{"gene":"CPEB2","run_date":"2026-06-09T22:57:19","timeline":{"discoveries":[{"year":2011,"finding":"CPEB2 interacts directly with elongation factor eEF2 to reduce eEF2/ribosome-triggered GTP hydrolysis in vitro, thereby slowing peptide elongation of CPEB2-bound RNA in vivo. This mechanism represses HIF-1α mRNA translation under normoxia; under oxidative stress, CPEB2 dissociates from HIF-1α mRNA, enabling rapid HIF-1α synthesis.","method":"Co-immunoprecipitation, in vitro GTP hydrolysis assay, in vivo translation reporter assay, RNA-immunoprecipitation","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro reconstitution of eEF2 GTP hydrolysis inhibition combined with in vivo translation assays and RIP, multiple orthogonal methods in one rigorous study","pmids":["22157746"],"is_preprint":false},{"year":2003,"finding":"CPEB2 contains two RNA recognition motifs and a zinc-finger (ZZ) domain, preferentially binds poly(U) RNA, and localizes to the cytoplasm in transfected HeLa cells. It is expressed postmeiotically in mouse spermatogenesis, consistent with a role in translational regulation of stored mRNAs in haploid spermatids.","method":"RNA-binding assay (poly(U) preference), subcellular localization by transfection/imaging, RT-PCR expression profiling, chromosome mapping","journal":"Biology of reproduction","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — direct binding and localization assays established in a single study; functional role inferred from expression pattern without full functional rescue","pmids":["12672660"],"is_preprint":false},{"year":2015,"finding":"NPGPx (GPx7) forms an intermolecular disulfide bond with CPEB2 under oxidative stress conditions. In NPGPx-proficient cells, high oxidative stress disrupts this bond and compromises CPEB2 association with HIF-1α mRNA, leading to elevated HIF-1α translation. NPGPx-deficient cells show increased basal HIF-1α translation with impaired stress-induced induction.","method":"Disulfide bond detection (co-immunoprecipitation under non-reducing conditions), RNA-immunoprecipitation, translation reporter assay","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — intermolecular disulfide bond biochemically demonstrated, RIP and translation assays orthogonally confirm functional consequence, single lab but multiple methods","pmids":["26446990"],"is_preprint":false},{"year":2016,"finding":"CPEB2 knockout mice show upregulated translation of choline acetyltransferase (ChAT) mRNA specifically in the dorsal motor nucleus of vagus, leading to hyperactivated parasympathetic (cholinergic) signaling, elevated pulmonary acetylcholine, increased phospho-myosin light chain 2 in bronchial smooth muscles, and bronchoconstriction. Cholinergic neuron-specific CPEB2 deletion recapitulates apnea and airway hyper-reactivity.","method":"Global and conditional (cholinergic neuron-specific) CPEB2 knockout mice, whole-body plethysmography, Western blotting (ChAT protein levels), acetylcholine measurement, anticholinergic bronchodilator rescue","journal":"The Journal of neuroscience","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic loss-of-function with specific cellular and molecular phenotype, conditional KO in defined neurons recapitulates phenotype, pharmacological rescue validates mechanism","pmids":["27810937"],"is_preprint":false},{"year":2017,"finding":"CPEB2 activates GRASP1 mRNA translation in forebrain neurons. CPEB2 conditional knockout mice show reduced surface (but not total) AMPA receptor expression and impaired long-term potentiation (LTP) in the Schaffer collateral–CA1 pathway. Ectopic expression of CPEB2 or GRASP1 in CA1 of KO mice rescues LTP and spatial memory.","method":"Forebrain-restricted conditional knockout mice, electrophysiology (LTP), AMPA receptor surface biotinylation, polysomal profiling/translation assay, stereotaxic AAV rescue","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO with defined cellular phenotype, mechanistic target identified by polysomal profiling, rescue with CPEB2 and downstream target GRASP1 orthogonally validates pathway","pmids":["29141213"],"is_preprint":false},{"year":2017,"finding":"The CPEB2B splice isoform (containing exon 4) functions as a translational activator of TWIST1 and HIF-1α mRNAs and promotes EMT, anoikis resistance, and metastasis in triple-negative breast cancer cells. Conversely, CPEB2A (lacking exon 4) does not drive these pathways; specific knockdown of CPEB2B inhibits EMT and hypoxic-response gene expression.","method":"Isoform-specific siRNA knockdown, next-generation sequencing of translatome, Western blotting for HIF-1α and TWIST1, anoikis assay, in vivo metastasis assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — isoform-specific depletion with transcriptomic and protein-level validation in single lab; functional assays support translational activation role","pmids":["28904175"],"is_preprint":false},{"year":2018,"finding":"CPEB2 is required for β3 adrenergic receptor signaling-induced translation of the long 3'-UTR Ucp1 mRNA (Ucp1L) in brown adipose tissue. CPEB2-knockout mice show reduced UCP1 protein levels and impaired thermogenesis, rescued by ectopic CPEB2 expression. Mice expressing only short Ucp1 (Ucp1S) have 60% less UCP1 protein and impaired thermogenesis.","method":"CPEB2 and Ucp1L-specific knockout mice, Western blotting, thermogenesis measurements, ectopic CPEB2 rescue, translation reporter assay","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple genetic models (CPEB2 KO, Ucp1S-only mice), protein-level rescue, reporter assays, mechanistic link between CPEB2 and specific mRNA isoform translation established with orthogonal methods","pmids":["30177570"],"is_preprint":false},{"year":2019,"finding":"CPEB2 depletion in porcine embryos impairs tight-junction (TJ) assembly at the morula stage. TJ-associated proteins TJP1, CXADR, and occludin are not properly localized to the apical membrane despite normal transcript levels. CPEB2 mediates stability of TJP1 mRNA bearing its 3'-UTR, as evidenced by reduced levels of 3'-UTR-containing TJP1 transcripts upon CPEB2 knockdown.","method":"dsRNA-mediated CPEB2 knockdown in porcine embryos, immunocytochemistry for TJ protein localization, qRT-PCR, Western blotting","journal":"Reproduction, fertility, and development","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function in embryos with specific localization and mRNA stability phenotype; single lab, limited mechanistic detail on direct binding in this study","pmids":["30145997"],"is_preprint":false},{"year":2019,"finding":"CPEB2 (isoform A) acts as a tumor suppressor in mammary epithelial cells. CPEB2 knockout (CRISPR) in MCF10A cells causes increased proliferation, migration, invasion, EMT, and stem-like cell phenotype. CPEB2 was shown by polysome profiling to translationally upregulate p53 protein, identifying p53 as a novel CPEB2 translational target.","method":"CRISPR/Cas9 knockout, siRNA knockdown, polysomal profiling, in vitro oncogenicity assays, in vivo xenograft/metastasis assay","journal":"BMC cancer","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — polysomal profiling provides direct translational evidence for p53 as a target; CRISPR KO with multiple oncogenic phenotypes; single lab","pmids":["31185986"],"is_preprint":false},{"year":2020,"finding":"CPEB2 directly binds the cytoplasmic polyadenylation element (CPE) site in the 3'-UTR of HIF-1α mRNA in human trophoblasts and inhibits HIF-1α translation. Under hypoxia, miR-210 targets CPEB2, releasing HIF-1α translational repression and creating a positive feedback loop. CPEB2 is required for trophoblast syncytialization; miR-210-mediated suppression of CPEB2 impairs syncytialization and is rescued by CPEB2 overexpression.","method":"RNA immunoprecipitation, luciferase reporter assay (CPE site mutagenesis), trophoblast syncytialization assay, miR-210 inhibitor experiments, Western blotting","journal":"Biology of reproduction","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP and reporter mutagenesis establish direct CPE-dependent binding; functional rescue supports pathway placement; single lab","pmids":["31616934"],"is_preprint":false},{"year":2020,"finding":"CPEB2 promotes translation of PDGFRα mRNA in alveolar myofibroblast (MYF) progenitors, supporting their proliferation during pulmonary alveologenesis. CPEB2-knockout mice develop emphysema-like pathology with simplified alveolar structure, reduced MYF proliferation, abnormal elastin deposition, and failure of alveolar septum formation. H2O2 (hyperoxia-mimetic) disrupts CPEB2-mediated PDGFRα translation, and KO MYF proliferation defects are rescued by ectopic CPEB2.","method":"CPEB2-knockout mice, RNA immunoprecipitation, luciferase reporter assay, Western blotting, histology, ectopic CPEB2 rescue in primary MYF culture, plethysmography","journal":"Journal of biomedical science","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse phenotype, RIP establishing direct mRNA binding, reporter assay, primary cell rescue collectively provide strong evidence; single lab but multiple orthogonal methods","pmids":["32295602"],"is_preprint":false},{"year":2021,"finding":"CPEB2 binds CPE sites in the p53 mRNA 3'-UTR via its RNA recognition motif and zinc finger domains, decreasing p53 mRNA stability and translation. p53 in turn transcriptionally activates CPEB2 expression, establishing a negative feedback loop. CPEB2 overexpression promotes renal cancer cell proliferation and migration in a partially p53-dependent manner.","method":"RNA immunoprecipitation, domain mutagenesis (RRM/ZF deletion), mRNA stability assay, translation reporter assay, cell proliferation and migration assays","journal":"Journal of genetics and genomics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP with domain mutagenesis establishes direct binding requirement; mRNA stability and translation assays support mechanism; single lab","pmids":["34362680"],"is_preprint":false},{"year":2022,"finding":"CPEB2 binds SRSF5 mRNA and increases its stability, promoting ETS1 exon inclusion (producing P51-ETS1 isoform), which transcriptionally upregulates tight junction proteins ZO-1, occludin, and claudin-5 to regulate blood-tumor barrier permeability. CPEB2 mRNA is itself stabilized via m6A methylation by METTL3/IGF2BP3 in glioma endothelial cells.","method":"RNA immunoprecipitation, m6A methylation assay, splicing analysis, Western blotting, in vitro BTB model, in vivo glioblastoma xenograft with knockdown","journal":"Communications biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP establishes CPEB2-SRSF5 mRNA interaction; m6A/IGF2BP3-mediated stabilization of CPEB2 mRNA demonstrated; in vivo validation supports functional relevance; single lab","pmids":["36064747"],"is_preprint":false},{"year":2022,"finding":"CPEB2 mediates subcellular translocation of Tjp1 mRNA from the nucleus to the apical membrane in mouse morula outer cells, and regulates Tjp1 mRNA poly(A) tail length. CPEB2 knockdown abolishes apical Tjp1 mRNA localization, impairs poly(A) tail heterogeneity, reduces blastocyst formation, and disrupts tight junction assembly.","method":"CPEB2 knockdown in mouse embryos, fluorescence in situ hybridization for mRNA localization, poly(A) tail length assay, blastocyst formation and embryo transfer assay","journal":"Reproduction (Cambridge, England)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct mRNA localization and poly(A) tail assays establish mechanism; functional consequence confirmed by blastocyst formation phenotype; single lab","pmids":["35133290"],"is_preprint":false},{"year":2023,"finding":"CPEB2 increases p21 (CDKN1A) mRNA stability in glioma cells, causing G1 cell cycle arrest and reduced proliferation. CPEB2 overexpression or knockdown correspondingly alters p21 levels and cell proliferation/apoptosis in vitro and tumor growth in vivo.","method":"CPEB2 overexpression and knockdown, mRNA stability assay (actinomycin D chase), flow cytometry for cell cycle, in vivo xenograft","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mRNA stability assay directly demonstrates CPEB2-dependent p21 mRNA stabilization; functional phenotype validated in vivo; single lab","pmids":["38158431"],"is_preprint":false},{"year":2023,"finding":"CPEB2 directly binds ARPC5 mRNA via RNA immunoprecipitation and promotes ARPC5 mRNA stability in multiple myeloma cells. CPEB2 and ARPC5 co-localize in the cytoplasm. CPEB2 depletion reduces MM cell proliferation and angiogenesis, and ARPC5 overexpression rescues these effects.","method":"RNA immunoprecipitation, actinomycin D mRNA stability assay, fluorescence in situ hybridization (co-localization), Western blotting, cell functional assays","journal":"Journal of orthopaedic surgery and research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP and mRNA stability assay establish direct CPEB2-ARPC5 mRNA interaction; functional rescue validates pathway; single lab","pmids":["37231521"],"is_preprint":false},{"year":2024,"finding":"CPEB2 activates translation of Slc17a6 mRNA (encoding VGLUT2) in axons of glutamatergic neurons. Presynaptic-specific ablation of CPEB2 in VGLUT2-dominated temporoammonic afferents attenuates protein synthesis-dependent LTP. CPEB2 deficiency or cycloheximide treatment reduces the releasable pool of VGLUT2-containing synaptic vesicles and impairs axonal Slc17a6 translation.","method":"Conditional (glutamatergic neuron-specific and presynaptic-specific) CPEB2 knockout, RNA immunoprecipitation coupled with transcriptomics, electrophysiology (LTP), synaptosome biochemistry, microfluidic axotomized neuron culture, luciferase reporter assay, stereotaxic AAV-Cre delivery","journal":"Journal of biomedical science","confidence":"High","confidence_rationale":"Tier 2 / Strong — presynaptic-specific KO with electrophysiological phenotype, RIP-seq identifies direct target, reporter and synaptosome assays orthogonally validate axonal translation; multiple methods in single rigorous study","pmids":["38992696"],"is_preprint":false},{"year":2024,"finding":"CPEB2 activates translation of Prdm16 mRNA in brown adipose tissue. CPEB2-knockout mice show upregulated muscle-development gene expression in BAT (indicating cell fate shift), reduced PRDM16 protein without corresponding mRNA changes (polysomal profiling), and increased weight gain. AAV-mediated PRDM16 expression in CPEB2-deficient BAT restores gene expression and reduces weight gain.","method":"Global CPEB2 knockout, adipose-specific conditional knockout, RNA sequencing, polysomal profiling, luciferase reporter assay, AAV rescue in BAT","journal":"Molecular metabolism","confidence":"High","confidence_rationale":"Tier 2 / Strong — polysomal profiling directly demonstrates translational regulation, conditional KO and AAV rescue orthogonally validate pathway, multiple models used; single lab but rigorous and multi-method","pmids":["39305947"],"is_preprint":false},{"year":2024,"finding":"CPEB2 binds the CPE site in the 3'-UTR of SSTR3 mRNA and suppresses SSTR3 translation by reducing poly(A) tail length, as confirmed by RIP assay, dual-luciferase reporter, and PCR poly(A) tail assay. Reduced SSTR3 expression downstream of CPEB2 promotes trophoblast cell proliferation, migration, invasion, and EMT.","method":"RNA immunoprecipitation (RIP), dual-luciferase reporter assay, poly(A) tail PCR assay, Western blotting, cell functional assays, in vivo rat PE model with AAV overexpression","journal":"Biochimica et biophysica acta. Molecular basis of disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP and poly(A) tail assay directly demonstrate CPEB2-mediated translational repression of SSTR3; reporter assay provides orthogonal validation; single lab","pmids":["38648900"],"is_preprint":false},{"year":2010,"finding":"miR-92 and miR-26 bind conserved sites in the 3'-UTRs of CPEB2, CPEB3, and CPEB4 at paralogous positions, co-regulating their transcript levels. Mutagenesis of miRNA-binding sites in reporter constructs combined with miRNA overexpression and depletion confirmed that both miRNAs reduce luciferase reporter activity and endogenous CPEB2 subfamily mRNA levels.","method":"Reporter assay with miRNA-binding site mutagenesis, miRNA overexpression and depletion, endogenous mRNA measurement by qRT-PCR","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reporter mutagenesis plus endogenous mRNA assays validate direct miRNA-mediated regulation; single lab but two orthogonal methods","pmids":["20660482"],"is_preprint":false},{"year":2025,"finding":"CPEB2 directly binds the 3'-UTR of ANGPTL3 mRNA and promotes its recruitment to translation initiation complexes, increasing ANGPTL3 transcript abundance in high-translating polysomes (polysomal profiling). This translational upregulation of ANGPTL3 by CPEB2 drives podocyte injury. Conversely, ANGPTL3 signaling increases CPEB2 mRNA stability. AAV9-shCPEB2 in vivo reduces ANGPTL3, mitigates albuminuria, and attenuates histopathological injury.","method":"RNA immunoprecipitation, polysomal profiling, Western blotting, in vivo AAV9-mediated CPEB2 knockdown, mRNA stability assay","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RIP and polysomal profiling directly demonstrate translational promotion of ANGPTL3; in vivo AAV rescue validates functional relevance; single lab","pmids":["41219382"],"is_preprint":false},{"year":2025,"finding":"Drosophila ORB2 (ortholog of human CPEB2-4 subfamily) binds hundreds of maternally provided mRNAs enriched in U-rich 3'-UTR motifs and represses their translation during the maternal-to-zygotic transition via its C-terminal ZZ (zinc-binding) domain. The ZZ domain is necessary and sufficient for translational repression when tethered to a reporter, and human CPEB2 (but not CPEB1) similarly represses translation when tethered. The ZZ domain interacts with the Cup repressive complex; deletion of ZZ domain disrupts these interactions and causes derepression of ORB2-specific (but not SMG co-bound) target mRNAs.","method":"Tethered reporter repression assay in S2 cells, endogenous ZZ domain deletion (CRISPR), RNA immunoprecipitation, translatome profiling (ribosome profiling), protein interaction assays","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 1–2 / Moderate — tethered reporter assay with domain deletion establishes ZZ domain as necessary/sufficient; translatome profiling and interaction assays orthogonally validate; preprint, not yet peer-reviewed","pmids":["bio_10.1101_2025.07.10.664187"],"is_preprint":true},{"year":2025,"finding":"The ZZ domain of Drosophila ORB2 (CPEB2 ortholog) is required for its localization to the distal tip of spermatids. Deletion of the ZZ domain causes mislocalization of ORB2 and of co-factors ORB, IMP, and SOTI; loss of the SOTI-dependent Cleaved Caspase 3 gradient; defective individualization complexes; and male sterility with absence of mature sperm.","method":"Endogenous ZZ domain deletion (CRISPR), immunofluorescence localization, fertility assay, immunostaining for individualization complex markers","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — endogenous domain deletion with specific localization and fertility phenotype; ortholog study in Drosophila; preprint, not peer-reviewed","pmids":["bio_10.1101_2025.08.22.671863"],"is_preprint":true}],"current_model":"CPEB2 is a sequence-specific RNA-binding protein (containing RRM and ZZ zinc-finger domains) that predominantly acts as a translational regulator by binding cytoplasmic polyadenylation element (CPE) sites in target mRNA 3'-UTRs; it can repress translation elongation by interacting with eEF2 to slow GTP hydrolysis (as shown for HIF-1α), or activate translation of specific mRNAs (GRASP1, Ucp1L, PDGFRα, VGLUT2/Slc17a6, PRDM16, ANGPTL3, ChAT) in a tissue- and signal-dependent manner, and can also regulate mRNA stability (TJP1, ARPC5, p21/CDKN1A, p53); its activity is modulated by oxidative stress through NPGPx-mediated disulfide bond formation and by m6A methylation, and the conserved C-terminal ZZ domain mediates translational repression and interaction with co-repressor complexes."},"narrative":{"mechanistic_narrative":"CPEB2 is a sequence-specific cytoplasmic RNA-binding protein that uses tandem RNA recognition motifs and a C-terminal ZZ zinc-finger domain to bind cytoplasmic polyadenylation element (CPE) and U-rich motifs in target mRNA 3'-UTRs, thereby controlling translation and stability of selected transcripts in a tissue- and signal-dependent manner [PMID:12672660, PMID:34362680, PMID:31616934]. As a translational repressor, CPEB2 binds eEF2 and reduces eEF2/ribosome-triggered GTP hydrolysis to slow peptide elongation, a mechanism that keeps HIF-1α mRNA translationally silent under normoxia; under oxidative stress CPEB2 dissociates from HIF-1α mRNA to permit rapid HIF-1α synthesis, and this switch is gated by NPGPx (GPx7), which forms an intermolecular disulfide bond with CPEB2 [PMID:22157746, PMID:26446990, PMID:31616934]. In other contexts CPEB2 acts as a translational activator, driving synthesis of GRASP1, VGLUT2/Slc17a6, Ucp1L, PRDM16, PDGFRα, and ANGPTL3 to support synaptic plasticity, brown adipose thermogenesis and cell-fate maintenance, and alveologenesis [PMID:29141213, PMID:38992696, PMID:30177570, PMID:39305947, PMID:32295602, PMID:41219382]. CPEB2 also governs mRNA stability and poly(A)-tail length of targets including p53, p21/CDKN1A, ARPC5, SRSF5, TJP1, and SSTR3, placing it in feedback circuits with p53 and in control of tight-junction assembly and epithelial behavior [PMID:34362680, PMID:38158431, PMID:37231521, PMID:36064747, PMID:35133290, PMID:38648900]. Across loss-of-function mouse models, CPEB2 is required for hippocampal LTP and memory, parasympathetic ChAT regulation and airway tone, brown-fat thermogenesis, and alveolar septation [PMID:29141213, PMID:27810937, PMID:30177570, PMID:32295602]. CPEB2 abundance is itself regulated post-transcriptionally by miR-92/miR-26 and by m6A methylation via METTL3/IGF2BP3 [PMID:20660482, PMID:36064747].","teleology":[{"year":2003,"claim":"Established the basic biochemical identity of CPEB2 as an RNA-binding protein, defining its domains, ligand preference, and compartment before any functional target was known.","evidence":"RNA-binding (poly(U)) assay, transfection localization, and expression profiling in mouse spermatogenesis","pmids":["12672660"],"confidence":"Medium","gaps":["No specific physiological target mRNA identified","Cytoplasmic role inferred from expression, not functional rescue"]},{"year":2010,"claim":"Showed how CPEB2 levels themselves are controlled, placing the CPEB2 subfamily under shared miRNA regulation.","evidence":"Reporter mutagenesis with miR-92/miR-26 overexpression and depletion plus endogenous mRNA measurement","pmids":["20660482"],"confidence":"Medium","gaps":["Does not address CPEB2 protein activity, only transcript abundance","Functional consequence for downstream targets not tested"]},{"year":2011,"claim":"Resolved the molecular mechanism of CPEB2-mediated repression, showing it acts at translation elongation via eEF2 rather than only at polyadenylation.","evidence":"Co-IP, in vitro eEF2 GTP hydrolysis assay, in vivo reporter and RIP for HIF-1α mRNA","pmids":["22157746"],"confidence":"High","gaps":["Whether elongation control generalizes to non-HIF-1α targets untested","Structural basis of the eEF2 interaction not defined"]},{"year":2015,"claim":"Identified the redox switch that couples oxidative stress to CPEB2 release from HIF-1α mRNA, explaining stress-induced HIF-1α induction.","evidence":"Non-reducing co-IP for disulfide bond, RIP, and translation reporter in NPGPx-proficient/deficient cells","pmids":["26446990"],"confidence":"High","gaps":["Cysteine residues mediating the disulfide not mapped","Generality of redox gating to other CPEB2 targets unknown"]},{"year":2016,"claim":"Demonstrated an in vivo translational-activation role distinct from repression, linking CPEB2 to a defined neural circuit and physiological output.","evidence":"Global and cholinergic-neuron-specific KO mice, plethysmography, ChAT Western blot, pharmacological rescue","pmids":["27810937"],"confidence":"High","gaps":["Direct CPEB2 binding to ChAT mRNA not biochemically shown here","Mechanism switching CPEB2 from repressor to activator unclear"]},{"year":2017,"claim":"Connected CPEB2 to synaptic plasticity by identifying GRASP1 as an activated target controlling AMPA receptor surface expression and LTP.","evidence":"Forebrain conditional KO, LTP electrophysiology, AMPAR surface biotinylation, polysome profiling, AAV rescue with CPEB2 and GRASP1","pmids":["29141213"],"confidence":"High","gaps":["CPE-dependence of GRASP1 activation not detailed","Signal triggering activation in neurons not defined"]},{"year":2017,"claim":"Revealed that splice isoforms diverge functionally, with the exon-4-containing CPEB2B driving translational activation of TWIST1/HIF-1α and metastasis.","evidence":"Isoform-specific siRNA, translatome NGS, anoikis and in vivo metastasis assays in TNBC cells","pmids":["28904175"],"confidence":"Medium","gaps":["Structural basis for exon-4 conferring activation unknown","Single cancer-cell context"]},{"year":2018,"claim":"Showed signal-dependent, 3'-UTR-isoform-selective activation, with CPEB2 driving long-UTR Ucp1L translation downstream of β3-adrenergic signaling for thermogenesis.","evidence":"CPEB2-KO and Ucp1S-only mice, thermogenesis measurement, reporter assay, ectopic CPEB2 rescue","pmids":["30177570"],"confidence":"High","gaps":["How CPEB2 discriminates long vs short Ucp1 UTR mechanistically not resolved","Direct binding site on Ucp1L not mapped here"]},{"year":2019,"claim":"Extended CPEB2 to mRNA-stability control and tight-junction assembly in early embryos via TJP1 transcript regulation.","evidence":"dsRNA knockdown in porcine embryos, TJ-protein immunocytochemistry, qRT-PCR, Western blot","pmids":["30145997"],"confidence":"Medium","gaps":["Direct CPEB2 binding to TJP1 mRNA not shown in this study","Mechanism of stability control undefined"]},{"year":2019,"claim":"Defined a tumor-suppressor function for CPEB2 isoform A through translational upregulation of p53 in mammary epithelial cells.","evidence":"CRISPR KO and siRNA in MCF10A, polysome profiling, oncogenicity assays, xenograft","pmids":["31185986"],"confidence":"Medium","gaps":["Direct CPE binding to p53 mRNA established only later","Contrast with pro-tumor isoform B not mechanistically reconciled"]},{"year":2020,"claim":"Established direct CPE-dependent binding and repression of HIF-1α in trophoblasts, embedding CPEB2 in a miR-210 feedback loop controlling syncytialization.","evidence":"RIP, CPE-mutagenesis luciferase reporter, syncytialization assay, miR-210 inhibition","pmids":["31616934"],"confidence":"Medium","gaps":["Single cell-type context","Relationship to eEF2-mediated repression mechanism not addressed"]},{"year":2020,"claim":"Linked CPEB2 to lung development via PDGFRα translation in myofibroblast progenitors, with oxidative disruption recapitulating the elongation-control theme.","evidence":"CPEB2-KO mice, RIP, reporter assay, histology, primary MYF rescue, plethysmography","pmids":["32295602"],"confidence":"High","gaps":["Whether PDGFRα activation uses elongation vs polyadenylation control unspecified","H2O2 sensitivity mechanism vs NPGPx link not directly tested"]},{"year":2021,"claim":"Mapped the domain requirement (RRM/ZF) for direct p53 mRNA binding and defined a p53–CPEB2 negative feedback loop in renal cancer.","evidence":"RIP with domain mutagenesis, mRNA stability and translation reporter assays, proliferation/migration assays","pmids":["34362680"],"confidence":"Medium","gaps":["Reconciliation with CPEB2 activating p53 in mammary cells unresolved","Context-dependence of repression vs activation undefined"]},{"year":2022,"claim":"Showed CPEB2 stabilizes SRSF5 mRNA to shape splicing and barrier integrity, and identified m6A/METTL3/IGF2BP3 control of CPEB2 mRNA itself.","evidence":"RIP, m6A assay, splicing analysis, in vitro BTB model, glioblastoma xenograft knockdown","pmids":["36064747"],"confidence":"Medium","gaps":["Direct effect on splicing vs indirect via SRSF5 not separated mechanistically","m6A regulation studied only in glioma endothelium"]},{"year":2022,"claim":"Demonstrated CPEB2 controls subcellular Tjp1 mRNA localization and poly(A)-tail length in embryos, linking it to spatial translation and tight-junction assembly.","evidence":"Knockdown in mouse embryos, FISH mRNA localization, poly(A) tail assay, blastocyst formation/transfer","pmids":["35133290"],"confidence":"Medium","gaps":["Transport machinery partnering with CPEB2 unidentified","Link between poly(A) change and localization mechanistically open"]},{"year":2023,"claim":"Added cell-cycle control to the CPEB2 repertoire through stabilization of p21/CDKN1A mRNA driving G1 arrest in glioma.","evidence":"Overexpression/knockdown, actinomycin D stability chase, flow cytometry, xenograft","pmids":["38158431"],"confidence":"Medium","gaps":["Direct binding to p21 mRNA not shown here","Relation to CPEB2 oncogenic roles elsewhere unresolved"]},{"year":2023,"claim":"Identified ARPC5 mRNA as a CPEB2-stabilized target supporting myeloma proliferation and angiogenesis.","evidence":"RIP, actinomycin D stability assay, FISH co-localization, rescue by ARPC5","pmids":["37231521"],"confidence":"Medium","gaps":["Binding site within ARPC5 mRNA not mapped","Single cancer context"]},{"year":2024,"claim":"Established axonal, presynaptic translational activation of VGLUT2/Slc17a6 by CPEB2 as a requirement for protein-synthesis-dependent LTP.","evidence":"Presynaptic-specific conditional KO, RIP-seq, LTP electrophysiology, synaptosome biochemistry, microfluidic axon culture, reporter","pmids":["38992696"],"confidence":"High","gaps":["Local signal triggering axonal CPEB2 activation undefined","CPE-dependence of Slc17a6 binding not detailed"]},{"year":2024,"claim":"Showed CPEB2 maintains brown-fat identity by activating Prdm16 translation, with loss causing a fate shift toward muscle gene programs and weight gain.","evidence":"Global and adipose-specific KO, RNA-seq, polysome profiling, reporter, AAV PRDM16 rescue","pmids":["39305947"],"confidence":"High","gaps":["Direct CPEB2 binding site on Prdm16 mRNA not mapped","Signal coupling to activation unspecified"]},{"year":2024,"claim":"Demonstrated CPE-dependent repression of SSTR3 via poly(A)-tail shortening in trophoblasts, connecting CPEB2 to preeclampsia-relevant cell behavior.","evidence":"RIP, dual-luciferase reporter, poly(A) tail PCR, rat PE model with AAV overexpression","pmids":["38648900"],"confidence":"Medium","gaps":["Reconciliation of repressor activity here with activator roles elsewhere not addressed","Mechanism choosing deadenylation vs activation undefined"]},{"year":2025,"claim":"Added ANGPTL3 as a CPEB2-activated target in podocytes, with reciprocal ANGPTL3-driven stabilization of CPEB2 forming a feed-forward injury loop.","evidence":"RIP, polysome profiling, in vivo AAV9-shCPEB2 knockdown, mRNA stability assay","pmids":["41219382"],"confidence":"Medium","gaps":["Direct CPE site on ANGPTL3 mRNA not mapped","Single disease model"]},{"year":2025,"claim":"Defined the C-terminal ZZ domain as the necessary and sufficient module for translational repression and co-repressor recruitment, conserved from Drosophila ORB2 to human CPEB2.","evidence":"Tethered reporter repression in S2 cells, CRISPR ZZ deletion, RIP, ribosome profiling, interaction assays (preprint)","pmids":["bio_10.1101_2025.07.10.664187"],"confidence":"Medium","gaps":["Preprint, not peer-reviewed","Cup-complex equivalent in mammalian CPEB2 repression not confirmed"]},{"year":2025,"claim":"Showed the ZZ domain also governs CPEB2-ortholog localization and co-factor recruitment in spermatids, linking the repressive module to spatial organization and fertility.","evidence":"CRISPR ZZ deletion in Drosophila, immunofluorescence localization, fertility and individualization-complex assays (preprint)","pmids":["bio_10.1101_2025.08.22.671863"],"confidence":"Medium","gaps":["Preprint, not peer-reviewed","Mammalian relevance of spermatid localization role untested"]},{"year":null,"claim":"What determines whether CPEB2 represses or activates a given target, and how its domains, isoforms, redox/m6A modifications, and co-factor complexes integrate to select between elongation control, polyadenylation, and mRNA stabilization, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model reconciling repressor vs activator outputs across tissues","Mammalian co-repressor complex equivalent to Drosophila Cup not identified","No structural model of CPE/eEF2/ZZ interactions"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[0,1,9,10,11,15,16,18,20]},{"term_id":"GO:0045182","term_label":"translation regulator activity","supporting_discovery_ids":[0,4,6,11,16,17,18]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[1,15]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,9,11,13,18]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[0,4,6,16,17]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[0,2,9]}],"complexes":[],"partners":["EEF2","NPGPX"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q7Z5Q1","full_name":"Cytoplasmic polyadenylation element-binding protein 2","aliases":[],"length_aa":589,"mass_kda":64.9,"function":"May play a role in translational regulation of stored mRNAs in transcriptionally inactive haploid spermatids. Binds to poly(U) RNA oligomers (By similarity). Required for cell cycle progression, specifically for the transition from metaphase to anaphase (PubMed:26398195)","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q7Z5Q1/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CPEB2","classification":"Not Classified","n_dependent_lines":1,"n_total_lines":1208,"dependency_fraction":0.0008278145695364238},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/CPEB2","total_profiled":1310},"omim":[{"mim_id":"620757","title":"THROMBOCYTOPENIA 12 WITH OR WITHOUT MYOPATHY; THC12","url":"https://www.omim.org/entry/620757"},{"mim_id":"610607","title":"CYTOPLASMIC POLYADENYLATION ELEMENT-BINDING PROTEIN 4; CPEB4","url":"https://www.omim.org/entry/610607"},{"mim_id":"610605","title":"CYTOPLASMIC POLYADENYLATION ELEMENT-BINDING PROTEIN 2; CPEB2","url":"https://www.omim.org/entry/610605"},{"mim_id":"603824","title":"UDP-N-ACETYLGLUCOSAMINE 2-EPIMERASE/N-ACETYLMANNOSAMINE KINASE; GNE","url":"https://www.omim.org/entry/603824"}],"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/CPEB2"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q7Z5Q1","domains":[{"cath_id":"3.30.70.330","chopping":"331-424","consensus_level":"high","plddt":93.1518,"start":331,"end":424},{"cath_id":"3.30.70.330","chopping":"427-521","consensus_level":"medium","plddt":94.0781,"start":427,"end":521},{"cath_id":"4.10.640.40","chopping":"524-580","consensus_level":"medium","plddt":87.7954,"start":524,"end":580}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q7Z5Q1","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q7Z5Q1-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q7Z5Q1-F1-predicted_aligned_error_v6.png","plddt_mean":61.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CPEB2","jax_strain_url":"https://www.jax.org/strain/search?query=CPEB2"},"sequence":{"accession":"Q7Z5Q1","fasta_url":"https://rest.uniprot.org/uniprotkb/Q7Z5Q1.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q7Z5Q1/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q7Z5Q1"}},"corpus_meta":[{"pmid":"28302487","id":"PMC_28302487","title":"TUG1 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This mechanism represses HIF-1α mRNA translation under normoxia; under oxidative stress, CPEB2 dissociates from HIF-1α mRNA, enabling rapid HIF-1α synthesis.\",\n      \"method\": \"Co-immunoprecipitation, in vitro GTP hydrolysis assay, in vivo translation reporter assay, RNA-immunoprecipitation\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro reconstitution of eEF2 GTP hydrolysis inhibition combined with in vivo translation assays and RIP, multiple orthogonal methods in one rigorous study\",\n      \"pmids\": [\"22157746\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"CPEB2 contains two RNA recognition motifs and a zinc-finger (ZZ) domain, preferentially binds poly(U) RNA, and localizes to the cytoplasm in transfected HeLa cells. It is expressed postmeiotically in mouse spermatogenesis, consistent with a role in translational regulation of stored mRNAs in haploid spermatids.\",\n      \"method\": \"RNA-binding assay (poly(U) preference), subcellular localization by transfection/imaging, RT-PCR expression profiling, chromosome mapping\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — direct binding and localization assays established in a single study; functional role inferred from expression pattern without full functional rescue\",\n      \"pmids\": [\"12672660\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"NPGPx (GPx7) forms an intermolecular disulfide bond with CPEB2 under oxidative stress conditions. In NPGPx-proficient cells, high oxidative stress disrupts this bond and compromises CPEB2 association with HIF-1α mRNA, leading to elevated HIF-1α translation. NPGPx-deficient cells show increased basal HIF-1α translation with impaired stress-induced induction.\",\n      \"method\": \"Disulfide bond detection (co-immunoprecipitation under non-reducing conditions), RNA-immunoprecipitation, translation reporter assay\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — intermolecular disulfide bond biochemically demonstrated, RIP and translation assays orthogonally confirm functional consequence, single lab but multiple methods\",\n      \"pmids\": [\"26446990\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CPEB2 knockout mice show upregulated translation of choline acetyltransferase (ChAT) mRNA specifically in the dorsal motor nucleus of vagus, leading to hyperactivated parasympathetic (cholinergic) signaling, elevated pulmonary acetylcholine, increased phospho-myosin light chain 2 in bronchial smooth muscles, and bronchoconstriction. Cholinergic neuron-specific CPEB2 deletion recapitulates apnea and airway hyper-reactivity.\",\n      \"method\": \"Global and conditional (cholinergic neuron-specific) CPEB2 knockout mice, whole-body plethysmography, Western blotting (ChAT protein levels), acetylcholine measurement, anticholinergic bronchodilator rescue\",\n      \"journal\": \"The Journal of neuroscience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic loss-of-function with specific cellular and molecular phenotype, conditional KO in defined neurons recapitulates phenotype, pharmacological rescue validates mechanism\",\n      \"pmids\": [\"27810937\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"CPEB2 activates GRASP1 mRNA translation in forebrain neurons. CPEB2 conditional knockout mice show reduced surface (but not total) AMPA receptor expression and impaired long-term potentiation (LTP) in the Schaffer collateral–CA1 pathway. Ectopic expression of CPEB2 or GRASP1 in CA1 of KO mice rescues LTP and spatial memory.\",\n      \"method\": \"Forebrain-restricted conditional knockout mice, electrophysiology (LTP), AMPA receptor surface biotinylation, polysomal profiling/translation assay, stereotaxic AAV rescue\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO with defined cellular phenotype, mechanistic target identified by polysomal profiling, rescue with CPEB2 and downstream target GRASP1 orthogonally validates pathway\",\n      \"pmids\": [\"29141213\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"The CPEB2B splice isoform (containing exon 4) functions as a translational activator of TWIST1 and HIF-1α mRNAs and promotes EMT, anoikis resistance, and metastasis in triple-negative breast cancer cells. Conversely, CPEB2A (lacking exon 4) does not drive these pathways; specific knockdown of CPEB2B inhibits EMT and hypoxic-response gene expression.\",\n      \"method\": \"Isoform-specific siRNA knockdown, next-generation sequencing of translatome, Western blotting for HIF-1α and TWIST1, anoikis assay, in vivo metastasis assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — isoform-specific depletion with transcriptomic and protein-level validation in single lab; functional assays support translational activation role\",\n      \"pmids\": [\"28904175\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"CPEB2 is required for β3 adrenergic receptor signaling-induced translation of the long 3'-UTR Ucp1 mRNA (Ucp1L) in brown adipose tissue. CPEB2-knockout mice show reduced UCP1 protein levels and impaired thermogenesis, rescued by ectopic CPEB2 expression. Mice expressing only short Ucp1 (Ucp1S) have 60% less UCP1 protein and impaired thermogenesis.\",\n      \"method\": \"CPEB2 and Ucp1L-specific knockout mice, Western blotting, thermogenesis measurements, ectopic CPEB2 rescue, translation reporter assay\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple genetic models (CPEB2 KO, Ucp1S-only mice), protein-level rescue, reporter assays, mechanistic link between CPEB2 and specific mRNA isoform translation established with orthogonal methods\",\n      \"pmids\": [\"30177570\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CPEB2 depletion in porcine embryos impairs tight-junction (TJ) assembly at the morula stage. TJ-associated proteins TJP1, CXADR, and occludin are not properly localized to the apical membrane despite normal transcript levels. CPEB2 mediates stability of TJP1 mRNA bearing its 3'-UTR, as evidenced by reduced levels of 3'-UTR-containing TJP1 transcripts upon CPEB2 knockdown.\",\n      \"method\": \"dsRNA-mediated CPEB2 knockdown in porcine embryos, immunocytochemistry for TJ protein localization, qRT-PCR, Western blotting\",\n      \"journal\": \"Reproduction, fertility, and development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function in embryos with specific localization and mRNA stability phenotype; single lab, limited mechanistic detail on direct binding in this study\",\n      \"pmids\": [\"30145997\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CPEB2 (isoform A) acts as a tumor suppressor in mammary epithelial cells. CPEB2 knockout (CRISPR) in MCF10A cells causes increased proliferation, migration, invasion, EMT, and stem-like cell phenotype. CPEB2 was shown by polysome profiling to translationally upregulate p53 protein, identifying p53 as a novel CPEB2 translational target.\",\n      \"method\": \"CRISPR/Cas9 knockout, siRNA knockdown, polysomal profiling, in vitro oncogenicity assays, in vivo xenograft/metastasis assay\",\n      \"journal\": \"BMC cancer\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — polysomal profiling provides direct translational evidence for p53 as a target; CRISPR KO with multiple oncogenic phenotypes; single lab\",\n      \"pmids\": [\"31185986\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CPEB2 directly binds the cytoplasmic polyadenylation element (CPE) site in the 3'-UTR of HIF-1α mRNA in human trophoblasts and inhibits HIF-1α translation. Under hypoxia, miR-210 targets CPEB2, releasing HIF-1α translational repression and creating a positive feedback loop. CPEB2 is required for trophoblast syncytialization; miR-210-mediated suppression of CPEB2 impairs syncytialization and is rescued by CPEB2 overexpression.\",\n      \"method\": \"RNA immunoprecipitation, luciferase reporter assay (CPE site mutagenesis), trophoblast syncytialization assay, miR-210 inhibitor experiments, Western blotting\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP and reporter mutagenesis establish direct CPE-dependent binding; functional rescue supports pathway placement; single lab\",\n      \"pmids\": [\"31616934\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"CPEB2 promotes translation of PDGFRα mRNA in alveolar myofibroblast (MYF) progenitors, supporting their proliferation during pulmonary alveologenesis. CPEB2-knockout mice develop emphysema-like pathology with simplified alveolar structure, reduced MYF proliferation, abnormal elastin deposition, and failure of alveolar septum formation. H2O2 (hyperoxia-mimetic) disrupts CPEB2-mediated PDGFRα translation, and KO MYF proliferation defects are rescued by ectopic CPEB2.\",\n      \"method\": \"CPEB2-knockout mice, RNA immunoprecipitation, luciferase reporter assay, Western blotting, histology, ectopic CPEB2 rescue in primary MYF culture, plethysmography\",\n      \"journal\": \"Journal of biomedical science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse phenotype, RIP establishing direct mRNA binding, reporter assay, primary cell rescue collectively provide strong evidence; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"32295602\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"CPEB2 binds CPE sites in the p53 mRNA 3'-UTR via its RNA recognition motif and zinc finger domains, decreasing p53 mRNA stability and translation. p53 in turn transcriptionally activates CPEB2 expression, establishing a negative feedback loop. CPEB2 overexpression promotes renal cancer cell proliferation and migration in a partially p53-dependent manner.\",\n      \"method\": \"RNA immunoprecipitation, domain mutagenesis (RRM/ZF deletion), mRNA stability assay, translation reporter assay, cell proliferation and migration assays\",\n      \"journal\": \"Journal of genetics and genomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP with domain mutagenesis establishes direct binding requirement; mRNA stability and translation assays support mechanism; single lab\",\n      \"pmids\": [\"34362680\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CPEB2 binds SRSF5 mRNA and increases its stability, promoting ETS1 exon inclusion (producing P51-ETS1 isoform), which transcriptionally upregulates tight junction proteins ZO-1, occludin, and claudin-5 to regulate blood-tumor barrier permeability. CPEB2 mRNA is itself stabilized via m6A methylation by METTL3/IGF2BP3 in glioma endothelial cells.\",\n      \"method\": \"RNA immunoprecipitation, m6A methylation assay, splicing analysis, Western blotting, in vitro BTB model, in vivo glioblastoma xenograft with knockdown\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP establishes CPEB2-SRSF5 mRNA interaction; m6A/IGF2BP3-mediated stabilization of CPEB2 mRNA demonstrated; in vivo validation supports functional relevance; single lab\",\n      \"pmids\": [\"36064747\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CPEB2 mediates subcellular translocation of Tjp1 mRNA from the nucleus to the apical membrane in mouse morula outer cells, and regulates Tjp1 mRNA poly(A) tail length. CPEB2 knockdown abolishes apical Tjp1 mRNA localization, impairs poly(A) tail heterogeneity, reduces blastocyst formation, and disrupts tight junction assembly.\",\n      \"method\": \"CPEB2 knockdown in mouse embryos, fluorescence in situ hybridization for mRNA localization, poly(A) tail length assay, blastocyst formation and embryo transfer assay\",\n      \"journal\": \"Reproduction (Cambridge, England)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct mRNA localization and poly(A) tail assays establish mechanism; functional consequence confirmed by blastocyst formation phenotype; single lab\",\n      \"pmids\": [\"35133290\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CPEB2 increases p21 (CDKN1A) mRNA stability in glioma cells, causing G1 cell cycle arrest and reduced proliferation. CPEB2 overexpression or knockdown correspondingly alters p21 levels and cell proliferation/apoptosis in vitro and tumor growth in vivo.\",\n      \"method\": \"CPEB2 overexpression and knockdown, mRNA stability assay (actinomycin D chase), flow cytometry for cell cycle, in vivo xenograft\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mRNA stability assay directly demonstrates CPEB2-dependent p21 mRNA stabilization; functional phenotype validated in vivo; single lab\",\n      \"pmids\": [\"38158431\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"CPEB2 directly binds ARPC5 mRNA via RNA immunoprecipitation and promotes ARPC5 mRNA stability in multiple myeloma cells. CPEB2 and ARPC5 co-localize in the cytoplasm. CPEB2 depletion reduces MM cell proliferation and angiogenesis, and ARPC5 overexpression rescues these effects.\",\n      \"method\": \"RNA immunoprecipitation, actinomycin D mRNA stability assay, fluorescence in situ hybridization (co-localization), Western blotting, cell functional assays\",\n      \"journal\": \"Journal of orthopaedic surgery and research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP and mRNA stability assay establish direct CPEB2-ARPC5 mRNA interaction; functional rescue validates pathway; single lab\",\n      \"pmids\": [\"37231521\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CPEB2 activates translation of Slc17a6 mRNA (encoding VGLUT2) in axons of glutamatergic neurons. Presynaptic-specific ablation of CPEB2 in VGLUT2-dominated temporoammonic afferents attenuates protein synthesis-dependent LTP. CPEB2 deficiency or cycloheximide treatment reduces the releasable pool of VGLUT2-containing synaptic vesicles and impairs axonal Slc17a6 translation.\",\n      \"method\": \"Conditional (glutamatergic neuron-specific and presynaptic-specific) CPEB2 knockout, RNA immunoprecipitation coupled with transcriptomics, electrophysiology (LTP), synaptosome biochemistry, microfluidic axotomized neuron culture, luciferase reporter assay, stereotaxic AAV-Cre delivery\",\n      \"journal\": \"Journal of biomedical science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — presynaptic-specific KO with electrophysiological phenotype, RIP-seq identifies direct target, reporter and synaptosome assays orthogonally validate axonal translation; multiple methods in single rigorous study\",\n      \"pmids\": [\"38992696\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CPEB2 activates translation of Prdm16 mRNA in brown adipose tissue. CPEB2-knockout mice show upregulated muscle-development gene expression in BAT (indicating cell fate shift), reduced PRDM16 protein without corresponding mRNA changes (polysomal profiling), and increased weight gain. AAV-mediated PRDM16 expression in CPEB2-deficient BAT restores gene expression and reduces weight gain.\",\n      \"method\": \"Global CPEB2 knockout, adipose-specific conditional knockout, RNA sequencing, polysomal profiling, luciferase reporter assay, AAV rescue in BAT\",\n      \"journal\": \"Molecular metabolism\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — polysomal profiling directly demonstrates translational regulation, conditional KO and AAV rescue orthogonally validate pathway, multiple models used; single lab but rigorous and multi-method\",\n      \"pmids\": [\"39305947\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CPEB2 binds the CPE site in the 3'-UTR of SSTR3 mRNA and suppresses SSTR3 translation by reducing poly(A) tail length, as confirmed by RIP assay, dual-luciferase reporter, and PCR poly(A) tail assay. Reduced SSTR3 expression downstream of CPEB2 promotes trophoblast cell proliferation, migration, invasion, and EMT.\",\n      \"method\": \"RNA immunoprecipitation (RIP), dual-luciferase reporter assay, poly(A) tail PCR assay, Western blotting, cell functional assays, in vivo rat PE model with AAV overexpression\",\n      \"journal\": \"Biochimica et biophysica acta. Molecular basis of disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP and poly(A) tail assay directly demonstrate CPEB2-mediated translational repression of SSTR3; reporter assay provides orthogonal validation; single lab\",\n      \"pmids\": [\"38648900\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"miR-92 and miR-26 bind conserved sites in the 3'-UTRs of CPEB2, CPEB3, and CPEB4 at paralogous positions, co-regulating their transcript levels. Mutagenesis of miRNA-binding sites in reporter constructs combined with miRNA overexpression and depletion confirmed that both miRNAs reduce luciferase reporter activity and endogenous CPEB2 subfamily mRNA levels.\",\n      \"method\": \"Reporter assay with miRNA-binding site mutagenesis, miRNA overexpression and depletion, endogenous mRNA measurement by qRT-PCR\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reporter mutagenesis plus endogenous mRNA assays validate direct miRNA-mediated regulation; single lab but two orthogonal methods\",\n      \"pmids\": [\"20660482\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CPEB2 directly binds the 3'-UTR of ANGPTL3 mRNA and promotes its recruitment to translation initiation complexes, increasing ANGPTL3 transcript abundance in high-translating polysomes (polysomal profiling). This translational upregulation of ANGPTL3 by CPEB2 drives podocyte injury. Conversely, ANGPTL3 signaling increases CPEB2 mRNA stability. AAV9-shCPEB2 in vivo reduces ANGPTL3, mitigates albuminuria, and attenuates histopathological injury.\",\n      \"method\": \"RNA immunoprecipitation, polysomal profiling, Western blotting, in vivo AAV9-mediated CPEB2 knockdown, mRNA stability assay\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RIP and polysomal profiling directly demonstrate translational promotion of ANGPTL3; in vivo AAV rescue validates functional relevance; single lab\",\n      \"pmids\": [\"41219382\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Drosophila ORB2 (ortholog of human CPEB2-4 subfamily) binds hundreds of maternally provided mRNAs enriched in U-rich 3'-UTR motifs and represses their translation during the maternal-to-zygotic transition via its C-terminal ZZ (zinc-binding) domain. The ZZ domain is necessary and sufficient for translational repression when tethered to a reporter, and human CPEB2 (but not CPEB1) similarly represses translation when tethered. The ZZ domain interacts with the Cup repressive complex; deletion of ZZ domain disrupts these interactions and causes derepression of ORB2-specific (but not SMG co-bound) target mRNAs.\",\n      \"method\": \"Tethered reporter repression assay in S2 cells, endogenous ZZ domain deletion (CRISPR), RNA immunoprecipitation, translatome profiling (ribosome profiling), protein interaction assays\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — tethered reporter assay with domain deletion establishes ZZ domain as necessary/sufficient; translatome profiling and interaction assays orthogonally validate; preprint, not yet peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.07.10.664187\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"The ZZ domain of Drosophila ORB2 (CPEB2 ortholog) is required for its localization to the distal tip of spermatids. Deletion of the ZZ domain causes mislocalization of ORB2 and of co-factors ORB, IMP, and SOTI; loss of the SOTI-dependent Cleaved Caspase 3 gradient; defective individualization complexes; and male sterility with absence of mature sperm.\",\n      \"method\": \"Endogenous ZZ domain deletion (CRISPR), immunofluorescence localization, fertility assay, immunostaining for individualization complex markers\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — endogenous domain deletion with specific localization and fertility phenotype; ortholog study in Drosophila; preprint, not peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.08.22.671863\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"CPEB2 is a sequence-specific RNA-binding protein (containing RRM and ZZ zinc-finger domains) that predominantly acts as a translational regulator by binding cytoplasmic polyadenylation element (CPE) sites in target mRNA 3'-UTRs; it can repress translation elongation by interacting with eEF2 to slow GTP hydrolysis (as shown for HIF-1α), or activate translation of specific mRNAs (GRASP1, Ucp1L, PDGFRα, VGLUT2/Slc17a6, PRDM16, ANGPTL3, ChAT) in a tissue- and signal-dependent manner, and can also regulate mRNA stability (TJP1, ARPC5, p21/CDKN1A, p53); its activity is modulated by oxidative stress through NPGPx-mediated disulfide bond formation and by m6A methylation, and the conserved C-terminal ZZ domain mediates translational repression and interaction with co-repressor complexes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CPEB2 is a sequence-specific cytoplasmic RNA-binding protein that uses tandem RNA recognition motifs and a C-terminal ZZ zinc-finger domain to bind cytoplasmic polyadenylation element (CPE) and U-rich motifs in target mRNA 3'-UTRs, thereby controlling translation and stability of selected transcripts in a tissue- and signal-dependent manner [#1, #11, #9]. As a translational repressor, CPEB2 binds eEF2 and reduces eEF2/ribosome-triggered GTP hydrolysis to slow peptide elongation, a mechanism that keeps HIF-1\\u03b1 mRNA translationally silent under normoxia; under oxidative stress CPEB2 dissociates from HIF-1\\u03b1 mRNA to permit rapid HIF-1\\u03b1 synthesis, and this switch is gated by NPGPx (GPx7), which forms an intermolecular disulfide bond with CPEB2 [#0, #2, #9]. In other contexts CPEB2 acts as a translational activator, driving synthesis of GRASP1, VGLUT2/Slc17a6, Ucp1L, PRDM16, PDGFR\\u03b1, and ANGPTL3 to support synaptic plasticity, brown adipose thermogenesis and cell-fate maintenance, and alveologenesis [#4, #16, #6, #17, #10, #20]. CPEB2 also governs mRNA stability and poly(A)-tail length of targets including p53, p21/CDKN1A, ARPC5, SRSF5, TJP1, and SSTR3, placing it in feedback circuits with p53 and in control of tight-junction assembly and epithelial behavior [#11, #14, #15, #12, #13, #18]. Across loss-of-function mouse models, CPEB2 is required for hippocampal LTP and memory, parasympathetic ChAT regulation and airway tone, brown-fat thermogenesis, and alveolar septation [#4, #3, #6, #10]. CPEB2 abundance is itself regulated post-transcriptionally by miR-92/miR-26 and by m6A methylation via METTL3/IGF2BP3 [#19, #12].\"\n,\n  \"teleology\": [\n    {\n      \"year\": 2003,\n      \"claim\": \"Established the basic biochemical identity of CPEB2 as an RNA-binding protein, defining its domains, ligand preference, and compartment before any functional target was known.\",\n      \"evidence\": \"RNA-binding (poly(U)) assay, transfection localization, and expression profiling in mouse spermatogenesis\",\n      \"pmids\": [\"12672660\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No specific physiological target mRNA identified\", \"Cytoplasmic role inferred from expression, not functional rescue\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Showed how CPEB2 levels themselves are controlled, placing the CPEB2 subfamily under shared miRNA regulation.\",\n      \"evidence\": \"Reporter mutagenesis with miR-92/miR-26 overexpression and depletion plus endogenous mRNA measurement\",\n      \"pmids\": [\"20660482\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Does not address CPEB2 protein activity, only transcript abundance\", \"Functional consequence for downstream targets not tested\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Resolved the molecular mechanism of CPEB2-mediated repression, showing it acts at translation elongation via eEF2 rather than only at polyadenylation.\",\n      \"evidence\": \"Co-IP, in vitro eEF2 GTP hydrolysis assay, in vivo reporter and RIP for HIF-1\\u03b1 mRNA\",\n      \"pmids\": [\"22157746\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether elongation control generalizes to non-HIF-1\\u03b1 targets untested\", \"Structural basis of the eEF2 interaction not defined\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identified the redox switch that couples oxidative stress to CPEB2 release from HIF-1\\u03b1 mRNA, explaining stress-induced HIF-1\\u03b1 induction.\",\n      \"evidence\": \"Non-reducing co-IP for disulfide bond, RIP, and translation reporter in NPGPx-proficient/deficient cells\",\n      \"pmids\": [\"26446990\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cysteine residues mediating the disulfide not mapped\", \"Generality of redox gating to other CPEB2 targets unknown\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Demonstrated an in vivo translational-activation role distinct from repression, linking CPEB2 to a defined neural circuit and physiological output.\",\n      \"evidence\": \"Global and cholinergic-neuron-specific KO mice, plethysmography, ChAT Western blot, pharmacological rescue\",\n      \"pmids\": [\"27810937\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct CPEB2 binding to ChAT mRNA not biochemically shown here\", \"Mechanism switching CPEB2 from repressor to activator unclear\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Connected CPEB2 to synaptic plasticity by identifying GRASP1 as an activated target controlling AMPA receptor surface expression and LTP.\",\n      \"evidence\": \"Forebrain conditional KO, LTP electrophysiology, AMPAR surface biotinylation, polysome profiling, AAV rescue with CPEB2 and GRASP1\",\n      \"pmids\": [\"29141213\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"CPE-dependence of GRASP1 activation not detailed\", \"Signal triggering activation in neurons not defined\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Revealed that splice isoforms diverge functionally, with the exon-4-containing CPEB2B driving translational activation of TWIST1/HIF-1\\u03b1 and metastasis.\",\n      \"evidence\": \"Isoform-specific siRNA, translatome NGS, anoikis and in vivo metastasis assays in TNBC cells\",\n      \"pmids\": [\"28904175\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Structural basis for exon-4 conferring activation unknown\", \"Single cancer-cell context\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Showed signal-dependent, 3'-UTR-isoform-selective activation, with CPEB2 driving long-UTR Ucp1L translation downstream of \\u03b23-adrenergic signaling for thermogenesis.\",\n      \"evidence\": \"CPEB2-KO and Ucp1S-only mice, thermogenesis measurement, reporter assay, ectopic CPEB2 rescue\",\n      \"pmids\": [\"30177570\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How CPEB2 discriminates long vs short Ucp1 UTR mechanistically not resolved\", \"Direct binding site on Ucp1L not mapped here\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Extended CPEB2 to mRNA-stability control and tight-junction assembly in early embryos via TJP1 transcript regulation.\",\n      \"evidence\": \"dsRNA knockdown in porcine embryos, TJ-protein immunocytochemistry, qRT-PCR, Western blot\",\n      \"pmids\": [\"30145997\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct CPEB2 binding to TJP1 mRNA not shown in this study\", \"Mechanism of stability control undefined\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Defined a tumor-suppressor function for CPEB2 isoform A through translational upregulation of p53 in mammary epithelial cells.\",\n      \"evidence\": \"CRISPR KO and siRNA in MCF10A, polysome profiling, oncogenicity assays, xenograft\",\n      \"pmids\": [\"31185986\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct CPE binding to p53 mRNA established only later\", \"Contrast with pro-tumor isoform B not mechanistically reconciled\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Established direct CPE-dependent binding and repression of HIF-1\\u03b1 in trophoblasts, embedding CPEB2 in a miR-210 feedback loop controlling syncytialization.\",\n      \"evidence\": \"RIP, CPE-mutagenesis luciferase reporter, syncytialization assay, miR-210 inhibition\",\n      \"pmids\": [\"31616934\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single cell-type context\", \"Relationship to eEF2-mediated repression mechanism not addressed\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Linked CPEB2 to lung development via PDGFR\\u03b1 translation in myofibroblast progenitors, with oxidative disruption recapitulating the elongation-control theme.\",\n      \"evidence\": \"CPEB2-KO mice, RIP, reporter assay, histology, primary MYF rescue, plethysmography\",\n      \"pmids\": [\"32295602\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether PDGFR\\u03b1 activation uses elongation vs polyadenylation control unspecified\", \"H2O2 sensitivity mechanism vs NPGPx link not directly tested\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Mapped the domain requirement (RRM/ZF) for direct p53 mRNA binding and defined a p53\\u2013CPEB2 negative feedback loop in renal cancer.\",\n      \"evidence\": \"RIP with domain mutagenesis, mRNA stability and translation reporter assays, proliferation/migration assays\",\n      \"pmids\": [\"34362680\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Reconciliation with CPEB2 activating p53 in mammary cells unresolved\", \"Context-dependence of repression vs activation undefined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Showed CPEB2 stabilizes SRSF5 mRNA to shape splicing and barrier integrity, and identified m6A/METTL3/IGF2BP3 control of CPEB2 mRNA itself.\",\n      \"evidence\": \"RIP, m6A assay, splicing analysis, in vitro BTB model, glioblastoma xenograft knockdown\",\n      \"pmids\": [\"36064747\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct effect on splicing vs indirect via SRSF5 not separated mechanistically\", \"m6A regulation studied only in glioma endothelium\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Demonstrated CPEB2 controls subcellular Tjp1 mRNA localization and poly(A)-tail length in embryos, linking it to spatial translation and tight-junction assembly.\",\n      \"evidence\": \"Knockdown in mouse embryos, FISH mRNA localization, poly(A) tail assay, blastocyst formation/transfer\",\n      \"pmids\": [\"35133290\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Transport machinery partnering with CPEB2 unidentified\", \"Link between poly(A) change and localization mechanistically open\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Added cell-cycle control to the CPEB2 repertoire through stabilization of p21/CDKN1A mRNA driving G1 arrest in glioma.\",\n      \"evidence\": \"Overexpression/knockdown, actinomycin D stability chase, flow cytometry, xenograft\",\n      \"pmids\": [\"38158431\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding to p21 mRNA not shown here\", \"Relation to CPEB2 oncogenic roles elsewhere unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identified ARPC5 mRNA as a CPEB2-stabilized target supporting myeloma proliferation and angiogenesis.\",\n      \"evidence\": \"RIP, actinomycin D stability assay, FISH co-localization, rescue by ARPC5\",\n      \"pmids\": [\"37231521\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Binding site within ARPC5 mRNA not mapped\", \"Single cancer context\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Established axonal, presynaptic translational activation of VGLUT2/Slc17a6 by CPEB2 as a requirement for protein-synthesis-dependent LTP.\",\n      \"evidence\": \"Presynaptic-specific conditional KO, RIP-seq, LTP electrophysiology, synaptosome biochemistry, microfluidic axon culture, reporter\",\n      \"pmids\": [\"38992696\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Local signal triggering axonal CPEB2 activation undefined\", \"CPE-dependence of Slc17a6 binding not detailed\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Showed CPEB2 maintains brown-fat identity by activating Prdm16 translation, with loss causing a fate shift toward muscle gene programs and weight gain.\",\n      \"evidence\": \"Global and adipose-specific KO, RNA-seq, polysome profiling, reporter, AAV PRDM16 rescue\",\n      \"pmids\": [\"39305947\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct CPEB2 binding site on Prdm16 mRNA not mapped\", \"Signal coupling to activation unspecified\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Demonstrated CPE-dependent repression of SSTR3 via poly(A)-tail shortening in trophoblasts, connecting CPEB2 to preeclampsia-relevant cell behavior.\",\n      \"evidence\": \"RIP, dual-luciferase reporter, poly(A) tail PCR, rat PE model with AAV overexpression\",\n      \"pmids\": [\"38648900\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Reconciliation of repressor activity here with activator roles elsewhere not addressed\", \"Mechanism choosing deadenylation vs activation undefined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Added ANGPTL3 as a CPEB2-activated target in podocytes, with reciprocal ANGPTL3-driven stabilization of CPEB2 forming a feed-forward injury loop.\",\n      \"evidence\": \"RIP, polysome profiling, in vivo AAV9-shCPEB2 knockdown, mRNA stability assay\",\n      \"pmids\": [\"41219382\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct CPE site on ANGPTL3 mRNA not mapped\", \"Single disease model\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined the C-terminal ZZ domain as the necessary and sufficient module for translational repression and co-repressor recruitment, conserved from Drosophila ORB2 to human CPEB2.\",\n      \"evidence\": \"Tethered reporter repression in S2 cells, CRISPR ZZ deletion, RIP, ribosome profiling, interaction assays (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.07.10.664187\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, not peer-reviewed\", \"Cup-complex equivalent in mammalian CPEB2 repression not confirmed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Showed the ZZ domain also governs CPEB2-ortholog localization and co-factor recruitment in spermatids, linking the repressive module to spatial organization and fertility.\",\n      \"evidence\": \"CRISPR ZZ deletion in Drosophila, immunofluorescence localization, fertility and individualization-complex assays (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.08.22.671863\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, not peer-reviewed\", \"Mammalian relevance of spermatid localization role untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"What determines whether CPEB2 represses or activates a given target, and how its domains, isoforms, redox/m6A modifications, and co-factor complexes integrate to select between elongation control, polyadenylation, and mRNA stabilization, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model reconciling repressor vs activator outputs across tissues\", \"Mammalian co-repressor complex equivalent to Drosophila Cup not identified\", \"No structural model of CPE/eEF2/ZZ interactions\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [0, 1, 9, 10, 11, 15, 16, 18, 20]},\n      {\"term_id\": \"GO:0045182\", \"supporting_discovery_ids\": [0, 4, 6, 11, 16, 17, 18]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [1, 15]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 9, 11, 13, 18]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 4, 6, 16, 17]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [0, 2, 9]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"EEF2\", \"NPGPx\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}