{"gene":"GNL1","run_date":"2026-06-10T01:55:21","timeline":{"discoveries":[{"year":2012,"finding":"GNL1 contains a novel arginine/lysine-rich nucleolar localization signal in its NH2-terminus that directs GNL1 (and a heterologous protein) to the nucleus/nucleolus via an importin-α/β-independent pathway. GNL1 localizes to the nucleus and nucleolus specifically in G2 phase, and to the cytoplasm in G1 and S phases. GNL1 shuttles between nucleus and cytoplasm; amino acids 201–225 are required for CRM1-independent nuclear export. The G2 motif of the G-domain is critical for GTP binding, and nucleolar retention is regulated by a GTP-gating mechanism. Expression of wild-type GNL1 promotes G2/M transition, whereas a G2-domain mutant fails to localize to the nucleolus and does not promote this transition. Ongoing transcription is required for efficient nucleolar localization.","method":"Fluorescence microscopy of GFP-fusion constructs, cell-cycle synchronization, alanine-scanning mutagenesis of G-domain residues, heterokaryon shuttling assay, importin-α/β exclusion assay, CRM1 inhibitor (leptomycin B) treatment","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (mutagenesis, cell-cycle synchronization, heterokaryon assay, inhibitor treatments) in a single focused mechanistic study of this protein","pmids":["22244851"],"is_preprint":false},{"year":2018,"finding":"GNL1 physically interacts with ribosomal protein RPS20; this interaction was identified by yeast two-hybrid screening and confirmed by GST pull-down and co-immunoprecipitation. GNL1 promotes cell proliferation by inducing hyperphosphorylation of retinoblastoma protein (Rb), and this proliferative effect is dependent on RPS20, as RPS20 knockdown or expression of an RPS20-interaction-deficient GNL1 mutant significantly impairs cell proliferation.","method":"Yeast two-hybrid screen, GST pull-down, co-immunoprecipitation, RPS20 siRNA knockdown, GNL1 interaction-deficient mutant expression, cell proliferation assay, Rb phosphorylation immunoblot","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP + GST pull-down + genetic (interaction-deficient mutant + KD) in single lab with multiple orthogonal methods","pmids":["30061673"],"is_preprint":false},{"year":2020,"finding":"GNL1 inhibits apoptosis in colon cancer cells by modulating expression of Bcl2-family proteins and suppressing cleavage of caspases 7 and 8, and protects cells from chemo-drug-induced apoptosis. GNL1 upregulates p53 and its transcriptional target p21 (via both p53-dependent and p53-independent mechanisms), and promotes cytoplasmic retention and stabilization of p21 through AKT-mediated phosphorylation of p21. GNL1's anti-apoptotic function requires p21, as p21 knockdown abolishes GNL1-mediated cell survival.","method":"GNL1 overexpression/knockdown, caspase cleavage immunoblot, Bcl2-family protein immunoblot, p21 knockdown (siRNA), AKT inhibitor treatment, p53 knockdown, subcellular fractionation, cell survival assay","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple functional assays (apoptosis, caspase cleavage, p21 subcellular localization, AKT pathway) in a single lab with genetic epistasis (p21 KD rescue)","pmids":["33147101"],"is_preprint":false},{"year":2020,"finding":"GNL1 protein was isolated by label-free RNA affinity purification using G-quadruplex (G4) sequences from the 5′UTRs of PRKN and VPS35 mRNAs as bait. GNL1 displayed higher binding affinity for the G4 sequences than for their mutated (non-G4-forming) counterparts, identifying GNL1 as a G-quadruplex RNA-binding protein.","method":"Label-free RNA affinity purification with G4 RNA bait, binding affinity comparison between wild-type G4 and mutant sequences","journal":"RNA biology","confidence":"Medium","confidence_rationale":"Tier 3 / Weak — single pulldown-based identification with affinity comparison; single lab, no reciprocal validation or mutagenesis of GNL1","pmids":["33305682"],"is_preprint":false}],"current_model":"GNL1 is a nucleolar GTPase that cycles between cytoplasm (G1/S) and nucleus/nucleolus (G2) via an importin-independent, CRM1-independent nuclear export pathway regulated by GTP binding; in the nucleolus it promotes G2/M transition, drives Rb hyperphosphorylation and cell proliferation through interaction with RPS20, and suppresses apoptosis by modulating Bcl2-family proteins and stabilizing cytoplasmic p21 via AKT-mediated phosphorylation; additionally, GNL1 can bind RNA G-quadruplex structures in PD-associated transcripts."},"narrative":{"mechanistic_narrative":"GNL1 is a nucleolar GTPase that couples cell-cycle-regulated nucleocytoplasmic shuttling to control of proliferation and cell survival [PMID:22244851, PMID:30061673]. An N-terminal arginine/lysine-rich nucleolar localization signal directs GNL1 to the nucleus and nucleolus specifically in G2 phase through an importin-α/β-independent pathway, while a distinct region (amino acids 201–225) mediates CRM1-independent nuclear export, returning the protein to the cytoplasm in G1 and S; nucleolar retention is gated by GTP binding via the G2 motif of the G-domain, and disrupting this gating abolishes both nucleolar localization and GNL1-driven G2/M transition [PMID:22244851]. In the nucleolus GNL1 binds the ribosomal protein RPS20 and drives Rb hyperphosphorylation to promote proliferation, an effect lost when RPS20 is depleted or when an interaction-deficient GNL1 mutant is used [PMID:30061673]. GNL1 additionally suppresses apoptosis by modulating Bcl2-family proteins and blocking caspase-7/8 cleavage, and stabilizes cytoplasmic p21 through AKT-mediated phosphorylation, with its pro-survival activity dependent on p21 [PMID:33147101]. GNL1 also binds G-quadruplex structures in the 5′UTRs of PRKN and VPS35 transcripts, identifying it as a G-quadruplex RNA-binding protein [PMID:33305682].","teleology":[{"year":2012,"claim":"Established how GNL1 traffics within the cell and that its localization is mechanistically tied to cell-cycle progression, defining it as a GTP-gated nucleolar shuttling GTPase that promotes G2/M transition.","evidence":"GFP-fusion microscopy with cell-cycle synchronization, alanine-scanning G-domain mutagenesis, heterokaryon shuttling, importin and CRM1 exclusion assays","pmids":["22244851"],"confidence":"High","gaps":["Direct GTPase enzymatic kinetics not measured","The export receptor mediating CRM1-independent export is unidentified","Nucleolar substrates/effectors downstream of G2/M promotion not defined in this study"]},{"year":2018,"claim":"Connected GNL1's proliferative function to a physical partner and a downstream cell-cycle target, showing it acts through RPS20 to drive Rb hyperphosphorylation.","evidence":"Yeast two-hybrid screen, GST pull-down, reciprocal co-IP, RPS20 knockdown and interaction-deficient mutant in proliferation and Rb phosphorylation assays","pmids":["30061673"],"confidence":"High","gaps":["The kinase mediating Rb hyperphosphorylation downstream of GNL1–RPS20 is unidentified","Whether the interaction occurs in the nucleolus is not established","Direct biochemical contact surface not mapped"]},{"year":2020,"claim":"Defined GNL1 as an anti-apoptotic factor that promotes survival via Bcl2-family modulation and AKT-dependent cytoplasmic stabilization of p21.","evidence":"GNL1 overexpression/knockdown with caspase and Bcl2 immunoblots, subcellular fractionation, AKT inhibitor, p53 and p21 knockdown epistasis in cancer cells","pmids":["33147101"],"confidence":"Medium","gaps":["Whether GNL1 acts directly or indirectly on AKT/p21 is unresolved","Mechanism of p53 upregulation not defined","Single-lab functional study without orthogonal in vivo confirmation"]},{"year":2020,"claim":"Identified an RNA-binding activity for GNL1, showing it recognizes G-quadruplex structures in disease-associated transcript 5′UTRs.","evidence":"Label-free G4 RNA affinity purification with wild-type versus mutant G4 bait from PRKN and VPS35 5′UTRs","pmids":["33305682"],"confidence":"Medium","gaps":["Single pulldown-based identification without reciprocal validation or GNL1 mutagenesis","Functional consequence of G4 binding on transcript translation/stability not tested","Whether this activity links to its nucleolar GTPase role is unknown"]},{"year":null,"claim":"How GNL1's GTPase cycle, RPS20-dependent proliferative signaling, anti-apoptotic p21/AKT axis, and G-quadruplex RNA binding integrate into a single coherent mechanism remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No unifying model linking nucleolar GTPase activity to RNA binding","No structural data for GNL1 or its complexes","Physiological GTPase substrate/regulators unidentified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003924","term_label":"GTPase activity","supporting_discovery_ids":[0]},{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[3]}],"localization":[{"term_id":"GO:0005730","term_label":"nucleolus","supporting_discovery_ids":[0]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0,1]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[2]}],"complexes":[],"partners":["RPS20"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P36915","full_name":"Guanine nucleotide-binding protein-like 1","aliases":["GTP-binding protein HSR1"],"length_aa":607,"mass_kda":68.7,"function":"Possible regulatory or functional link with the histocompatibility cluster","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/P36915/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/GNL1","classification":"Not Classified","n_dependent_lines":63,"n_total_lines":1208,"dependency_fraction":0.052152317880794705},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"CSNK2B","stoichiometry":0.2},{"gene":"PGK1","stoichiometry":0.2},{"gene":"RACK1","stoichiometry":0.2},{"gene":"SRP14","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/GNL1","total_profiled":1310},"omim":[{"mim_id":"616880","title":"TBC1 DOMAIN FAMILY, MEMBER 22B; TBC1D22B","url":"https://www.omim.org/entry/616880"},{"mim_id":"143024","title":"GUANINE NUCLEOTIDE-BINDING PROTEIN-LIKE 1; GNL1","url":"https://www.omim.org/entry/143024"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Vesicles","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/GNL1"},"hgnc":{"alias_symbol":["HSR1"],"prev_symbol":[]},"alphafold":{"accession":"P36915","domains":[{"cath_id":"-","chopping":"78-107_421-514","consensus_level":"medium","plddt":92.4415,"start":78,"end":514},{"cath_id":"3.40.50.300","chopping":"172-261_276-319_334-410","consensus_level":"high","plddt":87.6457,"start":172,"end":410}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P36915","model_url":"https://alphafold.ebi.ac.uk/files/AF-P36915-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P36915-F1-predicted_aligned_error_v6.png","plddt_mean":76.75},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GNL1","jax_strain_url":"https://www.jax.org/strain/search?query=GNL1"},"sequence":{"accession":"P36915","fasta_url":"https://rest.uniprot.org/uniprotkb/P36915.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P36915/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P36915"}},"corpus_meta":[{"pmid":"15109406","id":"PMC_15109406","title":"Coronaviridae and SARS-associated coronavirus strain HSR1.","date":"2004","source":"Emerging infectious diseases","url":"https://pubmed.ncbi.nlm.nih.gov/15109406","citation_count":101,"is_preprint":false},{"pmid":"30061673","id":"PMC_30061673","title":"Interplay between human nucleolar GNL1 and RPS20 is critical to modulate cell proliferation.","date":"2018","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/30061673","citation_count":20,"is_preprint":false},{"pmid":"33305682","id":"PMC_33305682","title":"Guanine Nucleotide-Binding Protein-Like 1 (GNL1) binds RNA G-quadruplex structures in genes associated with Parkinson's disease.","date":"2020","source":"RNA biology","url":"https://pubmed.ncbi.nlm.nih.gov/33305682","citation_count":15,"is_preprint":false},{"pmid":"22244851","id":"PMC_22244851","title":"Subcellular distribution of the human putative nucleolar GTPase GNL1 is regulated by a novel arginine/lysine-rich domain and a GTP binding domain in a cell cycle-dependent manner.","date":"2012","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/22244851","citation_count":13,"is_preprint":false},{"pmid":"23125314","id":"PMC_23125314","title":"The integrity of the plant Golgi apparatus depends on cell growth-controlled activity of GNL1.","date":"2012","source":"Molecular plant","url":"https://pubmed.ncbi.nlm.nih.gov/23125314","citation_count":12,"is_preprint":false},{"pmid":"24908204","id":"PMC_24908204","title":"Single nucleotide polymorphisms at the PRR3, ABCF1, and GNL1 genes in the HLA class I region are associated with Graves' ophthalmopathy in a gender-dependent manner.","date":"2014","source":"Ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/24908204","citation_count":10,"is_preprint":false},{"pmid":"33147101","id":"PMC_33147101","title":"Guanine nucleotide binding protein like-1 (GNL1) promotes cancer cell proliferation and survival through AKT/p21 CIP1 signaling cascade.","date":"2020","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/33147101","citation_count":8,"is_preprint":false},{"pmid":"40601628","id":"PMC_40601628","title":"A Mycobacterium tuberculosis secreted virulence factor Rv1435c/hsr1 disrupts host snRNP biogenesis.","date":"2025","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/40601628","citation_count":2,"is_preprint":false},{"pmid":"11329171","id":"PMC_11329171","title":"Identification of Candida tropicalis HSR1, a gene of the heat-shock factor-related family, which confers salt tolerance in Saccharomyces cerevisiae.","date":"2001","source":"Yeast (Chichester, England)","url":"https://pubmed.ncbi.nlm.nih.gov/11329171","citation_count":2,"is_preprint":false},{"pmid":"41954063","id":"PMC_41954063","title":"Ultrasound-Assisted Radiopharmaceutical Investigation of GNL1-Mediated AKT-P53-P21 Axis Activation in Cervical Cancer Progression.","date":"2026","source":"Cancer biotherapy & radiopharmaceuticals","url":"https://pubmed.ncbi.nlm.nih.gov/41954063","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.09.17.676758","title":"Proteomic and Kinetic Characterization of Prion Seeding in Distinct Human CJD Strains Unveils Early Diagnostic Biomarkers","date":"2025-09-17","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.17.676758","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.01.31.635892","title":"Contrasting patterns of subtelomeric satellite superfamily in the  <i>Cannabaceae</i>  family","date":"2025-02-03","source":"bioRxiv","url":"https://doi.org/10.1101/2025.01.31.635892","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8358,"output_tokens":1487,"usd":0.023689,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8214,"output_tokens":2132,"usd":0.047185,"stage2_stop_reason":"end_turn"},"total_usd":0.070874,"stage1_batch_id":"msgbatch_01DUPACZi7AAWwuZiUjseQF4","stage2_batch_id":"msgbatch_018yt7chE3f48PEFtDwtj6AE","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2012,\n      \"finding\": \"GNL1 contains a novel arginine/lysine-rich nucleolar localization signal in its NH2-terminus that directs GNL1 (and a heterologous protein) to the nucleus/nucleolus via an importin-α/β-independent pathway. GNL1 localizes to the nucleus and nucleolus specifically in G2 phase, and to the cytoplasm in G1 and S phases. GNL1 shuttles between nucleus and cytoplasm; amino acids 201–225 are required for CRM1-independent nuclear export. The G2 motif of the G-domain is critical for GTP binding, and nucleolar retention is regulated by a GTP-gating mechanism. Expression of wild-type GNL1 promotes G2/M transition, whereas a G2-domain mutant fails to localize to the nucleolus and does not promote this transition. Ongoing transcription is required for efficient nucleolar localization.\",\n      \"method\": \"Fluorescence microscopy of GFP-fusion constructs, cell-cycle synchronization, alanine-scanning mutagenesis of G-domain residues, heterokaryon shuttling assay, importin-α/β exclusion assay, CRM1 inhibitor (leptomycin B) treatment\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (mutagenesis, cell-cycle synchronization, heterokaryon assay, inhibitor treatments) in a single focused mechanistic study of this protein\",\n      \"pmids\": [\"22244851\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"GNL1 physically interacts with ribosomal protein RPS20; this interaction was identified by yeast two-hybrid screening and confirmed by GST pull-down and co-immunoprecipitation. GNL1 promotes cell proliferation by inducing hyperphosphorylation of retinoblastoma protein (Rb), and this proliferative effect is dependent on RPS20, as RPS20 knockdown or expression of an RPS20-interaction-deficient GNL1 mutant significantly impairs cell proliferation.\",\n      \"method\": \"Yeast two-hybrid screen, GST pull-down, co-immunoprecipitation, RPS20 siRNA knockdown, GNL1 interaction-deficient mutant expression, cell proliferation assay, Rb phosphorylation immunoblot\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP + GST pull-down + genetic (interaction-deficient mutant + KD) in single lab with multiple orthogonal methods\",\n      \"pmids\": [\"30061673\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"GNL1 inhibits apoptosis in colon cancer cells by modulating expression of Bcl2-family proteins and suppressing cleavage of caspases 7 and 8, and protects cells from chemo-drug-induced apoptosis. GNL1 upregulates p53 and its transcriptional target p21 (via both p53-dependent and p53-independent mechanisms), and promotes cytoplasmic retention and stabilization of p21 through AKT-mediated phosphorylation of p21. GNL1's anti-apoptotic function requires p21, as p21 knockdown abolishes GNL1-mediated cell survival.\",\n      \"method\": \"GNL1 overexpression/knockdown, caspase cleavage immunoblot, Bcl2-family protein immunoblot, p21 knockdown (siRNA), AKT inhibitor treatment, p53 knockdown, subcellular fractionation, cell survival assay\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple functional assays (apoptosis, caspase cleavage, p21 subcellular localization, AKT pathway) in a single lab with genetic epistasis (p21 KD rescue)\",\n      \"pmids\": [\"33147101\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"GNL1 protein was isolated by label-free RNA affinity purification using G-quadruplex (G4) sequences from the 5′UTRs of PRKN and VPS35 mRNAs as bait. GNL1 displayed higher binding affinity for the G4 sequences than for their mutated (non-G4-forming) counterparts, identifying GNL1 as a G-quadruplex RNA-binding protein.\",\n      \"method\": \"Label-free RNA affinity purification with G4 RNA bait, binding affinity comparison between wild-type G4 and mutant sequences\",\n      \"journal\": \"RNA biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single pulldown-based identification with affinity comparison; single lab, no reciprocal validation or mutagenesis of GNL1\",\n      \"pmids\": [\"33305682\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"GNL1 is a nucleolar GTPase that cycles between cytoplasm (G1/S) and nucleus/nucleolus (G2) via an importin-independent, CRM1-independent nuclear export pathway regulated by GTP binding; in the nucleolus it promotes G2/M transition, drives Rb hyperphosphorylation and cell proliferation through interaction with RPS20, and suppresses apoptosis by modulating Bcl2-family proteins and stabilizing cytoplasmic p21 via AKT-mediated phosphorylation; additionally, GNL1 can bind RNA G-quadruplex structures in PD-associated transcripts.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"GNL1 is a nucleolar GTPase that couples cell-cycle-regulated nucleocytoplasmic shuttling to control of proliferation and cell survival [#0, #1]. An N-terminal arginine/lysine-rich nucleolar localization signal directs GNL1 to the nucleus and nucleolus specifically in G2 phase through an importin-α/β-independent pathway, while a distinct region (amino acids 201–225) mediates CRM1-independent nuclear export, returning the protein to the cytoplasm in G1 and S; nucleolar retention is gated by GTP binding via the G2 motif of the G-domain, and disrupting this gating abolishes both nucleolar localization and GNL1-driven G2/M transition [#0]. In the nucleolus GNL1 binds the ribosomal protein RPS20 and drives Rb hyperphosphorylation to promote proliferation, an effect lost when RPS20 is depleted or when an interaction-deficient GNL1 mutant is used [#1]. GNL1 additionally suppresses apoptosis by modulating Bcl2-family proteins and blocking caspase-7/8 cleavage, and stabilizes cytoplasmic p21 through AKT-mediated phosphorylation, with its pro-survival activity dependent on p21 [#2]. GNL1 also binds G-quadruplex structures in the 5′UTRs of PRKN and VPS35 transcripts, identifying it as a G-quadruplex RNA-binding protein [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Established how GNL1 traffics within the cell and that its localization is mechanistically tied to cell-cycle progression, defining it as a GTP-gated nucleolar shuttling GTPase that promotes G2/M transition.\",\n      \"evidence\": \"GFP-fusion microscopy with cell-cycle synchronization, alanine-scanning G-domain mutagenesis, heterokaryon shuttling, importin and CRM1 exclusion assays\",\n      \"pmids\": [\"22244851\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct GTPase enzymatic kinetics not measured\", \"The export receptor mediating CRM1-independent export is unidentified\", \"Nucleolar substrates/effectors downstream of G2/M promotion not defined in this study\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Connected GNL1's proliferative function to a physical partner and a downstream cell-cycle target, showing it acts through RPS20 to drive Rb hyperphosphorylation.\",\n      \"evidence\": \"Yeast two-hybrid screen, GST pull-down, reciprocal co-IP, RPS20 knockdown and interaction-deficient mutant in proliferation and Rb phosphorylation assays\",\n      \"pmids\": [\"30061673\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"The kinase mediating Rb hyperphosphorylation downstream of GNL1–RPS20 is unidentified\", \"Whether the interaction occurs in the nucleolus is not established\", \"Direct biochemical contact surface not mapped\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Defined GNL1 as an anti-apoptotic factor that promotes survival via Bcl2-family modulation and AKT-dependent cytoplasmic stabilization of p21.\",\n      \"evidence\": \"GNL1 overexpression/knockdown with caspase and Bcl2 immunoblots, subcellular fractionation, AKT inhibitor, p53 and p21 knockdown epistasis in cancer cells\",\n      \"pmids\": [\"33147101\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether GNL1 acts directly or indirectly on AKT/p21 is unresolved\", \"Mechanism of p53 upregulation not defined\", \"Single-lab functional study without orthogonal in vivo confirmation\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified an RNA-binding activity for GNL1, showing it recognizes G-quadruplex structures in disease-associated transcript 5′UTRs.\",\n      \"evidence\": \"Label-free G4 RNA affinity purification with wild-type versus mutant G4 bait from PRKN and VPS35 5′UTRs\",\n      \"pmids\": [\"33305682\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single pulldown-based identification without reciprocal validation or GNL1 mutagenesis\", \"Functional consequence of G4 binding on transcript translation/stability not tested\", \"Whether this activity links to its nucleolar GTPase role is unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How GNL1's GTPase cycle, RPS20-dependent proliferative signaling, anti-apoptotic p21/AKT axis, and G-quadruplex RNA binding integrate into a single coherent mechanism remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No unifying model linking nucleolar GTPase activity to RNA binding\", \"No structural data for GNL1 or its complexes\", \"Physiological GTPase substrate/regulators unidentified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005730\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"RPS20\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}