{"gene":"PELO","run_date":"2026-06-10T05:19:53","timeline":{"discoveries":[{"year":2014,"finding":"Pelo (Drosophila ortholog) is required for dissociation of stalled 80S ribosomes and clearance of aberrant viral RNA/proteins, and this function is specifically required for high-level synthesis of viral capsid proteins. pelo deficiency limits high-level synthesis of DCV capsid proteins but has little effect on bulk cellular protein synthesis or other viral proteins.","method":"Forward genetic screen in Drosophila, genetic loss-of-function (pelo mutant flies), Western blot analysis of viral protein levels, ribosome sedimentation assays detecting aberrant 80S ribosomes","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean genetic loss-of-function with specific phenotypic readout (viral capsid synthesis) and ribosome sedimentation assay; single lab but multiple orthogonal methods","pmids":["24722736"],"is_preprint":false},{"year":2015,"finding":"The Pelo-Hbs1 mRNA surveillance complex functions in the Drosophila germline to silence transposable elements at the translational level; this function requires interaction with Hbs1, and overexpression of RpS30a partially reverts TE-silencing defects in pelo mutants. Pelo acts independently of piRNA biogenesis.","method":"Genetic loss-of-function analysis (pelo mutant gonads), RT-PCR/Western blot for TE mRNA/protein levels, piRNA profiling, genetic epistasis with RpS30a overexpression, rescue by mammalian PELO ortholog","journal":"EMBO reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal genetic methods (mutant analysis, epistasis, ortholog rescue), single lab","pmids":["26124316"],"is_preprint":false},{"year":2013,"finding":"PELO binds to active HER2 and EGFR and attenuates PI3K/AKT signalling, likely through regulation of p85-PI3K recruitment to activated receptors; PELO negatively regulates cell migration and metastasis in vivo.","method":"Cell-based proteomic identification of HER2-binding proteins, co-immunoprecipitation, functional migration/invasion assays, in vivo metastasis assay, knockdown experiments","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — Co-IP binding plus functional KD assays with multiple phenotypic readouts; single lab","pmids":["23435426"],"is_preprint":false},{"year":2022,"finding":"PELO forms a protein complex with PLK1 and Smad4, binding different domains of Smad4 from PLK1. PELO facilitates PLK1-induced ubiquitination and proteasomal degradation of Smad4 in prostate cancer cells, promoting cancer cell proliferation and metastasis.","method":"Co-immunoprecipitation, domain-mapping experiments, ubiquitination assays, knockdown/overexpression studies, in vitro and in vivo functional assays, blocking peptide targeting PELO-Smad4 interaction","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP, ubiquitination assay, domain mapping, in vivo validation; single lab with multiple orthogonal methods","pmids":["35437307"],"is_preprint":false},{"year":2023,"finding":"PELO interacts with all cytosolic NLR family proteins and activates their ATPase activity. In flagellin-initiated NLRC4 inflammasome assembly, PELO acts as a catalytic assembly factor: after flagellin-bound NAIP5 recruits the first NLRC4, PELO is required for correctly assembling subsequent NLRC4 subunits into the inflammasome complex by activating NLRC4 ATPase activity. Stoichiometric analyses showed PELO is not a structural constituent of the final NLRC4 inflammasome.","method":"Co-immunoprecipitation, ATPase activity assays, stoichiometric analysis, NLRC4 inflammasome reconstitution experiments, functional loss-of-function studies","journal":"Immunity","confidence":"High","confidence_rationale":"Tier 1 / Strong — ATPase activity reconstitution assay, Co-IP, stoichiometric analysis, and functional epistasis in a single rigorous study","pmids":["36948192"],"is_preprint":false},{"year":2018,"finding":"In Aedes aegypti, pelo is upregulated during DENV replication and its silencing reduces DENV virion production. In the presence of Wolbachia (in female mosquitoes), pelo protein is downregulated and its subcellular localization is altered, which may contribute to reduced DENV replication. The microRNA aae-miR-2940-5p, enriched in Wolbachia-infected mosquitoes, may mediate regulation of pelo.","method":"RNAi silencing of pelo, viral titer measurement, subcellular localization imaging, miRNA profiling, Wolbachia infection experiments","journal":"PLoS neglected tropical diseases","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — RNAi knockdown with viral titer readout, subcellular localization imaging with functional context; single lab, multiple methods","pmids":["29641562"],"is_preprint":false},{"year":2025,"finding":"In SKIc (superkiller complex)-deficient cancer cells (caused by FOCAD deletion in 9p21.3-deleted cancers or TTC37 mutations in MSI-H cancers), PELO depletion induces the unfolded protein response, a stress response to accumulation of misfolded/unfolded nascent polypeptides. This indicates PELO is synthetically lethal with SKIc loss because both pathways handle stalled ribosomes/aberrant mRNAs.","method":"Large-scale CRISPR knockout screening (Cancer Dependency Map), genetic validation of synthetic lethality, unfolded protein response assays upon PELO depletion in SKIc-deficient cells","journal":"Nature","confidence":"High","confidence_rationale":"Tier 2 / Strong — large-scale CRISPR screen plus mechanistic validation (UPR induction) across two independent cancer molecular subtypes, replicated across multiple cell contexts","pmids":["39910293"],"is_preprint":false},{"year":2024,"finding":"PELO regulates erythroid differentiation by interacting with MYC to upregulate KLF10 expression. PELO knockdown inhibits K562 cell proliferation, cell cycle progression, and promotes apoptosis while enhancing hemin-induced erythroid differentiation.","method":"RNAi knockdown, Co-immunoprecipitation (PELO-MYC interaction), RT-PCR for KLF10 and erythroid gene expression, benzidine staining, cell cycle analysis","journal":"The FEBS journal","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — Co-IP identifying PELO-MYC interaction linked to KLF10 regulation, supported by knockdown phenotype; single lab, single study","pmids":["39206622"],"is_preprint":false},{"year":2024,"finding":"The insect Pelo-Hbs1 complex is expressed on the sperm surface and mediates paternal arbovirus transmission by targeting virus-containing tubules (formed by viral nonstructural protein Pns11) to the sperm surface via direct Pns11-Pelo interaction. Pelo-Hbs1 complex normally inhibits tubule assembly by suppressing Hsp70 activity, but virus-activated ubiquitin ligase E3 mediates Pelo ubiquitinated degradation (with synergistic Hbs1 degradation), and Pns11 competes with Pelo for E3 binding, thereby antagonizing Pelo-Hbs1 degradation to promote tubule assembly.","method":"Co-immunoprecipitation (Pns11-Pelo interaction), subcellular localization imaging, ubiquitination assays, Hsp70 activity assays, competition binding assays, RNAi knockdown","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (Co-IP, ubiquitination assay, activity assay, competition assay) in single study; insect ortholog system","pmids":["39122673"],"is_preprint":false},{"year":2025,"finding":"The Hbs1-Pelo complex (Drosophila) promotes translation reinitiation at the ATF4 ORF by facilitating proper translation termination at preceding upstream open reading frames (uORFs) in the ATF4 5' leader. This mechanism is conserved in human cells (HBS1L and Pelo). Loss of Pelo or Hbs1 reduces ATF4 protein levels, leading to vision defects in Drosophila; restoring ATF4 in lamina neurons partially rescues ERG defects in Hbs1 mutants.","method":"Drosophila genetics (loss-of-function mutants, tissue-specific depletion), electroretinogram (ERG) functional assay, human cell culture knockdown, translation reporter assays for ATF4 uORF reinitiation, confocal imaging","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis (ATF4 rescue of pelo/hbs1 phenotype), translation reporter assays, cross-species validation; preprint, single lab","pmids":["41279977"],"is_preprint":true}],"current_model":"PELO (Pelota) is a multifunctional ribosome-rescue and translational quality-control factor that, as part of the Pelo-Hbs1 complex, dissociates stalled 80S ribosomes, facilitates translation termination/reinitiation at upstream ORFs (e.g., ATF4), and silences transposable elements at the translational level in the germline; beyond ribosome rescue, PELO acts as a catalytic assembly factor for cytosolic NLR inflammasomes by activating NLR ATPase activity, interacts with HER2/EGFR to attenuate PI3K/AKT signaling, forms a complex with PLK1 and Smad4 to facilitate Smad4 ubiquitination and degradation, interacts with MYC to regulate KLF10 and erythroid differentiation, and is synthetically lethal with superkiller complex (SKIc) loss through induction of the unfolded protein response."},"narrative":{"mechanistic_narrative":"PELO (Pelota) is a ribosome-rescue and translational quality-control factor that, partnered with Hbs1, recognizes and dissociates stalled 80S ribosomes to clear aberrant mRNAs and nascent proteins [PMID:24722736]. Through this surveillance activity the Pelo-Hbs1 complex silences transposable elements at the translational level in the germline, independently of piRNA biogenesis [PMID:26124316], and shapes upstream-ORF handling: it promotes proper termination at uORFs in the ATF4 5' leader to enable downstream ATF4 reinitiation, a mechanism conserved from Drosophila to human cells [PMID:41279977]. The functional importance of this rescue pathway is underscored by a synthetic-lethal relationship in which PELO depletion in SKIc (superkiller complex)-deficient cancer cells triggers the unfolded protein response, indicating that PELO and the SKIc pathway redundantly resolve stalled ribosomes and aberrant transcripts [PMID:39910293]. Beyond ribosome rescue, PELO acts as a catalytic, non-structural assembly factor for cytosolic NLR inflammasomes, binding NLR proteins and activating their ATPase activity to drive correct stepwise assembly of the flagellin-initiated NLRC4 complex [PMID:36948192]. PELO additionally participates in growth and signaling control as a protein interactor — it binds active HER2/EGFR to attenuate PI3K/AKT signaling and limit migration and metastasis [PMID:23435426], forms a complex with PLK1 and Smad4 to facilitate Smad4 ubiquitination and degradation [PMID:35437307], and interacts with MYC to upregulate KLF10 during erythroid differentiation [PMID:39206622].","teleology":[{"year":2014,"claim":"Established PELO's core biochemical role: resolving stalled ribosomes, answering whether Pelota acts as a general translation factor or a targeted rescue factor for aberrant translation.","evidence":"Forward genetic screen and ribosome sedimentation in Drosophila pelo mutants, with viral capsid synthesis readout","pmids":["24722736"],"confidence":"Medium","gaps":["Does not define the structural basis of 80S recognition","Mammalian ortholog activity inferred, not directly tested here"]},{"year":2013,"claim":"Extended PELO beyond ribosome rescue by showing it physically engages activated receptor tyrosine kinases to dampen downstream signaling, raising the question of how a rescue factor influences oncogenic signaling.","evidence":"Proteomic identification of HER2 binders, co-IP, migration/invasion and in vivo metastasis assays with knockdown","pmids":["23435426"],"confidence":"Medium","gaps":["Mechanism of p85-PI3K displacement not resolved","Single lab; reciprocal validation limited"]},{"year":2015,"claim":"Connected the Pelo-Hbs1 complex to germline transposon control, showing the rescue machinery silences TEs translationally rather than through piRNA biogenesis.","evidence":"Drosophila genetic loss-of-function, epistasis with RpS30a overexpression, and mammalian PELO rescue","pmids":["26124316"],"confidence":"Medium","gaps":["How TE mRNAs are selected as substrates is unknown","Direct biochemical link between TE mRNA stalling and silencing not shown"]},{"year":2018,"claim":"Showed pelo is a host factor for arboviral replication and a target of antiviral symbiont-mediated regulation, framing PELO as a node where translational surveillance intersects viral fitness.","evidence":"RNAi silencing in Aedes aegypti with viral titer, subcellular localization imaging, miRNA profiling under Wolbachia infection","pmids":["29641562"],"confidence":"Medium","gaps":["miR-2940-5p regulation of pelo correlative, not demonstrated mechanistically","Mechanism linking PELO to virion production undefined"]},{"year":2022,"claim":"Defined a scaffolding role in targeted protein degradation, showing PELO bridges PLK1 and Smad4 to drive Smad4 ubiquitination, distinct from its ribosomal function.","evidence":"Reciprocal co-IP, domain mapping, ubiquitination assays, and in vivo prostate cancer assays with a blocking peptide","pmids":["35437307"],"confidence":"Medium","gaps":["E3 ligase responsible for Smad4 ubiquitination not identified","Whether this role depends on ribosome-rescue activity unknown"]},{"year":2023,"claim":"Revealed a catalytic, non-structural function for PELO in innate immunity: activating NLR ATPase activity to template stepwise inflammasome assembly, expanding its enzymatic repertoire beyond ribosome dissociation.","evidence":"Co-IP, ATPase activity assays, stoichiometric analysis, and NLRC4 reconstitution with loss-of-function studies","pmids":["36948192"],"confidence":"High","gaps":["Structural mechanism of ATPase activation unresolved","Relationship between inflammasome role and ribosome-rescue activity unclear"]},{"year":2024,"claim":"Linked PELO to lineage-specific transcriptional control by showing it cooperates with MYC to regulate KLF10 and modulate erythroid differentiation and proliferation.","evidence":"RNAi knockdown, PELO-MYC co-IP, KLF10/erythroid gene expression analysis, benzidine staining, and cell cycle analysis in K562 cells","pmids":["39206622"],"confidence":"Medium","gaps":["Whether PELO directly affects MYC activity or is recruited to chromatin unknown","Single cell-line context"]},{"year":2024,"claim":"Demonstrated that the Pelo-Hbs1 complex restrains viral tubule assembly via Hsp70 suppression, and that viruses promote PELO ubiquitinated degradation to enable paternal transmission, defining PELO as a regulated antiviral checkpoint.","evidence":"Co-IP (Pns11-Pelo), localization imaging, ubiquitination and Hsp70 activity assays, competition binding, and RNAi in an insect system","pmids":["39122673"],"confidence":"Medium","gaps":["Identity of the activated E3 ligase not fully defined","Conservation of the sperm-surface role beyond insects unknown"]},{"year":2025,"claim":"Established a clinically actionable synthetic-lethal dependency, showing PELO loss kills SKIc-deficient cancer cells through UPR induction, confirming functional redundancy between PELO and SKIc in clearing aberrant translation.","evidence":"Genome-wide CRISPR knockout screening (DepMap) with genetic validation and UPR assays across two cancer molecular subtypes","pmids":["39910293"],"confidence":"High","gaps":["Precise substrate overlap between PELO and SKIc not enumerated","Therapeutic window not characterized"]},{"year":2025,"claim":"Defined a mechanism by which Pelo-Hbs1 governs ATF4 expression, showing proper uORF termination is required for downstream reinitiation, connecting ribosome rescue to stress-responsive gene control.","evidence":"Drosophila genetics with ERG assay, ATF4-rescue epistasis, human cell knockdown, and ATF4 uORF translation reporters (preprint)","pmids":["41279977"],"confidence":"Medium","gaps":["Preprint; not yet peer-reviewed","Whether ATF4 regulation accounts for the UPR phenotype in SKIc-deficient cells not directly tested"]},{"year":null,"claim":"How PELO's single biochemical activity (ribosome/ATPase engagement) is partitioned across its many roles — ribosome rescue, inflammasome assembly, receptor signaling, and targeted protein degradation — remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unifying structural model across functions","Substrate-selection rules for each context undefined","Whether non-ribosomal roles require Hbs1 partnership unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140098","term_label":"catalytic activity, acting on RNA","supporting_discovery_ids":[0,1,9]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[4]},{"term_id":"GO:0045182","term_label":"translation regulator activity","supporting_discovery_ids":[9]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[4]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,1]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[4]},{"term_id":"R-HSA-8953897","term_label":"Cellular responses to stimuli","supporting_discovery_ids":[6,9]}],"complexes":["Pelo-Hbs1 complex"],"partners":["HBS1L","HER2","EGFR","PLK1","SMAD4","MYC","NLRC4"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9BRX2","full_name":"Protein pelota homolog","aliases":["Protein Dom34 homolog"],"length_aa":385,"mass_kda":43.4,"function":"Component of the Pelota-HBS1L complex, a complex that recognizes stalled ribosomes and triggers the No-Go Decay (NGD) pathway (PubMed:21448132, PubMed:23667253, PubMed:27543824, PubMed:27863242). In the Pelota-HBS1L complex, PELO recognizes ribosomes stalled at the 3' end of an mRNA and engages stalled ribosomes by destabilizing mRNA in the mRNA channel (PubMed:27543824, PubMed:27863242). Following mRNA extraction from stalled ribosomes by the SKI complex, the Pelota-HBS1L complex promotes recruitment of ABCE1, which drives the disassembly of stalled ribosomes, followed by degradation of damaged mRNAs as part of the NGD pathway (PubMed:21448132, PubMed:32006463). As part of the PINK1-regulated signaling, upon mitochondrial damage is recruited to the ribosome/mRNA-ribonucleoprotein complex associated to mitochondrial outer membrane thereby enabling the recruitment of autophagy receptors and induction of mitophagy (PubMed:29861391)","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q9BRX2/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/PELO","classification":"Common Essential","n_dependent_lines":1049,"n_total_lines":1208,"dependency_fraction":0.8683774834437086},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/PELO","total_profiled":1310},"omim":[{"mim_id":"605757","title":"PELOTA mRNA SURVEILLANCE AND RIBOSOME RESCUE FACTOR; PELO","url":"https://www.omim.org/entry/605757"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoli fibrillar center","reliability":"Approved"},{"location":"Nucleoplasm","reliability":"Additional"},{"location":"Mitotic chromosome","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/PELO"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q9BRX2","domains":[{"cath_id":"2.30.30.870","chopping":"3-130","consensus_level":"high","plddt":91.1454,"start":3,"end":130},{"cath_id":"3.30.420.60","chopping":"138-269","consensus_level":"high","plddt":89.712,"start":138,"end":269},{"cath_id":"3.30.1330.30","chopping":"272-374","consensus_level":"high","plddt":89.287,"start":272,"end":374}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BRX2","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BRX2-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9BRX2-F1-predicted_aligned_error_v6.png","plddt_mean":88.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PELO","jax_strain_url":"https://www.jax.org/strain/search?query=PELO"},"sequence":{"accession":"Q9BRX2","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9BRX2.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9BRX2/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9BRX2"}},"corpus_meta":[{"pmid":"24722736","id":"PMC_24722736","title":"pelo is required for high efficiency viral replication.","date":"2014","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/24722736","citation_count":33,"is_preprint":false},{"pmid":"29641562","id":"PMC_29641562","title":"Suppression of the pelo protein by Wolbachia and its effect on dengue virus in Aedes aegypti.","date":"2018","source":"PLoS neglected tropical diseases","url":"https://pubmed.ncbi.nlm.nih.gov/29641562","citation_count":26,"is_preprint":false},{"pmid":"36948192","id":"PMC_36948192","title":"Ribosome-rescuer PELO catalyzes the oligomeric assembly of NOD-like receptor family proteins via activating their ATPase enzymatic activity.","date":"2023","source":"Immunity","url":"https://pubmed.ncbi.nlm.nih.gov/36948192","citation_count":26,"is_preprint":false},{"pmid":"35437307","id":"PMC_35437307","title":"PELO facilitates PLK1-induced the ubiquitination and degradation of Smad4 and promotes the progression of prostate cancer.","date":"2022","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/35437307","citation_count":21,"is_preprint":false},{"pmid":"17669516","id":"PMC_17669516","title":"Transcriptional and epigenetic regulation of the integrin collagen receptor locus ITGA1-PELO-ITGA2.","date":"2007","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/17669516","citation_count":21,"is_preprint":false},{"pmid":"23435426","id":"PMC_23435426","title":"PELO negatively regulates HER receptor signalling and metastasis.","date":"2013","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/23435426","citation_count":17,"is_preprint":false},{"pmid":"26124316","id":"PMC_26124316","title":"The RNA surveillance complex Pelo-Hbs1 is required for transposon silencing in the Drosophila germline.","date":"2015","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/26124316","citation_count":17,"is_preprint":false},{"pmid":"39910293","id":"PMC_39910293","title":"SKI complex loss renders 9p21.3-deleted or MSI-H cancers dependent on PELO.","date":"2025","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/39910293","citation_count":15,"is_preprint":false},{"pmid":"11060452","id":"PMC_11060452","title":"Molecular cloning, expression and chromosome location of the human pelota gene PELO.","date":"2000","source":"Cytogenetics and cell genetics","url":"https://pubmed.ncbi.nlm.nih.gov/11060452","citation_count":15,"is_preprint":false},{"pmid":"12438745","id":"PMC_12438745","title":"Mouse pelota gene (Pelo): cDNA cloning, genomic structure, and chromosomal localization.","date":"2002","source":"Cytogenetic and genome research","url":"https://pubmed.ncbi.nlm.nih.gov/12438745","citation_count":11,"is_preprint":false},{"pmid":"39122673","id":"PMC_39122673","title":"Insect ribosome-rescuer Pelo-Hbs1 complex on sperm surface mediates paternal arbovirus transmission.","date":"2024","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/39122673","citation_count":8,"is_preprint":false},{"pmid":"39206622","id":"PMC_39206622","title":"PELO regulates erythroid differentiation through interaction with MYC to upregulate KLF10.","date":"2024","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/39206622","citation_count":0,"is_preprint":false},{"pmid":"41279977","id":"PMC_41279977","title":"Translation regulation of ATF4 by the termination complex Hbs1-Pelo is required for visual system development and function.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/41279977","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7591,"output_tokens":2896,"usd":0.033106,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10244,"output_tokens":3479,"usd":0.069098,"stage2_stop_reason":"end_turn"},"total_usd":0.102204,"stage1_batch_id":"msgbatch_013a8chtv3AWyTqv4z4sEF4C","stage2_batch_id":"msgbatch_01AHsuW63vinsvuTgzmQ3n62","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2014,\n      \"finding\": \"Pelo (Drosophila ortholog) is required for dissociation of stalled 80S ribosomes and clearance of aberrant viral RNA/proteins, and this function is specifically required for high-level synthesis of viral capsid proteins. pelo deficiency limits high-level synthesis of DCV capsid proteins but has little effect on bulk cellular protein synthesis or other viral proteins.\",\n      \"method\": \"Forward genetic screen in Drosophila, genetic loss-of-function (pelo mutant flies), Western blot analysis of viral protein levels, ribosome sedimentation assays detecting aberrant 80S ribosomes\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean genetic loss-of-function with specific phenotypic readout (viral capsid synthesis) and ribosome sedimentation assay; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"24722736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"The Pelo-Hbs1 mRNA surveillance complex functions in the Drosophila germline to silence transposable elements at the translational level; this function requires interaction with Hbs1, and overexpression of RpS30a partially reverts TE-silencing defects in pelo mutants. Pelo acts independently of piRNA biogenesis.\",\n      \"method\": \"Genetic loss-of-function analysis (pelo mutant gonads), RT-PCR/Western blot for TE mRNA/protein levels, piRNA profiling, genetic epistasis with RpS30a overexpression, rescue by mammalian PELO ortholog\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal genetic methods (mutant analysis, epistasis, ortholog rescue), single lab\",\n      \"pmids\": [\"26124316\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"PELO binds to active HER2 and EGFR and attenuates PI3K/AKT signalling, likely through regulation of p85-PI3K recruitment to activated receptors; PELO negatively regulates cell migration and metastasis in vivo.\",\n      \"method\": \"Cell-based proteomic identification of HER2-binding proteins, co-immunoprecipitation, functional migration/invasion assays, in vivo metastasis assay, knockdown experiments\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — Co-IP binding plus functional KD assays with multiple phenotypic readouts; single lab\",\n      \"pmids\": [\"23435426\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"PELO forms a protein complex with PLK1 and Smad4, binding different domains of Smad4 from PLK1. PELO facilitates PLK1-induced ubiquitination and proteasomal degradation of Smad4 in prostate cancer cells, promoting cancer cell proliferation and metastasis.\",\n      \"method\": \"Co-immunoprecipitation, domain-mapping experiments, ubiquitination assays, knockdown/overexpression studies, in vitro and in vivo functional assays, blocking peptide targeting PELO-Smad4 interaction\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP, ubiquitination assay, domain mapping, in vivo validation; single lab with multiple orthogonal methods\",\n      \"pmids\": [\"35437307\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"PELO interacts with all cytosolic NLR family proteins and activates their ATPase activity. In flagellin-initiated NLRC4 inflammasome assembly, PELO acts as a catalytic assembly factor: after flagellin-bound NAIP5 recruits the first NLRC4, PELO is required for correctly assembling subsequent NLRC4 subunits into the inflammasome complex by activating NLRC4 ATPase activity. Stoichiometric analyses showed PELO is not a structural constituent of the final NLRC4 inflammasome.\",\n      \"method\": \"Co-immunoprecipitation, ATPase activity assays, stoichiometric analysis, NLRC4 inflammasome reconstitution experiments, functional loss-of-function studies\",\n      \"journal\": \"Immunity\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — ATPase activity reconstitution assay, Co-IP, stoichiometric analysis, and functional epistasis in a single rigorous study\",\n      \"pmids\": [\"36948192\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"In Aedes aegypti, pelo is upregulated during DENV replication and its silencing reduces DENV virion production. In the presence of Wolbachia (in female mosquitoes), pelo protein is downregulated and its subcellular localization is altered, which may contribute to reduced DENV replication. The microRNA aae-miR-2940-5p, enriched in Wolbachia-infected mosquitoes, may mediate regulation of pelo.\",\n      \"method\": \"RNAi silencing of pelo, viral titer measurement, subcellular localization imaging, miRNA profiling, Wolbachia infection experiments\",\n      \"journal\": \"PLoS neglected tropical diseases\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — RNAi knockdown with viral titer readout, subcellular localization imaging with functional context; single lab, multiple methods\",\n      \"pmids\": [\"29641562\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In SKIc (superkiller complex)-deficient cancer cells (caused by FOCAD deletion in 9p21.3-deleted cancers or TTC37 mutations in MSI-H cancers), PELO depletion induces the unfolded protein response, a stress response to accumulation of misfolded/unfolded nascent polypeptides. This indicates PELO is synthetically lethal with SKIc loss because both pathways handle stalled ribosomes/aberrant mRNAs.\",\n      \"method\": \"Large-scale CRISPR knockout screening (Cancer Dependency Map), genetic validation of synthetic lethality, unfolded protein response assays upon PELO depletion in SKIc-deficient cells\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — large-scale CRISPR screen plus mechanistic validation (UPR induction) across two independent cancer molecular subtypes, replicated across multiple cell contexts\",\n      \"pmids\": [\"39910293\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"PELO regulates erythroid differentiation by interacting with MYC to upregulate KLF10 expression. PELO knockdown inhibits K562 cell proliferation, cell cycle progression, and promotes apoptosis while enhancing hemin-induced erythroid differentiation.\",\n      \"method\": \"RNAi knockdown, Co-immunoprecipitation (PELO-MYC interaction), RT-PCR for KLF10 and erythroid gene expression, benzidine staining, cell cycle analysis\",\n      \"journal\": \"The FEBS journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — Co-IP identifying PELO-MYC interaction linked to KLF10 regulation, supported by knockdown phenotype; single lab, single study\",\n      \"pmids\": [\"39206622\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"The insect Pelo-Hbs1 complex is expressed on the sperm surface and mediates paternal arbovirus transmission by targeting virus-containing tubules (formed by viral nonstructural protein Pns11) to the sperm surface via direct Pns11-Pelo interaction. Pelo-Hbs1 complex normally inhibits tubule assembly by suppressing Hsp70 activity, but virus-activated ubiquitin ligase E3 mediates Pelo ubiquitinated degradation (with synergistic Hbs1 degradation), and Pns11 competes with Pelo for E3 binding, thereby antagonizing Pelo-Hbs1 degradation to promote tubule assembly.\",\n      \"method\": \"Co-immunoprecipitation (Pns11-Pelo interaction), subcellular localization imaging, ubiquitination assays, Hsp70 activity assays, competition binding assays, RNAi knockdown\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (Co-IP, ubiquitination assay, activity assay, competition assay) in single study; insect ortholog system\",\n      \"pmids\": [\"39122673\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"The Hbs1-Pelo complex (Drosophila) promotes translation reinitiation at the ATF4 ORF by facilitating proper translation termination at preceding upstream open reading frames (uORFs) in the ATF4 5' leader. This mechanism is conserved in human cells (HBS1L and Pelo). Loss of Pelo or Hbs1 reduces ATF4 protein levels, leading to vision defects in Drosophila; restoring ATF4 in lamina neurons partially rescues ERG defects in Hbs1 mutants.\",\n      \"method\": \"Drosophila genetics (loss-of-function mutants, tissue-specific depletion), electroretinogram (ERG) functional assay, human cell culture knockdown, translation reporter assays for ATF4 uORF reinitiation, confocal imaging\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis (ATF4 rescue of pelo/hbs1 phenotype), translation reporter assays, cross-species validation; preprint, single lab\",\n      \"pmids\": [\"41279977\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"PELO (Pelota) is a multifunctional ribosome-rescue and translational quality-control factor that, as part of the Pelo-Hbs1 complex, dissociates stalled 80S ribosomes, facilitates translation termination/reinitiation at upstream ORFs (e.g., ATF4), and silences transposable elements at the translational level in the germline; beyond ribosome rescue, PELO acts as a catalytic assembly factor for cytosolic NLR inflammasomes by activating NLR ATPase activity, interacts with HER2/EGFR to attenuate PI3K/AKT signaling, forms a complex with PLK1 and Smad4 to facilitate Smad4 ubiquitination and degradation, interacts with MYC to regulate KLF10 and erythroid differentiation, and is synthetically lethal with superkiller complex (SKIc) loss through induction of the unfolded protein response.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PELO (Pelota) is a ribosome-rescue and translational quality-control factor that, partnered with Hbs1, recognizes and dissociates stalled 80S ribosomes to clear aberrant mRNAs and nascent proteins [#0]. Through this surveillance activity the Pelo-Hbs1 complex silences transposable elements at the translational level in the germline, independently of piRNA biogenesis [#1], and shapes upstream-ORF handling: it promotes proper termination at uORFs in the ATF4 5' leader to enable downstream ATF4 reinitiation, a mechanism conserved from Drosophila to human cells [#9]. The functional importance of this rescue pathway is underscored by a synthetic-lethal relationship in which PELO depletion in SKIc (superkiller complex)-deficient cancer cells triggers the unfolded protein response, indicating that PELO and the SKIc pathway redundantly resolve stalled ribosomes and aberrant transcripts [#6]. Beyond ribosome rescue, PELO acts as a catalytic, non-structural assembly factor for cytosolic NLR inflammasomes, binding NLR proteins and activating their ATPase activity to drive correct stepwise assembly of the flagellin-initiated NLRC4 complex [#4]. PELO additionally participates in growth and signaling control as a protein interactor — it binds active HER2/EGFR to attenuate PI3K/AKT signaling and limit migration and metastasis [#2], forms a complex with PLK1 and Smad4 to facilitate Smad4 ubiquitination and degradation [#3], and interacts with MYC to upregulate KLF10 during erythroid differentiation [#7].\",\n  \"teleology\": [\n    {\n      \"year\": 2014,\n      \"claim\": \"Established PELO's core biochemical role: resolving stalled ribosomes, answering whether Pelota acts as a general translation factor or a targeted rescue factor for aberrant translation.\",\n      \"evidence\": \"Forward genetic screen and ribosome sedimentation in Drosophila pelo mutants, with viral capsid synthesis readout\",\n      \"pmids\": [\"24722736\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Does not define the structural basis of 80S recognition\", \"Mammalian ortholog activity inferred, not directly tested here\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Extended PELO beyond ribosome rescue by showing it physically engages activated receptor tyrosine kinases to dampen downstream signaling, raising the question of how a rescue factor influences oncogenic signaling.\",\n      \"evidence\": \"Proteomic identification of HER2 binders, co-IP, migration/invasion and in vivo metastasis assays with knockdown\",\n      \"pmids\": [\"23435426\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of p85-PI3K displacement not resolved\", \"Single lab; reciprocal validation limited\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Connected the Pelo-Hbs1 complex to germline transposon control, showing the rescue machinery silences TEs translationally rather than through piRNA biogenesis.\",\n      \"evidence\": \"Drosophila genetic loss-of-function, epistasis with RpS30a overexpression, and mammalian PELO rescue\",\n      \"pmids\": [\"26124316\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"How TE mRNAs are selected as substrates is unknown\", \"Direct biochemical link between TE mRNA stalling and silencing not shown\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Showed pelo is a host factor for arboviral replication and a target of antiviral symbiont-mediated regulation, framing PELO as a node where translational surveillance intersects viral fitness.\",\n      \"evidence\": \"RNAi silencing in Aedes aegypti with viral titer, subcellular localization imaging, miRNA profiling under Wolbachia infection\",\n      \"pmids\": [\"29641562\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"miR-2940-5p regulation of pelo correlative, not demonstrated mechanistically\", \"Mechanism linking PELO to virion production undefined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined a scaffolding role in targeted protein degradation, showing PELO bridges PLK1 and Smad4 to drive Smad4 ubiquitination, distinct from its ribosomal function.\",\n      \"evidence\": \"Reciprocal co-IP, domain mapping, ubiquitination assays, and in vivo prostate cancer assays with a blocking peptide\",\n      \"pmids\": [\"35437307\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"E3 ligase responsible for Smad4 ubiquitination not identified\", \"Whether this role depends on ribosome-rescue activity unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Revealed a catalytic, non-structural function for PELO in innate immunity: activating NLR ATPase activity to template stepwise inflammasome assembly, expanding its enzymatic repertoire beyond ribosome dissociation.\",\n      \"evidence\": \"Co-IP, ATPase activity assays, stoichiometric analysis, and NLRC4 reconstitution with loss-of-function studies\",\n      \"pmids\": [\"36948192\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural mechanism of ATPase activation unresolved\", \"Relationship between inflammasome role and ribosome-rescue activity unclear\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Linked PELO to lineage-specific transcriptional control by showing it cooperates with MYC to regulate KLF10 and modulate erythroid differentiation and proliferation.\",\n      \"evidence\": \"RNAi knockdown, PELO-MYC co-IP, KLF10/erythroid gene expression analysis, benzidine staining, and cell cycle analysis in K562 cells\",\n      \"pmids\": [\"39206622\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether PELO directly affects MYC activity or is recruited to chromatin unknown\", \"Single cell-line context\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Demonstrated that the Pelo-Hbs1 complex restrains viral tubule assembly via Hsp70 suppression, and that viruses promote PELO ubiquitinated degradation to enable paternal transmission, defining PELO as a regulated antiviral checkpoint.\",\n      \"evidence\": \"Co-IP (Pns11-Pelo), localization imaging, ubiquitination and Hsp70 activity assays, competition binding, and RNAi in an insect system\",\n      \"pmids\": [\"39122673\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Identity of the activated E3 ligase not fully defined\", \"Conservation of the sperm-surface role beyond insects unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Established a clinically actionable synthetic-lethal dependency, showing PELO loss kills SKIc-deficient cancer cells through UPR induction, confirming functional redundancy between PELO and SKIc in clearing aberrant translation.\",\n      \"evidence\": \"Genome-wide CRISPR knockout screening (DepMap) with genetic validation and UPR assays across two cancer molecular subtypes\",\n      \"pmids\": [\"39910293\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Precise substrate overlap between PELO and SKIc not enumerated\", \"Therapeutic window not characterized\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined a mechanism by which Pelo-Hbs1 governs ATF4 expression, showing proper uORF termination is required for downstream reinitiation, connecting ribosome rescue to stress-responsive gene control.\",\n      \"evidence\": \"Drosophila genetics with ERG assay, ATF4-rescue epistasis, human cell knockdown, and ATF4 uORF translation reporters (preprint)\",\n      \"pmids\": [\"41279977\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint; not yet peer-reviewed\", \"Whether ATF4 regulation accounts for the UPR phenotype in SKIc-deficient cells not directly tested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How PELO's single biochemical activity (ribosome/ATPase engagement) is partitioned across its many roles — ribosome rescue, inflammasome assembly, receptor signaling, and targeted protein degradation — remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unifying structural model across functions\", \"Substrate-selection rules for each context undefined\", \"Whether non-ribosomal roles require Hbs1 partnership unknown\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140098\", \"supporting_discovery_ids\": [0, 1, 9]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"GO:0045182\", \"supporting_discovery_ids\": [9]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [4]},\n      {\"term_id\": \"R-HSA-8953897\", \"supporting_discovery_ids\": [6, 9]}\n    ],\n    \"complexes\": [\"Pelo-Hbs1 complex\"],\n    \"partners\": [\"HBS1L\", \"HER2\", \"EGFR\", \"PLK1\", \"SMAD4\", \"MYC\", \"NLRC4\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"tie","faith_supported":5,"faith_total":5,"faith_pct":100.0}}