{"gene":"POC1B","run_date":"2026-04-28T19:45:44","timeline":{"discoveries":[{"year":2012,"finding":"POC1B localizes to centrioles and spindle poles; a fraction remains stably associated with parental centrioles while preventing incorporation into nascent centrioles when depleted. Co-depletion of POC1A and POC1B causes loss of nascent centriole integrity and maturation, failure of centriole duplication, and defects in spindle organization (unequal or monopolar spindles). POC1B, but not POC1A, is phosphorylated during mitosis, and depletion of POC1B alone is sufficient to perturb cell proliferation.","method":"Isoform-specific antibodies, RNAi depletion, live-cell imaging, immunofluorescence, cell cycle analysis in human cells","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 — reciprocal depletion with multiple orthogonal readouts (localization, spindle defects, proliferation), moderate evidence from single lab with rigorous controls","pmids":["23015594"],"is_preprint":false},{"year":2014,"finding":"POC1B wild-type protein localizes to the basal body of the primary cilium in retinal pigment epithelium cells; disease-associated missense variants p.Arg106Pro and p.Gln67del abolish this basal body localization. POC1B interacts with FAM161A (a ciliopathy-associated protein at the base of the photoreceptor connecting cilium), and this interaction is disrupted by the p.Arg106Pro and p.Gln67del variants.","method":"Overexpression in hTERT-RPE1 cells with immunofluorescence localization; yeast two-hybrid screening of human 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 — multiple orthogonal methods (Y2H, Co-IP, colocalization, in vivo rescue) from single study with functional validation of 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 and retinal degeneration, establishing POC1B as required for retinal integrity and ciliogenesis.","method":"Immunohistochemistry in human and mouse retina; zebrafish morpholino knockdown","journal":"Human mutation","confidence":"Medium","confidence_rationale":"Tier 2/3 — direct localization with functional in vivo knockdown, but single lab","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. Morpholino knockdown of poc1b in zebrafish results in delayed retinal laminar development, shortened photoreceptor outer segments, impaired visual function, and ciliopathy-associated defects (small eyes, curved body axis, heart defects, shortened cilia in Kupffer's vesicle).","method":"Tagged recombinant protein expression in renal epithelial cells and rat retina; zebrafish morpholino knockdown with visual behavior assays","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2/3 — direct localization plus in vivo loss-of-function with multiple phenotypic readouts, single lab","pmids":["26188096"],"is_preprint":false},{"year":2019,"finding":"In Drosophila, Poc1B is recruited to the giant centriole base during atypical centriole (PCL) formation in a Sas-6-dependent manner. Poc1B and Sas-6 colocalize in the PCL/centriole core, and co-overexpression of Poc1B and Sas-6 induces formation of PCL-like structures; Poc1 mutant flies show disruption of these ectopic structures, indicating that Poc1 proteins stabilize centriolar structures formed by Sas-6.","method":"Immunofluorescence, genetic epistasis (Poc1 mutant flies), overexpression assays in Drosophila","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 — genetic epistasis plus colocalization with functional overexpression data in Drosophila ortholog context","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 with abnormal acrosome and flagella formation, establishing POC1B as required for normal sperm development and flagellar cilia integrity.","method":"Whole-exome sequencing; protein analysis of patient biological samples; CRISPR/Cas9 knock-in mouse model; testicular histology; transmission electron microscopy of testes and sperm","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 1/2 — CRISPR knock-in mouse model with ultrastructural analysis (TEM) plus human patient protein data, moderate evidence","pmids":["37070736"],"is_preprint":false},{"year":2024,"finding":"POC1B forms heterodimers with POC1A within the centriole lumen, where the WD40 domain of POC1B localizes close to the centriole wall. POC1A-POC1B heterodimers organize an interaction network with POC5 and microtubule-binding proteins FAM161A and MDM1; FAM161A and MDM1 bind to POC1A-POC1B and likely position the POC5 tetramer near the centriole wall. Disruption of POC1B alone causes centriole microtubule defects, and deletion of both POC1A and POC1B causes centriole disintegration.","method":"Structural localization (super-resolution microscopy), co-immunoprecipitation/interaction network mapping, domain-function analysis, genetic deletion (POC1A, POC1B single and double knockouts) with electron microscopy of centriole ultrastructure","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1/2 — multiple orthogonal methods including structural localization, interaction network reconstitution, and genetic deletion with ultrastructural readouts","pmids":["39543170"],"is_preprint":false},{"year":2026,"finding":"POC1B mRNA is subject to o8G (8-oxoguanosine) oxidative modification; the piRNA MCPPIR prevents HNRNPH1-mediated repression of POC1B mRNA, thereby maintaining POC1B protein levels. POC1B acts downstream in the MCPPIR-HNRNPH1-POC1B axis to maintain centrosome integrity and promote cardiomyocyte proliferation.","method":"RNA pull-down, mass spectrometry (HNRNPH1 as binding partner of MCPPIR), o8G-RNA immunoprecipitation sequencing, cardiomyocyte-specific HNRNPH1 knockout mice, MCPPIR genetic ablation and overexpression in mice","journal":"Cardiovascular research","confidence":"Medium","confidence_rationale":"Tier 2 — o8G-RIP-seq plus genetic mouse models identify POC1B as downstream target, single lab with multiple methods","pmids":["41325109"],"is_preprint":false}],"current_model":"POC1B is a centriolar scaffold protein that, as part of a POC1A-POC1B heterodimer, organizes an inner centriole interaction network with POC5, FAM161A, and MDM1 to maintain centriole integrity, centriole duplication, and ciliogenesis; it localizes to the basal body of primary and photoreceptor sensory cilia, is required for photoreceptor outer segment development and sperm flagella formation, is phosphorylated during mitosis with independent roles in cell cycle progression, and its mRNA is regulated post-transcriptionally via o8G oxidation to control centrosome integrity in cardiomyocytes."},"narrative":{"teleology":[{"year":2012,"claim":"Resolving whether POC1 paralogs have distinct centriolar roles, this study showed POC1B stably associates with parental centrioles, is uniquely phosphorylated in mitosis, and is individually required for cell proliferation, while co-depletion with POC1A causes centriole integrity loss and spindle defects.","evidence":"RNAi depletion with isoform-specific antibodies, live-cell imaging, and cell cycle analysis in human cells","pmids":["23015594"],"confidence":"High","gaps":["The phosphorylation sites on POC1B and their functional consequences during mitosis were not mapped","Whether POC1B's centriolar role is purely structural or involves enzymatic/regulatory activity was not established","Interaction partners of POC1B within the centriole were unknown"]},{"year":2014,"claim":"Linking POC1B to ciliopathy, two studies demonstrated its localization to basal bodies of primary cilia and photoreceptor connecting cilia, its physical interaction with FAM161A, and that loss of POC1B in zebrafish causes photoreceptor degeneration and shortened connecting cilia.","evidence":"Yeast two-hybrid, co-immunoprecipitation, immunohistochemistry in human/mouse retina, zebrafish morpholino knockdown with mRNA rescue","pmids":["25018096","25044745"],"confidence":"High","gaps":["The precise mechanism by which POC1B supports connecting cilium formation versus maintenance was not distinguished","Whether FAM161A interaction is direct or within a larger complex was unresolved","The structural basis for disease-causing missense variants disrupting basal body localization was unknown"]},{"year":2015,"claim":"Extending the ciliary phenotype, zebrafish poc1b knockdown produced multi-organ ciliopathy features including impaired visual function, shortened Kupffer's vesicle cilia, and heart defects, broadening POC1B's role beyond the retina.","evidence":"Zebrafish morpholino knockdown with visual behavior assays and multi-organ phenotyping","pmids":["26188096"],"confidence":"Medium","gaps":["Whether these phenotypes reflect a general basal body defect versus tissue-specific POC1B functions was unclear","Morpholino off-target effects were not ruled out with genetic mutants"]},{"year":2019,"claim":"Addressing how POC1B contributes to centriole assembly, Drosophila studies showed Poc1B is recruited to the centriole base in a Sas-6-dependent manner and stabilizes Sas-6-nucleated centriolar structures.","evidence":"Genetic epistasis with Poc1 mutant flies and Sas-6 co-overexpression assays in Drosophila","pmids":["31387336"],"confidence":"Medium","gaps":["Direct biochemical interaction between Poc1B and Sas-6 was not demonstrated","Whether this stabilization mechanism is conserved in vertebrates was untested"]},{"year":2023,"claim":"Establishing POC1B as required for male fertility, a human frameshift variant and corresponding CRISPR knock-in mouse model demonstrated that loss of POC1B protein causes oligoasthenoteratozoospermia with defective acrosome and flagella.","evidence":"Whole-exome sequencing of infertile patient, CRISPR/Cas9 knock-in mouse, transmission electron microscopy of sperm","pmids":["37070736"],"confidence":"High","gaps":["Whether the flagellar defect is due to basal body dysfunction or axonemal assembly failure was not resolved","Rescue experiments restoring POC1B in the mouse model were not performed"]},{"year":2024,"claim":"Providing a molecular architecture for POC1B function, this study revealed POC1A-POC1B heterodimers organize a luminal interaction network with POC5, FAM161A, and MDM1 that positions these proteins near the centriole wall to maintain microtubule integrity.","evidence":"Super-resolution microscopy, co-immunoprecipitation network mapping, single and double genetic knockouts with electron microscopy of centriole ultrastructure","pmids":["39543170"],"confidence":"High","gaps":["Atomic-resolution structure of the POC1A-POC1B heterodimer and its interfaces with POC5/FAM161A/MDM1 is lacking","How the luminal network mechanistically stabilizes centriole wall microtubules is not defined","Whether this network is remodeled during centriole maturation or ciliogenesis was not addressed"]},{"year":2026,"claim":"Revealing a post-transcriptional regulatory layer, POC1B mRNA was identified as a target of o8G oxidative modification repressed by HNRNPH1, with the piRNA MCPPIR antagonizing this repression to maintain POC1B protein levels and centrosome integrity in cardiomyocytes.","evidence":"o8G-RIP-seq, RNA pull-down with mass spectrometry, cardiomyocyte-specific HNRNPH1 knockout and MCPPIR genetic ablation/overexpression in mice","pmids":["41325109"],"confidence":"Medium","gaps":["Whether o8G-mediated regulation of POC1B operates in cell types beyond cardiomyocytes is unknown","The specific o8G-modified sites on POC1B mRNA that mediate HNRNPH1 binding were not mapped","Independent replication of the MCPPIR-POC1B regulatory axis has not been reported"]},{"year":null,"claim":"Key unresolved questions include the atomic structure of the POC1A-POC1B heterodimer, the identity and functional significance of POC1B's mitotic phosphorylation sites, and the mechanism by which the luminal centriole network transitions to support basal body function during ciliogenesis.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structural data for the POC1B-containing luminal complex exist","The kinase(s) responsible for POC1B mitotic phosphorylation are unidentified","Whether POC1B has tissue-specific interaction partners in photoreceptors versus sperm is unexplored"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,6]}],"localization":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[0,1,2,3,6]},{"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":[0,4,6]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0]}],"complexes":["POC1A-POC1B heterodimer","POC1A-POC1B-POC5-FAM161A-MDM1 luminal network"],"partners":["POC1A","FAM161A","POC5","MDM1","SAS6","HNRNPH1"],"other_free_text":[]},"mechanistic_narrative":"POC1B is a centriolar scaffold protein essential for centriole integrity, ciliogenesis, and cell division. It forms heterodimers with POC1A in the centriole lumen, where its WD40 domain positions near the centriole wall to organize an inner interaction network with POC5, FAM161A, and MDM1 that maintains centriole microtubule architecture; disruption of POC1B alone causes microtubule defects, and co-deletion with POC1A leads to centriole disintegration [PMID:39543170, PMID:23015594]. POC1B localizes to basal bodies of primary and photoreceptor sensory cilia and interacts with FAM161A at the connecting cilium base; loss of POC1B in zebrafish and mice causes shortened photoreceptor outer segments, retinal degeneration, and defective sperm flagella formation, establishing it as a ciliopathy gene required for both retinal integrity and male fertility [PMID:25018096, PMID:25044745, PMID:37070736]. POC1B is phosphorylated during mitosis with independent roles in cell cycle progression, and its mRNA is post-transcriptionally regulated via o8G oxidative modification to sustain centrosome integrity in cardiomyocytes [PMID:23015594, PMID:41325109]."},"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":22,"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":19,"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":"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":"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":"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":"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":13,"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":7,"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":3,"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":3,"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":10680,"output_tokens":2343,"usd":0.033592},"stage2":{"model":"claude-opus-4-6","input_tokens":5614,"output_tokens":2412,"usd":0.132555},"total_usd":0.166147,"stage1_batch_id":"msgbatch_01SUR8NDzVrNmyszWyJeCct7","stage2_batch_id":"msgbatch_01G7Yfutko3cDWzejrwH5AMx","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; a fraction remains stably associated with parental centrioles while preventing incorporation into nascent centrioles when depleted. Co-depletion of POC1A and POC1B causes loss of nascent centriole integrity and maturation, failure of centriole duplication, and defects in spindle organization (unequal or monopolar spindles). POC1B, but not POC1A, is phosphorylated during mitosis, and depletion of POC1B alone is sufficient to perturb cell proliferation.\",\n      \"method\": \"Isoform-specific antibodies, RNAi depletion, live-cell imaging, immunofluorescence, cell cycle analysis in human cells\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal depletion with multiple orthogonal readouts (localization, spindle defects, proliferation), moderate evidence from single lab with rigorous controls\",\n      \"pmids\": [\"23015594\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"POC1B wild-type protein localizes to the basal body of the primary cilium in retinal pigment epithelium cells; disease-associated missense variants p.Arg106Pro and p.Gln67del abolish this basal body localization. POC1B interacts with FAM161A (a ciliopathy-associated protein at the base of the photoreceptor connecting cilium), and this interaction is disrupted by the p.Arg106Pro and p.Gln67del variants.\",\n      \"method\": \"Overexpression in hTERT-RPE1 cells with immunofluorescence localization; yeast two-hybrid screening of human 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 — multiple orthogonal methods (Y2H, Co-IP, colocalization, in vivo rescue) from single study with functional validation of 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 and retinal degeneration, establishing POC1B as required for retinal integrity and ciliogenesis.\",\n      \"method\": \"Immunohistochemistry in human and mouse retina; zebrafish morpholino knockdown\",\n      \"journal\": \"Human mutation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — direct localization with functional in vivo knockdown, but single lab\",\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. Morpholino knockdown of poc1b in zebrafish results in delayed retinal laminar development, shortened photoreceptor outer segments, impaired visual function, and ciliopathy-associated defects (small eyes, curved body axis, heart defects, shortened cilia in Kupffer's vesicle).\",\n      \"method\": \"Tagged recombinant protein expression in renal epithelial cells and rat retina; zebrafish morpholino knockdown with visual behavior assays\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 — direct localization plus in vivo loss-of-function with multiple phenotypic readouts, single lab\",\n      \"pmids\": [\"26188096\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In Drosophila, Poc1B is recruited to the giant centriole base during atypical centriole (PCL) formation in a Sas-6-dependent manner. Poc1B and Sas-6 colocalize in the PCL/centriole core, and co-overexpression of Poc1B and Sas-6 induces formation of PCL-like structures; Poc1 mutant flies show disruption of these ectopic structures, indicating that Poc1 proteins stabilize centriolar structures formed by Sas-6.\",\n      \"method\": \"Immunofluorescence, genetic epistasis (Poc1 mutant flies), overexpression assays in Drosophila\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — genetic epistasis plus colocalization with functional overexpression data in Drosophila ortholog context\",\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 with abnormal acrosome and flagella formation, establishing POC1B as required for normal sperm development and flagellar cilia integrity.\",\n      \"method\": \"Whole-exome sequencing; protein analysis of patient biological samples; CRISPR/Cas9 knock-in mouse model; testicular histology; transmission electron microscopy of testes and sperm\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — CRISPR knock-in mouse model with ultrastructural analysis (TEM) plus human patient protein data, moderate evidence\",\n      \"pmids\": [\"37070736\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"POC1B forms heterodimers with POC1A within the centriole lumen, where the WD40 domain of POC1B localizes close to the centriole wall. POC1A-POC1B heterodimers organize an interaction network with POC5 and microtubule-binding proteins FAM161A and MDM1; FAM161A and MDM1 bind to POC1A-POC1B and likely position the POC5 tetramer near the centriole wall. Disruption of POC1B alone causes centriole microtubule defects, and deletion of both POC1A and POC1B causes centriole disintegration.\",\n      \"method\": \"Structural localization (super-resolution microscopy), co-immunoprecipitation/interaction network mapping, domain-function analysis, genetic deletion (POC1A, POC1B single and double knockouts) with electron microscopy of centriole ultrastructure\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 — multiple orthogonal methods including structural localization, interaction network reconstitution, and genetic deletion with ultrastructural readouts\",\n      \"pmids\": [\"39543170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"POC1B mRNA is subject to o8G (8-oxoguanosine) oxidative modification; the piRNA MCPPIR prevents HNRNPH1-mediated repression of POC1B mRNA, thereby maintaining POC1B protein levels. POC1B acts downstream in the MCPPIR-HNRNPH1-POC1B axis to maintain centrosome integrity and promote cardiomyocyte proliferation.\",\n      \"method\": \"RNA pull-down, mass spectrometry (HNRNPH1 as binding partner of MCPPIR), o8G-RNA immunoprecipitation sequencing, cardiomyocyte-specific HNRNPH1 knockout mice, MCPPIR genetic ablation and overexpression in mice\",\n      \"journal\": \"Cardiovascular research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — o8G-RIP-seq plus genetic mouse models identify POC1B as downstream target, single lab with multiple methods\",\n      \"pmids\": [\"41325109\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"POC1B is a centriolar scaffold protein that, as part of a POC1A-POC1B heterodimer, organizes an inner centriole interaction network with POC5, FAM161A, and MDM1 to maintain centriole integrity, centriole duplication, and ciliogenesis; it localizes to the basal body of primary and photoreceptor sensory cilia, is required for photoreceptor outer segment development and sperm flagella formation, is phosphorylated during mitosis with independent roles in cell cycle progression, and its mRNA is regulated post-transcriptionally via o8G oxidation to control centrosome integrity in cardiomyocytes.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"POC1B is a centriolar scaffold protein essential for centriole integrity, ciliogenesis, and cell division. It forms heterodimers with POC1A in the centriole lumen, where its WD40 domain positions near the centriole wall to organize an inner interaction network with POC5, FAM161A, and MDM1 that maintains centriole microtubule architecture; disruption of POC1B alone causes microtubule defects, and co-deletion with POC1A leads to centriole disintegration [PMID:39543170, PMID:23015594]. POC1B localizes to basal bodies of primary and photoreceptor sensory cilia and interacts with FAM161A at the connecting cilium base; loss of POC1B in zebrafish and mice causes shortened photoreceptor outer segments, retinal degeneration, and defective sperm flagella formation, establishing it as a ciliopathy gene required for both retinal integrity and male fertility [PMID:25018096, PMID:25044745, PMID:37070736]. POC1B is phosphorylated during mitosis with independent roles in cell cycle progression, and its mRNA is post-transcriptionally regulated via o8G oxidative modification to sustain centrosome integrity in cardiomyocytes [PMID:23015594, PMID:41325109].\",\n  \"teleology\": [\n    {\n      \"year\": 2012,\n      \"claim\": \"Resolving whether POC1 paralogs have distinct centriolar roles, this study showed POC1B stably associates with parental centrioles, is uniquely phosphorylated in mitosis, and is individually required for cell proliferation, while co-depletion with POC1A causes centriole integrity loss and spindle defects.\",\n      \"evidence\": \"RNAi depletion with isoform-specific antibodies, live-cell imaging, and cell cycle analysis in human cells\",\n      \"pmids\": [\"23015594\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The phosphorylation sites on POC1B and their functional consequences during mitosis were not mapped\",\n        \"Whether POC1B's centriolar role is purely structural or involves enzymatic/regulatory activity was not established\",\n        \"Interaction partners of POC1B within the centriole were unknown\"\n      ]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Linking POC1B to ciliopathy, two studies demonstrated its localization to basal bodies of primary cilia and photoreceptor connecting cilia, its physical interaction with FAM161A, and that loss of POC1B in zebrafish causes photoreceptor degeneration and shortened connecting cilia.\",\n      \"evidence\": \"Yeast two-hybrid, co-immunoprecipitation, immunohistochemistry in human/mouse retina, zebrafish morpholino knockdown with mRNA rescue\",\n      \"pmids\": [\"25018096\", \"25044745\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The precise mechanism by which POC1B supports connecting cilium formation versus maintenance was not distinguished\",\n        \"Whether FAM161A interaction is direct or within a larger complex was unresolved\",\n        \"The structural basis for disease-causing missense variants disrupting basal body localization was unknown\"\n      ]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Extending the ciliary phenotype, zebrafish poc1b knockdown produced multi-organ ciliopathy features including impaired visual function, shortened Kupffer's vesicle cilia, and heart defects, broadening POC1B's role beyond the retina.\",\n      \"evidence\": \"Zebrafish morpholino knockdown with visual behavior assays and multi-organ phenotyping\",\n      \"pmids\": [\"26188096\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether these phenotypes reflect a general basal body defect versus tissue-specific POC1B functions was unclear\",\n        \"Morpholino off-target effects were not ruled out with genetic mutants\"\n      ]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Addressing how POC1B contributes to centriole assembly, Drosophila studies showed Poc1B is recruited to the centriole base in a Sas-6-dependent manner and stabilizes Sas-6-nucleated centriolar structures.\",\n      \"evidence\": \"Genetic epistasis with Poc1 mutant flies and Sas-6 co-overexpression assays in Drosophila\",\n      \"pmids\": [\"31387336\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct biochemical interaction between Poc1B and Sas-6 was not demonstrated\",\n        \"Whether this stabilization mechanism is conserved in vertebrates was untested\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Establishing POC1B as required for male fertility, a human frameshift variant and corresponding CRISPR knock-in mouse model demonstrated that loss of POC1B protein causes oligoasthenoteratozoospermia with defective acrosome and flagella.\",\n      \"evidence\": \"Whole-exome sequencing of infertile patient, CRISPR/Cas9 knock-in mouse, transmission electron microscopy of sperm\",\n      \"pmids\": [\"37070736\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether the flagellar defect is due to basal body dysfunction or axonemal assembly failure was not resolved\",\n        \"Rescue experiments restoring POC1B in the mouse model were not performed\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Providing a molecular architecture for POC1B function, this study revealed POC1A-POC1B heterodimers organize a luminal interaction network with POC5, FAM161A, and MDM1 that positions these proteins near the centriole wall to maintain microtubule integrity.\",\n      \"evidence\": \"Super-resolution microscopy, co-immunoprecipitation network mapping, single and double genetic knockouts with electron microscopy of centriole ultrastructure\",\n      \"pmids\": [\"39543170\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Atomic-resolution structure of the POC1A-POC1B heterodimer and its interfaces with POC5/FAM161A/MDM1 is lacking\",\n        \"How the luminal network mechanistically stabilizes centriole wall microtubules is not defined\",\n        \"Whether this network is remodeled during centriole maturation or ciliogenesis was not addressed\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Revealing a post-transcriptional regulatory layer, POC1B mRNA was identified as a target of o8G oxidative modification repressed by HNRNPH1, with the piRNA MCPPIR antagonizing this repression to maintain POC1B protein levels and centrosome integrity in cardiomyocytes.\",\n      \"evidence\": \"o8G-RIP-seq, RNA pull-down with mass spectrometry, cardiomyocyte-specific HNRNPH1 knockout and MCPPIR genetic ablation/overexpression in mice\",\n      \"pmids\": [\"41325109\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether o8G-mediated regulation of POC1B operates in cell types beyond cardiomyocytes is unknown\",\n        \"The specific o8G-modified sites on POC1B mRNA that mediate HNRNPH1 binding were not mapped\",\n        \"Independent replication of the MCPPIR-POC1B regulatory axis has not been reported\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Key unresolved questions include the atomic structure of the POC1A-POC1B heterodimer, the identity and functional significance of POC1B's mitotic phosphorylation sites, and the mechanism by which the luminal centriole network transitions to support basal body function during ciliogenesis.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No high-resolution structural data for the POC1B-containing luminal complex exist\",\n        \"The kinase(s) responsible for POC1B mitotic phosphorylation are unidentified\",\n        \"Whether POC1B has tissue-specific interaction partners in photoreceptors versus sperm is unexplored\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [0, 1, 2, 3, 6]},\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [1, 2, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 4, 6]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"complexes\": [\n      \"POC1A-POC1B heterodimer\",\n      \"POC1A-POC1B-POC5-FAM161A-MDM1 luminal network\"\n    ],\n    \"partners\": [\n      \"POC1A\",\n      \"FAM161A\",\n      \"POC5\",\n      \"MDM1\",\n      \"SAS6\",\n      \"HNRNPH1\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}