{"gene":"EI24","run_date":"2026-06-09T23:54:42","timeline":{"discoveries":[{"year":1996,"finding":"EI24 mRNA is induced by etoposide and ionizing irradiation in a p53-dependent manner, establishing EI24 as a direct transcriptional target of wild-type p53 in response to DNA damage.","method":"Differential display, p53-deficient MEF rescue experiments, ectopic p53 overexpression","journal":"Oncogene","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal genetic models (p53-null MEFs, p53 overexpression, ionizing radiation), replicated across two independent stimuli","pmids":["8649819"],"is_preprint":false},{"year":2000,"finding":"Ectopic EI24 overexpression inhibits cell colony formation and induces apoptotic cell death; this apoptotic activity is blocked by co-expression of Bcl-XL, placing EI24 upstream of or at the mitochondrial apoptosis checkpoint.","method":"Colony formation assay, morphological apoptosis assessment, Bcl-XL co-expression epistasis, beta-galactosidase cell-counting assay","journal":"Molecular and cellular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — epistasis with Bcl-XL combined with multiple functional readouts, replicated in multiple cell systems","pmids":["10594026"],"is_preprint":false},{"year":2005,"finding":"EI24/PIG8 localizes to the endoplasmic reticulum (ER) and physically binds Bcl-2 via its N-terminal region interacting with the BH3 domain of Bcl-2.","method":"Immunofluorescence microscopy, subcellular fractionation, pull-down assay, co-immunoprecipitation, in vitro and in vivo protein-protein binding assays, N-terminal deletion mapping","journal":"Cancer research","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — multiple orthogonal binding assays (pull-down, Co-IP, in vitro binding) combined with localization and domain mapping in a single rigorous study","pmids":["15781622"],"is_preprint":false},{"year":2012,"finding":"EI24 is an essential component of the basal autophagy pathway; conditional knockout of Ei24 in neurons causes age-dependent axon degeneration, neuron loss, and demyelination, while liver-specific knockout causes hepatomegaly and hepatocyte hypertrophy, both associated with impaired autophagic flux, accumulation of LC3, p62 aggregates, and ubiquitin-positive inclusions.","method":"Conditional knockout mice (neural-specific and liver-specific), histopathology, LC3/p62/ubiquitin immunostaining, autophagic flux assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo conditional KO in two independent tissue types with consistent phenotypic and molecular readouts","pmids":["23074225"],"is_preprint":false},{"year":2012,"finding":"Ei24 stabilizes PKCα by competing with the E3 ligase RINCK1 for binding to the C1a domain of PKCα, thereby preventing RINCK1-mediated PKCα degradation, and promotes PKCα membrane localization and interaction with EGFR.","method":"Ei24-heterozygous knockout mice, DMBA/TPA carcinogenesis model, co-immunoprecipitation, domain competition binding assay, subcellular fractionation","journal":"The international journal of biochemistry & cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP and competition binding in single lab study; in vivo KO supports physiological relevance","pmids":["22771957"],"is_preprint":false},{"year":2013,"finding":"EI24 attenuates NF-κB activity by binding to TRAF2 (a Complex I component) and inducing its lysosome-dependent degradation, suppressing EMT and reducing cell invasiveness and anoikis resistance.","method":"EI24 knockdown and overexpression in epithelial tumor cells, co-immunoprecipitation of EI24-TRAF2, lysosome inhibitor assays, NF-κB reporter assay, in vivo metastasis assay","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP plus lysosome inhibitor rescue, single lab, multiple cellular readouts","pmids":["24280371"],"is_preprint":false},{"year":2013,"finding":"Ei24 is a novel E2F1 target gene; E2F1 directly binds the Ei24 promoter via multiple E2F-responsive elements independently of the p53-responsive element, and Ei24 contributes to survival of p53-deficient cells after UVC irradiation.","method":"Chromatin immunoprecipitation (ChIP), promoter reporter assays, Rb-/- and E2f1-/- MEF genetic epistasis, Ei24 siRNA knockdown in p53-/- MEFs","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — ChIP demonstrating direct E2F1 occupancy combined with genetic epistasis across multiple MEF genotypes","pmids":["24014029"],"is_preprint":false},{"year":2014,"finding":"Ei24 contains an importin β-binding-like (IBBL) domain that enables it to bind specifically to IMPβ1 and IMPα2 (but not other importins), competing with the IMPα IBB domain for the same site on IMPβ1, thereby inhibiting IMPβ1- and IMPα/β1-dependent nuclear protein import. Alanine substitutions within the IBBL abrogated this activity.","method":"Unbiased proteomics/pull-down for interactor identification, co-immunoprecipitation, competitive binding with mutant IMPβ1, nuclear import assay, IBBL alanine-substitution mutagenesis, etoposide induction of endogenous Ei24 in MEFs","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — reconstituted nuclear import assay plus site-directed mutagenesis plus endogenous induction model, multiple orthogonal methods in single rigorous study","pmids":["24821838"],"is_preprint":false},{"year":2016,"finding":"EI24 mediates autophagy-dependent degradation of RING-domain E3 ubiquitin ligases, providing a mechanistic link between autophagy and the ubiquitin-proteasome system; 14 physiologically important RING E3 ligases were confirmed as EI24 substrates.","method":"EI24 knockdown/knockout with E3 ligase protein-level readout, autophagy inhibitor controls, statistical modeling of substrate prediction","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — systematic loss-of-function with multiple substrates in single lab; mechanistic link to autophagy established but biochemical reconstitution not described in abstract","pmids":["27541728"],"is_preprint":false},{"year":2019,"finding":"EI24 is enriched at ER-mitochondria contact sites (mitochondria-associated membranes, MAM); its C-terminal domain is required for MAM integrity and autophagy flux. EI24 forms a complex with VDAC1, IP3R, and GRP75 at MAM; EI24 knockout impairs IP3R–VDAC1 interaction.","method":"Subcellular fractionation, immunoprecipitation-mass spectrometry, EI24-ΔC deletion mutant rescue, IP3R–VDAC1 co-immunoprecipitation in EI24-KO cells, p62/LC3II aggregation assays","journal":"Cellular and molecular life sciences : CMLS","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — IP-MS interaction identification plus domain deletion rescue plus downstream complex disruption, single lab","pmids":["31332481"],"is_preprint":false},{"year":2019,"finding":"EI24 overexpression in pancreatic cancer cells activates autophagic lysosomal degradation of c-Myc (reducing c-Myc protein levels with increased LC3B-II, increased Beclin-1, and reduced p62), suppressing cell proliferation and inducing S-phase arrest without caspase-dependent apoptosis.","method":"EI24 overexpression, Western blot for autophagy markers and c-Myc, cell cycle analysis, in vivo xenograft","journal":"Gastroenterology research and practice","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single lab, overexpression only with correlative autophagy markers; no direct demonstration of autophagic c-Myc degradation via flux experiments or rescue","pmids":["30369947"],"is_preprint":false},{"year":2020,"finding":"WWP1 E3 ubiquitin ligase interacts with EI24 and ubiquitinates/degrades EI24 protein, promoting hepatocellular carcinoma cell proliferation; WWP1 overexpression decreases EI24 protein level and vice versa.","method":"Yeast two-hybrid screening, co-immunoprecipitation, lentiviral stable overexpression/knockdown, CCK-8 and colony formation assays, xenograft mouse model","journal":"Zhonghua zhong liu za zhi [Chinese journal of oncology]","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid plus co-IP for interaction, protein level reciprocal manipulation confirms ubiquitin-degradation relationship, single lab","pmids":["32252198"],"is_preprint":false},{"year":2022,"finding":"Under non-stressed conditions, EI24 binds to the kinase domain of IRE1 to inhibit its activation. Upon ER stress, EI24 dissociates from IRE1 to permit UPR activation, while simultaneously targeting IP3R1 to prevent ER calcium depletion, together promoting cell adaptation to ER stress. EI24 knockout causes failure of ER stress adaptation and apoptosis.","method":"Co-immunoprecipitation of EI24–IRE1 complex, EI24 knockout cells with ER stress induction, calcium flux measurements, UPR activation assays","journal":"EMBO reports","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP demonstrating stress-dependent complex dissociation, KO phenotype with multiple orthogonal readouts (IRE1 activation, calcium, apoptosis) in single rigorous study","pmids":["35005829"],"is_preprint":false},{"year":2023,"finding":"Under high arsenic (NaAsO2) conditions, p53 activation driven by ER stress facilitates translocation of EI24 from the ER to mitochondria, where EI24 interacts with VDAC2 to increase mitochondrial permeability and activate the mitochondrial apoptotic pathway; this translocation is inhibited by p53 inhibitor pifithrin-α and ER stress inhibitor 4-PBA.","method":"Subcellular fractionation of ER/mitochondria fractions, co-immunoprecipitation of EI24–VDAC2, pharmacological inhibition of p53 and ER stress, dose-response NaAsO2 treatment in L-02 cells","journal":"Biological trace element research","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — fractionation plus Co-IP plus pharmacological rescue in single lab; mechanistically novel but single study","pmids":["38017236"],"is_preprint":false},{"year":2025,"finding":"EI24 binds to the transmembrane domain of IGF1R near the cytoplasmic membrane and suppresses IGF1R phosphorylation, contributing to improved glucose uptake and resistance to STZ-induced diabetes in Ei24 transgenic mice.","method":"Co-immunoprecipitation, IGF1R phosphorylation assay, Ei24 transgenic mouse model, glucose tolerance test, Glut4 expression assay, STZ-induced diabetes model","journal":"Frontiers in aging","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — co-IP plus functional in vivo phenotype, domain-level binding identified, single lab with no mutagenesis confirmation in abstract","pmids":["40556865"],"is_preprint":false},{"year":2025,"finding":"Ei24 deficiency in brown adipocytes disrupts mitochondrial cristae structure, dissipates mitochondrial membrane potential, reduces matrix pH, and severely depletes ATP, leading to lethal hypothermia under cold challenge independent of UCP1 expression/activity. The C-terminal region of Ei24 is essential for ATP synthase support.","method":"Adipocyte-specific Ei24 knockout (Lyz2cre/EI24fl/fl), cold-challenge survival assay, electron microscopy of cristae, mitochondrial membrane potential measurement, matrix pH measurement, ATP quantification, UCP1 activity assay, C-terminal deletion analysis","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — conditional KO with multiple orthogonal mitochondrial readouts plus domain dissection, single lab but rigorous multi-method study","pmids":["41326403"],"is_preprint":false},{"year":2026,"finding":"EI24 expression in alveolar macrophages is upregulated by commensal microbiota through TLR2/4 signaling; EI24 deficiency in macrophages disrupts alveolar macrophage homeostasis but enhances phagocytosis and inflammatory responses via metabolic rewiring.","method":"Lyz2-cre EI24-floxed conditional macrophage-specific knockout mice, microbiota manipulation, TLR2/4 signaling inhibitors, phagocytosis and inflammatory response assays, metabolic profiling","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — macrophage-specific conditional KO with multiple functional readouts and signaling pathway identification, single study","pmids":["41620436"],"is_preprint":false}],"current_model":"EI24 is a p53- and E2F1-regulated ER-transmembrane protein that functions as an essential autophagy component, facilitates ER–mitochondria contact (MAM) integrity via a C-terminal domain and a complex with VDAC1/IP3R/GRP75, degrades RING-domain E3 ligases through autophagy, suppresses nuclear import by binding IMPβ1/IMPα2 via an IBB-like domain, modulates ER stress adaptation by gating IRE1 activation and IP3R1-mediated calcium release, can translocate to mitochondria under severe stress to interact with VDAC2 and trigger apoptosis, promotes mitochondrial ATP synthesis and cristae integrity (C-terminal dependent) essential for thermogenesis in brown adipocytes, binds the IGF1R transmembrane domain to suppress its signaling, and in the tumor-suppressor context binds Bcl-2 (via its N-terminus engaging Bcl-2's BH3 domain) and targets TRAF2 for lysosomal degradation to attenuate NF-κB-driven EMT."},"narrative":{"mechanistic_narrative":"EI24 is a p53- and E2F1-regulated endoplasmic reticulum transmembrane protein that serves as an essential component of the basal autophagy pathway and a regulator of ER-mitochondria physiology and cell fate [PMID:8649819, PMID:23074225, PMID:24014029]. It was first identified as a direct transcriptional target induced by DNA damage in a p53-dependent manner, and is independently driven by E2F1 binding to its promoter, contributing to survival of p53-deficient cells after irradiation [PMID:8649819, PMID:24014029]. Loss of EI24 in vivo impairs autophagic flux, producing accumulation of LC3, p62, and ubiquitin-positive inclusions and causing tissue degeneration [PMID:23074225]; mechanistically, EI24 links autophagy to protein degradation by mediating autophagy-dependent turnover of RING-domain E3 ubiquitin ligases [PMID:27541728]. At the ER, EI24 binds Bcl-2 through its N-terminus engaging the Bcl-2 BH3 domain and acts at the mitochondrial apoptosis checkpoint, an activity antagonized by Bcl-XL [PMID:10594026, PMID:15781622]. EI24 is enriched at ER-mitochondria contact sites (MAM), where its C-terminal domain supports MAM integrity and it assembles with VDAC1, IP3R, and GRP75 to control IP3R-VDAC1 coupling [PMID:31332481]. It gates ER stress adaptation by binding the IRE1 kinase domain to restrain UPR activation under basal conditions and dissociating upon stress while limiting IP3R1-mediated calcium depletion [PMID:35005829], and under severe stress translocates to mitochondria to interact with VDAC2 and trigger mitochondrial apoptosis [PMID:38017236]. Beyond the secretory/apoptotic axis, EI24 governs mitochondrial bioenergetics: its C-terminal region is essential for ATP synthase support and cristae integrity required for thermogenesis in brown adipocytes [PMID:41326403]. EI24 additionally restrains oncogenic signaling, binding TRAF2 to drive its lysosomal degradation and attenuate NF-κB-driven EMT [PMID:24280371], and binding the IGF1R transmembrane domain to suppress IGF1R phosphorylation and improve glucose handling [PMID:40556865]. EI24 protein levels are themselves controlled by the E3 ligase WWP1, which ubiquitinates and degrades EI24 to promote hepatocellular carcinoma proliferation [PMID:32252198].","teleology":[{"year":1996,"claim":"Established EI24's transcriptional origin by showing it is a direct p53 target induced by DNA damage, placing it within the p53 stress-response program.","evidence":"Differential display with p53-null MEF rescue and ectopic p53 overexpression after etoposide/irradiation","pmids":["8649819"],"confidence":"High","gaps":["Did not define the protein's biochemical activity","p53 binding site on the EI24 promoter not mapped in this study"]},{"year":2000,"claim":"Defined an early functional readout — EI24 overexpression triggers apoptosis blocked by Bcl-XL — positioning it at the mitochondrial apoptosis checkpoint.","evidence":"Colony formation and apoptosis assays with Bcl-XL co-expression epistasis","pmids":["10594026"],"confidence":"High","gaps":["Molecular target of the apoptotic activity not identified","Endogenous role under physiological stress untested"]},{"year":2005,"claim":"Provided a molecular mechanism for the apoptotic phenotype by localizing EI24 to the ER and identifying a direct N-terminus-to-BH3 interaction with Bcl-2.","evidence":"Immunofluorescence, fractionation, pull-down, Co-IP, and N-terminal deletion mapping","pmids":["15781622"],"confidence":"High","gaps":["Functional consequence of Bcl-2 sequestration on apoptosis not quantified in vivo","Stoichiometry and regulation of the interaction unknown"]},{"year":2012,"claim":"Established EI24 as an essential basal autophagy component through tissue-specific knockouts showing impaired autophagic flux and toxic protein accumulation.","evidence":"Neural- and liver-specific conditional KO mice with LC3/p62/ubiquitin pathology and flux assays","pmids":["23074225"],"confidence":"High","gaps":["The biochemical step EI24 performs in autophagy not defined","Relationship between autophagy role and ER/apoptosis roles unresolved"]},{"year":2012,"claim":"Extended EI24's regulatory reach to kinase stability, showing it shields PKCα from RINCK1-mediated degradation and promotes PKCα membrane localization.","evidence":"Ei24-heterozygous mice in DMBA/TPA model, Co-IP, and domain competition binding","pmids":["22771957"],"confidence":"Medium","gaps":["Single-lab co-IP/competition without reconstitution","Mechanism by which EI24 outcompetes RINCK1 not structurally defined"]},{"year":2013,"claim":"Showed EI24 transcription is not solely p53-dependent by demonstrating direct E2F1 promoter occupancy and a survival role in p53-deficient cells.","evidence":"ChIP, promoter reporters, and Rb-/-/E2f1-/- MEF epistasis with siRNA knockdown","pmids":["24014029"],"confidence":"High","gaps":["How dual p53/E2F1 inputs are coordinated in vivo unknown","Context determining pro-survival vs pro-apoptotic output unresolved"]},{"year":2013,"claim":"Linked EI24 to tumor suppression by showing it binds TRAF2 and drives its lysosomal degradation to attenuate NF-κB-driven EMT and invasion.","evidence":"Knockdown/overexpression, reciprocal Co-IP, lysosome inhibitor rescue, NF-κB reporter, metastasis assay","pmids":["24280371"],"confidence":"Medium","gaps":["Whether degradation is autophagy-dependent versus another lysosomal route not distinguished","Single-lab study"]},{"year":2016,"claim":"Generalized the autophagy function into a degradation principle — EI24 directs autophagic turnover of RING-domain E3 ligases, bridging autophagy and the ubiquitin system.","evidence":"Loss-of-function with E3 ligase protein readouts, autophagy inhibitor controls, substrate prediction modeling","pmids":["27541728"],"confidence":"Medium","gaps":["No biochemical reconstitution of substrate recognition","Selectivity determinant for RING-domain ligases unknown"]},{"year":2014,"claim":"Revealed a non-autophagy nuclear-transport function: an IBB-like domain lets EI24 bind IMPβ1/IMPα2 and competitively block importin-dependent nuclear import.","evidence":"Proteomics, Co-IP, competitive binding with mutant IMPβ1, nuclear import assay, IBBL alanine mutagenesis","pmids":["24821838"],"confidence":"High","gaps":["Physiological cargoes whose import is regulated not identified","Interplay with EI24's ER membrane localization unclear"]},{"year":2019,"claim":"Placed EI24 at ER-mitochondria contact sites, identifying a C-terminal-dependent role in MAM integrity and assembly of a VDAC1/IP3R/GRP75 complex.","evidence":"Fractionation, IP-MS, EI24-ΔC rescue, IP3R-VDAC1 Co-IP in KO cells, autophagy marker assays","pmids":["31332481"],"confidence":"Medium","gaps":["Direct versus scaffolded interactions within the complex not resolved","Link between MAM integrity and autophagy flux mechanistically incomplete"]},{"year":2019,"claim":"Proposed EI24 promotes autophagic degradation of c-Myc to suppress pancreatic cancer proliferation.","evidence":"EI24 overexpression, autophagy marker Western blots, cell cycle analysis, xenograft","pmids":["30369947"],"confidence":"Low","gaps":["Overexpression-only with correlative markers; no flux or rescue experiment demonstrating direct autophagic c-Myc degradation","Single lab"]},{"year":2022,"claim":"Defined EI24 as a gatekeeper of ER stress adaptation that restrains IRE1 basally and limits IP3R1 calcium depletion, with loss causing maladaptive apoptosis.","evidence":"EI24-IRE1 reciprocal Co-IP showing stress-dependent dissociation, KO cells with UPR, calcium and apoptosis readouts","pmids":["35005829"],"confidence":"High","gaps":["Trigger for stress-dependent EI24-IRE1 dissociation not defined","How one protein coordinates IRE1 and IP3R1 simultaneously unresolved"]},{"year":2023,"claim":"Showed that under severe (arsenic-induced) stress, p53-driven EI24 relocates from ER to mitochondria and engages VDAC2 to execute mitochondrial apoptosis.","evidence":"ER/mito fractionation, EI24-VDAC2 Co-IP, pifithrin-α and 4-PBA pharmacological inhibition in L-02 cells","pmids":["38017236"],"confidence":"Medium","gaps":["Mechanism of EI24 translocation not defined","Single-lab, single-cell-line study"]},{"year":2025,"claim":"Established a bioenergetic function — EI24's C-terminus supports ATP synthase and cristae integrity essential for brown-adipocyte thermogenesis independent of UCP1.","evidence":"Adipocyte-specific KO, cold-challenge survival, EM cristae imaging, membrane potential/pH/ATP measurements, C-terminal deletion","pmids":["41326403"],"confidence":"High","gaps":["Direct molecular partner at ATP synthase not identified","How an ER/MAM protein supports matrix ATP synthesis mechanistically unclear"]},{"year":2025,"claim":"Identified EI24 as a suppressor of IGF1R signaling by binding the IGF1R transmembrane domain, improving glucose uptake and diabetes resistance.","evidence":"Co-IP, IGF1R phosphorylation assay, Ei24 transgenic mice, glucose tolerance test, STZ diabetes model","pmids":["40556865"],"confidence":"Medium","gaps":["No mutagenesis confirming the transmembrane-domain interaction","Single-lab study"]},{"year":2026,"claim":"Connected EI24 to innate immunity, showing microbiota-driven TLR2/4 induction of EI24 maintains alveolar macrophage homeostasis and restrains phagocytosis/inflammation via metabolic rewiring.","evidence":"Macrophage-specific conditional KO, microbiota manipulation, TLR2/4 inhibitors, phagocytosis/inflammation assays, metabolic profiling","pmids":["41620436"],"confidence":"Medium","gaps":["Whether the immune role depends on EI24's autophagy or MAM functions unknown","Single study"]},{"year":null,"claim":"How EI24 unifies its distinct activities — autophagic E3-ligase degradation, MAM scaffolding, ER-stress gating, mitochondrial bioenergetics, nuclear-import suppression, and receptor signaling regulation — through a single ER-membrane protein remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model relating its N-terminal, IBBL, and C-terminal functional regions","Mechanism switching EI24 between pro-survival and pro-apoptotic outputs undefined","Direct enzymatic activity, if any, unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[5,8]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[12,14,7]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[9,2]}],"localization":[{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[2,9,12]},{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[13,15,9]}],"pathway":[{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[3,8]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[12,0]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[1,13]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5,14]}],"complexes":["VDAC1-IP3R-GRP75 MAM complex"],"partners":["BCL2","IRE1","IP3R1","VDAC1","VDAC2","TRAF2","IGF1R","KPNB1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O14681","full_name":"Etoposide-induced protein 2.4 homolog","aliases":["p53-induced gene 8 protein"],"length_aa":340,"mass_kda":39.0,"function":"Acts as a negative growth regulator via p53-mediated apoptosis pathway. Regulates formation of degradative autolysosomes during autophagy (By similarity)","subcellular_location":"Nucleus membrane; Cytoplasm; Endoplasmic reticulum membrane","url":"https://www.uniprot.org/uniprotkb/O14681/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/EI24","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":74,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CANX","stoichiometry":0.2},{"gene":"COPB2","stoichiometry":0.2},{"gene":"EMC9","stoichiometry":0.2},{"gene":"RTN4","stoichiometry":0.2},{"gene":"YIPF5","stoichiometry":0.2},{"gene":"CCDC47","stoichiometry":0.2},{"gene":"NCLN","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/EI24","total_profiled":1310},"omim":[{"mim_id":"605170","title":"ETOPOSIDE-INDUCED 1.4 mRNA; EI24","url":"https://www.omim.org/entry/605170"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Cytosol","reliability":"Supported"},{"location":"Endoplasmic reticulum","reliability":"Additional"},{"location":"Golgi apparatus","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"parathyroid gland","ntpm":434.6}],"url":"https://www.proteinatlas.org/search/EI24"},"hgnc":{"alias_symbol":["PIG8","TP53I8","EPG4"],"prev_symbol":[]},"alphafold":{"accession":"O14681","domains":[{"cath_id":"-","chopping":"9-308","consensus_level":"high","plddt":89.5648,"start":9,"end":308}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O14681","model_url":"https://alphafold.ebi.ac.uk/files/AF-O14681-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O14681-F1-predicted_aligned_error_v6.png","plddt_mean":86.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=EI24","jax_strain_url":"https://www.jax.org/strain/search?query=EI24"},"sequence":{"accession":"O14681","fasta_url":"https://rest.uniprot.org/uniprotkb/O14681.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O14681/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O14681"}},"corpus_meta":[{"pmid":"10594026","id":"PMC_10594026","title":"ei24, a p53 response gene involved in growth suppression and apoptosis.","date":"2000","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/10594026","citation_count":103,"is_preprint":false},{"pmid":"8649819","id":"PMC_8649819","title":"Identification and cloning of EI24, a gene induced by p53 in etoposide-treated cells.","date":"1996","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/8649819","citation_count":69,"is_preprint":false},{"pmid":"28038450","id":"PMC_28038450","title":"MicroRNA-455-3p promotes invasion and migration in triple negative breast cancer by targeting tumor suppressor EI24.","date":"2017","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/28038450","citation_count":67,"is_preprint":false},{"pmid":"23074225","id":"PMC_23074225","title":"The p53-induced gene Ei24 is an essential component of the basal autophagy pathway.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/23074225","citation_count":61,"is_preprint":false},{"pmid":"15781622","id":"PMC_15781622","title":"Apoptosis factor EI24/PIG8 is a novel endoplasmic reticulum-localized Bcl-2-binding protein which is associated with suppression of breast cancer invasiveness.","date":"2005","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/15781622","citation_count":57,"is_preprint":false},{"pmid":"11753653","id":"PMC_11753653","title":"Candidate tumour suppressor genes at 11q23-q24 in breast cancer: evidence of alterations in PIG8, a gene involved in p53-induced apoptosis.","date":"2001","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/11753653","citation_count":55,"is_preprint":false},{"pmid":"31332481","id":"PMC_31332481","title":"EI24 tethers endoplasmic reticulum and mitochondria to regulate autophagy flux.","date":"2019","source":"Cellular and molecular life sciences : CMLS","url":"https://pubmed.ncbi.nlm.nih.gov/31332481","citation_count":35,"is_preprint":false},{"pmid":"27541728","id":"PMC_27541728","title":"Functional characterization of EI24-induced autophagy in the degradation of RING-domain E3 ligases.","date":"2016","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/27541728","citation_count":32,"is_preprint":false},{"pmid":"26801660","id":"PMC_26801660","title":"miR-483-3p plays an oncogenic role in esophageal squamous cell carcinoma by targeting tumor suppressor EI24.","date":"2016","source":"Cell biology international","url":"https://pubmed.ncbi.nlm.nih.gov/26801660","citation_count":32,"is_preprint":false},{"pmid":"24280371","id":"PMC_24280371","title":"EI24 regulates epithelial-to-mesenchymal transition and tumor progression by suppressing TRAF2-mediated NF-κB activity.","date":"2013","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/24280371","citation_count":31,"is_preprint":false},{"pmid":"17981155","id":"PMC_17981155","title":"Loss of putative tumor suppressor EI24/PIG8 confers resistance to etoposide.","date":"2007","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/17981155","citation_count":29,"is_preprint":false},{"pmid":"35005829","id":"PMC_35005829","title":"EI24 promotes cell adaption to ER stress by coordinating IRE1 signaling and calcium homeostasis.","date":"2022","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/35005829","citation_count":23,"is_preprint":false},{"pmid":"24821838","id":"PMC_24821838","title":"The p53-induced factor Ei24 inhibits nuclear import through an importin β-binding-like domain.","date":"2014","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/24821838","citation_count":23,"is_preprint":false},{"pmid":"22771957","id":"PMC_22771957","title":"Ei24-deficiency attenuates protein kinase Cα signaling and skin carcinogenesis in mice.","date":"2012","source":"The international journal of biochemistry & cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/22771957","citation_count":19,"is_preprint":false},{"pmid":"31396480","id":"PMC_31396480","title":"EI24, as a Component of Autophagy, Is Involved in Pancreatic Cell Proliferation.","date":"2019","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/31396480","citation_count":18,"is_preprint":false},{"pmid":"10965130","id":"PMC_10965130","title":"The p53-inducible gene EI24/PIG8 localizes to human chromosome 11q23 and the proximal region of mouse chromosome 9.","date":"2000","source":"Cytogenetics and cell genetics","url":"https://pubmed.ncbi.nlm.nih.gov/10965130","citation_count":17,"is_preprint":false},{"pmid":"24014029","id":"PMC_24014029","title":"Ei24, a novel E2F target gene, affects p53-independent cell death upon ultraviolet C irradiation.","date":"2013","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24014029","citation_count":15,"is_preprint":false},{"pmid":"33127511","id":"PMC_33127511","title":"Autophagy-related protein EI24 delays the development of pulmonary fibrosis by promoting autophagy.","date":"2020","source":"Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/33127511","citation_count":15,"is_preprint":false},{"pmid":"30369947","id":"PMC_30369947","title":"EI24 Suppresses Tumorigenesis in Pancreatic Cancer via Regulating c-Myc.","date":"2018","source":"Gastroenterology research and practice","url":"https://pubmed.ncbi.nlm.nih.gov/30369947","citation_count":14,"is_preprint":false},{"pmid":"26342551","id":"PMC_26342551","title":"Reduced expression of EI24 confers resistance to gefitinib through IGF-1R signaling in PC9 NSCLC cells.","date":"2015","source":"Lung cancer (Amsterdam, Netherlands)","url":"https://pubmed.ncbi.nlm.nih.gov/26342551","citation_count":13,"is_preprint":false},{"pmid":"32974192","id":"PMC_32974192","title":"EI24 Inhibits Cell Proliferation and Drug Resistance of Esophageal Squamous Cell Carcinoma.","date":"2020","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/32974192","citation_count":12,"is_preprint":false},{"pmid":"20731388","id":"PMC_20731388","title":"An analysis of an interactome for apoptosis factor, Ei24/PIG8, using the inducible expression system and shotgun proteomics.","date":"2010","source":"Journal of proteome research","url":"https://pubmed.ncbi.nlm.nih.gov/20731388","citation_count":10,"is_preprint":false},{"pmid":"34800978","id":"PMC_34800978","title":"Circular RNA hsa_circ_0043278 inhibits breast cancer progression via the miR-455-3p/EI24 signalling pathway.","date":"2021","source":"BMC cancer","url":"https://pubmed.ncbi.nlm.nih.gov/34800978","citation_count":7,"is_preprint":false},{"pmid":"31097220","id":"PMC_31097220","title":"Effect of EI24 expression on the tumorigenesis of ApcMin/+ colorectal cancer mouse model.","date":"2019","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/31097220","citation_count":6,"is_preprint":false},{"pmid":"33368642","id":"PMC_33368642","title":"EI24 alleviates renal interstitial fibrosis through inhibition of epithelial-mesenchymal transition and fibroblast activation.","date":"2021","source":"FASEB journal : official publication of the Federation of American Societies for Experimental Biology","url":"https://pubmed.ncbi.nlm.nih.gov/33368642","citation_count":6,"is_preprint":false},{"pmid":"29877566","id":"PMC_29877566","title":"Deletion of etoposide-induced 2.4 kb transcript (ei24) reduced cell proliferation and aggregate-size in Dictyostelium discoideum.","date":"2018","source":"The International journal of developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/29877566","citation_count":5,"is_preprint":false},{"pmid":"32252198","id":"PMC_32252198","title":"[WWP1 promotes cell proliferation in hepatocellular carcinoma through ubiquitin-degradation EI24].","date":"2020","source":"Zhonghua zhong liu za zhi [Chinese journal of oncology]","url":"https://pubmed.ncbi.nlm.nih.gov/32252198","citation_count":3,"is_preprint":false},{"pmid":"38017236","id":"PMC_38017236","title":"p53-Mediated Mitochondrial Translocation of EI24 Triggered by ER Stress Plays an Important Role in Arsenic-Induced Liver Damage via Activating Mitochondrial Apoptotic Pathway.","date":"2023","source":"Biological trace element research","url":"https://pubmed.ncbi.nlm.nih.gov/38017236","citation_count":3,"is_preprint":false},{"pmid":"40155367","id":"PMC_40155367","title":"Hesperidin alleviates pulmonary fibrosis by regulating EI24-mediated autophagy.","date":"2025","source":"Future science OA","url":"https://pubmed.ncbi.nlm.nih.gov/40155367","citation_count":1,"is_preprint":false},{"pmid":"40556865","id":"PMC_40556865","title":"EI24 binds to IGF1R, enhancing glucose homeostasis and fostering healthy aging in male mice.","date":"2025","source":"Frontiers in aging","url":"https://pubmed.ncbi.nlm.nih.gov/40556865","citation_count":0,"is_preprint":false},{"pmid":"41326403","id":"PMC_41326403","title":"Ei24 deficiency in brown adipocytes induces severe hypothermia under cold stress independent of UCP1 activity.","date":"2025","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/41326403","citation_count":0,"is_preprint":false},{"pmid":"41473975","id":"PMC_41473975","title":"Biological significance, molecular mechanisms and clinical potential of EI24 in cancer.","date":"2025","source":"Chinese medical journal","url":"https://pubmed.ncbi.nlm.nih.gov/41473975","citation_count":0,"is_preprint":false},{"pmid":"41620436","id":"PMC_41620436","title":"Microbiota-induced EI24 improves homeostasis but impedes function of alveolar macrophages via metabolic regulation.","date":"2026","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/41620436","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":17770,"output_tokens":4359,"usd":0.059347,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":12398,"output_tokens":5073,"usd":0.094408,"stage2_stop_reason":"end_turn"},"total_usd":0.153755,"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\": 1996,\n      \"finding\": \"EI24 mRNA is induced by etoposide and ionizing irradiation in a p53-dependent manner, establishing EI24 as a direct transcriptional target of wild-type p53 in response to DNA damage.\",\n      \"method\": \"Differential display, p53-deficient MEF rescue experiments, ectopic p53 overexpression\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal genetic models (p53-null MEFs, p53 overexpression, ionizing radiation), replicated across two independent stimuli\",\n      \"pmids\": [\"8649819\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"Ectopic EI24 overexpression inhibits cell colony formation and induces apoptotic cell death; this apoptotic activity is blocked by co-expression of Bcl-XL, placing EI24 upstream of or at the mitochondrial apoptosis checkpoint.\",\n      \"method\": \"Colony formation assay, morphological apoptosis assessment, Bcl-XL co-expression epistasis, beta-galactosidase cell-counting assay\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — epistasis with Bcl-XL combined with multiple functional readouts, replicated in multiple cell systems\",\n      \"pmids\": [\"10594026\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"EI24/PIG8 localizes to the endoplasmic reticulum (ER) and physically binds Bcl-2 via its N-terminal region interacting with the BH3 domain of Bcl-2.\",\n      \"method\": \"Immunofluorescence microscopy, subcellular fractionation, pull-down assay, co-immunoprecipitation, in vitro and in vivo protein-protein binding assays, N-terminal deletion mapping\",\n      \"journal\": \"Cancer research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — multiple orthogonal binding assays (pull-down, Co-IP, in vitro binding) combined with localization and domain mapping in a single rigorous study\",\n      \"pmids\": [\"15781622\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"EI24 is an essential component of the basal autophagy pathway; conditional knockout of Ei24 in neurons causes age-dependent axon degeneration, neuron loss, and demyelination, while liver-specific knockout causes hepatomegaly and hepatocyte hypertrophy, both associated with impaired autophagic flux, accumulation of LC3, p62 aggregates, and ubiquitin-positive inclusions.\",\n      \"method\": \"Conditional knockout mice (neural-specific and liver-specific), histopathology, LC3/p62/ubiquitin immunostaining, autophagic flux assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo conditional KO in two independent tissue types with consistent phenotypic and molecular readouts\",\n      \"pmids\": [\"23074225\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Ei24 stabilizes PKCα by competing with the E3 ligase RINCK1 for binding to the C1a domain of PKCα, thereby preventing RINCK1-mediated PKCα degradation, and promotes PKCα membrane localization and interaction with EGFR.\",\n      \"method\": \"Ei24-heterozygous knockout mice, DMBA/TPA carcinogenesis model, co-immunoprecipitation, domain competition binding assay, subcellular fractionation\",\n      \"journal\": \"The international journal of biochemistry & cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP and competition binding in single lab study; in vivo KO supports physiological relevance\",\n      \"pmids\": [\"22771957\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"EI24 attenuates NF-κB activity by binding to TRAF2 (a Complex I component) and inducing its lysosome-dependent degradation, suppressing EMT and reducing cell invasiveness and anoikis resistance.\",\n      \"method\": \"EI24 knockdown and overexpression in epithelial tumor cells, co-immunoprecipitation of EI24-TRAF2, lysosome inhibitor assays, NF-κB reporter assay, in vivo metastasis assay\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP plus lysosome inhibitor rescue, single lab, multiple cellular readouts\",\n      \"pmids\": [\"24280371\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Ei24 is a novel E2F1 target gene; E2F1 directly binds the Ei24 promoter via multiple E2F-responsive elements independently of the p53-responsive element, and Ei24 contributes to survival of p53-deficient cells after UVC irradiation.\",\n      \"method\": \"Chromatin immunoprecipitation (ChIP), promoter reporter assays, Rb-/- and E2f1-/- MEF genetic epistasis, Ei24 siRNA knockdown in p53-/- MEFs\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — ChIP demonstrating direct E2F1 occupancy combined with genetic epistasis across multiple MEF genotypes\",\n      \"pmids\": [\"24014029\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Ei24 contains an importin β-binding-like (IBBL) domain that enables it to bind specifically to IMPβ1 and IMPα2 (but not other importins), competing with the IMPα IBB domain for the same site on IMPβ1, thereby inhibiting IMPβ1- and IMPα/β1-dependent nuclear protein import. Alanine substitutions within the IBBL abrogated this activity.\",\n      \"method\": \"Unbiased proteomics/pull-down for interactor identification, co-immunoprecipitation, competitive binding with mutant IMPβ1, nuclear import assay, IBBL alanine-substitution mutagenesis, etoposide induction of endogenous Ei24 in MEFs\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — reconstituted nuclear import assay plus site-directed mutagenesis plus endogenous induction model, multiple orthogonal methods in single rigorous study\",\n      \"pmids\": [\"24821838\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"EI24 mediates autophagy-dependent degradation of RING-domain E3 ubiquitin ligases, providing a mechanistic link between autophagy and the ubiquitin-proteasome system; 14 physiologically important RING E3 ligases were confirmed as EI24 substrates.\",\n      \"method\": \"EI24 knockdown/knockout with E3 ligase protein-level readout, autophagy inhibitor controls, statistical modeling of substrate prediction\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — systematic loss-of-function with multiple substrates in single lab; mechanistic link to autophagy established but biochemical reconstitution not described in abstract\",\n      \"pmids\": [\"27541728\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"EI24 is enriched at ER-mitochondria contact sites (mitochondria-associated membranes, MAM); its C-terminal domain is required for MAM integrity and autophagy flux. EI24 forms a complex with VDAC1, IP3R, and GRP75 at MAM; EI24 knockout impairs IP3R–VDAC1 interaction.\",\n      \"method\": \"Subcellular fractionation, immunoprecipitation-mass spectrometry, EI24-ΔC deletion mutant rescue, IP3R–VDAC1 co-immunoprecipitation in EI24-KO cells, p62/LC3II aggregation assays\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — IP-MS interaction identification plus domain deletion rescue plus downstream complex disruption, single lab\",\n      \"pmids\": [\"31332481\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"EI24 overexpression in pancreatic cancer cells activates autophagic lysosomal degradation of c-Myc (reducing c-Myc protein levels with increased LC3B-II, increased Beclin-1, and reduced p62), suppressing cell proliferation and inducing S-phase arrest without caspase-dependent apoptosis.\",\n      \"method\": \"EI24 overexpression, Western blot for autophagy markers and c-Myc, cell cycle analysis, in vivo xenograft\",\n      \"journal\": \"Gastroenterology research and practice\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single lab, overexpression only with correlative autophagy markers; no direct demonstration of autophagic c-Myc degradation via flux experiments or rescue\",\n      \"pmids\": [\"30369947\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"WWP1 E3 ubiquitin ligase interacts with EI24 and ubiquitinates/degrades EI24 protein, promoting hepatocellular carcinoma cell proliferation; WWP1 overexpression decreases EI24 protein level and vice versa.\",\n      \"method\": \"Yeast two-hybrid screening, co-immunoprecipitation, lentiviral stable overexpression/knockdown, CCK-8 and colony formation assays, xenograft mouse model\",\n      \"journal\": \"Zhonghua zhong liu za zhi [Chinese journal of oncology]\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid plus co-IP for interaction, protein level reciprocal manipulation confirms ubiquitin-degradation relationship, single lab\",\n      \"pmids\": [\"32252198\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Under non-stressed conditions, EI24 binds to the kinase domain of IRE1 to inhibit its activation. Upon ER stress, EI24 dissociates from IRE1 to permit UPR activation, while simultaneously targeting IP3R1 to prevent ER calcium depletion, together promoting cell adaptation to ER stress. EI24 knockout causes failure of ER stress adaptation and apoptosis.\",\n      \"method\": \"Co-immunoprecipitation of EI24–IRE1 complex, EI24 knockout cells with ER stress induction, calcium flux measurements, UPR activation assays\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP demonstrating stress-dependent complex dissociation, KO phenotype with multiple orthogonal readouts (IRE1 activation, calcium, apoptosis) in single rigorous study\",\n      \"pmids\": [\"35005829\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Under high arsenic (NaAsO2) conditions, p53 activation driven by ER stress facilitates translocation of EI24 from the ER to mitochondria, where EI24 interacts with VDAC2 to increase mitochondrial permeability and activate the mitochondrial apoptotic pathway; this translocation is inhibited by p53 inhibitor pifithrin-α and ER stress inhibitor 4-PBA.\",\n      \"method\": \"Subcellular fractionation of ER/mitochondria fractions, co-immunoprecipitation of EI24–VDAC2, pharmacological inhibition of p53 and ER stress, dose-response NaAsO2 treatment in L-02 cells\",\n      \"journal\": \"Biological trace element research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — fractionation plus Co-IP plus pharmacological rescue in single lab; mechanistically novel but single study\",\n      \"pmids\": [\"38017236\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"EI24 binds to the transmembrane domain of IGF1R near the cytoplasmic membrane and suppresses IGF1R phosphorylation, contributing to improved glucose uptake and resistance to STZ-induced diabetes in Ei24 transgenic mice.\",\n      \"method\": \"Co-immunoprecipitation, IGF1R phosphorylation assay, Ei24 transgenic mouse model, glucose tolerance test, Glut4 expression assay, STZ-induced diabetes model\",\n      \"journal\": \"Frontiers in aging\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — co-IP plus functional in vivo phenotype, domain-level binding identified, single lab with no mutagenesis confirmation in abstract\",\n      \"pmids\": [\"40556865\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Ei24 deficiency in brown adipocytes disrupts mitochondrial cristae structure, dissipates mitochondrial membrane potential, reduces matrix pH, and severely depletes ATP, leading to lethal hypothermia under cold challenge independent of UCP1 expression/activity. The C-terminal region of Ei24 is essential for ATP synthase support.\",\n      \"method\": \"Adipocyte-specific Ei24 knockout (Lyz2cre/EI24fl/fl), cold-challenge survival assay, electron microscopy of cristae, mitochondrial membrane potential measurement, matrix pH measurement, ATP quantification, UCP1 activity assay, C-terminal deletion analysis\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — conditional KO with multiple orthogonal mitochondrial readouts plus domain dissection, single lab but rigorous multi-method study\",\n      \"pmids\": [\"41326403\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"EI24 expression in alveolar macrophages is upregulated by commensal microbiota through TLR2/4 signaling; EI24 deficiency in macrophages disrupts alveolar macrophage homeostasis but enhances phagocytosis and inflammatory responses via metabolic rewiring.\",\n      \"method\": \"Lyz2-cre EI24-floxed conditional macrophage-specific knockout mice, microbiota manipulation, TLR2/4 signaling inhibitors, phagocytosis and inflammatory response assays, metabolic profiling\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — macrophage-specific conditional KO with multiple functional readouts and signaling pathway identification, single study\",\n      \"pmids\": [\"41620436\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"EI24 is a p53- and E2F1-regulated ER-transmembrane protein that functions as an essential autophagy component, facilitates ER–mitochondria contact (MAM) integrity via a C-terminal domain and a complex with VDAC1/IP3R/GRP75, degrades RING-domain E3 ligases through autophagy, suppresses nuclear import by binding IMPβ1/IMPα2 via an IBB-like domain, modulates ER stress adaptation by gating IRE1 activation and IP3R1-mediated calcium release, can translocate to mitochondria under severe stress to interact with VDAC2 and trigger apoptosis, promotes mitochondrial ATP synthesis and cristae integrity (C-terminal dependent) essential for thermogenesis in brown adipocytes, binds the IGF1R transmembrane domain to suppress its signaling, and in the tumor-suppressor context binds Bcl-2 (via its N-terminus engaging Bcl-2's BH3 domain) and targets TRAF2 for lysosomal degradation to attenuate NF-κB-driven EMT.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"EI24 is a p53- and E2F1-regulated endoplasmic reticulum transmembrane protein that serves as an essential component of the basal autophagy pathway and a regulator of ER-mitochondria physiology and cell fate [#0, #3, #6]. It was first identified as a direct transcriptional target induced by DNA damage in a p53-dependent manner, and is independently driven by E2F1 binding to its promoter, contributing to survival of p53-deficient cells after irradiation [#0, #6]. Loss of EI24 in vivo impairs autophagic flux, producing accumulation of LC3, p62, and ubiquitin-positive inclusions and causing tissue degeneration [#3]; mechanistically, EI24 links autophagy to protein degradation by mediating autophagy-dependent turnover of RING-domain E3 ubiquitin ligases [#8]. At the ER, EI24 binds Bcl-2 through its N-terminus engaging the Bcl-2 BH3 domain and acts at the mitochondrial apoptosis checkpoint, an activity antagonized by Bcl-XL [#1, #2]. EI24 is enriched at ER-mitochondria contact sites (MAM), where its C-terminal domain supports MAM integrity and it assembles with VDAC1, IP3R, and GRP75 to control IP3R-VDAC1 coupling [#9]. It gates ER stress adaptation by binding the IRE1 kinase domain to restrain UPR activation under basal conditions and dissociating upon stress while limiting IP3R1-mediated calcium depletion [#12], and under severe stress translocates to mitochondria to interact with VDAC2 and trigger mitochondrial apoptosis [#13]. Beyond the secretory/apoptotic axis, EI24 governs mitochondrial bioenergetics: its C-terminal region is essential for ATP synthase support and cristae integrity required for thermogenesis in brown adipocytes [#15]. EI24 additionally restrains oncogenic signaling, binding TRAF2 to drive its lysosomal degradation and attenuate NF-\\u03baB-driven EMT [#5], and binding the IGF1R transmembrane domain to suppress IGF1R phosphorylation and improve glucose handling [#14]. EI24 protein levels are themselves controlled by the E3 ligase WWP1, which ubiquitinates and degrades EI24 to promote hepatocellular carcinoma proliferation [#11].\",\n  \"teleology\": [\n    {\n      \"year\": 1996,\n      \"claim\": \"Established EI24's transcriptional origin by showing it is a direct p53 target induced by DNA damage, placing it within the p53 stress-response program.\",\n      \"evidence\": \"Differential display with p53-null MEF rescue and ectopic p53 overexpression after etoposide/irradiation\",\n      \"pmids\": [\"8649819\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the protein's biochemical activity\", \"p53 binding site on the EI24 promoter not mapped in this study\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Defined an early functional readout — EI24 overexpression triggers apoptosis blocked by Bcl-XL — positioning it at the mitochondrial apoptosis checkpoint.\",\n      \"evidence\": \"Colony formation and apoptosis assays with Bcl-XL co-expression epistasis\",\n      \"pmids\": [\"10594026\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular target of the apoptotic activity not identified\", \"Endogenous role under physiological stress untested\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Provided a molecular mechanism for the apoptotic phenotype by localizing EI24 to the ER and identifying a direct N-terminus-to-BH3 interaction with Bcl-2.\",\n      \"evidence\": \"Immunofluorescence, fractionation, pull-down, Co-IP, and N-terminal deletion mapping\",\n      \"pmids\": [\"15781622\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of Bcl-2 sequestration on apoptosis not quantified in vivo\", \"Stoichiometry and regulation of the interaction unknown\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Established EI24 as an essential basal autophagy component through tissue-specific knockouts showing impaired autophagic flux and toxic protein accumulation.\",\n      \"evidence\": \"Neural- and liver-specific conditional KO mice with LC3/p62/ubiquitin pathology and flux assays\",\n      \"pmids\": [\"23074225\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"The biochemical step EI24 performs in autophagy not defined\", \"Relationship between autophagy role and ER/apoptosis roles unresolved\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended EI24's regulatory reach to kinase stability, showing it shields PKC\\u03b1 from RINCK1-mediated degradation and promotes PKC\\u03b1 membrane localization.\",\n      \"evidence\": \"Ei24-heterozygous mice in DMBA/TPA model, Co-IP, and domain competition binding\",\n      \"pmids\": [\"22771957\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single-lab co-IP/competition without reconstitution\", \"Mechanism by which EI24 outcompetes RINCK1 not structurally defined\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed EI24 transcription is not solely p53-dependent by demonstrating direct E2F1 promoter occupancy and a survival role in p53-deficient cells.\",\n      \"evidence\": \"ChIP, promoter reporters, and Rb-/-/E2f1-/- MEF epistasis with siRNA knockdown\",\n      \"pmids\": [\"24014029\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How dual p53/E2F1 inputs are coordinated in vivo unknown\", \"Context determining pro-survival vs pro-apoptotic output unresolved\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Linked EI24 to tumor suppression by showing it binds TRAF2 and drives its lysosomal degradation to attenuate NF-\\u03baB-driven EMT and invasion.\",\n      \"evidence\": \"Knockdown/overexpression, reciprocal Co-IP, lysosome inhibitor rescue, NF-\\u03baB reporter, metastasis assay\",\n      \"pmids\": [\"24280371\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether degradation is autophagy-dependent versus another lysosomal route not distinguished\", \"Single-lab study\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Generalized the autophagy function into a degradation principle — EI24 directs autophagic turnover of RING-domain E3 ligases, bridging autophagy and the ubiquitin system.\",\n      \"evidence\": \"Loss-of-function with E3 ligase protein readouts, autophagy inhibitor controls, substrate prediction modeling\",\n      \"pmids\": [\"27541728\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No biochemical reconstitution of substrate recognition\", \"Selectivity determinant for RING-domain ligases unknown\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Revealed a non-autophagy nuclear-transport function: an IBB-like domain lets EI24 bind IMP\\u03b21/IMP\\u03b12 and competitively block importin-dependent nuclear import.\",\n      \"evidence\": \"Proteomics, Co-IP, competitive binding with mutant IMP\\u03b21, nuclear import assay, IBBL alanine mutagenesis\",\n      \"pmids\": [\"24821838\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological cargoes whose import is regulated not identified\", \"Interplay with EI24's ER membrane localization unclear\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Placed EI24 at ER-mitochondria contact sites, identifying a C-terminal-dependent role in MAM integrity and assembly of a VDAC1/IP3R/GRP75 complex.\",\n      \"evidence\": \"Fractionation, IP-MS, EI24-\\u0394C rescue, IP3R-VDAC1 Co-IP in KO cells, autophagy marker assays\",\n      \"pmids\": [\"31332481\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus scaffolded interactions within the complex not resolved\", \"Link between MAM integrity and autophagy flux mechanistically incomplete\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Proposed EI24 promotes autophagic degradation of c-Myc to suppress pancreatic cancer proliferation.\",\n      \"evidence\": \"EI24 overexpression, autophagy marker Western blots, cell cycle analysis, xenograft\",\n      \"pmids\": [\"30369947\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Overexpression-only with correlative markers; no flux or rescue experiment demonstrating direct autophagic c-Myc degradation\", \"Single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined EI24 as a gatekeeper of ER stress adaptation that restrains IRE1 basally and limits IP3R1 calcium depletion, with loss causing maladaptive apoptosis.\",\n      \"evidence\": \"EI24-IRE1 reciprocal Co-IP showing stress-dependent dissociation, KO cells with UPR, calcium and apoptosis readouts\",\n      \"pmids\": [\"35005829\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Trigger for stress-dependent EI24-IRE1 dissociation not defined\", \"How one protein coordinates IRE1 and IP3R1 simultaneously unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showed that under severe (arsenic-induced) stress, p53-driven EI24 relocates from ER to mitochondria and engages VDAC2 to execute mitochondrial apoptosis.\",\n      \"evidence\": \"ER/mito fractionation, EI24-VDAC2 Co-IP, pifithrin-\\u03b1 and 4-PBA pharmacological inhibition in L-02 cells\",\n      \"pmids\": [\"38017236\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of EI24 translocation not defined\", \"Single-lab, single-cell-line study\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Established a bioenergetic function — EI24's C-terminus supports ATP synthase and cristae integrity essential for brown-adipocyte thermogenesis independent of UCP1.\",\n      \"evidence\": \"Adipocyte-specific KO, cold-challenge survival, EM cristae imaging, membrane potential/pH/ATP measurements, C-terminal deletion\",\n      \"pmids\": [\"41326403\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct molecular partner at ATP synthase not identified\", \"How an ER/MAM protein supports matrix ATP synthesis mechanistically unclear\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identified EI24 as a suppressor of IGF1R signaling by binding the IGF1R transmembrane domain, improving glucose uptake and diabetes resistance.\",\n      \"evidence\": \"Co-IP, IGF1R phosphorylation assay, Ei24 transgenic mice, glucose tolerance test, STZ diabetes model\",\n      \"pmids\": [\"40556865\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No mutagenesis confirming the transmembrane-domain interaction\", \"Single-lab study\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Connected EI24 to innate immunity, showing microbiota-driven TLR2/4 induction of EI24 maintains alveolar macrophage homeostasis and restrains phagocytosis/inflammation via metabolic rewiring.\",\n      \"evidence\": \"Macrophage-specific conditional KO, microbiota manipulation, TLR2/4 inhibitors, phagocytosis/inflammation assays, metabolic profiling\",\n      \"pmids\": [\"41620436\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether the immune role depends on EI24's autophagy or MAM functions unknown\", \"Single study\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How EI24 unifies its distinct activities — autophagic E3-ligase degradation, MAM scaffolding, ER-stress gating, mitochondrial bioenergetics, nuclear-import suppression, and receptor signaling regulation — through a single ER-membrane protein remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model relating its N-terminal, IBBL, and C-terminal functional regions\", \"Mechanism switching EI24 between pro-survival and pro-apoptotic outputs undefined\", \"Direct enzymatic activity, if any, unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [5, 8]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [12, 14, 7]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [9, 2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [2, 9, 12]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [13, 15, 9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [3, 8]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [12, 0]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [1, 13]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5, 14]}\n    ],\n    \"complexes\": [\"VDAC1-IP3R-GRP75 MAM complex\"],\n    \"partners\": [\"BCL2\", \"IRE1\", \"IP3R1\", \"VDAC1\", \"VDAC2\", \"TRAF2\", \"IGF1R\", \"KPNB1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":9,"faith_total":9,"faith_pct":100.0}}