{"gene":"POC1B","run_date":"2026-06-10T06:43:35","timeline":{"discoveries":[{"year":2012,"finding":"POC1B localizes to centrioles and spindle poles independently of POC1A, with different dynamics. A fraction of POC1B remains stably associated with parental centrioles once incorporated. Co-depletion of POC1A and POC1B leads to loss of nascent centriole integrity and maturation, spindle organization defects (unequal or monopolar spindles), and failure of centriole duplication. POC1B (but not POC1A) is phosphorylated during mitosis, and depletion of POC1B alone is sufficient to perturb cell proliferation, indicating an additional independent function beyond the redundant centriole-integrity role.","method":"Isoform-specific antibodies, RNAi depletion, live-cell imaging, immunofluorescence, FRAP, and mitotic progression assays in human cells","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal localization, RNAi with defined cellular phenotypes, multiple orthogonal methods (antibody localization, FRAP, mitotic assays) in a single focused study","pmids":["23015594"],"is_preprint":false},{"year":2014,"finding":"POC1B localizes to the basal body of the primary cilium in human RPE1 cells. Disease-associated missense variants p.Arg106Pro and p.Gln67del abolish this basal body localization. POC1B interacts with FAM161A (a connecting-cilium protein implicated in retinitis pigmentosa) as shown by yeast two-hybrid screening, co-immunoprecipitation, and colocalization; both p.Arg106Pro and p.Gln67del disrupt this interaction.","method":"Overexpression localization in RPE1 cells, yeast two-hybrid screening of retinal cDNA library, co-immunoprecipitation, colocalization assays, zebrafish morpholino knockdown with mRNA rescue","journal":"American journal of human genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (Y2H, reciprocal Co-IP, colocalization, in vivo rescue), replicated across mutant variants","pmids":["25018096"],"is_preprint":false},{"year":2014,"finding":"POC1B localizes to the basal body and centriole adjacent to the connecting cilium of photoreceptors in human and mouse retina, and also to synapses of the outer plexiform layer. Knockdown of Poc1b in zebrafish causes shortened and reduced photoreceptor connecting cilia, cystic kidneys, and retinal degeneration.","method":"Immunofluorescence localization in human/mouse retina, zebrafish morpholino knockdown with phenotypic analysis","journal":"Human mutation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization in tissue and in vivo loss-of-function, single lab, two orthogonal approaches","pmids":["25044745"],"is_preprint":false},{"year":2015,"finding":"Poc1b localizes to centrioles and spindle bundles during cell cycle progression and to the basal body of photoreceptor sensory cilia in rat retina. Morpholino knockdown of poc1b in zebrafish causes delayed retinal laminar development, shortened photoreceptor outer segments, impaired visual function, and broader ciliopathy phenotypes (curved body axis, heart defects, shortened Kupffer's vesicle cilia).","method":"Tagged recombinant protein expression in renal epithelial cells and rat retina, zebrafish morpholino knockdown with behavioral and morphological analysis","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization experiment with functional consequence (in vivo KD), single lab, two orthogonal methods","pmids":["26188096"],"is_preprint":false},{"year":2019,"finding":"In Drosophila melanogaster sperm, Poc1B is recruited to the giant centriole base during proximal centriole-like structure (PCL) formation in a Sas-6-dependent manner. Poc1B and Sas-6 co-localize in the PCL/centriole core, Poc1B affects cellular and PCL Sas-6 levels, and co-overexpression of Poc1B and Sas-6 induces formation of PCL-like structures. Poc1 mutant flies show disruption of ectopic PCL-like particles induced by Ana2/Sas-6 co-overexpression, indicating Poc1 proteins stabilize these structures.","method":"Immunofluorescence, genetic co-overexpression, Poc1 mutant fly analysis, co-localization studies in Drosophila","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo genetic epistasis and co-localization in Drosophila model, single lab, multiple complementary genetic and imaging methods","pmids":["31387336"],"is_preprint":false},{"year":2023,"finding":"A homozygous frameshift variant (c.151delG) in POC1B causes loss of POC1B protein in sperm cells. In poc1b knock-in mice, this mutation results in oligoasthenoteratozoospermia (OAT) with abnormal formation of acrosomes and flagella, demonstrating POC1B is required for normal sperm ciliogenesis/flagella formation.","method":"Whole-exome sequencing, protein analysis of patient sperm, CRISPR/Cas9 knock-in mice, testicular histology, transmission electron microscopy","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — CRISPR knock-in mouse model with TEM ultrastructural analysis, corroborated by patient protein data, multiple orthogonal methods","pmids":["37070736"],"is_preprint":false},{"year":2024,"finding":"POC1B forms heterodimers with POC1A within the centriole lumen to organize an interaction network of inner scaffold proteins. The WD40 domain of POC1B localizes close to the centriole wall, while the POC5-interacting WD40 of POC1A resides in the centriole lumen. POC1B (via POC1A-POC1B heterodimers) interacts with the microtubule-binding proteins FAM161A and MDM1, which likely position POC5 tetramers near the centriole wall. Disruption of POC1B alone causes centriole microtubule defects; deletion of both POC1A and POC1B causes centriole disintegration.","method":"Co-immunoprecipitation, superresolution microscopy (localization mapping), genetic deletion/disruption in human cells, structural/functional interaction assays","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — multiple orthogonal methods (Co-IP, super-resolution localization, genetic knockouts with ultrastructural phenotypes) in a single rigorous study establishing domain-level mechanism","pmids":["39543170"],"is_preprint":false},{"year":2026,"finding":"HNRNPH1 represses POC1B mRNA via o8G oxidation-dependent post-transcriptional regulation. The piRNA MCPPIR prevents HNRNPH1-mediated repression of POC1B mRNA, maintaining POC1B protein levels. POC1B downstream maintains centrosome integrity, thereby promoting cardiomyocyte proliferation and cardiac repair. Cardiomyocyte-specific HNRNPH1 knockout enhances proliferative capacity consistent with de-repression of POC1B.","method":"Mass spectrometry, RNA pull-down assay (HNRNPH1-MCPPIR interaction), o8G-RNA immunoprecipitation sequencing (identifying POC1B as downstream target), cardiomyocyte-specific HNRNPH1 knockout mice, MCPPIR genetic ablation/overexpression in mice","journal":"Cardiovascular research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (MS, RNA pulldown, o8G-RIP-seq, conditional KO mice) in single lab identifying POC1B as downstream effector of centrosome integrity in cardiomyocytes","pmids":["41325109"],"is_preprint":false}],"current_model":"POC1B is an inner scaffold centriolar protein that forms POC1A-POC1B heterodimers within the centriole lumen, where its WD40 domain localizes near the centriole wall; together with POC5, FAM161A, and MDM1, it maintains centriole microtubule integrity, supports centriole duplication and ciliogenesis, is required for photoreceptor basal body function and connecting cilium formation, is essential for sperm flagella assembly, undergoes mitosis-specific phosphorylation with an independent role in cell cycle progression, and its mRNA is post-transcriptionally regulated by HNRNPH1-mediated o8G oxidation to control centrosome integrity in cardiomyocytes."},"narrative":{"mechanistic_narrative":"POC1B is a centriolar inner-scaffold protein that maintains centriole microtubule integrity, supports centriole duplication, and is required for ciliogenesis across tissues [PMID:23015594, PMID:39543170]. It forms heterodimers with POC1A within the centriole lumen, where its WD40 domain localizes close to the centriole wall and the heterodimer organizes an inner-scaffold interaction network with the microtubule-binding proteins FAM161A and MDM1 that position POC5; disruption of POC1B alone causes centriole microtubule defects, whereas loss of both POC1A and POC1B causes centriole disintegration [PMID:39543170]. POC1B localizes to centrioles, spindle poles, and the basal body of primary and photoreceptor sensory cilia, and its interaction with the connecting-cilium protein FAM161A is required for basal body targeting [PMID:25018096, PMID:25044745]. Beyond a centriole-integrity role redundant with POC1A, POC1B is specifically phosphorylated during mitosis and is independently required for normal cell proliferation [PMID:23015594]. POC1B function is essential in specialized ciliated cells: a homozygous frameshift variant abolishes sperm POC1B and causes oligoasthenoteratozoospermia with abnormal acrosome and flagella formation in knock-in mice [PMID:37070736], and disease-associated POC1B variants that disrupt basal body localization and FAM161A binding underlie retinal and ciliopathy phenotypes [PMID:25018096, PMID:25044745]. POC1B protein levels are also set post-transcriptionally, with HNRNPH1-mediated o8G oxidation repressing POC1B mRNA to control centrosome integrity in cardiomyocytes [PMID:41325109].","teleology":[{"year":2012,"claim":"Establishing whether POC1B acts only redundantly with its paralog defined its dual role: it maintains nascent centriole integrity together with POC1A but also has an independent, mitosis-specific function.","evidence":"Isoform-specific antibody localization, FRAP, RNAi co-depletion and mitotic progression assays in human cells","pmids":["23015594"],"confidence":"High","gaps":["Molecular target of the mitosis-specific phosphorylation and the kinase responsible were not identified","The mechanistic basis of the proliferation defect independent of centriole integrity was not resolved"]},{"year":2014,"claim":"Identifying a direct POC1B-FAM161A interaction and showing disease variants abolish basal body localization connected POC1B to connecting-cilium biology and human ciliopathy.","evidence":"Yeast two-hybrid, reciprocal Co-IP, colocalization in RPE1 cells, and zebrafish morpholino rescue, with two missense/deletion variants tested","pmids":["25018096"],"confidence":"High","gaps":["Structural interface between POC1B and FAM161A not defined","How loss of the interaction translates into ciliary dysfunction at the molecular level unresolved"]},{"year":2014,"claim":"Localization to photoreceptor basal body and connecting cilium with in vivo knockdown phenotypes tied POC1B loss to retinal degeneration and broader ciliopathy.","evidence":"Immunofluorescence in human/mouse retina and zebrafish morpholino knockdown","pmids":["25044745","26188096"],"confidence":"Medium","gaps":["Morpholino phenotypes not confirmed with stable genetic mutants","Synaptic outer-plexiform-layer localization role not mechanistically characterized"]},{"year":2019,"claim":"Genetic epistasis in Drosophila sperm showed POC1B is recruited to centriole/PCL cores in a Sas-6-dependent manner and reciprocally stabilizes Sas-6-dependent structures, placing it in the centriole-assembly hierarchy.","evidence":"Co-localization, genetic co-overexpression, and Poc1 mutant analysis in Drosophila","pmids":["31387336"],"confidence":"Medium","gaps":["Whether the same Sas-6 dependency operates in mammalian centriole assembly not tested","Biochemical nature of POC1B-Sas-6 stabilization unknown"]},{"year":2023,"claim":"A patient frameshift variant modeled in knock-in mice established POC1B as essential for mammalian sperm flagella and acrosome formation, extending its requirement to motile ciliogenesis.","evidence":"Whole-exome sequencing, patient sperm protein analysis, CRISPR knock-in mice, testicular histology and TEM","pmids":["37070736"],"confidence":"High","gaps":["Molecular step in flagellar assembly that requires POC1B not pinpointed","Relationship between sperm defects and the inner-scaffold function not directly connected"]},{"year":2024,"claim":"Mapping the POC1A-POC1B heterodimer and its WD40 domain orientation within the centriole lumen resolved how POC1B organizes the inner scaffold via FAM161A, MDM1 and POC5.","evidence":"Co-IP, super-resolution localization mapping, and genetic deletion with ultrastructural phenotypes in human cells","pmids":["39543170"],"confidence":"High","gaps":["High-resolution structure of the assembled scaffold not solved","How the scaffold mechanically reinforces centriole microtubules not defined"]},{"year":2026,"claim":"Discovery that HNRNPH1 represses POC1B mRNA through o8G oxidation, antagonized by a piRNA, revealed post-transcriptional control of POC1B as a lever for centrosome integrity and cardiomyocyte proliferation.","evidence":"Mass spectrometry, RNA pull-down, o8G-RIP-seq, and cardiomyocyte-specific HNRNPH1 knockout and piRNA manipulation in mice","pmids":["41325109"],"confidence":"Medium","gaps":["Direct demonstration that POC1B restoration alone rescues the cardiac phenotype not established","Whether o8G regulation of POC1B operates outside cardiomyocytes unknown"]},{"year":null,"claim":"The molecular identity and consequence of the mitosis-specific POC1B phosphorylation that drives its centriole-independent proliferation role remain undefined.","evidence":"","pmids":[],"confidence":"Low","gaps":["Responsible kinase and phosphosites unknown","Mechanistic link between phosphorylation and cell cycle progression unresolved"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,6]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[6]}],"localization":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[0]},{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[1,2,3]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,6]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0]}],"complexes":["POC1A-POC1B heterodimer","centriole inner scaffold"],"partners":["POC1A","FAM161A","MDM1","POC5","SAS-6","HNRNPH1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8TC44","full_name":"POC1 centriolar protein homolog B","aliases":["Pix1","Proteome of centriole protein 1B","WD repeat-containing protein 51B"],"length_aa":478,"mass_kda":53.7,"function":"Plays an important role in centriole assembly and/or stability and ciliogenesis (PubMed:20008567, PubMed:32060285). Involved in early steps of centriole duplication, as well as in the later steps of centriole length control (PubMed:19109428). Acts in concert with POC1A to ensure centriole integrity and proper mitotic spindle formation (PubMed:32060285). Required for primary cilia formation, ciliary length and also cell proliferation (PubMed:23015594). Required for retinal integrity (PubMed:25044745). Acts as a positive regulator of centriole elongation (PubMed:37934472)","subcellular_location":"Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriole; Cytoplasm, cytoskeleton, cilium basal body; Cytoplasm, cytoskeleton, spindle pole","url":"https://www.uniprot.org/uniprotkb/Q8TC44/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/POC1B","classification":"Not Classified","n_dependent_lines":32,"n_total_lines":1208,"dependency_fraction":0.026490066225165563},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/POC1B","total_profiled":1310},"omim":[{"mim_id":"620217","title":"CENTROSOMAL PROTEIN, 44-KD; CEP44","url":"https://www.omim.org/entry/620217"},{"mim_id":"617728","title":"CENTROSOMAL PROTEIN, 295-KD; CEP295","url":"https://www.omim.org/entry/617728"},{"mim_id":"615973","title":"CONE-ROD DYSTROPHY 20; CORD20","url":"https://www.omim.org/entry/615973"},{"mim_id":"614784","title":"POC1 CENTRIOLAR PROTEIN B; POC1B","url":"https://www.omim.org/entry/614784"},{"mim_id":"614783","title":"POC1 CENTRIOLAR PROTEIN A; POC1A","url":"https://www.omim.org/entry/614783"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Uncertain","locations":[{"location":"Cytosol","reliability":"Uncertain"},{"location":"Flagellar centriole","reliability":"Uncertain"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/POC1B"},"hgnc":{"alias_symbol":["TUWD12","FLJ14923"],"prev_symbol":["WDR51B"]},"alphafold":{"accession":"Q8TC44","domains":[{"cath_id":"2.130.10.10","chopping":"8-301_342-360","consensus_level":"high","plddt":91.1888,"start":8,"end":360},{"cath_id":"1.10.287","chopping":"436-478","consensus_level":"medium","plddt":86.7735,"start":436,"end":478}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TC44","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TC44-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8TC44-F1-predicted_aligned_error_v6.png","plddt_mean":77.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=POC1B","jax_strain_url":"https://www.jax.org/strain/search?query=POC1B"},"sequence":{"accession":"Q8TC44","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8TC44.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8TC44/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8TC44"}},"corpus_meta":[{"pmid":"25018096","id":"PMC_25018096","title":"Disruption of the basal body protein POC1B results in autosomal-recessive cone-rod dystrophy.","date":"2014","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/25018096","citation_count":68,"is_preprint":false},{"pmid":"23015594","id":"PMC_23015594","title":"Poc1A and Poc1B act together in human cells to ensure centriole integrity.","date":"2012","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/23015594","citation_count":67,"is_preprint":false},{"pmid":"25044745","id":"PMC_25044745","title":"Mutation of POC1B in a severe syndromic retinal ciliopathy.","date":"2014","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/25044745","citation_count":61,"is_preprint":false},{"pmid":"24945461","id":"PMC_24945461","title":"Novel recessive cone-rod dystrophy caused by POC1B mutation.","date":"2014","source":"JAMA ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/24945461","citation_count":30,"is_preprint":false},{"pmid":"31390656","id":"PMC_31390656","title":"Phenotypical Characteristics of POC1B-Associated Retinopathy in Japanese Cohort: Cone Dystrophy With Normal Funduscopic Appearance.","date":"2019","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/31390656","citation_count":23,"is_preprint":false},{"pmid":"29220607","id":"PMC_29220607","title":"Case of cone dystrophy with normal fundus appearance associated with biallelic POC1B variants.","date":"2017","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/29220607","citation_count":20,"is_preprint":false},{"pmid":"34065499","id":"PMC_34065499","title":"Clinical Characteristics of POC1B-Associated Retinopathy and Assignment of Pathogenicity to Novel Deep Intronic and Non-Canonical Splice Site Variants.","date":"2021","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/34065499","citation_count":16,"is_preprint":false},{"pmid":"39543170","id":"PMC_39543170","title":"An interaction network of inner centriole proteins organised by POC1A-POC1B heterodimer crosslinks ensures centriolar integrity.","date":"2024","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/39543170","citation_count":15,"is_preprint":false},{"pmid":"31387336","id":"PMC_31387336","title":"Poc1B and Sas-6 Function Together during the Atypical Centriole Formation in Drosophila melanogaster.","date":"2019","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/31387336","citation_count":14,"is_preprint":false},{"pmid":"37070736","id":"PMC_37070736","title":"Homozygous frameshift variant in POC1B causes male infertility with oligoasthenoteratozoospermia in human and mice.","date":"2023","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/37070736","citation_count":14,"is_preprint":false},{"pmid":"26188096","id":"PMC_26188096","title":"Knockdown of poc1b causes abnormal photoreceptor sensory cilium and vision impairment in zebrafish.","date":"2015","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/26188096","citation_count":14,"is_preprint":false},{"pmid":"29377742","id":"PMC_29377742","title":"Novel compound heterozygous mutation in the POC1B gene underlie peripheral cone dystrophy in a Chinese family.","date":"2018","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/29377742","citation_count":14,"is_preprint":false},{"pmid":"33657974","id":"PMC_33657974","title":"A homozygous POC1B variant causes recessive cone-rod dystrophy.","date":"2021","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33657974","citation_count":8,"is_preprint":false},{"pmid":"41325109","id":"PMC_41325109","title":"MCPPIR promotes cardiomyocyte proliferation and cardiac repair via o8G oxidation of POC1B mRNA.","date":"2026","source":"Cardiovascular research","url":"https://pubmed.ncbi.nlm.nih.gov/41325109","citation_count":4,"is_preprint":false},{"pmid":"37246743","id":"PMC_37246743","title":"Phenotypic and genotypic features of POC1B-associated cone dystrophy.","date":"2023","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/37246743","citation_count":4,"is_preprint":false},{"pmid":"36094084","id":"PMC_36094084","title":"Seroreactivity against retinal proteins in a case of POC1B gene associated cone dystrophy with normal funduscopic appearance: a systematic approach to diagnosis.","date":"2022","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/36094084","citation_count":2,"is_preprint":false},{"pmid":"40170356","id":"PMC_40170356","title":"Severe Joubert syndrome in family with homozygous POC1B p.Arg106Pro variant is due to a co-inherited deep-intronic mutation in the neighboring CEP290 gene.","date":"2025","source":"HGG advances","url":"https://pubmed.ncbi.nlm.nih.gov/40170356","citation_count":0,"is_preprint":false},{"pmid":"41552296","id":"PMC_41552296","title":"Long non-coding RNA POC1B-AS1 depletion represses colorectal cancer progression through the microRNA-625-5p/FOXK1 axis.","date":"2025","source":"American journal of translational research","url":"https://pubmed.ncbi.nlm.nih.gov/41552296","citation_count":0,"is_preprint":false},{"pmid":"41293231","id":"PMC_41293231","title":"POC1B-associated cone-rod dystrophy with bilateral optic disc swelling: A novel clinical observation.","date":"2025","source":"American journal of ophthalmology case reports","url":"https://pubmed.ncbi.nlm.nih.gov/41293231","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":11450,"output_tokens":2522,"usd":0.03609,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9607,"output_tokens":2813,"usd":0.05918,"stage2_stop_reason":"end_turn"},"total_usd":0.09527,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2012,\n      \"finding\": \"POC1B localizes to centrioles and spindle poles independently of POC1A, with different dynamics. A fraction of POC1B remains stably associated with parental centrioles once incorporated. Co-depletion of POC1A and POC1B leads to loss of nascent centriole integrity and maturation, spindle organization defects (unequal or monopolar spindles), and failure of centriole duplication. POC1B (but not POC1A) is phosphorylated during mitosis, and depletion of POC1B alone is sufficient to perturb cell proliferation, indicating an additional independent function beyond the redundant centriole-integrity role.\",\n      \"method\": \"Isoform-specific antibodies, RNAi depletion, live-cell imaging, immunofluorescence, FRAP, and mitotic progression assays in human cells\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal localization, RNAi with defined cellular phenotypes, multiple orthogonal methods (antibody localization, FRAP, mitotic assays) in a single focused study\",\n      \"pmids\": [\"23015594\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"POC1B localizes to the basal body of the primary cilium in human RPE1 cells. Disease-associated missense variants p.Arg106Pro and p.Gln67del abolish this basal body localization. POC1B interacts with FAM161A (a connecting-cilium protein implicated in retinitis pigmentosa) as shown by yeast two-hybrid screening, co-immunoprecipitation, and colocalization; both p.Arg106Pro and p.Gln67del disrupt this interaction.\",\n      \"method\": \"Overexpression localization in RPE1 cells, yeast two-hybrid screening of retinal cDNA library, co-immunoprecipitation, colocalization assays, zebrafish morpholino knockdown with mRNA rescue\",\n      \"journal\": \"American journal of human genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (Y2H, reciprocal Co-IP, colocalization, in vivo rescue), replicated across mutant variants\",\n      \"pmids\": [\"25018096\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"POC1B localizes to the basal body and centriole adjacent to the connecting cilium of photoreceptors in human and mouse retina, and also to synapses of the outer plexiform layer. Knockdown of Poc1b in zebrafish causes shortened and reduced photoreceptor connecting cilia, cystic kidneys, and retinal degeneration.\",\n      \"method\": \"Immunofluorescence localization in human/mouse retina, zebrafish morpholino knockdown with phenotypic analysis\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization in tissue and in vivo loss-of-function, single lab, two orthogonal approaches\",\n      \"pmids\": [\"25044745\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Poc1b localizes to centrioles and spindle bundles during cell cycle progression and to the basal body of photoreceptor sensory cilia in rat retina. Morpholino knockdown of poc1b in zebrafish causes delayed retinal laminar development, shortened photoreceptor outer segments, impaired visual function, and broader ciliopathy phenotypes (curved body axis, heart defects, shortened Kupffer's vesicle cilia).\",\n      \"method\": \"Tagged recombinant protein expression in renal epithelial cells and rat retina, zebrafish morpholino knockdown with behavioral and morphological analysis\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization experiment with functional consequence (in vivo KD), single lab, two orthogonal methods\",\n      \"pmids\": [\"26188096\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In Drosophila melanogaster sperm, Poc1B is recruited to the giant centriole base during proximal centriole-like structure (PCL) formation in a Sas-6-dependent manner. Poc1B and Sas-6 co-localize in the PCL/centriole core, Poc1B affects cellular and PCL Sas-6 levels, and co-overexpression of Poc1B and Sas-6 induces formation of PCL-like structures. Poc1 mutant flies show disruption of ectopic PCL-like particles induced by Ana2/Sas-6 co-overexpression, indicating Poc1 proteins stabilize these structures.\",\n      \"method\": \"Immunofluorescence, genetic co-overexpression, Poc1 mutant fly analysis, co-localization studies in Drosophila\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo genetic epistasis and co-localization in Drosophila model, single lab, multiple complementary genetic and imaging methods\",\n      \"pmids\": [\"31387336\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"A homozygous frameshift variant (c.151delG) in POC1B causes loss of POC1B protein in sperm cells. In poc1b knock-in mice, this mutation results in oligoasthenoteratozoospermia (OAT) with abnormal formation of acrosomes and flagella, demonstrating POC1B is required for normal sperm ciliogenesis/flagella formation.\",\n      \"method\": \"Whole-exome sequencing, protein analysis of patient sperm, CRISPR/Cas9 knock-in mice, testicular histology, transmission electron microscopy\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — CRISPR knock-in mouse model with TEM ultrastructural analysis, corroborated by patient protein data, multiple orthogonal methods\",\n      \"pmids\": [\"37070736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"POC1B forms heterodimers with POC1A within the centriole lumen to organize an interaction network of inner scaffold proteins. The WD40 domain of POC1B localizes close to the centriole wall, while the POC5-interacting WD40 of POC1A resides in the centriole lumen. POC1B (via POC1A-POC1B heterodimers) interacts with the microtubule-binding proteins FAM161A and MDM1, which likely position POC5 tetramers near the centriole wall. Disruption of POC1B alone causes centriole microtubule defects; deletion of both POC1A and POC1B causes centriole disintegration.\",\n      \"method\": \"Co-immunoprecipitation, superresolution microscopy (localization mapping), genetic deletion/disruption in human cells, structural/functional interaction assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — multiple orthogonal methods (Co-IP, super-resolution localization, genetic knockouts with ultrastructural phenotypes) in a single rigorous study establishing domain-level mechanism\",\n      \"pmids\": [\"39543170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"HNRNPH1 represses POC1B mRNA via o8G oxidation-dependent post-transcriptional regulation. The piRNA MCPPIR prevents HNRNPH1-mediated repression of POC1B mRNA, maintaining POC1B protein levels. POC1B downstream maintains centrosome integrity, thereby promoting cardiomyocyte proliferation and cardiac repair. Cardiomyocyte-specific HNRNPH1 knockout enhances proliferative capacity consistent with de-repression of POC1B.\",\n      \"method\": \"Mass spectrometry, RNA pull-down assay (HNRNPH1-MCPPIR interaction), o8G-RNA immunoprecipitation sequencing (identifying POC1B as downstream target), cardiomyocyte-specific HNRNPH1 knockout mice, MCPPIR genetic ablation/overexpression in mice\",\n      \"journal\": \"Cardiovascular research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (MS, RNA pulldown, o8G-RIP-seq, conditional KO mice) in single lab identifying POC1B as downstream effector of centrosome integrity in cardiomyocytes\",\n      \"pmids\": [\"41325109\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"POC1B is an inner scaffold centriolar protein that forms POC1A-POC1B heterodimers within the centriole lumen, where its WD40 domain localizes near the centriole wall; together with POC5, FAM161A, and MDM1, it maintains centriole microtubule integrity, supports centriole duplication and ciliogenesis, is required for photoreceptor basal body function and connecting cilium formation, is essential for sperm flagella assembly, undergoes mitosis-specific phosphorylation with an independent role in cell cycle progression, and its mRNA is post-transcriptionally regulated by HNRNPH1-mediated o8G oxidation to control centrosome integrity in cardiomyocytes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"POC1B is a centriolar inner-scaffold protein that maintains centriole microtubule integrity, supports centriole duplication, and is required for ciliogenesis across tissues [#0, #6]. It forms heterodimers with POC1A within the centriole lumen, where its WD40 domain localizes close to the centriole wall and the heterodimer organizes an inner-scaffold interaction network with the microtubule-binding proteins FAM161A and MDM1 that position POC5; disruption of POC1B alone causes centriole microtubule defects, whereas loss of both POC1A and POC1B causes centriole disintegration [#6]. POC1B localizes to centrioles, spindle poles, and the basal body of primary and photoreceptor sensory cilia, and its interaction with the connecting-cilium protein FAM161A is required for basal body targeting [#1, #2]. Beyond a centriole-integrity role redundant with POC1A, POC1B is specifically phosphorylated during mitosis and is independently required for normal cell proliferation [#0]. POC1B function is essential in specialized ciliated cells: a homozygous frameshift variant abolishes sperm POC1B and causes oligoasthenoteratozoospermia with abnormal acrosome and flagella formation in knock-in mice [#5], and disease-associated POC1B variants that disrupt basal body localization and FAM161A binding underlie retinal and ciliopathy phenotypes [#1, #2]. POC1B protein levels are also set post-transcriptionally, with HNRNPH1-mediated o8G oxidation repressing POC1B mRNA to control centrosome integrity in cardiomyocytes [#7].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Establishing whether POC1B acts only redundantly with its paralog defined its dual role: it maintains nascent centriole integrity together with POC1A but also has an independent, mitosis-specific function.\",\n      \"evidence\": \"Isoform-specific antibody localization, FRAP, RNAi co-depletion and mitotic progression assays in human cells\",\n      \"pmids\": [\"23015594\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular target of the mitosis-specific phosphorylation and the kinase responsible were not identified\", \"The mechanistic basis of the proliferation defect independent of centriole integrity was not resolved\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Identifying a direct POC1B-FAM161A interaction and showing disease variants abolish basal body localization connected POC1B to connecting-cilium biology and human ciliopathy.\",\n      \"evidence\": \"Yeast two-hybrid, reciprocal Co-IP, colocalization in RPE1 cells, and zebrafish morpholino rescue, with two missense/deletion variants tested\",\n      \"pmids\": [\"25018096\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural interface between POC1B and FAM161A not defined\", \"How loss of the interaction translates into ciliary dysfunction at the molecular level unresolved\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Localization to photoreceptor basal body and connecting cilium with in vivo knockdown phenotypes tied POC1B loss to retinal degeneration and broader ciliopathy.\",\n      \"evidence\": \"Immunofluorescence in human/mouse retina and zebrafish morpholino knockdown\",\n      \"pmids\": [\"25044745\", \"26188096\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Morpholino phenotypes not confirmed with stable genetic mutants\", \"Synaptic outer-plexiform-layer localization role not mechanistically characterized\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Genetic epistasis in Drosophila sperm showed POC1B is recruited to centriole/PCL cores in a Sas-6-dependent manner and reciprocally stabilizes Sas-6-dependent structures, placing it in the centriole-assembly hierarchy.\",\n      \"evidence\": \"Co-localization, genetic co-overexpression, and Poc1 mutant analysis in Drosophila\",\n      \"pmids\": [\"31387336\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether the same Sas-6 dependency operates in mammalian centriole assembly not tested\", \"Biochemical nature of POC1B-Sas-6 stabilization unknown\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"A patient frameshift variant modeled in knock-in mice established POC1B as essential for mammalian sperm flagella and acrosome formation, extending its requirement to motile ciliogenesis.\",\n      \"evidence\": \"Whole-exome sequencing, patient sperm protein analysis, CRISPR knock-in mice, testicular histology and TEM\",\n      \"pmids\": [\"37070736\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular step in flagellar assembly that requires POC1B not pinpointed\", \"Relationship between sperm defects and the inner-scaffold function not directly connected\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Mapping the POC1A-POC1B heterodimer and its WD40 domain orientation within the centriole lumen resolved how POC1B organizes the inner scaffold via FAM161A, MDM1 and POC5.\",\n      \"evidence\": \"Co-IP, super-resolution localization mapping, and genetic deletion with ultrastructural phenotypes in human cells\",\n      \"pmids\": [\"39543170\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"High-resolution structure of the assembled scaffold not solved\", \"How the scaffold mechanically reinforces centriole microtubules not defined\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Discovery that HNRNPH1 represses POC1B mRNA through o8G oxidation, antagonized by a piRNA, revealed post-transcriptional control of POC1B as a lever for centrosome integrity and cardiomyocyte proliferation.\",\n      \"evidence\": \"Mass spectrometry, RNA pull-down, o8G-RIP-seq, and cardiomyocyte-specific HNRNPH1 knockout and piRNA manipulation in mice\",\n      \"pmids\": [\"41325109\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct demonstration that POC1B restoration alone rescues the cardiac phenotype not established\", \"Whether o8G regulation of POC1B operates outside cardiomyocytes unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The molecular identity and consequence of the mitosis-specific POC1B phosphorylation that drives its centriole-independent proliferation role remain undefined.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Responsible kinase and phosphosites unknown\", \"Mechanistic link between phosphorylation and cell cycle progression unresolved\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 6]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005814\", \"supporting_discovery_ids\": [0, 6]},\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [1, 2, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 6]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"complexes\": [\"POC1A-POC1B heterodimer\", \"centriole inner scaffold\"],\n    \"partners\": [\"POC1A\", \"FAM161A\", \"MDM1\", \"POC5\", \"Sas-6\", \"HNRNPH1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}