisomal enzymes, elevated hepatic triacylglycerols and cholesterylesters, and accumulation of phytanic and pristanic acid (as both free acids and CoA esters), partially mediated by PPARα. Other peroxisomal pathways (bile acid synthesis, VLCFA metabolism, plasmalogen levels) were unaffected, suggesting the role of PMP34 is specifically linked to branched-chain fatty acid CoA metabolism or SCPx-catalyzed thiolytic cleavage.\",\n      \"method\": \"Slc25a17 gene-trap knockout mouse model, dietary phytol challenge, lipid profiling (acyl-CoA esters, free fatty acids), bile acid analysis, peroxisomal enzyme assays, PPARα pathway analysis\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO mouse model with dietary challenge, multiple biochemical readouts establishing specific role in branched-chain fatty acid metabolism, single lab but multiple orthogonal assays\",\n      \"pmids\": [\"32266253\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"SLC25A17 inactivation in mammalian cells (HEK-293, HeLa, SV40-MEFs) shifts the glutathione redox couple toward a more reductive state (lower GSSG/GSH), with variable effects on NADPH and NAD+/NADH. This phenotype was rescued by expression of Candida boidinii Pmp47 (a putative ortholog). The redox change was not due to alterations in peroxisomal antioxidant enzyme expression, catalase activity, H2O2 permeability, or mitochondrial fitness. DEHA treatment revealed kinetic disconnection between peroxisomal and cytosolic glutathione pools and highlighted impact on peroxisomal NADPH metabolism.\",\n      \"method\": \"CRISPR/genetic inactivation of SLC25A17, redox sensor measurements (GSSG/GSH, NADPH, NAD+/NADH) in multiple cell lines, rescue with CbPmp47 expression, pharmacological dissection with DEHA\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — defined cellular phenotype in three independent cell lines with rescue experiment and pharmacological dissection, establishing SLC25A17 as a regulator of peroxisomal redox homeostasis\",\n      \"pmids\": [\"38159891\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"USF2 transcriptionally activates PEX3, and upregulated PEX3 interacts with SLC25A17 to stabilize/upregulate its protein levels, thereby activating JAK2/STAT3 signaling and promoting lipid accumulation in lung adenocarcinoma cells. JAK2 inhibitor AG490 eliminated the lipid-accumulation effect of SLC25A17 overexpression.\",\n      \"method\": \"Chromatin binding assay (USF2 binding to PEX3 promoter), co-immunoprecipitation (PEX3-SLC25A17 interaction), overexpression/knockdown, western blotting, JAK2 inhibitor treatment\",\n      \"journal\": \"Toxicology and applied pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — co-IP for PEX3-SLC25A17 interaction plus pharmacological rescue, single lab, establishes upstream regulation and downstream JAK2/STAT3 pathway link\",\n      \"pmids\": [\"40885408\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"MARCH1 (an E3 ubiquitin ligase) directly ubiquitinates SLC25A17, promoting its degradation. Loss of SLC25A17 protein (via MARCH1-mediated ubiquitination) attenuates M2 macrophage polarization and cisplatin resistance in lung adenocarcinoma; re-expression of SLC25A17 reverses the sensitization to cisplatin induced by MARCH1 overexpression.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, rescue overexpression experiment, flow cytometry, ELISA, western blotting\",\n      \"journal\": \"Integrative biology : quantitative biosciences from nano to macro\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP and ubiquitination assay with rescue experiment in single lab identifying MARCH1 as the E3 ligase writing ubiquitin on SLC25A17\",\n      \"pmids\": [\"41758657\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SLC25A17 (PMP34) is a peroxisomal integral membrane protein belonging to the mitochondrial carrier family that functions as a counter-exchange transporter for multiple adenine-containing cofactors—primarily CoA, FAD, FMN, and AMP, and to a lesser extent NAD+, PAP, and ADP—importing CoA, FAD, and NAD+ into the peroxisomal matrix in exchange for intraperoxisomally generated metabolites; its N- and C-termini face the cytosol, and a basic loop between TM segments 4 and 5 with flanking hydrophobic segments constitutes the peroxisomal targeting/topogenic signal; in vivo, it is essential for peroxisomal degradation of branched-chain fatty acids (phytanic/pristanic acid) and for maintaining peroxisomal redox homeostasis (glutathione and NADPH pools); it is subject to regulation by PEX3-mediated stabilization and MARCH1-mediated ubiquitination and degradation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SLC25A17 (PMP34) is a peroxisomal integral membrane carrier of the mitochondrial solute carrier family that supplies the peroxisomal matrix with adenine-containing cofactors required for its metabolic reactions [#0, #2]. Topologically it spans the membrane with both N- and C-termini facing the cytosol, and a basic loop between transmembrane segments 4 and 5, flanked by three essential hydrophobic segments, encodes its peroxisomal targeting and membrane-integration signal [#1]. Reconstituted in liposomes, the protein operates almost exclusively by saturable counter-exchange, importing CoA, FAD, and NAD+ (with AMP, FMN, PAP, and ADP as additional substrates) in exchange for intraperoxisomally generated metabolites, and is blocked by pyridoxal 5'-phosphate and other mitochondrial-carrier inhibitors [#3]. Its principal physiological cargo in vivo is CoA: zebrafish knockdown defects are rescued by CoA but not NAD+ [#4], and knockout mice fail to degrade the branched-chain fatty acids phytanic and pristanic acid, accumulating their free acids and CoA esters in a partly PPARα-dependent manner [#5]. SLC25A17 also maintains peroxisomal redox homeostasis, since its inactivation shifts the glutathione couple toward a reductive state and perturbs peroxisomal NADPH metabolism [#6]. Its protein abundance is set by opposing post-translational inputs: PEX3 binds and stabilizes SLC25A17 to drive JAK2/STAT3 signaling and lipid accumulation [#7], while the E3 ligase MARCH1 directly ubiquitinates it to promote degradation, influencing macrophage polarization and chemoresistance [#8].\",\n  \"teleology\": [\n    {\n      \"year\": 1998,\n      \"claim\": \"Established that SLC25A17 is a bona fide peroxisomal membrane protein of the mitochondrial carrier family, raising the question of what it transports across the peroxisomal membrane.\",\n      \"evidence\": \"GFP fusion localization and co-localization with peroxisomal thiolase in HepG2 and fibroblasts, with altered pattern in PEX5-knockout cells\",\n      \"pmids\": [\"9874197\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No transport substrate identified\", \"Membrane topology not yet resolved\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Defined the protein's membrane topology and the topogenic signal directing it to peroxisomes, explaining how the carrier is correctly inserted and targeted.\",\n      \"evidence\": \"Differential permeabilization, epitope-tagged topology mapping, and deletion/alanine-substitution mutagenesis in HeLa and CHO-K1 cells\",\n      \"pmids\": [\"11121399\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not identify the import machinery recognizing the loop signal\", \"Transport function still unknown\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Provided the first direct functional evidence that SLC25A17 transports adenine nucleotides, addressing what the carrier actually moves.\",\n      \"evidence\": \"Complementation of yeast ANT1 deletion and in vitro transport assay of reconstituted purified PMP34 in proteoliposomes\",\n      \"pmids\": [\"12445829\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full substrate range and exchange mechanism not yet defined\", \"Physiological substrate in mammals not established\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Expanded and refined the substrate spectrum and demonstrated a counter-exchange mechanism, defining how cofactors enter the peroxisome.\",\n      \"evidence\": \"Recombinant protein reconstitution into liposomes with transport kinetics and inhibitor profiling\",\n      \"pmids\": [\"22185573\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vitro substrate preference not yet validated as the in vivo physiological function\", \"Counter-exchange partners inside peroxisome inferred, not directly measured in cells\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identified CoA as the primary physiological cargo in a whole organism, resolving which substrate matters most in vivo.\",\n      \"evidence\": \"Zebrafish morpholino knockdown with lipid profiling and substrate-specific rescue (CoA but not NAD+)\",\n      \"pmids\": [\"31187491\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Morpholino knockdown subject to off-target effects\", \"Does not exclude additional roles for FAD/NAD+ transport\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Linked the carrier to a specific metabolic pathway, showing it is required for peroxisomal degradation of branched-chain fatty acids in mammals.\",\n      \"evidence\": \"Slc25a17 gene-trap knockout mice under dietary phytol with acyl-CoA, free fatty acid, bile acid, and PPARα pathway profiling\",\n      \"pmids\": [\"32266253\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Why other peroxisomal pathways (VLCFA, plasmalogens, bile acids) are spared is unexplained\", \"Mechanistic coupling between CoA import and SCPx-catalyzed cleavage not directly demonstrated\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Established a role in peroxisomal redox homeostasis, broadening the functional consequence of cofactor transport beyond fatty acid catabolism.\",\n      \"evidence\": \"CRISPR/genetic inactivation in three cell lines with redox sensor measurements, CbPmp47 rescue, and DEHA pharmacological dissection\",\n      \"pmids\": [\"38159891\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Variable NADPH/NAD+ effects not fully resolved\", \"Direct mechanistic link between altered cofactor import and glutathione redox shift not pinpointed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identified PEX3 as a stabilizer of SLC25A17 protein driving a JAK2/STAT3 lipid-accumulation axis, introducing upstream regulation and a disease-relevant signaling output.\",\n      \"evidence\": \"USF2 chromatin binding to PEX3 promoter, PEX3-SLC25A17 co-IP, overexpression/knockdown, and AG490 JAK2 inhibition in lung adenocarcinoma cells\",\n      \"pmids\": [\"40885408\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single Co-IP for PEX3-SLC25A17 without reciprocal validation\", \"Mechanism linking SLC25A17 transport activity to JAK2/STAT3 activation unclear\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Identified MARCH1 as the E3 ligase that ubiquitinates and degrades SLC25A17, defining a post-translational control point with consequences for macrophage polarization and chemoresistance.\",\n      \"evidence\": \"Co-IP, in vitro ubiquitination assay, and rescue overexpression in lung adenocarcinoma with flow cytometry and ELISA readouts\",\n      \"pmids\": [\"41758657\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Ubiquitination site(s) on SLC25A17 not mapped\", \"Relationship between MARCH1-mediated degradation and PEX3 stabilization not integrated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How cofactor import by SLC25A17 is mechanistically coupled to specific peroxisomal pathways (branched-chain fatty acid catabolism, glutathione/NADPH redox) and how its abundance is balanced by PEX3 stabilization versus MARCH1 degradation in physiological versus tumor contexts remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of the transport cycle\", \"Counter-exchange partners not directly measured inside peroxisomes\", \"Interplay of opposing regulatory inputs on protein level not reconciled\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005215\", \"supporting_discovery_ids\": [2, 3, 4]},\n      {\"term_id\": \"GO:0140104\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005777\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [3, 5]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"PEX3\", \"MARCH1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}