{"gene":"WRAP73","run_date":"2026-06-11T09:02:06","timeline":{"discoveries":[{"year":2015,"finding":"Fission yeast Wdr8 forms a ternary complex with Msd1 and the minus end-directed kinesin-14 Pkl1 at spindle pole bodies (SPBs). Msd1 and Wdr8 are delivered to mitotic SPBs by Pkl1, where Pkl1 is tethered through Msd1-Wdr8. The spindle-anchoring defect imposed by msd1/wdr8/pkl1 deletions is suppressed by a mutation in plus end-directed Cut7/kinesin-5, indicating that the Msd1-Wdr8-Pkl1 complex balances Cut7-mediated outward force at the SPB to ensure spindle bipolarity. Pkl1 motor activity was not required for its anchoring role once targeted to the SPB.","method":"Genetic deletion analysis, genetic epistasis (double mutant suppression), live fluorescence microscopy, co-immunoprecipitation","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal genetic epistasis, multiple deletion mutants, live imaging, multiple orthogonal methods across multiple labs","pmids":["25987607"],"is_preprint":false},{"year":2015,"finding":"Human WDR8 (WRAP73) localizes to centriolar satellites and to the proximal end of the mother centriole. WDR8 interacts with the satellite proteins SSX2IP and PCM1, and with the centriolar proximal end component Cep135. Cep135 is required for WDR8 recruitment to centrioles. WDR8 and Cep135 are both indispensable for ciliary vesicle docking to the mother centriole and for displacement of the ciliary inhibitory complex CP110-Cep97, establishing a role for WDR8 in the initial steps of ciliogenesis.","method":"Co-immunoprecipitation, RNAi depletion with ciliogenesis phenotypic readout, immunofluorescence localization, super-resolution microscopy","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, RNAi depletion with specific phenotypic readouts, super-resolution localization, multiple orthogonal methods in single study","pmids":["26675238"],"is_preprint":false},{"year":2013,"finding":"In Aspergillus nidulans, An-WDR8 (ortholog of WRAP73/WDR8) co-purifies with TINA (a NIMA-interacting protein) and is required for TINA stability and mitotic targeting; reciprocally, TINA is required for mitotic SPB targeting of An-WDR8. Together, TINA and An-WDR8 are required for anchoring mitotic microtubules to SPBs and for successful mitosis.","method":"Affinity purification, 4D spinning disk confocal microscopy, deletion mutant analysis, GFP-tagging localization studies","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — affinity purification plus deletion phenotyping and live imaging, single lab, fungal ortholog","pmids":["24152731"],"is_preprint":false},{"year":2015,"finding":"Human Wdr8 constitutively localizes to the centrosome, enriched at the proximal end of the mother centriole. Wdr8 forms a complex with hMsd1/SSX2IP identified by mass spectrometry. Knockdown of Wdr8 results in shortened and misoriented spindle microtubules, and reduces recruitment of hMsd1/SSX2IP to the mitotic centrosome (but depletion of hMsd1/SSX2IP does not affect Wdr8 centrosomal localization), indicating that Wdr8 acts upstream of hMsd1/SSX2IP in a conserved complex controlling spindle length and orientation.","method":"Mass spectrometry (interactor identification), RNAi knockdown, super-resolution microscopy, immunofluorescence, co-immunoprecipitation","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mass spectrometry identification, RNAi phenotyping, super-resolution localization, single lab","pmids":["26545777"],"is_preprint":false},{"year":2017,"finding":"Wdr8 is a maternally essential protein required for centrosome assembly during embryonic mitoses in medaka fish. CRISPR-Cas9 knockout of maternal/zygotic Wdr8 causes defects in centrosome structure leading to asymmetric division, multipolar spindles, and chromosome alignment errors. Via its WD40 domains, Wdr8 interacts with the centriolar satellite protein SSX2IP. In vivo reconstitution of the Wdr8-SSX2IP complex reveals an essential link between maternal centrosome proteins and zygotic genome stability.","method":"CRISPR-Cas9 knockout, in vivo reconstitution, co-immunoprecipitation, live fluorescence microscopy","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — CRISPR knockout with defined phenotypic rescue, Co-IP, in vivo reconstitution, multiple orthogonal methods in single study","pmids":["28098238"],"is_preprint":false},{"year":2021,"finding":"A homozygous missense mutation in WDR8 (p.Pro383Leu) causes isolated Microspherophakia in humans. In vitro experiments showed the mutation renders the protein unstable. Co-immunoprecipitation from HeLa cells indicated the mutation interferes with WDR8 interaction with its binding partners. In zebrafish, morpholino knockdown and CRISPR/Cas9 knockout of wdr8 resulted in decreased eye and lens size and defective cell cycle progression in retinal cells; these defects were rescued by wild-type human WDR8 but not by the p.Pro383Leu mutant.","method":"Homozygosity mapping, whole-exome sequencing, in vitro protein stability assay, co-immunoprecipitation, morpholino knockdown, CRISPR/Cas9 knockout, rescue experiments in zebrafish","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — CRISPR knockout with phenotypic rescue, Co-IP, in vitro stability assay, multiple orthogonal methods in single study","pmids":["33693649"],"is_preprint":false},{"year":2022,"finding":"In human somatic cells, SSX2IP, WDR8, and CEP135 form a complex that is assembled before centrosome assembly in vertebrate oocytes and functionally interacts in somatic cells. Stable knockout of WDR8 in human cells is compensated for during mitosis; WDR8 loss does not cause severe mitotic phenotypes in established somatic cell lines, unlike CEP135 knockout which compromises PCM recruitment and causes premature centrosome splitting.","method":"Stable CRISPR knockout in human cell lines, immunofluorescence, centrosome phenotype analysis","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — stable knockout with quantitative phenotype analysis, single lab, two orthogonal methods","pmids":["35406752"],"is_preprint":false},{"year":2001,"finding":"WDR8 encodes a novel WD-repeat protein of 460 amino acids (human) that is expressed in almost all tissues including bone and cartilage. It represents a novel subfamily of WD-repeat proteins distinctly different from other family members. Wdr8 expression in cartilage is regulated during the transition from hypertrophic to mineralizing stages in a chondrogenic cell line (ATDC5), suggesting a role in ossification.","method":"Differential display cloning, Northern blot, expression profiling in cell lines","journal":"Genomics","confidence":"Low","confidence_rationale":"Tier 4 / Weak — identification and expression profiling only, no functional mechanistic experiments","pmids":["11401440"],"is_preprint":false}],"current_model":"WDR8/WRAP73 is a conserved WD40-repeat protein that localizes constitutively to the proximal end of the mother centriole and to centriolar satellites, where it forms a complex with SSX2IP/hMsd1 and CEP135; this complex is essential for ciliary vesicle docking and displacement of the CP110-Cep97 inhibitory complex during ciliogenesis, and for anchoring spindle microtubule minus ends at spindle pole bodies to balance opposing kinesin forces and maintain spindle bipolarity and proper orientation during mitosis."},"narrative":{"mechanistic_narrative":"WRAP73 (WDR8) is a conserved WD40-repeat protein that organizes centrosome and spindle architecture by acting as a scaffold at centriolar and spindle pole structures [PMID:26675238, PMID:28098238]. In human cells it localizes constitutively to centriolar satellites and the proximal end of the mother centriole, where it associates with the satellite proteins SSX2IP and PCM1 and with the proximal-end component CEP135; CEP135 recruits WRAP73 to centrioles, and together WRAP73 and CEP135 drive ciliary vesicle docking and displacement of the CP110-Cep97 inhibitory complex to initiate ciliogenesis [PMID:26675238]. WRAP73 acts upstream of SSX2IP at the mitotic centrosome, where its depletion shortens and misorients spindle microtubules, defining a conserved SSX2IP-WRAP73-CEP135 module that controls spindle length and orientation [PMID:26545777, PMID:35406752]. The conserved mechanism is illuminated by the fission yeast ortholog, where a Msd1-Wdr8-kinesin-14 (Pkl1) complex anchors spindle microtubule minus ends at spindle pole bodies and balances outward kinesin-5 (Cut7) force to maintain spindle bipolarity [PMID:25987607], and by the medaka ortholog, where Wdr8 is a maternally essential centrosome-assembly factor whose WD40 domains bind SSX2IP to safeguard zygotic genome stability [PMID:28098238]. A homozygous WRAP73 missense mutation (p.Pro383Leu) that destabilizes the protein and disrupts partner binding causes isolated Microspherophakia, with eye and lens defects in zebrafish rescued by wild-type but not mutant human WRAP73 [PMID:33693649].","teleology":[{"year":2001,"claim":"Established WDR8 as a distinct WD-repeat protein and raised the first functional hint by linking its expression to a developmental transition.","evidence":"Differential display cloning, Northern blot, and expression profiling in a chondrogenic cell line","pmids":["11401440"],"confidence":"Low","gaps":["Identification and expression profiling only, no mechanistic or interaction data","No subcellular localization or molecular partners defined","Proposed ossification role untested functionally"]},{"year":2013,"claim":"First mitotic function: showed an Aspergillus WDR8 ortholog acts in a mutual stabilization/targeting relationship with TINA to anchor mitotic microtubules at spindle pole bodies.","evidence":"Affinity purification, deletion mutant analysis, and 4D confocal live imaging in Aspergillus nidulans","pmids":["24152731"],"confidence":"Medium","gaps":["Fungal ortholog; human TINA equivalent not addressed","Single lab","Molecular basis of microtubule anchoring not resolved"]},{"year":2015,"claim":"Defined a conserved force-balancing mechanism: the Msd1-Wdr8-Pkl1 complex tethers a minus-end-directed kinesin at the SPB to counter kinesin-5 outward force and maintain spindle bipolarity.","evidence":"Genetic deletion and epistasis (double-mutant suppression), live fluorescence microscopy, and co-immunoprecipitation in fission yeast","pmids":["25987607"],"confidence":"High","gaps":["Whether the human complex engages an analogous kinesin force balance untested","Structural basis of Pkl1 tethering by Msd1-Wdr8 unresolved"]},{"year":2015,"claim":"Placed human WDR8 at the proximal mother centriole and centriolar satellites and assigned it an SSX2IP/CEP135-linked role initiating ciliogenesis through ciliary vesicle docking and CP110-Cep97 displacement.","evidence":"Reciprocal Co-IP, RNAi depletion with ciliogenesis readouts, and super-resolution immunofluorescence in human cells","pmids":["26675238"],"confidence":"High","gaps":["How WDR8/CEP135 mechanistically promotes vesicle docking is undefined","No structure of the SSX2IP-WDR8-CEP135 complex"]},{"year":2015,"claim":"Ordered the human complex hierarchy, showing WDR8 acts upstream of SSX2IP recruitment to the mitotic centrosome and controls spindle length and orientation.","evidence":"Mass spectrometry interactor identification, RNAi knockdown, super-resolution microscopy, and Co-IP in human cells","pmids":["26545777"],"confidence":"Medium","gaps":["Single lab","Direct versus indirect WDR8-SSX2IP binding not separated from satellite context","Force-generating mechanism for spindle length control not shown"]},{"year":2017,"claim":"Demonstrated an essential physiological role: maternal Wdr8 is required for embryonic centrosome assembly, with its WD40 domains binding SSX2IP to preserve zygotic genome stability.","evidence":"CRISPR-Cas9 maternal/zygotic knockout, in vivo reconstitution, Co-IP, and live imaging in medaka","pmids":["28098238"],"confidence":"High","gaps":["Relevance to mammalian embryonic centrosome assembly not tested","How Wdr8 templates centrosome structure mechanistically unresolved"]},{"year":2021,"claim":"Linked WDR8 to human disease, showing a destabilizing missense mutation that disrupts partner binding causes isolated Microspherophakia with cell-cycle defects in retinal/lens tissue.","evidence":"Homozygosity mapping, exome sequencing, in vitro stability assay, Co-IP, and morpholino/CRISPR knockdown with human-WRAP73 rescue in zebrafish","pmids":["33693649"],"confidence":"High","gaps":["Which specific partner interactions drive the lens phenotype not pinpointed","Tissue-specific basis for an isolated ocular phenotype unexplained"]},{"year":2022,"claim":"Refined the somatic-cell picture, showing the SSX2IP-WDR8-CEP135 complex assembles before centrosome formation but WDR8 loss is compensated in established somatic lines, unlike CEP135.","evidence":"Stable CRISPR knockout and quantitative centrosome phenotype analysis in human cell lines","pmids":["35406752"],"confidence":"Medium","gaps":["Nature of the compensatory mechanism for WDR8 loss unknown","Why WDR8 is dispensable somatically but essential maternally unresolved"]},{"year":null,"claim":"How the WDR8-SSX2IP-CEP135 complex is structurally organized and mechanistically couples centriolar anchoring to spindle force balance, ciliary vesicle docking, and tissue-specific developmental outcomes remains open.","evidence":"No structural or reconstituted-mechanism study in the timeline","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of the complex","Direct biochemical demonstration of microtubule minus-end anchoring by human WDR8 absent","Mechanistic link between molecular defect and isolated ocular disease undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,3]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[1,3,4]}],"localization":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[1,3]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0,3,4]},{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[1,4]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[4,5]}],"complexes":["SSX2IP-WDR8-CEP135 complex","Msd1-Wdr8-Pkl1 complex (fission yeast)"],"partners":["SSX2IP","CEP135","PCM1","PKL1","TINA"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9P2S5","full_name":"WD repeat-containing protein WRAP73","aliases":["WD repeat-containing protein 8","WD repeat-containing protein antisense to TP73 gene"],"length_aa":460,"mass_kda":51.6,"function":"The SSX2IP:WRAP73 complex is proposed to act as regulator of spindle anchoring at the mitotic centrosome. Required for the centrosomal localization of SSX2IP and normal mitotic bipolar spindle morphology (PubMed:26545777). Required for the targeting of centriole satellite proteins to centrosomes such as of PCM1, SSX2IP, CEP290 and PIBF1/CEP90. Required for ciliogenesis and involved in the removal of the CEP97:CCP110 complex from the mother centriole. Involved in ciliary vesicle formation at the mother centriole and required for the docking of vesicles to the basal body during ciliogenesis; may promote docking of RAB8A- and ARL13B-containing vesicles (PubMed:26675238)","subcellular_location":"Cytoplasm; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriole; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriolar satellite","url":"https://www.uniprot.org/uniprotkb/Q9P2S5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/WRAP73","classification":"Not Classified","n_dependent_lines":65,"n_total_lines":1208,"dependency_fraction":0.05380794701986755},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"FKBP5","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/WRAP73","total_profiled":1310},"omim":[],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Mid piece","reliability":"Approved"},{"location":"Principal piece","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/WRAP73"},"hgnc":{"alias_symbol":[],"prev_symbol":["WDR8"]},"alphafold":{"accession":"Q9P2S5","domains":[{"cath_id":"2.130.10.10","chopping":"1-130","consensus_level":"medium","plddt":96.0616,"start":1,"end":130}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9P2S5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9P2S5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9P2S5-F1-predicted_aligned_error_v6.png","plddt_mean":89.5},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=WRAP73","jax_strain_url":"https://www.jax.org/strain/search?query=WRAP73"},"sequence":{"accession":"Q9P2S5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9P2S5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9P2S5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9P2S5"}},"corpus_meta":[{"pmid":"31165884","id":"PMC_31165884","title":"Association of dietary folate and vitamin B-12 intake with genome-wide DNA methylation in blood: a large-scale epigenome-wide association analysis in 5841 individuals.","date":"2019","source":"The American journal of clinical nutrition","url":"https://pubmed.ncbi.nlm.nih.gov/31165884","citation_count":56,"is_preprint":false},{"pmid":"25987607","id":"PMC_25987607","title":"The Msd1-Wdr8-Pkl1 complex anchors microtubule minus ends to fission yeast spindle pole bodies.","date":"2015","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/25987607","citation_count":47,"is_preprint":false},{"pmid":"26675238","id":"PMC_26675238","title":"WDR8 is a centriolar satellite and centriole-associated protein that promotes ciliary vesicle docking during ciliogenesis.","date":"2015","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/26675238","citation_count":32,"is_preprint":false},{"pmid":"24152731","id":"PMC_24152731","title":"Regulation of mitosis by the NIMA kinase involves TINA and its newly discovered partner, An-WDR8, at spindle pole bodies.","date":"2013","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/24152731","citation_count":22,"is_preprint":false},{"pmid":"11401440","id":"PMC_11401440","title":"Isolation, characterization, and mapping of the mouse and human WDR8 genes, members of a novel WD-repeat gene family.","date":"2001","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/11401440","citation_count":18,"is_preprint":false},{"pmid":"37793095","id":"PMC_37793095","title":"Blood DNA methylation signature of diet quality and association with cardiometabolic traits.","date":"2024","source":"European journal of preventive cardiology","url":"https://pubmed.ncbi.nlm.nih.gov/37793095","citation_count":18,"is_preprint":false},{"pmid":"26545777","id":"PMC_26545777","title":"The conserved Wdr8-hMsd1/SSX2IP complex localises to the centrosome and ensures proper spindle length and orientation.","date":"2015","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/26545777","citation_count":17,"is_preprint":false},{"pmid":"34140499","id":"PMC_34140499","title":"An anchoring complex recruits katanin for microtubule severing at the plant cortical nucleation sites.","date":"2021","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/34140499","citation_count":17,"is_preprint":false},{"pmid":"37331566","id":"PMC_37331566","title":"Genome-Wide Methylation Profiling in 229 Patients With Crohn's Disease Requiring Intestinal Resection: Epigenetic Analysis of the Trial of Prevention of Post-operative Crohn's Disease (TOPPIC).","date":"2023","source":"Cellular and molecular gastroenterology and hepatology","url":"https://pubmed.ncbi.nlm.nih.gov/37331566","citation_count":13,"is_preprint":false},{"pmid":"28098238","id":"PMC_28098238","title":"Expression of the novel maternal centrosome assembly factor Wdr8 is required for vertebrate embryonic mitoses.","date":"2017","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/28098238","citation_count":9,"is_preprint":false},{"pmid":"35580864","id":"PMC_35580864","title":"Identification of combined biomarkers for predicting the risk of osteoporosis using machine learning.","date":"2022","source":"Aging","url":"https://pubmed.ncbi.nlm.nih.gov/35580864","citation_count":9,"is_preprint":false},{"pmid":"39232346","id":"PMC_39232346","title":"Plant microtubule nucleating apparatus and its potential signaling pathway.","date":"2024","source":"Current opinion in plant biology","url":"https://pubmed.ncbi.nlm.nih.gov/39232346","citation_count":7,"is_preprint":false},{"pmid":"35406752","id":"PMC_35406752","title":"Mitotic Maturation Compensates for Premature Centrosome Splitting and PCM Loss in Human cep135 Knockout Cells.","date":"2022","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/35406752","citation_count":7,"is_preprint":false},{"pmid":"18285824","id":"PMC_18285824","title":"A genome-wide linkage scan for low spinal bone mineral density in a single extended family confirms linkage to 1p36.3.","date":"2008","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/18285824","citation_count":5,"is_preprint":false},{"pmid":"33693649","id":"PMC_33693649","title":"Exome sequencing and functional studies in zebrafish identify WDR8 as the causative gene for isolated Microspherophakia in Indian families.","date":"2021","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33693649","citation_count":2,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":9625,"output_tokens":2421,"usd":0.032595,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9523,"output_tokens":3147,"usd":0.063145,"stage2_stop_reason":"end_turn"},"total_usd":0.09574,"stage1_batch_id":"msgbatch_01UT1AahFPCAyn2uVweS7A9z","stage2_batch_id":"msgbatch_01HuKWtKNT4Pqj1bc8eEP5RV","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2015,\n      \"finding\": \"Fission yeast Wdr8 forms a ternary complex with Msd1 and the minus end-directed kinesin-14 Pkl1 at spindle pole bodies (SPBs). Msd1 and Wdr8 are delivered to mitotic SPBs by Pkl1, where Pkl1 is tethered through Msd1-Wdr8. The spindle-anchoring defect imposed by msd1/wdr8/pkl1 deletions is suppressed by a mutation in plus end-directed Cut7/kinesin-5, indicating that the Msd1-Wdr8-Pkl1 complex balances Cut7-mediated outward force at the SPB to ensure spindle bipolarity. Pkl1 motor activity was not required for its anchoring role once targeted to the SPB.\",\n      \"method\": \"Genetic deletion analysis, genetic epistasis (double mutant suppression), live fluorescence microscopy, co-immunoprecipitation\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal genetic epistasis, multiple deletion mutants, live imaging, multiple orthogonal methods across multiple labs\",\n      \"pmids\": [\"25987607\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Human WDR8 (WRAP73) localizes to centriolar satellites and to the proximal end of the mother centriole. WDR8 interacts with the satellite proteins SSX2IP and PCM1, and with the centriolar proximal end component Cep135. Cep135 is required for WDR8 recruitment to centrioles. WDR8 and Cep135 are both indispensable for ciliary vesicle docking to the mother centriole and for displacement of the ciliary inhibitory complex CP110-Cep97, establishing a role for WDR8 in the initial steps of ciliogenesis.\",\n      \"method\": \"Co-immunoprecipitation, RNAi depletion with ciliogenesis phenotypic readout, immunofluorescence localization, super-resolution microscopy\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, RNAi depletion with specific phenotypic readouts, super-resolution localization, multiple orthogonal methods in single study\",\n      \"pmids\": [\"26675238\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In Aspergillus nidulans, An-WDR8 (ortholog of WRAP73/WDR8) co-purifies with TINA (a NIMA-interacting protein) and is required for TINA stability and mitotic targeting; reciprocally, TINA is required for mitotic SPB targeting of An-WDR8. Together, TINA and An-WDR8 are required for anchoring mitotic microtubules to SPBs and for successful mitosis.\",\n      \"method\": \"Affinity purification, 4D spinning disk confocal microscopy, deletion mutant analysis, GFP-tagging localization studies\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — affinity purification plus deletion phenotyping and live imaging, single lab, fungal ortholog\",\n      \"pmids\": [\"24152731\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Human Wdr8 constitutively localizes to the centrosome, enriched at the proximal end of the mother centriole. Wdr8 forms a complex with hMsd1/SSX2IP identified by mass spectrometry. Knockdown of Wdr8 results in shortened and misoriented spindle microtubules, and reduces recruitment of hMsd1/SSX2IP to the mitotic centrosome (but depletion of hMsd1/SSX2IP does not affect Wdr8 centrosomal localization), indicating that Wdr8 acts upstream of hMsd1/SSX2IP in a conserved complex controlling spindle length and orientation.\",\n      \"method\": \"Mass spectrometry (interactor identification), RNAi knockdown, super-resolution microscopy, immunofluorescence, co-immunoprecipitation\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mass spectrometry identification, RNAi phenotyping, super-resolution localization, single lab\",\n      \"pmids\": [\"26545777\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Wdr8 is a maternally essential protein required for centrosome assembly during embryonic mitoses in medaka fish. CRISPR-Cas9 knockout of maternal/zygotic Wdr8 causes defects in centrosome structure leading to asymmetric division, multipolar spindles, and chromosome alignment errors. Via its WD40 domains, Wdr8 interacts with the centriolar satellite protein SSX2IP. In vivo reconstitution of the Wdr8-SSX2IP complex reveals an essential link between maternal centrosome proteins and zygotic genome stability.\",\n      \"method\": \"CRISPR-Cas9 knockout, in vivo reconstitution, co-immunoprecipitation, live fluorescence microscopy\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — CRISPR knockout with defined phenotypic rescue, Co-IP, in vivo reconstitution, multiple orthogonal methods in single study\",\n      \"pmids\": [\"28098238\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"A homozygous missense mutation in WDR8 (p.Pro383Leu) causes isolated Microspherophakia in humans. In vitro experiments showed the mutation renders the protein unstable. Co-immunoprecipitation from HeLa cells indicated the mutation interferes with WDR8 interaction with its binding partners. In zebrafish, morpholino knockdown and CRISPR/Cas9 knockout of wdr8 resulted in decreased eye and lens size and defective cell cycle progression in retinal cells; these defects were rescued by wild-type human WDR8 but not by the p.Pro383Leu mutant.\",\n      \"method\": \"Homozygosity mapping, whole-exome sequencing, in vitro protein stability assay, co-immunoprecipitation, morpholino knockdown, CRISPR/Cas9 knockout, rescue experiments in zebrafish\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — CRISPR knockout with phenotypic rescue, Co-IP, in vitro stability assay, multiple orthogonal methods in single study\",\n      \"pmids\": [\"33693649\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"In human somatic cells, SSX2IP, WDR8, and CEP135 form a complex that is assembled before centrosome assembly in vertebrate oocytes and functionally interacts in somatic cells. Stable knockout of WDR8 in human cells is compensated for during mitosis; WDR8 loss does not cause severe mitotic phenotypes in established somatic cell lines, unlike CEP135 knockout which compromises PCM recruitment and causes premature centrosome splitting.\",\n      \"method\": \"Stable CRISPR knockout in human cell lines, immunofluorescence, centrosome phenotype analysis\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — stable knockout with quantitative phenotype analysis, single lab, two orthogonal methods\",\n      \"pmids\": [\"35406752\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2001,\n      \"finding\": \"WDR8 encodes a novel WD-repeat protein of 460 amino acids (human) that is expressed in almost all tissues including bone and cartilage. It represents a novel subfamily of WD-repeat proteins distinctly different from other family members. Wdr8 expression in cartilage is regulated during the transition from hypertrophic to mineralizing stages in a chondrogenic cell line (ATDC5), suggesting a role in ossification.\",\n      \"method\": \"Differential display cloning, Northern blot, expression profiling in cell lines\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — identification and expression profiling only, no functional mechanistic experiments\",\n      \"pmids\": [\"11401440\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"WDR8/WRAP73 is a conserved WD40-repeat protein that localizes constitutively to the proximal end of the mother centriole and to centriolar satellites, where it forms a complex with SSX2IP/hMsd1 and CEP135; this complex is essential for ciliary vesicle docking and displacement of the CP110-Cep97 inhibitory complex during ciliogenesis, and for anchoring spindle microtubule minus ends at spindle pole bodies to balance opposing kinesin forces and maintain spindle bipolarity and proper orientation during mitosis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"WRAP73 (WDR8) is a conserved WD40-repeat protein that organizes centrosome and spindle architecture by acting as a scaffold at centriolar and spindle pole structures [#1, #4]. In human cells it localizes constitutively to centriolar satellites and the proximal end of the mother centriole, where it associates with the satellite proteins SSX2IP and PCM1 and with the proximal-end component CEP135; CEP135 recruits WRAP73 to centrioles, and together WRAP73 and CEP135 drive ciliary vesicle docking and displacement of the CP110-Cep97 inhibitory complex to initiate ciliogenesis [#1]. WRAP73 acts upstream of SSX2IP at the mitotic centrosome, where its depletion shortens and misorients spindle microtubules, defining a conserved SSX2IP-WRAP73-CEP135 module that controls spindle length and orientation [#3, #6]. The conserved mechanism is illuminated by the fission yeast ortholog, where a Msd1-Wdr8-kinesin-14 (Pkl1) complex anchors spindle microtubule minus ends at spindle pole bodies and balances outward kinesin-5 (Cut7) force to maintain spindle bipolarity [#0], and by the medaka ortholog, where Wdr8 is a maternally essential centrosome-assembly factor whose WD40 domains bind SSX2IP to safeguard zygotic genome stability [#4]. A homozygous WRAP73 missense mutation (p.Pro383Leu) that destabilizes the protein and disrupts partner binding causes isolated Microspherophakia, with eye and lens defects in zebrafish rescued by wild-type but not mutant human WRAP73 [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Established WDR8 as a distinct WD-repeat protein and raised the first functional hint by linking its expression to a developmental transition.\",\n      \"evidence\": \"Differential display cloning, Northern blot, and expression profiling in a chondrogenic cell line\",\n      \"pmids\": [\"11401440\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Identification and expression profiling only, no mechanistic or interaction data\", \"No subcellular localization or molecular partners defined\", \"Proposed ossification role untested functionally\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"First mitotic function: showed an Aspergillus WDR8 ortholog acts in a mutual stabilization/targeting relationship with TINA to anchor mitotic microtubules at spindle pole bodies.\",\n      \"evidence\": \"Affinity purification, deletion mutant analysis, and 4D confocal live imaging in Aspergillus nidulans\",\n      \"pmids\": [\"24152731\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Fungal ortholog; human TINA equivalent not addressed\", \"Single lab\", \"Molecular basis of microtubule anchoring not resolved\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Defined a conserved force-balancing mechanism: the Msd1-Wdr8-Pkl1 complex tethers a minus-end-directed kinesin at the SPB to counter kinesin-5 outward force and maintain spindle bipolarity.\",\n      \"evidence\": \"Genetic deletion and epistasis (double-mutant suppression), live fluorescence microscopy, and co-immunoprecipitation in fission yeast\",\n      \"pmids\": [\"25987607\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether the human complex engages an analogous kinesin force balance untested\", \"Structural basis of Pkl1 tethering by Msd1-Wdr8 unresolved\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Placed human WDR8 at the proximal mother centriole and centriolar satellites and assigned it an SSX2IP/CEP135-linked role initiating ciliogenesis through ciliary vesicle docking and CP110-Cep97 displacement.\",\n      \"evidence\": \"Reciprocal Co-IP, RNAi depletion with ciliogenesis readouts, and super-resolution immunofluorescence in human cells\",\n      \"pmids\": [\"26675238\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How WDR8/CEP135 mechanistically promotes vesicle docking is undefined\", \"No structure of the SSX2IP-WDR8-CEP135 complex\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Ordered the human complex hierarchy, showing WDR8 acts upstream of SSX2IP recruitment to the mitotic centrosome and controls spindle length and orientation.\",\n      \"evidence\": \"Mass spectrometry interactor identification, RNAi knockdown, super-resolution microscopy, and Co-IP in human cells\",\n      \"pmids\": [\"26545777\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Direct versus indirect WDR8-SSX2IP binding not separated from satellite context\", \"Force-generating mechanism for spindle length control not shown\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Demonstrated an essential physiological role: maternal Wdr8 is required for embryonic centrosome assembly, with its WD40 domains binding SSX2IP to preserve zygotic genome stability.\",\n      \"evidence\": \"CRISPR-Cas9 maternal/zygotic knockout, in vivo reconstitution, Co-IP, and live imaging in medaka\",\n      \"pmids\": [\"28098238\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Relevance to mammalian embryonic centrosome assembly not tested\", \"How Wdr8 templates centrosome structure mechanistically unresolved\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Linked WDR8 to human disease, showing a destabilizing missense mutation that disrupts partner binding causes isolated Microspherophakia with cell-cycle defects in retinal/lens tissue.\",\n      \"evidence\": \"Homozygosity mapping, exome sequencing, in vitro stability assay, Co-IP, and morpholino/CRISPR knockdown with human-WRAP73 rescue in zebrafish\",\n      \"pmids\": [\"33693649\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Which specific partner interactions drive the lens phenotype not pinpointed\", \"Tissue-specific basis for an isolated ocular phenotype unexplained\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Refined the somatic-cell picture, showing the SSX2IP-WDR8-CEP135 complex assembles before centrosome formation but WDR8 loss is compensated in established somatic lines, unlike CEP135.\",\n      \"evidence\": \"Stable CRISPR knockout and quantitative centrosome phenotype analysis in human cell lines\",\n      \"pmids\": [\"35406752\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Nature of the compensatory mechanism for WDR8 loss unknown\", \"Why WDR8 is dispensable somatically but essential maternally unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the WDR8-SSX2IP-CEP135 complex is structurally organized and mechanistically couples centriolar anchoring to spindle force balance, ciliary vesicle docking, and tissue-specific developmental outcomes remains open.\",\n      \"evidence\": \"No structural or reconstituted-mechanism study in the timeline\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No high-resolution structure of the complex\", \"Direct biochemical demonstration of microtubule minus-end anchoring by human WDR8 absent\", \"Mechanistic link between molecular defect and isolated ocular disease undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [1, 3, 4]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [1, 3]},\n      {\"term_id\": \"GO:0005813\", \"supporting_discovery_ids\": [1, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0, 3, 4]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [1, 4]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [4, 5]}\n    ],\n    \"complexes\": [\"SSX2IP-WDR8-CEP135 complex\", \"Msd1-Wdr8-Pkl1 complex (fission yeast)\"],\n    \"partners\": [\"SSX2IP\", \"CEP135\", \"PCM1\", \"Pkl1\", \"TINA\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}