{"gene":"TNKS2","run_date":"2026-06-10T10:51:55","timeline":{"discoveries":[{"year":2001,"finding":"TNKS2 (TANK2) is a poly(ADP-ribose) polymerase that interacts with the telomere-binding protein TRF1 in yeast two-hybrid and in vitro assays, localizes predominantly to a perinuclear region, and causes rapid cell death by necrosis (loss of mitochondrial membrane potential, no PARP1 cleavage) when highly overexpressed; cell death is prevented by the PARP inhibitor 3-aminobenzamide.","method":"Yeast two-hybrid, in vitro binding, overexpression, subcellular localization, PARP inhibitor rescue","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal binding assays (yeast + in vitro), localization, and functional rescue with PARP inhibitor in a single foundational study","pmids":["11454873"],"is_preprint":false},{"year":2001,"finding":"TNKS2 (TNKL) encodes an ankyrin repeat-, sterile alpha-motif (SAM)-, and PARP catalytic domain-containing protein with 78% identity to tankyrase (TNKS1), mapping to chromosome 10, establishing a two-member tankyrase gene family.","method":"Serological cDNA library screening, sequence analysis, chromosomal mapping","journal":"Genes and immunity","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct cloning and sequencing with domain identification, single lab","pmids":["11294570"],"is_preprint":false},{"year":2016,"finding":"TNKS2 knockdown in triple-negative breast cancer cells phenocopies miR-490-3p overexpression (inhibiting proliferation and invasion), and overexpression of a miR-490-3p-resistant TNKS2 rescues these effects, placing TNKS2 downstream of miR-490-3p in the regulation of β-catenin signaling.","method":"siRNA knockdown, rescue with resistant TNKS2, 3′UTR luciferase reporter, β-catenin signaling assays, xenograft","journal":"Gene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — epistasis via rescue experiment, luciferase reporter, and in vivo validation in single lab","pmids":["27506313"],"is_preprint":false},{"year":2020,"finding":"TNKS2 (Golgi-associated) cooperates with ER-associated PARP-16 to poly-ADP-ribosylate VEGF in the secretory pathway: PARP-16 catalyzes priming mono-ADP-ribosylation of VEGF, which is a prerequisite for subsequent poly-ADP-ribosylation by TNKS-2, thereby reducing VEGF biological activity.","method":"Biochemical ADP-ribosylation assay, subcellular fractionation, interplay between PARP-16 and TNKS-2","journal":"Molecular and cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — in vitro biochemical assay demonstrating sequential modification, single lab, single method set","pmids":["32472322"],"is_preprint":false},{"year":2021,"finding":"Loss of PARP5B (TNKS2) in a carcinogen-induced squamous cell carcinoma model results in ATR activation, depletion of cancer stem cell fraction, absence of 53BP1+ double-strand break foci, ATM activation, and p53 induction; PARP5B-null tumor cells form a multiprotein complex (PML, pRPA, Rad50, Rad51, XRCC1, PCNA, Mcm2) indicating a shift to homologous recombination-mediated repair, establishing a required role for TNKS2 in nonhomologous end joining during tumorigenesis.","method":"PARP5B null mouse model, immunofluorescence for 53BP1/ATM, co-immunoprecipitation of repair complex, pharmacological inhibition (XAV939 + etoposide)","journal":"Molecular carcinogenesis","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo KO model with multiple mechanistic readouts (foci, complex formation, pathway shift), single lab","pmids":["34710250"],"is_preprint":false},{"year":2024,"finding":"TNKS2 binds the peroxisomal membrane protein PEX14 and, together with RNF146 (an E3 ligase activated by poly(ADP-ribose)), regulates peroxisome protein import efficiency via PARsylation of proteins at the peroxisome membrane; loss of peroxisomes increases TNKS2/RNF146-dependent degradation of AXIN1, thereby activating β-catenin transcription and linking peroxisome function to Wnt signaling.","method":"Genome-wide CRISPRi screen, genetic epistasis (TNKS/TNKS2 knockdown rescuing RNF146-loss phenotype), PEX14 binding, AXIN1 degradation assay, β-catenin reporter","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genome-wide unbiased screen followed by epistasis, binding partner identification, and functional pathway readout in a peer-reviewed study","pmids":["38967608"],"is_preprint":false},{"year":2023,"finding":"SASH1 physically binds TNKS2 through a bona fide tankyrase-binding motif (containing S519); the S519N disease variant alters SASH1-TNKS2 binding kinetics and affinity, and this interaction is required for SASH1's promotion of stem-like characteristics in human melanocytes.","method":"Co-immunoprecipitation, NMR binding kinetics, cell-based stem-cell assays, variant functional rescue","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple binding assays (Co-IP + NMR) plus functional consequence of binding disruption, single lab, preprint","pmids":["37808724"],"is_preprint":true},{"year":2025,"finding":"Selective inhibition of TNKS2 (in cells with chromosome 8p loss that depletes TNKS1) is sufficient to suppress WNT/β-catenin signaling, demonstrating that TNKS2 alone can sustain WNT pathway activity when TNKS1 is absent; a structure-guided first-in-class TNKS2-selective inhibitor achieves this tumor-selective WNT suppression.","method":"Structure-guided drug design, TNKS1-deficient cell and organoid models, WNT reporter assays, genetic dependency analysis","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 1-2 / Moderate — structure-guided design with functional validation in isogenic models, single lab, preprint","pmids":["40093088"],"is_preprint":true},{"year":2020,"finding":"X-ray crystal structure of the TNKS2 PARP catalytic domain in complex with inhibitor MC2050-derived bis-quinazolinone compounds identified a nicotinamide-binding pocket with structural differences from PARP1/2 that enable picomolar selectivity; the structure-based inhibitor suppresses WNT/β-catenin signaling in colorectal cancer cells.","method":"X-ray crystallography, structure-based drug design, antiproliferative cell assay, WNT pathway reporter","journal":"ACS medicinal chemistry letters","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — crystal structure with functional validation in cells, single lab, single study","pmids":["32435397"],"is_preprint":false},{"year":2024,"finding":"X-ray crystallography of TNKS2 catalytic domain with quinazolin-4-one derivatives revealed that nitro- and diol-substituents at C-8 engage a subsite between a mobile active-site loop and the canonical nicotinamide binding site of TNKS2, improving affinity (IC50 as low as 14 nM) and selectivity, and attenuating Wnt/β-catenin signaling in cells.","method":"X-ray crystallography, enzyme inhibition assays, WNT/β-catenin cell reporter assay","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — crystal structure plus biochemical IC50 and cell pathway assay, single lab, preprint","pmids":["bio_10.1101_2024.06.23.600314"],"is_preprint":true},{"year":2025,"finding":"A small molecule (ARCher-142/S8) was identified that binds selectively to the ARC4 peptide-binding domain of TNKS2 (8 µM potency), competing with substrate peptide and engaging a unique hydrophobic sub-pocket; binding was confirmed by NMR and X-ray crystallography, and the compound attenuates WNT/β-catenin signaling in cells despite not targeting the catalytic domain.","method":"FRET-based high-throughput screen, NMR, X-ray crystallography, WNT/β-catenin cell reporter assay","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — orthogonal structural methods (NMR + X-ray) plus functional cell assay, single lab, preprint","pmids":["bio_10.1101_2025.03.31.646301"],"is_preprint":true}],"current_model":"TNKS2 is a poly(ADP-ribose) polymerase (PARP family member, alias PARP-5b) that binds substrates through its ankyrin-repeat cluster (ARC) domains and modifies them via PARsylation: it interacts with TRF1 at telomeres, PEX14 at the peroxisomal membrane, and scaffold proteins such as AXIN1 to regulate β-catenin/WNT signaling; it co-operates with PARP-16 to poly-ADP-ribosylate VEGF in the secretory pathway; it is required for nonhomologous end joining at DNA double-strand breaks in vivo; and it is functionally redundant with TNKS1 in sustaining WNT pathway activity, making it a selective therapeutic target in TNKS1-deficient tumors."},"narrative":{"mechanistic_narrative":"TNKS2 (tankyrase-2, PARP-5b) is a poly(ADP-ribose) polymerase of the tankyrase subfamily that recognizes substrates through ankyrin-repeat clusters (ARCs) and modifies them by PARsylation to control WNT/β-catenin signaling, telomere protein interactions, peroxisome biology, and DNA repair [PMID:11294570, PMID:38967608]. It was first defined as a perinuclear PARP that binds the telomere protein TRF1, with enzymatic activity required for its overexpression-induced necrotic cell death [PMID:11454873]. A dominant cellular output is regulation of β-catenin: TNKS2 (with the PARsylation-dependent E3 ligase RNF146) drives degradation of the destruction-complex scaffold AXIN1, and this axis couples peroxisome status to WNT activity via the peroxisomal membrane partner PEX14 [PMID:38967608]. TNKS2 also engages substrate-recruitment partners through tankyrase-binding motifs, including SASH1 (via a motif containing S519), an interaction that supports stem-like properties in melanocytes [PMID:37808724], and it cooperates with PARP-16 to PARsylate VEGF in the secretory pathway, dampening VEGF activity [PMID:32472322]. In a carcinogen-induced squamous carcinoma model, loss of TNKS2 abolishes 53BP1+ double-strand-break foci and shifts repair toward homologous recombination, establishing a required role in nonhomologous end joining during tumorigenesis [PMID:34710250]. TNKS2 is functionally redundant with TNKS1 in sustaining WNT signaling, so selective TNKS2 inhibition suppresses WNT/β-catenin activity in tumors that have lost TNKS1, and structural studies of both the catalytic domain and the ARC4 peptide-binding site have enabled selective inhibitors that block this pathway [PMID:40093088, PMID:32435397, PMID:bio_10.1101_2025.03.31.646301].","teleology":[{"year":2001,"claim":"Established TNKS2 as a distinct PARP-family enzyme: it was cloned as a paralog of tankyrase with ankyrin-repeat, SAM, and PARP catalytic domains, and was shown to physically bind the telomere protein TRF1, defining a two-member tankyrase family with telomeric associations.","evidence":"Serological cDNA cloning, sequence/domain analysis, and chromosomal mapping; yeast two-hybrid and in vitro TRF1 binding with localization and PARP-inhibitor rescue of overexpression toxicity","pmids":["11294570","11454873"],"confidence":"Medium","gaps":["Endogenous telomeric function not demonstrated","Physiological substrates beyond TRF1 binding not identified","Necrotic phenotype derives from overexpression, not loss of function"]},{"year":2016,"claim":"Placed TNKS2 in a regulatory hierarchy controlling β-catenin signaling in cancer, showing it acts downstream of miR-490-3p to promote proliferation and invasion.","evidence":"siRNA knockdown with miR-resistant TNKS2 rescue, 3′UTR luciferase reporter, β-catenin assays, and xenografts in triple-negative breast cancer cells","pmids":["27506313"],"confidence":"Medium","gaps":["Direct enzymatic substrate in this context not defined","Redundancy with TNKS1 not addressed","Single tumor-type model"]},{"year":2020,"claim":"Defined a sequential ADP-ribosylation mechanism in the secretory pathway and the structural basis for selective catalytic inhibition.","evidence":"Biochemical ADP-ribosylation assays showing PARP-16 priming of VEGF for TNKS2 poly-ADP-ribosylation; X-ray crystallography of the TNKS2 catalytic domain with bis-quinazolinone inhibitors plus WNT reporter assays","pmids":["32472322","32435397"],"confidence":"Medium","gaps":["In vivo relevance of VEGF PARsylation not shown","PARP-16/TNKS2 cooperation tested in single lab/method set","Inhibitor selectivity not validated against full PARP panel in vivo"]},{"year":2021,"claim":"Demonstrated a required role for TNKS2 in nonhomologous end joining during tumorigenesis, with its loss driving a switch toward homologous recombination repair.","evidence":"PARP5B-null carcinogen-induced squamous carcinoma mouse model, 53BP1/ATM immunofluorescence, co-IP of an HR repair complex, and XAV939+etoposide treatment","pmids":["34710250"],"confidence":"Medium","gaps":["Direct DSB substrate of TNKS2 PARsylation not identified","Mechanism linking TNKS2 to 53BP1 foci formation unresolved","Single model system"]},{"year":2024,"claim":"Connected TNKS2 PARsylation to peroxisome biology and AXIN1-mediated WNT control, and identified SASH1 as a tankyrase-motif partner relevant to stem-like phenotypes.","evidence":"Genome-wide CRISPRi screen with epistasis, PEX14 binding and AXIN1 degradation assays, β-catenin reporters; Co-IP and NMR binding kinetics of SASH1 S519 motif with functional melanocyte assays (preprint)","pmids":["38967608","37808724"],"confidence":"Medium","gaps":["Direct peroxisomal PARsylation substrates not enumerated","SASH1 interaction from single lab and preprint","Relative TNKS1 vs TNKS2 contribution at peroxisomes not partitioned"]},{"year":2025,"claim":"Validated TNKS2 as a tumor-selective WNT target and expanded druggable sites beyond the catalytic pocket to the ARC4 substrate-binding domain.","evidence":"Structure-guided TNKS2-selective catalytic inhibitor tested in TNKS1-deficient (chr8p-loss) cell/organoid models; ARC4-targeting compound ARCher-142/S8 confirmed by FRET screen, NMR, and X-ray, with WNT reporter readouts (preprints)","pmids":["40093088","bio_10.1101_2025.03.31.646301"],"confidence":"Medium","gaps":["In vivo efficacy and on-target selectivity not established in the corpus","Preprint status","Whether ARC4 inhibition phenocopies catalytic inhibition broadly unresolved"]},{"year":null,"claim":"The full set of physiological TNKS2 PARsylation substrates and the determinants of TNKS1/TNKS2 functional division of labor across telomeres, peroxisomes, DNA repair, and WNT signaling remain undefined.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No comprehensive substrate map","Endogenous telomeric role not resolved in the corpus","Tissue-specific non-redundant TNKS2 functions unclear"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[3,5]},{"term_id":"GO:0016740","term_label":"transferase activity","supporting_discovery_ids":[0,3]},{"term_id":"GO:0016787","term_label":"hydrolase activity","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[3]},{"term_id":"GO:0005777","term_label":"peroxisome","supporting_discovery_ids":[5]}],"pathway":[{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5,7]},{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[4]}],"complexes":[],"partners":["TRF1","PEX14","RNF146","AXIN1","SASH1","PARP16","TNKS"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9H2K2","full_name":"Poly [ADP-ribose] polymerase tankyrase-2","aliases":["ADP-ribosyltransferase diphtheria toxin-like 6","ARTD6","Poly [ADP-ribose] polymerase 5B","Protein poly-ADP-ribosyltransferase tankyrase-2","TNKS-2","TRF1-interacting ankyrin-related ADP-ribose polymerase 2","Tankyrase II","Tankyrase-2","TANK2","Tankyrase-like protein","Tankyrase-related protein"],"length_aa":1166,"mass_kda":126.9,"function":"Poly-ADP-ribosyltransferase involved in various processes such as Wnt signaling pathway, telomere length and vesicle trafficking (PubMed:11739745, PubMed:11802774, PubMed:19759537, PubMed:21478859, PubMed:23622245, PubMed:25043379). Acts as an activator of the Wnt signaling pathway by mediating poly-ADP-ribosylation of AXIN1 and AXIN2, 2 key components of the beta-catenin destruction complex: poly-ADP-ribosylated target proteins are recognized by RNF146, which mediates their ubiquitination and subsequent degradation (PubMed:19759537, PubMed:21478859). Also mediates poly-ADP-ribosylation of BLZF1 and CASC3, followed by recruitment of RNF146 and subsequent ubiquitination (PubMed:21478859). Mediates poly-ADP-ribosylation of TERF1, thereby contributing to the regulation of telomere length (PubMed:11739745). Stimulates 26S proteasome activity (PubMed:23622245)","subcellular_location":"Cytoplasm; Golgi apparatus membrane; Nucleus; Chromosome, telomere","url":"https://www.uniprot.org/uniprotkb/Q9H2K2/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TNKS2","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/TNKS2","total_profiled":1310},"omim":[{"mim_id":"620871","title":"DNA DAMAGE-INDUCIBLE 1 HOMOLOG 2; DDI2","url":"https://www.omim.org/entry/620871"},{"mim_id":"620652","title":"SH3 DOMAIN-BINDING PROTEIN 5-LIKE; SH3BP5L","url":"https://www.omim.org/entry/620652"},{"mim_id":"607128","title":"TANKYRASE 2; TNKS2","url":"https://www.omim.org/entry/607128"},{"mim_id":"605612","title":"SH3 DOMAIN-BINDING PROTEIN 5; SH3BP5","url":"https://www.omim.org/entry/605612"},{"mim_id":"300410","title":"ANGIOMOTIN; AMOT","url":"https://www.omim.org/entry/300410"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Microtubules","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/TNKS2"},"hgnc":{"alias_symbol":["TNKL","TANK2","PARP-5b","PARP-5c","PARP5B","PARP5C","pART6","ARTD6"],"prev_symbol":[]},"alphafold":{"accession":"Q9H2K2","domains":[{"cath_id":"1.25.40.20","chopping":"22-172","consensus_level":"high","plddt":93.2993,"start":22,"end":172},{"cath_id":"1.25.40.20","chopping":"177-318","consensus_level":"high","plddt":96.8878,"start":177,"end":318},{"cath_id":"1.25.40.20","chopping":"336-482","consensus_level":"medium","plddt":92.8896,"start":336,"end":482},{"cath_id":"1.10.150.50","chopping":"877-934","consensus_level":"high","plddt":80.1997,"start":877,"end":934},{"cath_id":"3.90.228.10","chopping":"955-1156","consensus_level":"medium","plddt":68.8884,"start":955,"end":1156}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H2K2","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H2K2-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H2K2-F1-predicted_aligned_error_v6.png","plddt_mean":83.81},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=TNKS2","jax_strain_url":"https://www.jax.org/strain/search?query=TNKS2"},"sequence":{"accession":"Q9H2K2","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H2K2.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H2K2/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H2K2"}},"corpus_meta":[{"pmid":"11454873","id":"PMC_11454873","title":"TANK2, a new TRF1-associated poly(ADP-ribose) polymerase, causes rapid induction of cell death upon overexpression.","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11454873","citation_count":191,"is_preprint":false},{"pmid":"22449978","id":"PMC_22449978","title":"miR-20a promotes migration and invasion by regulating TNKS2 in human cervical cancer cells.","date":"2012","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/22449978","citation_count":99,"is_preprint":false},{"pmid":"27506313","id":"PMC_27506313","title":"miR-490-3p inhibits the growth and invasiveness in triple-negative breast cancer by repressing the expression of TNKS2.","date":"2016","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/27506313","citation_count":43,"is_preprint":false},{"pmid":"11294570","id":"PMC_11294570","title":"Cloning and characterization of TNKL, a member of tankyrase gene family.","date":"2001","source":"Genes and immunity","url":"https://pubmed.ncbi.nlm.nih.gov/11294570","citation_count":34,"is_preprint":false},{"pmid":"34861798","id":"PMC_34861798","title":"Down-regulation of hsa_circ_0045474 induces macrophage autophagy in tuberculosis via miR-582-5p/TNKS2 axis.","date":"2021","source":"Innate immunity","url":"https://pubmed.ncbi.nlm.nih.gov/34861798","citation_count":22,"is_preprint":false},{"pmid":"24291818","id":"PMC_24291818","title":"Molecular insights on TNKS1/TNKS2 and inhibitor-IWR1 interactions.","date":"2014","source":"Molecular bioSystems","url":"https://pubmed.ncbi.nlm.nih.gov/24291818","citation_count":16,"is_preprint":false},{"pmid":"36185280","id":"PMC_36185280","title":"Icariin attenuates the tumor growth by targeting miR-1-3p/TNKS2/Wnt/β-catenin signaling axis in ovarian cancer.","date":"2022","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/36185280","citation_count":15,"is_preprint":false},{"pmid":"32435397","id":"PMC_32435397","title":"From PARP1 to TNKS2 Inhibition: A Structure-Based Approach.","date":"2020","source":"ACS medicinal chemistry letters","url":"https://pubmed.ncbi.nlm.nih.gov/32435397","citation_count":13,"is_preprint":false},{"pmid":"32576588","id":"PMC_32576588","title":"Association of Relative Leucocyte Telomere Length and Gene Single Nucleotide Polymorphisms (TERT, TRF1, TNKS2) in Laryngeal Squamous Cell Carcinoma.","date":"2020","source":"Cancer genomics & proteomics","url":"https://pubmed.ncbi.nlm.nih.gov/32576588","citation_count":10,"is_preprint":false},{"pmid":"33565341","id":"PMC_33565341","title":"Association of relative leukocyte telomere length and genetic variants in telomere-related genes (TERT, TERT-CLPTM1, TRF1, TNKS2, TRF2) with atrophic age-related macular degeneration.","date":"2021","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33565341","citation_count":10,"is_preprint":false},{"pmid":"33849554","id":"PMC_33849554","title":"MicroRNA-490-3p inhibits migration and chemoresistance of colorectal cancer cells via targeting TNKS2.","date":"2021","source":"World journal of surgical oncology","url":"https://pubmed.ncbi.nlm.nih.gov/33849554","citation_count":9,"is_preprint":false},{"pmid":"34357507","id":"PMC_34357507","title":"miR-582-5p inhibits migration and chemo-resistant capabilities of colorectal cancer cells by targeting TNKS2.","date":"2021","source":"Genes & genomics","url":"https://pubmed.ncbi.nlm.nih.gov/34357507","citation_count":8,"is_preprint":false},{"pmid":"26293798","id":"PMC_26293798","title":"Tankyrase 2 (TNKS2) polymorphism associated with risk in developing non-small cell lung cancer in a Chinese population.","date":"2015","source":"Pathology, research and practice","url":"https://pubmed.ncbi.nlm.nih.gov/26293798","citation_count":6,"is_preprint":false},{"pmid":"38967608","id":"PMC_38967608","title":"A genome-wide screen links peroxisome regulation with Wnt signaling through RNF146 and TNKS/2.","date":"2024","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/38967608","citation_count":5,"is_preprint":false},{"pmid":"37581526","id":"PMC_37581526","title":"Therapeutic Path to Triple Knockout: Investigating the Pan-inhibitory Mechanisms of AKT, CDK9, and TNKS2 by a Novel 2-phenylquinazolinone Derivative in Cancer Therapy- An In-silico Investigation Therapy.","date":"2024","source":"Current pharmaceutical biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/37581526","citation_count":4,"is_preprint":false},{"pmid":"34710250","id":"PMC_34710250","title":"PARP5B is required for nonhomologous end joining during tumorigenesis in vivo.","date":"2021","source":"Molecular carcinogenesis","url":"https://pubmed.ncbi.nlm.nih.gov/34710250","citation_count":3,"is_preprint":false},{"pmid":"32472322","id":"PMC_32472322","title":"Regulation of poly ADP-ribosylation of VEGF by an interplay between PARP-16 and TNKS-2.","date":"2020","source":"Molecular and cellular biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/32472322","citation_count":3,"is_preprint":false},{"pmid":"37808724","id":"PMC_37808724","title":"SASH1 interacts with TNKS2 and promotes human melanocyte stem cell maintenance.","date":"2023","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/37808724","citation_count":2,"is_preprint":false},{"pmid":"40093088","id":"PMC_40093088","title":"A potent and selective TNKS2 inhibitor for tumor-selective WNT suppression.","date":"2025","source":"bioRxiv : the preprint server for biology","url":"https://pubmed.ncbi.nlm.nih.gov/40093088","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.06.23.600314","title":"Substitutions at the C-8 position of quinazolin-4-ones improve the potency of nicotinamide site binding tankyrase inhibitors","date":"2024-06-24","source":"bioRxiv","url":"https://doi.org/10.1101/2024.06.23.600314","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.31.646301","title":"Discovery of Tankyrase scaffolding inhibitor specifically targeting the ARC4 peptide binding domain","date":"2025-03-31","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.31.646301","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":12511,"output_tokens":2964,"usd":0.040996,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":10232,"output_tokens":2990,"usd":0.062955,"stage2_stop_reason":"end_turn"},"total_usd":0.103951,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2001,\n      \"finding\": \"TNKS2 (TANK2) is a poly(ADP-ribose) polymerase that interacts with the telomere-binding protein TRF1 in yeast two-hybrid and in vitro assays, localizes predominantly to a perinuclear region, and causes rapid cell death by necrosis (loss of mitochondrial membrane potential, no PARP1 cleavage) when highly overexpressed; cell death is prevented by the PARP inhibitor 3-aminobenzamide.\",\n      \"method\": \"Yeast two-hybrid, in vitro binding, overexpression, subcellular localization, PARP inhibitor rescue\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal binding assays (yeast + in vitro), localization, and functional rescue with PARP inhibitor in a single foundational study\",\n      \"pmids\": [\"11454873\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"TNKS2 (TNKL) encodes an ankyrin repeat-, sterile alpha-motif (SAM)-, and PARP catalytic domain-containing protein with 78% identity to tankyrase (TNKS1), mapping to chromosome 10, establishing a two-member tankyrase gene family.\",\n      \"method\": \"Serological cDNA library screening, sequence analysis, chromosomal mapping\",\n      \"journal\": \"Genes and immunity\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct cloning and sequencing with domain identification, single lab\",\n      \"pmids\": [\"11294570\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"TNKS2 knockdown in triple-negative breast cancer cells phenocopies miR-490-3p overexpression (inhibiting proliferation and invasion), and overexpression of a miR-490-3p-resistant TNKS2 rescues these effects, placing TNKS2 downstream of miR-490-3p in the regulation of β-catenin signaling.\",\n      \"method\": \"siRNA knockdown, rescue with resistant TNKS2, 3′UTR luciferase reporter, β-catenin signaling assays, xenograft\",\n      \"journal\": \"Gene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — epistasis via rescue experiment, luciferase reporter, and in vivo validation in single lab\",\n      \"pmids\": [\"27506313\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TNKS2 (Golgi-associated) cooperates with ER-associated PARP-16 to poly-ADP-ribosylate VEGF in the secretory pathway: PARP-16 catalyzes priming mono-ADP-ribosylation of VEGF, which is a prerequisite for subsequent poly-ADP-ribosylation by TNKS-2, thereby reducing VEGF biological activity.\",\n      \"method\": \"Biochemical ADP-ribosylation assay, subcellular fractionation, interplay between PARP-16 and TNKS-2\",\n      \"journal\": \"Molecular and cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — in vitro biochemical assay demonstrating sequential modification, single lab, single method set\",\n      \"pmids\": [\"32472322\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Loss of PARP5B (TNKS2) in a carcinogen-induced squamous cell carcinoma model results in ATR activation, depletion of cancer stem cell fraction, absence of 53BP1+ double-strand break foci, ATM activation, and p53 induction; PARP5B-null tumor cells form a multiprotein complex (PML, pRPA, Rad50, Rad51, XRCC1, PCNA, Mcm2) indicating a shift to homologous recombination-mediated repair, establishing a required role for TNKS2 in nonhomologous end joining during tumorigenesis.\",\n      \"method\": \"PARP5B null mouse model, immunofluorescence for 53BP1/ATM, co-immunoprecipitation of repair complex, pharmacological inhibition (XAV939 + etoposide)\",\n      \"journal\": \"Molecular carcinogenesis\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo KO model with multiple mechanistic readouts (foci, complex formation, pathway shift), single lab\",\n      \"pmids\": [\"34710250\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"TNKS2 binds the peroxisomal membrane protein PEX14 and, together with RNF146 (an E3 ligase activated by poly(ADP-ribose)), regulates peroxisome protein import efficiency via PARsylation of proteins at the peroxisome membrane; loss of peroxisomes increases TNKS2/RNF146-dependent degradation of AXIN1, thereby activating β-catenin transcription and linking peroxisome function to Wnt signaling.\",\n      \"method\": \"Genome-wide CRISPRi screen, genetic epistasis (TNKS/TNKS2 knockdown rescuing RNF146-loss phenotype), PEX14 binding, AXIN1 degradation assay, β-catenin reporter\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genome-wide unbiased screen followed by epistasis, binding partner identification, and functional pathway readout in a peer-reviewed study\",\n      \"pmids\": [\"38967608\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"SASH1 physically binds TNKS2 through a bona fide tankyrase-binding motif (containing S519); the S519N disease variant alters SASH1-TNKS2 binding kinetics and affinity, and this interaction is required for SASH1's promotion of stem-like characteristics in human melanocytes.\",\n      \"method\": \"Co-immunoprecipitation, NMR binding kinetics, cell-based stem-cell assays, variant functional rescue\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple binding assays (Co-IP + NMR) plus functional consequence of binding disruption, single lab, preprint\",\n      \"pmids\": [\"37808724\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Selective inhibition of TNKS2 (in cells with chromosome 8p loss that depletes TNKS1) is sufficient to suppress WNT/β-catenin signaling, demonstrating that TNKS2 alone can sustain WNT pathway activity when TNKS1 is absent; a structure-guided first-in-class TNKS2-selective inhibitor achieves this tumor-selective WNT suppression.\",\n      \"method\": \"Structure-guided drug design, TNKS1-deficient cell and organoid models, WNT reporter assays, genetic dependency analysis\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — structure-guided design with functional validation in isogenic models, single lab, preprint\",\n      \"pmids\": [\"40093088\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"X-ray crystal structure of the TNKS2 PARP catalytic domain in complex with inhibitor MC2050-derived bis-quinazolinone compounds identified a nicotinamide-binding pocket with structural differences from PARP1/2 that enable picomolar selectivity; the structure-based inhibitor suppresses WNT/β-catenin signaling in colorectal cancer cells.\",\n      \"method\": \"X-ray crystallography, structure-based drug design, antiproliferative cell assay, WNT pathway reporter\",\n      \"journal\": \"ACS medicinal chemistry letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — crystal structure with functional validation in cells, single lab, single study\",\n      \"pmids\": [\"32435397\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"X-ray crystallography of TNKS2 catalytic domain with quinazolin-4-one derivatives revealed that nitro- and diol-substituents at C-8 engage a subsite between a mobile active-site loop and the canonical nicotinamide binding site of TNKS2, improving affinity (IC50 as low as 14 nM) and selectivity, and attenuating Wnt/β-catenin signaling in cells.\",\n      \"method\": \"X-ray crystallography, enzyme inhibition assays, WNT/β-catenin cell reporter assay\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — crystal structure plus biochemical IC50 and cell pathway assay, single lab, preprint\",\n      \"pmids\": [\"bio_10.1101_2024.06.23.600314\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"A small molecule (ARCher-142/S8) was identified that binds selectively to the ARC4 peptide-binding domain of TNKS2 (8 µM potency), competing with substrate peptide and engaging a unique hydrophobic sub-pocket; binding was confirmed by NMR and X-ray crystallography, and the compound attenuates WNT/β-catenin signaling in cells despite not targeting the catalytic domain.\",\n      \"method\": \"FRET-based high-throughput screen, NMR, X-ray crystallography, WNT/β-catenin cell reporter assay\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — orthogonal structural methods (NMR + X-ray) plus functional cell assay, single lab, preprint\",\n      \"pmids\": [\"bio_10.1101_2025.03.31.646301\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"TNKS2 is a poly(ADP-ribose) polymerase (PARP family member, alias PARP-5b) that binds substrates through its ankyrin-repeat cluster (ARC) domains and modifies them via PARsylation: it interacts with TRF1 at telomeres, PEX14 at the peroxisomal membrane, and scaffold proteins such as AXIN1 to regulate β-catenin/WNT signaling; it co-operates with PARP-16 to poly-ADP-ribosylate VEGF in the secretory pathway; it is required for nonhomologous end joining at DNA double-strand breaks in vivo; and it is functionally redundant with TNKS1 in sustaining WNT pathway activity, making it a selective therapeutic target in TNKS1-deficient tumors.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TNKS2 (tankyrase-2, PARP-5b) is a poly(ADP-ribose) polymerase of the tankyrase subfamily that recognizes substrates through ankyrin-repeat clusters (ARCs) and modifies them by PARsylation to control WNT/\\u03b2-catenin signaling, telomere protein interactions, peroxisome biology, and DNA repair [#1, #5]. It was first defined as a perinuclear PARP that binds the telomere protein TRF1, with enzymatic activity required for its overexpression-induced necrotic cell death [#0]. A dominant cellular output is regulation of \\u03b2-catenin: TNKS2 (with the PARsylation-dependent E3 ligase RNF146) drives degradation of the destruction-complex scaffold AXIN1, and this axis couples peroxisome status to WNT activity via the peroxisomal membrane partner PEX14 [#5]. TNKS2 also engages substrate-recruitment partners through tankyrase-binding motifs, including SASH1 (via a motif containing S519), an interaction that supports stem-like properties in melanocytes [#6], and it cooperates with PARP-16 to PARsylate VEGF in the secretory pathway, dampening VEGF activity [#3]. In a carcinogen-induced squamous carcinoma model, loss of TNKS2 abolishes 53BP1+ double-strand-break foci and shifts repair toward homologous recombination, establishing a required role in nonhomologous end joining during tumorigenesis [#4]. TNKS2 is functionally redundant with TNKS1 in sustaining WNT signaling, so selective TNKS2 inhibition suppresses WNT/\\u03b2-catenin activity in tumors that have lost TNKS1, and structural studies of both the catalytic domain and the ARC4 peptide-binding site have enabled selective inhibitors that block this pathway [#7, #8, #10].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Established TNKS2 as a distinct PARP-family enzyme: it was cloned as a paralog of tankyrase with ankyrin-repeat, SAM, and PARP catalytic domains, and was shown to physically bind the telomere protein TRF1, defining a two-member tankyrase family with telomeric associations.\",\n      \"evidence\": \"Serological cDNA cloning, sequence/domain analysis, and chromosomal mapping; yeast two-hybrid and in vitro TRF1 binding with localization and PARP-inhibitor rescue of overexpression toxicity\",\n      \"pmids\": [\"11294570\", \"11454873\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Endogenous telomeric function not demonstrated\", \"Physiological substrates beyond TRF1 binding not identified\", \"Necrotic phenotype derives from overexpression, not loss of function\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Placed TNKS2 in a regulatory hierarchy controlling \\u03b2-catenin signaling in cancer, showing it acts downstream of miR-490-3p to promote proliferation and invasion.\",\n      \"evidence\": \"siRNA knockdown with miR-resistant TNKS2 rescue, 3\\u2032UTR luciferase reporter, \\u03b2-catenin assays, and xenografts in triple-negative breast cancer cells\",\n      \"pmids\": [\"27506313\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct enzymatic substrate in this context not defined\", \"Redundancy with TNKS1 not addressed\", \"Single tumor-type model\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Defined a sequential ADP-ribosylation mechanism in the secretory pathway and the structural basis for selective catalytic inhibition.\",\n      \"evidence\": \"Biochemical ADP-ribosylation assays showing PARP-16 priming of VEGF for TNKS2 poly-ADP-ribosylation; X-ray crystallography of the TNKS2 catalytic domain with bis-quinazolinone inhibitors plus WNT reporter assays\",\n      \"pmids\": [\"32472322\", \"32435397\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo relevance of VEGF PARsylation not shown\", \"PARP-16/TNKS2 cooperation tested in single lab/method set\", \"Inhibitor selectivity not validated against full PARP panel in vivo\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Demonstrated a required role for TNKS2 in nonhomologous end joining during tumorigenesis, with its loss driving a switch toward homologous recombination repair.\",\n      \"evidence\": \"PARP5B-null carcinogen-induced squamous carcinoma mouse model, 53BP1/ATM immunofluorescence, co-IP of an HR repair complex, and XAV939+etoposide treatment\",\n      \"pmids\": [\"34710250\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct DSB substrate of TNKS2 PARsylation not identified\", \"Mechanism linking TNKS2 to 53BP1 foci formation unresolved\", \"Single model system\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Connected TNKS2 PARsylation to peroxisome biology and AXIN1-mediated WNT control, and identified SASH1 as a tankyrase-motif partner relevant to stem-like phenotypes.\",\n      \"evidence\": \"Genome-wide CRISPRi screen with epistasis, PEX14 binding and AXIN1 degradation assays, \\u03b2-catenin reporters; Co-IP and NMR binding kinetics of SASH1 S519 motif with functional melanocyte assays (preprint)\",\n      \"pmids\": [\"38967608\", \"37808724\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct peroxisomal PARsylation substrates not enumerated\", \"SASH1 interaction from single lab and preprint\", \"Relative TNKS1 vs TNKS2 contribution at peroxisomes not partitioned\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Validated TNKS2 as a tumor-selective WNT target and expanded druggable sites beyond the catalytic pocket to the ARC4 substrate-binding domain.\",\n      \"evidence\": \"Structure-guided TNKS2-selective catalytic inhibitor tested in TNKS1-deficient (chr8p-loss) cell/organoid models; ARC4-targeting compound ARCher-142/S8 confirmed by FRET screen, NMR, and X-ray, with WNT reporter readouts (preprints)\",\n      \"pmids\": [\"40093088\", \"bio_10.1101_2025.03.31.646301\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"In vivo efficacy and on-target selectivity not established in the corpus\", \"Preprint status\", \"Whether ARC4 inhibition phenocopies catalytic inhibition broadly unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The full set of physiological TNKS2 PARsylation substrates and the determinants of TNKS1/TNKS2 functional division of labor across telomeres, peroxisomes, DNA repair, and WNT signaling remain undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No comprehensive substrate map\", \"Endogenous telomeric role not resolved in the corpus\", \"Tissue-specific non-redundant TNKS2 functions unclear\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [3, 5]},\n      {\"term_id\": \"GO:0016740\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0016787\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"GO:0005777\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5, 7]},\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"TRF1\", \"PEX14\", \"RNF146\", \"AXIN1\", \"SASH1\", \"PARP16\", \"TNKS\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}