{"gene":"DNAJC24","run_date":"2026-06-09T23:54:42","timeline":{"discoveries":[{"year":2004,"finding":"DPH4 (DNAJC24) encodes a CSL zinc finger-containing DnaJ-like protein required for diphthamide biosynthesis on translation elongation factor 2 (EF2); genetic evidence showed it has a sequence homolog in mammals and is functionally required for diphthamide modification.","method":"Genetic complementation and sequence homology analysis in yeast and mammals; functional knockout demonstrating loss of diphthamide biosynthesis","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic identification with functional validation across organisms, single study but multiple lines of evidence","pmids":["15485916"],"is_preprint":false},{"year":2007,"finding":"Yeast Jjj3 (ortholog of human DNAJC24/DPH4) has a non-redundant function among cytosolic J proteins; its absence phenotype could not be rescued by overexpression of any other cytosolic J protein, establishing a unique/specialized role.","method":"Comprehensive phenotypic rescue screen: deletion strains of 13 yeast cytosolic J proteins tested for cross-rescue by overexpression","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — systematic genetic rescue screen in yeast, single lab, clear functional specificity demonstrated","pmids":["17438278"],"is_preprint":false},{"year":2008,"finding":"Mouse Dph4 (ortholog of human DNAJC24) is required for diphthamide modification of eEF2; cells from homozygous mutant embryos lacked diphthamide on eEF2 and were resistant to diphtheria toxin killing. DPH4 protein localizes to the cytoskeleton and is not part of the DPH1/DPH2/DPH3 complex.","method":"Mouse genetic mutant analysis; biochemical assay of eEF2 diphthamide modification; diphtheria toxin resistance assay; reporter-tagged DPH4 localization imaging","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic loss-of-function with direct biochemical readout (diphthamide modification), toxin resistance assay, and subcellular localization; multiple orthogonal methods in one study","pmids":["18765564"],"is_preprint":false},{"year":2012,"finding":"Human DPH4 (DNAJC24) has a two-domain structure (J-domain and CSL-domain connected by a flexible linker-helix) determined by NMR. The protein binds iron in tetrahedral coordination through cysteines of its CSL-domain, forms oligomers when iron-bound (Fe-Dph4), and exhibits redox/electron carrier activity critical for diphthamide biosynthesis. Iron binding also enhances the protein's ability to perform Hsp70-dependent functions. The yeast ortholog Jjj3 shares the same iron-binding property.","method":"NMR structure determination; UV-visible and EPR spectroscopy of iron-bound form; in vitro redox activity assays; oligomerization assays; cross-species comparison with yeast Jjj3","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — NMR structure with multiple orthogonal biochemical validations (EPR, UV-vis, redox assays, oligomerization) in a single rigorous study","pmids":["22367199"],"is_preprint":false},{"year":2014,"finding":"Yeast Dph3 (KTI11), a CSL-type zinc finger protein functionally equivalent to DNAJC24/Dph4, can bind iron and in its reduced state serves as an electron donor for the Fe-S cluster in the Dph1-Dph2 complex, thereby supporting the first step of diphthamide biosynthesis. This places Dph3 (and by analogy Dph4) in an electron transfer role analogous to flavodoxins in bacteria.","method":"In vitro reconstitution of diphthamide biosynthesis first step; EPR spectroscopy; iron-binding assays; electron donor functional assays with dithionite as reductant","journal":"Journal of the American Chemical Society","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution with multiple spectroscopic and biochemical methods establishing electron donor mechanism","pmids":["24422557"],"is_preprint":false},{"year":2012,"finding":"Reduced DPH4 (DNAJC24) mRNA and protein levels prevent diphthamide biosynthesis on EF2, rendering EF2 refractory to ADP-ribosylation by Pseudomonas exotoxin A (immunotoxin HA22). This downregulation is caused by reversible CpG island hypermethylation of the DPH4 promoter in resistant cells.","method":"Isolation of immunotoxin-resistant cell lines; ADP-ribosylation assay of EF2; mRNA/protein quantification; promoter CpG methylation analysis; 5-azacytidine methylation inhibitor rescue experiment","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — mechanistic link from epigenetic silencing to loss of diphthamide modification demonstrated with multiple methods including functional rescue","pmids":["22509046"],"is_preprint":false},{"year":2015,"finding":"Complete knockout of DPH4 (DNAJC24) in MCF7 cells produces cells with unmodified eEF2 (no diphthamide), resistance to Pseudomonas exotoxin A and diphtheria toxin, and hypersensitivity to TNF-mediated apoptosis through pre-activation of NF-κB and death receptor pathways, without affecting sensitivity to other protein synthesis inhibitors.","method":"CRISPR/gene knockout of DPH4 in MCF7 cells; biochemical verification of eEF2 modification state; toxin sensitivity assays; TNF apoptosis assays; NF-κB pathway activity measurements","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO with direct biochemical readout plus multiple cellular phenotype assays, multiple pathway measurements","pmids":["26261303"],"is_preprint":false},{"year":2019,"finding":"Knockdown of DPH4 (DNAJC24) in immortalized human podocytes increased adhesion to fibronectin and sFLT1/Fc substrates and caused a spreading defect, establishing a role for the diphthamide biosynthesis pathway (including DPH4) in regulating podocyte adhesion and cytoskeletal organization.","method":"Genome-scale pooled RNAi screen; shRNA knockdown validation; CRISPR-Cas9 knockout adhesion assays; Drosophila nephrocyte-specific knockdown","journal":"American journal of physiology. Renal physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional screen followed by validation with multiple knockdown constructs and CRISPR KO, but mechanistic pathway link is inferential","pmids":["31566424"],"is_preprint":false},{"year":2024,"finding":"DNAJC24 directly interacts with PCNA and promotes AKT phosphorylation via the PI3K/AKT signaling pathway, thereby promoting proliferation and invasion of lung adenocarcinoma (LUAD) cells.","method":"Co-immunoprecipitation (Co-IP) and mass spectrometry to identify PCNA interaction; AKT phosphorylation western blot; knockdown/overexpression with proliferation and invasion assays in A549 and NCI-H1299 cell lines","journal":"FASEB journal","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — Co-IP plus mass spectrometry identifying PCNA as binding partner, and downstream AKT phosphorylation readout, but single lab and limited mechanistic depth in abstract","pmids":["38713100"],"is_preprint":false}],"current_model":"DNAJC24 (DPH4/JJJ3) is a type III J-protein cochaperone with a bipartite structure (J-domain + CSL zinc finger domain) that binds iron through its CSL-domain cysteines and functions as a redox/electron carrier to support the Dph1-Dph2 iron-sulfur enzyme complex in catalyzing the first step of diphthamide biosynthesis on translation elongation factor 2 (eEF2); loss of DNAJC24 abolishes diphthamide modification of eEF2, confers resistance to diphtheria toxin and Pseudomonas exotoxin A, triggers NF-κB/death receptor pathway pre-activation and TNF hypersensitivity, and alters podocyte adhesion, while in cancer contexts DNAJC24 also interacts with PCNA and activates AKT phosphorylation to promote tumor cell proliferation."},"narrative":{"mechanistic_narrative":"DNAJC24 (DPH4/JJJ3) is a type III J-protein cochaperone that catalyzes the first step of diphthamide biosynthesis on translation elongation factor 2 (eEF2) [PMID:15485916, PMID:18765564]. It has a bipartite architecture, with a J-domain and a CSL zinc-finger domain joined by a flexible linker-helix, and binds iron in tetrahedral coordination through CSL-domain cysteines; the iron-bound protein oligomerizes and acts as a redox/electron carrier required for diphthamide synthesis [PMID:22367199]. In this role its reduced, iron-loaded CSL domain serves as an electron donor to the Fe-S cluster of the Dph1-Dph2 enzyme complex, analogous to bacterial flavodoxins [PMID:24422557]. DNAJC24 has a non-redundant function among cytosolic J proteins that cannot be substituted by any other [PMID:17438278], and it localizes to the cytoskeleton rather than partitioning into the DPH1/DPH2/DPH3 complex [PMID:18765564]. Loss of DNAJC24 abolishes eEF2 diphthamide modification, conferring resistance to diphtheria toxin and Pseudomonas exotoxin A while sensitizing cells to TNF-mediated apoptosis via pre-activation of NF-κB and death receptor pathways [PMID:26261303]; in cancer cells its expression is silenced by reversible promoter CpG hypermethylation [PMID:22509046]. Beyond diphthamide biosynthesis, DNAJC24 regulates podocyte adhesion and cytoskeletal spreading [PMID:31566424], and in lung adenocarcinoma it interacts with PCNA and drives PI3K/AKT phosphorylation to promote proliferation and invasion [PMID:38713100].","teleology":[{"year":2004,"claim":"Established that DNAJC24/DPH4 is genetically required for diphthamide modification of eEF2, defining its core biological function and conservation from yeast to mammals.","evidence":"Genetic complementation, sequence homology, and functional knockout across yeast and mammals","pmids":["15485916"],"confidence":"Medium","gaps":["Did not define the biochemical step DPH4 performs","No structural or mechanistic detail of how it supports diphthamide synthesis"]},{"year":2007,"claim":"Showed that the cytosolic J protein Jjj3/DPH4 performs a specialized, non-redundant function distinct from all other cytosolic J proteins.","evidence":"Comprehensive cross-rescue screen of 13 yeast cytosolic J-protein deletion strains","pmids":["17438278"],"confidence":"Medium","gaps":["Did not identify the molecular basis of its specialized role","Performed in yeast; human specificity inferred"]},{"year":2008,"claim":"Confirmed in mammals that DPH4 loss abolishes eEF2 diphthamide and confers diphtheria toxin resistance, and localized the protein to the cytoskeleton and outside the DPH1/DPH2/DPH3 complex.","evidence":"Mouse genetic mutant analysis, eEF2 modification biochemistry, toxin resistance, and reporter localization imaging","pmids":["18765564"],"confidence":"High","gaps":["Mechanism of how a non-complex protein contributes to the DPH1-DPH2 reaction unresolved","Functional meaning of cytoskeletal localization unclear"]},{"year":2012,"claim":"Resolved the bipartite J-domain/CSL-domain structure and demonstrated iron binding through CSL cysteines with redox/electron-carrier activity, providing a biochemical mechanism for its role in diphthamide synthesis.","evidence":"NMR structure, UV-vis and EPR spectroscopy of iron-bound form, in vitro redox and oligomerization assays, cross-species comparison","pmids":["22367199"],"confidence":"High","gaps":["Did not directly demonstrate electron transfer to the Dph1-Dph2 complex","Physiological relevance of iron-dependent Hsp70 functions not established"]},{"year":2014,"claim":"Defined the electron-donor mechanism by which the reduced iron-bound CSL protein feeds electrons to the Fe-S cluster of the Dph1-Dph2 complex for the first diphthamide step.","evidence":"In vitro reconstitution of the first diphthamide step, EPR spectroscopy, iron-binding and electron-donor assays (studying the equivalent CSL protein Dph3/KTI11)","pmids":["24422557"],"confidence":"High","gaps":["Direct biochemical demonstration was on Dph3/KTI11 with DPH4 inferred by analogy","Relative contributions of DPH3 vs DPH4 as electron donors not delineated"]},{"year":2012,"claim":"Connected DPH4 expression to drug response by showing epigenetic silencing via promoter CpG hypermethylation prevents diphthamide synthesis and confers immunotoxin resistance.","evidence":"Immunotoxin-resistant cell lines, EF2 ADP-ribosylation assays, methylation analysis, and 5-azacytidine rescue","pmids":["22509046"],"confidence":"High","gaps":["Trigger of the methylation event in resistant cells unknown","In vivo relevance to clinical toxin resistance not addressed"]},{"year":2015,"claim":"Demonstrated that complete DPH4 knockout pre-activates NF-κB and death receptor pathways, sensitizing cells to TNF apoptosis while conferring toxin resistance, linking diphthamide loss to broader cellular signaling.","evidence":"CRISPR knockout in MCF7 cells with eEF2 modification verification, toxin and TNF apoptosis assays, and NF-κB activity measurements","pmids":["26261303"],"confidence":"High","gaps":["Mechanistic link between loss of diphthamide and NF-κB pre-activation not defined","Whether the TNF phenotype is mediated solely through eEF2 unclear"]},{"year":2019,"claim":"Extended DPH4 function to podocyte biology, showing its loss alters adhesion and cytoskeletal spreading via the diphthamide pathway.","evidence":"Genome-scale RNAi screen, shRNA and CRISPR validation in human podocytes, and Drosophila nephrocyte knockdown","pmids":["31566424"],"confidence":"Medium","gaps":["Mechanistic connection from diphthamide synthesis to adhesion is inferential","Effector linking DPH4 to cytoskeletal organization unidentified"]},{"year":2024,"claim":"Identified a diphthamide-independent oncogenic role in which DNAJC24 binds PCNA and activates PI3K/AKT signaling to promote tumor proliferation and invasion.","evidence":"Co-IP/mass spectrometry, AKT phosphorylation western blot, and knockdown/overexpression proliferation and invasion assays in LUAD cell lines","pmids":["38713100"],"confidence":"Medium","gaps":["Single lab; PCNA interaction lacks reciprocal validation","Whether AKT activation is direct or downstream of diphthamide function unresolved"]},{"year":null,"claim":"How DNAJC24's iron/redox cochaperone activity is mechanistically connected to its downstream cellular phenotypes (NF-κB pre-activation, podocyte adhesion, PCNA/AKT-driven proliferation) remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structural model of DPH4 within the diphthamide enzyme machinery in vivo","Whether the cancer and podocyte roles depend on diphthamide synthesis or represent moonlighting functions is unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016491","term_label":"oxidoreductase activity","supporting_discovery_ids":[3,4]},{"term_id":"GO:0044183","term_label":"protein folding chaperone","supporting_discovery_ids":[0,3]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[2]}],"pathway":[{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,2,6]}],"complexes":[],"partners":["PCNA"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q6P3W2","full_name":"DnaJ homolog subfamily C member 24","aliases":["CSL-type zinc finger-containing protein 3","Diphthamide biosynthesis protein 4"],"length_aa":149,"mass_kda":17.1,"function":"Stimulates the ATPase activity of several Hsp70-type chaperones. This ability is enhanced by iron-binding. The iron-bound form is redox-active and can function as electron carrier. Plays a role in the diphthamide biosynthesis, a post-translational modification of histidine which occurs in translation elongation factor 2 (EEF2) which can be ADP-ribosylated by diphtheria toxin and by Pseudomonas exotoxin A (Eta)","subcellular_location":"Cytoplasm, cytoskeleton","url":"https://www.uniprot.org/uniprotkb/Q6P3W2/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/DNAJC24","classification":"Not Classified","n_dependent_lines":17,"n_total_lines":1208,"dependency_fraction":0.014072847682119206},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000170946","cell_line_id":"CID000030","localizations":[{"compartment":"cytoplasmic","grade":3},{"compartment":"nucleoplasm","grade":2}],"interactors":[{"gene":"DNAJA2","stoichiometry":0.2},{"gene":"NUP88","stoichiometry":0.2},{"gene":"ASPSCR1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID000030","total_profiled":1310},"omim":[{"mim_id":"617141","title":"ANIRIDIA 2; AN2","url":"https://www.omim.org/entry/617141"},{"mim_id":"616902","title":"CHROMOSOME 11p13 DELETION SYNDROME, DISTAL","url":"https://www.omim.org/entry/616902"},{"mim_id":"611072","title":"DNAJ/HSP40 HOMOLOG, SUBFAMILY C, MEMBER 24; DNAJC24","url":"https://www.omim.org/entry/611072"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Cytosol","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/DNAJC24"},"hgnc":{"alias_symbol":["JJJ3"],"prev_symbol":["ZCSL3","DPH4"]},"alphafold":{"accession":"Q6P3W2","domains":[{"cath_id":"1.10.287.110","chopping":"12-86","consensus_level":"high","plddt":76.5996,"start":12,"end":86},{"cath_id":"3.10.660.10","chopping":"91-145","consensus_level":"high","plddt":80.4533,"start":91,"end":145}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P3W2","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P3W2-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6P3W2-F1-predicted_aligned_error_v6.png","plddt_mean":74.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=DNAJC24","jax_strain_url":"https://www.jax.org/strain/search?query=DNAJC24"},"sequence":{"accession":"Q6P3W2","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6P3W2.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6P3W2/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6P3W2"}},"corpus_meta":[{"pmid":"15485916","id":"PMC_15485916","title":"Identification of the proteins required for biosynthesis of diphthamide, the target of bacterial ADP-ribosylating toxins on translation elongation factor 2.","date":"2004","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/15485916","citation_count":146,"is_preprint":false},{"pmid":"17438278","id":"PMC_17438278","title":"Network of general and specialty J protein chaperones of the yeast cytosol.","date":"2007","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/17438278","citation_count":126,"is_preprint":false},{"pmid":"24422557","id":"PMC_24422557","title":"Dph3 is an electron donor for Dph1-Dph2 in the first step of eukaryotic diphthamide biosynthesis.","date":"2014","source":"Journal of the American Chemical Society","url":"https://pubmed.ncbi.nlm.nih.gov/24422557","citation_count":58,"is_preprint":false},{"pmid":"18765564","id":"PMC_18765564","title":"Diphthamide modification of eEF2 requires a J-domain protein and is essential for normal development.","date":"2008","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/18765564","citation_count":57,"is_preprint":false},{"pmid":"26261303","id":"PMC_26261303","title":"Loss of diphthamide pre-activates NF-κB and death receptor pathways and renders MCF7 cells hypersensitive to tumor necrosis factor.","date":"2015","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/26261303","citation_count":50,"is_preprint":false},{"pmid":"22509046","id":"PMC_22509046","title":"Immunotoxin resistance via reversible methylation of the DPH4 promoter is a unique survival strategy.","date":"2012","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/22509046","citation_count":43,"is_preprint":false},{"pmid":"16572726","id":"PMC_16572726","title":"A genomewide analysis of genes for the heat shock protein 70 chaperone system in the ascidian Ciona intestinalis.","date":"2006","source":"Cell stress & chaperones","url":"https://pubmed.ncbi.nlm.nih.gov/16572726","citation_count":30,"is_preprint":false},{"pmid":"22367199","id":"PMC_22367199","title":"Structure and mechanistic insights into novel iron-mediated moonlighting functions of human J-protein cochaperone, Dph4.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22367199","citation_count":27,"is_preprint":false},{"pmid":"22851130","id":"PMC_22851130","title":"Synthetic lethal interactions in yeast reveal functional roles of J protein co-chaperones.","date":"2012","source":"Molecular bioSystems","url":"https://pubmed.ncbi.nlm.nih.gov/22851130","citation_count":26,"is_preprint":false},{"pmid":"21321669","id":"PMC_21321669","title":"A 556 kb deletion in the downstream region of the PAX6 gene causes familial aniridia and other eye anomalies in a Chinese family.","date":"2011","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/21321669","citation_count":25,"is_preprint":false},{"pmid":"26362823","id":"PMC_26362823","title":"Protective effect of the multitarget compound DPH-4 on human SSAO/VAP-1-expressing hCMEC/D3 cells under oxygen-glucose deprivation conditions: an in vitro experimental model of cerebral ischaemia.","date":"2015","source":"British journal of pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/26362823","citation_count":14,"is_preprint":false},{"pmid":"34705337","id":"PMC_34705337","title":"Establishment of a pig CRISPR/Cas9 knockout library for functional gene screening in pig cells.","date":"2021","source":"Biotechnology journal","url":"https://pubmed.ncbi.nlm.nih.gov/34705337","citation_count":13,"is_preprint":false},{"pmid":"35606363","id":"PMC_35606363","title":"DNAJC24 is a potential therapeutic target in hepatocellular carcinoma through affecting ammonia 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Part A","url":"https://pubmed.ncbi.nlm.nih.gov/26419218","citation_count":8,"is_preprint":false},{"pmid":"30572005","id":"PMC_30572005","title":"Deletion distal to the PAX6 coding region reveals a novel basis for familial cosegregation of aniridia and diabetes mellitus.","date":"2018","source":"Diabetes research and clinical practice","url":"https://pubmed.ncbi.nlm.nih.gov/30572005","citation_count":7,"is_preprint":false},{"pmid":"40301754","id":"PMC_40301754","title":"A genome-wide association study identified candidate genes associated with egg quality traits in Muscovy duck.","date":"2025","source":"BMC genomics","url":"https://pubmed.ncbi.nlm.nih.gov/40301754","citation_count":6,"is_preprint":false},{"pmid":"38713100","id":"PMC_38713100","title":"DNAJC24 acts directly with PCNA and promotes malignant progression of LUAD by activating phosphorylation of AKT.","date":"2024","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/38713100","citation_count":3,"is_preprint":false},{"pmid":"38017322","id":"PMC_38017322","title":"Elucidation of novel SNPs affecting immune response to classical swine fever vaccination in pigs using immunogenomics approach.","date":"2023","source":"Veterinary research communications","url":"https://pubmed.ncbi.nlm.nih.gov/38017322","citation_count":3,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13753,"output_tokens":2537,"usd":0.039657,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9719,"output_tokens":3292,"usd":0.065448,"stage2_stop_reason":"end_turn"},"total_usd":0.105105,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2004,\n      \"finding\": \"DPH4 (DNAJC24) encodes a CSL zinc finger-containing DnaJ-like protein required for diphthamide biosynthesis on translation elongation factor 2 (EF2); genetic evidence showed it has a sequence homolog in mammals and is functionally required for diphthamide modification.\",\n      \"method\": \"Genetic complementation and sequence homology analysis in yeast and mammals; functional knockout demonstrating loss of diphthamide biosynthesis\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic identification with functional validation across organisms, single study but multiple lines of evidence\",\n      \"pmids\": [\"15485916\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Yeast Jjj3 (ortholog of human DNAJC24/DPH4) has a non-redundant function among cytosolic J proteins; its absence phenotype could not be rescued by overexpression of any other cytosolic J protein, establishing a unique/specialized role.\",\n      \"method\": \"Comprehensive phenotypic rescue screen: deletion strains of 13 yeast cytosolic J proteins tested for cross-rescue by overexpression\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — systematic genetic rescue screen in yeast, single lab, clear functional specificity demonstrated\",\n      \"pmids\": [\"17438278\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"Mouse Dph4 (ortholog of human DNAJC24) is required for diphthamide modification of eEF2; cells from homozygous mutant embryos lacked diphthamide on eEF2 and were resistant to diphtheria toxin killing. DPH4 protein localizes to the cytoskeleton and is not part of the DPH1/DPH2/DPH3 complex.\",\n      \"method\": \"Mouse genetic mutant analysis; biochemical assay of eEF2 diphthamide modification; diphtheria toxin resistance assay; reporter-tagged DPH4 localization imaging\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic loss-of-function with direct biochemical readout (diphthamide modification), toxin resistance assay, and subcellular localization; multiple orthogonal methods in one study\",\n      \"pmids\": [\"18765564\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Human DPH4 (DNAJC24) has a two-domain structure (J-domain and CSL-domain connected by a flexible linker-helix) determined by NMR. The protein binds iron in tetrahedral coordination through cysteines of its CSL-domain, forms oligomers when iron-bound (Fe-Dph4), and exhibits redox/electron carrier activity critical for diphthamide biosynthesis. Iron binding also enhances the protein's ability to perform Hsp70-dependent functions. The yeast ortholog Jjj3 shares the same iron-binding property.\",\n      \"method\": \"NMR structure determination; UV-visible and EPR spectroscopy of iron-bound form; in vitro redox activity assays; oligomerization assays; cross-species comparison with yeast Jjj3\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — NMR structure with multiple orthogonal biochemical validations (EPR, UV-vis, redox assays, oligomerization) in a single rigorous study\",\n      \"pmids\": [\"22367199\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Yeast Dph3 (KTI11), a CSL-type zinc finger protein functionally equivalent to DNAJC24/Dph4, can bind iron and in its reduced state serves as an electron donor for the Fe-S cluster in the Dph1-Dph2 complex, thereby supporting the first step of diphthamide biosynthesis. This places Dph3 (and by analogy Dph4) in an electron transfer role analogous to flavodoxins in bacteria.\",\n      \"method\": \"In vitro reconstitution of diphthamide biosynthesis first step; EPR spectroscopy; iron-binding assays; electron donor functional assays with dithionite as reductant\",\n      \"journal\": \"Journal of the American Chemical Society\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution with multiple spectroscopic and biochemical methods establishing electron donor mechanism\",\n      \"pmids\": [\"24422557\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Reduced DPH4 (DNAJC24) mRNA and protein levels prevent diphthamide biosynthesis on EF2, rendering EF2 refractory to ADP-ribosylation by Pseudomonas exotoxin A (immunotoxin HA22). This downregulation is caused by reversible CpG island hypermethylation of the DPH4 promoter in resistant cells.\",\n      \"method\": \"Isolation of immunotoxin-resistant cell lines; ADP-ribosylation assay of EF2; mRNA/protein quantification; promoter CpG methylation analysis; 5-azacytidine methylation inhibitor rescue experiment\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — mechanistic link from epigenetic silencing to loss of diphthamide modification demonstrated with multiple methods including functional rescue\",\n      \"pmids\": [\"22509046\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Complete knockout of DPH4 (DNAJC24) in MCF7 cells produces cells with unmodified eEF2 (no diphthamide), resistance to Pseudomonas exotoxin A and diphtheria toxin, and hypersensitivity to TNF-mediated apoptosis through pre-activation of NF-κB and death receptor pathways, without affecting sensitivity to other protein synthesis inhibitors.\",\n      \"method\": \"CRISPR/gene knockout of DPH4 in MCF7 cells; biochemical verification of eEF2 modification state; toxin sensitivity assays; TNF apoptosis assays; NF-κB pathway activity measurements\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO with direct biochemical readout plus multiple cellular phenotype assays, multiple pathway measurements\",\n      \"pmids\": [\"26261303\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Knockdown of DPH4 (DNAJC24) in immortalized human podocytes increased adhesion to fibronectin and sFLT1/Fc substrates and caused a spreading defect, establishing a role for the diphthamide biosynthesis pathway (including DPH4) in regulating podocyte adhesion and cytoskeletal organization.\",\n      \"method\": \"Genome-scale pooled RNAi screen; shRNA knockdown validation; CRISPR-Cas9 knockout adhesion assays; Drosophila nephrocyte-specific knockdown\",\n      \"journal\": \"American journal of physiology. Renal physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional screen followed by validation with multiple knockdown constructs and CRISPR KO, but mechanistic pathway link is inferential\",\n      \"pmids\": [\"31566424\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"DNAJC24 directly interacts with PCNA and promotes AKT phosphorylation via the PI3K/AKT signaling pathway, thereby promoting proliferation and invasion of lung adenocarcinoma (LUAD) cells.\",\n      \"method\": \"Co-immunoprecipitation (Co-IP) and mass spectrometry to identify PCNA interaction; AKT phosphorylation western blot; knockdown/overexpression with proliferation and invasion assays in A549 and NCI-H1299 cell lines\",\n      \"journal\": \"FASEB journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — Co-IP plus mass spectrometry identifying PCNA as binding partner, and downstream AKT phosphorylation readout, but single lab and limited mechanistic depth in abstract\",\n      \"pmids\": [\"38713100\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"DNAJC24 (DPH4/JJJ3) is a type III J-protein cochaperone with a bipartite structure (J-domain + CSL zinc finger domain) that binds iron through its CSL-domain cysteines and functions as a redox/electron carrier to support the Dph1-Dph2 iron-sulfur enzyme complex in catalyzing the first step of diphthamide biosynthesis on translation elongation factor 2 (eEF2); loss of DNAJC24 abolishes diphthamide modification of eEF2, confers resistance to diphtheria toxin and Pseudomonas exotoxin A, triggers NF-κB/death receptor pathway pre-activation and TNF hypersensitivity, and alters podocyte adhesion, while in cancer contexts DNAJC24 also interacts with PCNA and activates AKT phosphorylation to promote tumor cell proliferation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"DNAJC24 (DPH4/JJJ3) is a type III J-protein cochaperone that catalyzes the first step of diphthamide biosynthesis on translation elongation factor 2 (eEF2) [#0, #2]. It has a bipartite architecture, with a J-domain and a CSL zinc-finger domain joined by a flexible linker-helix, and binds iron in tetrahedral coordination through CSL-domain cysteines; the iron-bound protein oligomerizes and acts as a redox/electron carrier required for diphthamide synthesis [#3]. In this role its reduced, iron-loaded CSL domain serves as an electron donor to the Fe-S cluster of the Dph1-Dph2 enzyme complex, analogous to bacterial flavodoxins [#4]. DNAJC24 has a non-redundant function among cytosolic J proteins that cannot be substituted by any other [#1], and it localizes to the cytoskeleton rather than partitioning into the DPH1/DPH2/DPH3 complex [#2]. Loss of DNAJC24 abolishes eEF2 diphthamide modification, conferring resistance to diphtheria toxin and Pseudomonas exotoxin A while sensitizing cells to TNF-mediated apoptosis via pre-activation of NF-\\u03baB and death receptor pathways [#6]; in cancer cells its expression is silenced by reversible promoter CpG hypermethylation [#5]. Beyond diphthamide biosynthesis, DNAJC24 regulates podocyte adhesion and cytoskeletal spreading [#7], and in lung adenocarcinoma it interacts with PCNA and drives PI3K/AKT phosphorylation to promote proliferation and invasion [#8].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established that DNAJC24/DPH4 is genetically required for diphthamide modification of eEF2, defining its core biological function and conservation from yeast to mammals.\",\n      \"evidence\": \"Genetic complementation, sequence homology, and functional knockout across yeast and mammals\",\n      \"pmids\": [\"15485916\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Did not define the biochemical step DPH4 performs\", \"No structural or mechanistic detail of how it supports diphthamide synthesis\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Showed that the cytosolic J protein Jjj3/DPH4 performs a specialized, non-redundant function distinct from all other cytosolic J proteins.\",\n      \"evidence\": \"Comprehensive cross-rescue screen of 13 yeast cytosolic J-protein deletion strains\",\n      \"pmids\": [\"17438278\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Did not identify the molecular basis of its specialized role\", \"Performed in yeast; human specificity inferred\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Confirmed in mammals that DPH4 loss abolishes eEF2 diphthamide and confers diphtheria toxin resistance, and localized the protein to the cytoskeleton and outside the DPH1/DPH2/DPH3 complex.\",\n      \"evidence\": \"Mouse genetic mutant analysis, eEF2 modification biochemistry, toxin resistance, and reporter localization imaging\",\n      \"pmids\": [\"18765564\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Mechanism of how a non-complex protein contributes to the DPH1-DPH2 reaction unresolved\", \"Functional meaning of cytoskeletal localization unclear\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolved the bipartite J-domain/CSL-domain structure and demonstrated iron binding through CSL cysteines with redox/electron-carrier activity, providing a biochemical mechanism for its role in diphthamide synthesis.\",\n      \"evidence\": \"NMR structure, UV-vis and EPR spectroscopy of iron-bound form, in vitro redox and oligomerization assays, cross-species comparison\",\n      \"pmids\": [\"22367199\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Did not directly demonstrate electron transfer to the Dph1-Dph2 complex\", \"Physiological relevance of iron-dependent Hsp70 functions not established\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Defined the electron-donor mechanism by which the reduced iron-bound CSL protein feeds electrons to the Fe-S cluster of the Dph1-Dph2 complex for the first diphthamide step.\",\n      \"evidence\": \"In vitro reconstitution of the first diphthamide step, EPR spectroscopy, iron-binding and electron-donor assays (studying the equivalent CSL protein Dph3/KTI11)\",\n      \"pmids\": [\"24422557\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Direct biochemical demonstration was on Dph3/KTI11 with DPH4 inferred by analogy\", \"Relative contributions of DPH3 vs DPH4 as electron donors not delineated\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Connected DPH4 expression to drug response by showing epigenetic silencing via promoter CpG hypermethylation prevents diphthamide synthesis and confers immunotoxin resistance.\",\n      \"evidence\": \"Immunotoxin-resistant cell lines, EF2 ADP-ribosylation assays, methylation analysis, and 5-azacytidine rescue\",\n      \"pmids\": [\"22509046\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Trigger of the methylation event in resistant cells unknown\", \"In vivo relevance to clinical toxin resistance not addressed\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Demonstrated that complete DPH4 knockout pre-activates NF-\\u03baB and death receptor pathways, sensitizing cells to TNF apoptosis while conferring toxin resistance, linking diphthamide loss to broader cellular signaling.\",\n      \"evidence\": \"CRISPR knockout in MCF7 cells with eEF2 modification verification, toxin and TNF apoptosis assays, and NF-\\u03baB activity measurements\",\n      \"pmids\": [\"26261303\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Mechanistic link between loss of diphthamide and NF-\\u03baB pre-activation not defined\", \"Whether the TNF phenotype is mediated solely through eEF2 unclear\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Extended DPH4 function to podocyte biology, showing its loss alters adhesion and cytoskeletal spreading via the diphthamide pathway.\",\n      \"evidence\": \"Genome-scale RNAi screen, shRNA and CRISPR validation in human podocytes, and Drosophila nephrocyte knockdown\",\n      \"pmids\": [\"31566424\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Mechanistic connection from diphthamide synthesis to adhesion is inferential\", \"Effector linking DPH4 to cytoskeletal organization unidentified\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified a diphthamide-independent oncogenic role in which DNAJC24 binds PCNA and activates PI3K/AKT signaling to promote tumor proliferation and invasion.\",\n      \"evidence\": \"Co-IP/mass spectrometry, AKT phosphorylation western blot, and knockdown/overexpression proliferation and invasion assays in LUAD cell lines\",\n      \"pmids\": [\"38713100\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\"Single lab; PCNA interaction lacks reciprocal validation\", \"Whether AKT activation is direct or downstream of diphthamide function unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How DNAJC24's iron/redox cochaperone activity is mechanistically connected to its downstream cellular phenotypes (NF-\\u03baB pre-activation, podocyte adhesion, PCNA/AKT-driven proliferation) remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of DPH4 within the diphthamide enzyme machinery in vivo\", \"Whether the cancer and podocyte roles depend on diphthamide synthesis or represent moonlighting functions is unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016491\", \"supporting_discovery_ids\": [3, 4]},\n      {\"term_id\": \"GO:0044183\", \"supporting_discovery_ids\": [0, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 2, 6]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"PCNA\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}