{"gene":"ODF2","run_date":"2026-06-10T05:19:52","timeline":{"discoveries":[{"year":2005,"finding":"ODF2 is indispensable for the formation of distal/subdistal appendages on mother centrioles and for the generation of primary cilia. In Odf2−/− mouse F9 cells, both distal and subdistal appendages disappear from mother centrioles, and primary cilia formation is completely suppressed; these defects are rescued by exogenous Odf2 expression.","method":"Knockout cell line (Odf2−/− F9 cells), immunofluorescence, ultrathin-section electron microscopy, rescue by exogenous expression","journal":"Nature cell biology","confidence":"High","confidence_rationale":"Tier 1/2 / Strong — genetic KO with defined structural and functional phenotype, rescue experiment, electron microscopy, replicated in subsequent studies","pmids":["15852003"],"is_preprint":false},{"year":2012,"finding":"Odf2 is required for basal foot formation on basal bodies of ciliated epithelia; loss of basal feet disrupts polarized alignment of basal bodies and coordinated ciliary beating, without affecting planar cell polarity or ciliogenesis per se. The C-terminal region of Odf2 (encoded by exons 6–7) is specifically required for basal foot formation.","method":"Conditional knockout mice (Odf2 ΔEx6,7/ΔEx6,7), phenotypic analysis of tracheal cilia beating, electron microscopy, immunofluorescence","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo knockout mouse model with multiple orthogonal readouts (EM, IF, ciliary beating assay, PCP analysis), independently consistent with prior work","pmids":["22265411"],"is_preprint":false},{"year":1997,"finding":"ODF2 (Odf84) interacts with the outer dense fiber protein ODF1 (Odf27) via leucine zippers; all leucine residues in the upstream leucine zipper of ODF2 are required for this interaction. ODF2 contains two C-terminal leucine zippers and localizes to outer dense fibers by fluorescence and immunoelectron microscopy.","method":"Yeast two-hybrid screen using Odf27 leucine zipper as bait, leucine-to-alanine mutagenesis, immunofluorescence, immunoelectron microscopy","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — yeast two-hybrid plus mutagenesis defining essential residues, immunolocalization; single lab but multiple orthogonal methods","pmids":["9045620"],"is_preprint":false},{"year":2009,"finding":"The hCenexin1 splice variant (but not hODF2 itself) localizes to somatic centrosomes via its variant-specific C-terminal extension. The C-terminal extension contains a Cdc2-phosphorylated S796 motif that recruits Plk1; this Plk1 interaction is required for proper recruitment of pericentrin and gamma-tubulin and for bipolar spindle formation. Earlier in the cell cycle, hCenexin1 recruits ninein and promotes primary cilia formation independently of Plk1.","method":"Expression of hODF2 vs. hCenexin1 constructs and deletion mutants in cells, Co-IP/interaction assays, immunofluorescence, phospho-mutant analysis (S796A), spindle phenotype analysis","journal":"Developmental cell","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction assays, phospho-mutant rescue, multiple functional readouts (spindle formation, cilia, ninein/pericentrin recruitment) in single study","pmids":["19386263"],"is_preprint":false},{"year":2013,"finding":"Distinct domains of ODF2/cenexin are required for different appendage types: amino acids 188–806 are required for ciliogenesis and transition fiber (distal appendage) formation, whereas aa 1–59 combined with aa 188–806 are additionally required for basal foot (subdistal appendage) formation. Transition fibers/distal appendages are required for ciliogenesis, while subdistal appendages stabilize centrosomal microtubules.","method":"Odf2-knockout F9 cells rescued with Odf2 deletion constructs, electron microscopy, immunofluorescence, microtubule stability assays","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1/2 / Strong — domain-deletion mapping in KO rescue system, EM validation, multiple constructs tested with structural and functional readouts","pmids":["24189274"],"is_preprint":false},{"year":2004,"finding":"ODF2 is a self-interacting protein that forms fibrillar structures in vivo and associates with microtubules in vitro (microtubule cosedimentation and coprecipitation). However, direct interaction with tubulin alone was not detected, suggesting the microtubule association is mediated by additional proteins.","method":"GFP-fusion expression in mammalian cells, in vitro microtubule cosedimentation, coprecipitation assay","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro coprecipitation and cosedimentation plus cell imaging, single lab, negative result for direct tubulin binding noted","pmids":["15340007"],"is_preprint":false},{"year":2011,"finding":"Trichoplein binds both Odf2 and ninein at the centrosome. Odf2 depletion inhibits trichoplein recruitment to the mother centriole subdistal region, whereas ninein depletion does not, placing Odf2 upstream of trichoplein in the hierarchical assembly. Trichoplein depletion abolishes ninein but not Odf2 recruitment, and depletion of each impairs microtubule anchoring at the centrosome.","method":"Co-immunoprecipitation, siRNA knockdown, immunocytochemistry, microtubule anchoring assay","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus genetic epistasis via sequential knockdowns, single lab","pmids":["21325031"],"is_preprint":false},{"year":2008,"finding":"A peptide of 42 amino acids specific to the Cenexin isoform (encoded by exon 3b) is necessary for targeting ODF2/Cenexin to the centrosome and primary cilia. The C-terminal coiled-coil region of ODF2 also contributes to centrosomal/ciliary targeting, presumably via self-association. Centrosomal targeting does not depend on dynein-mediated transport.","method":"Series of GFP-tagged deletion constructs transfected into NIH3T3 cells, immunofluorescence localization, dynein inhibition experiment","journal":"European journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — multiple deletion constructs with localization readouts, single lab","pmids":["18171590"],"is_preprint":false},{"year":2013,"finding":"Cenexin1 (ODF2 isoform 9), but not ODF2, is necessary and sufficient for primary cilia assembly in odf2−/− cells. Cenexin1 interacts with GTP-loaded Rab8a and localizes to distal/subdistal appendages, facilitating recruitment of the centriolar component Chibby, which is important for ciliogenesis. ODF2 localizes along the ciliary axoneme but does not support ciliogenesis.","method":"Rescue experiments in odf2−/− cells expressing ODF2 or Cenexin1, Co-IP (Rab8a interaction), immunofluorescence, Chibby recruitment assay","journal":"Cell cycle","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO rescue combined with Co-IP for Rab8a interaction, single lab","pmids":["23343771"],"is_preprint":false},{"year":2016,"finding":"Testis-specific serine/threonine kinase 4 (Tssk4) phosphorylates ODF2 at serine 76. The C-terminal region (aa 214–638) of Odf2 is required for its association with Tssk4. Phosphorylation at S76 was confirmed in vivo in mouse sperm by phospho-specific antibody and LC-MS/MS.","method":"Co-immunoprecipitation (Tssk4–Odf2 interaction), Ser/Thr/Lys-to-Ala point mutagenesis, in vivo phosphorylation confirmed by phospho-specific antibody and LC-MS/MS","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 1 / Moderate — in vitro/in vivo phosphorylation site identified by mutagenesis and mass spectrometry, single lab","pmids":["26961893"],"is_preprint":false},{"year":2019,"finding":"Cep128 associates with Odf2 (confirmed by co-immunoprecipitation) and is required for subdistal appendage (SDA) assembly downstream of Odf2. Cep128 knockdown causes dissociation of SDA components (centriolin, Ndel1, ninein, Cep170) from the centriole while Odf2 and distal appendage components remain; Cep128 KD also decreases centriolar microtubule stability.","method":"Super-resolution structured illumination microscopy (SR-SIM), co-immunoprecipitation, siRNA knockdown, immunofluorescence","journal":"Genes to cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus hierarchical knockdown epistasis with multiple SDA component readouts, single lab","pmids":["30623524"],"is_preprint":false},{"year":2018,"finding":"ODF2 maintains centrosome cohesion by restricting β-catenin accumulation at the centrosome. Depletion of ODF2 causes premature centrosome splitting and formation of tripolar spindles, associated with elevated centrosomal β-catenin levels.","method":"siRNA depletion of ODF2 in cultured cells, immunofluorescence for centrosome number and β-catenin localization, spindle analysis","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss-of-function with defined structural/molecular phenotype, single lab, single main method","pmids":["30257984"],"is_preprint":false},{"year":2014,"finding":"Transcription factor Pax6 directly regulates Odf2 gene activity. In Pax6-deficient cortex (Sey/Sey mutant), mother centriole appendages are lost, RGCs fail to form primary cilia and detach from the ventricular surface, impairing interkinetic nuclear migration. Mechanistically, Pax6 acts upstream of Odf2 to control centriole maturation in cortical progenitors.","method":"Pax6-deficient mouse mutant (Sey/Sey), promoter reporter assay for Odf2 transcription, immunofluorescence of centrosomal appendages and cilia, interkinetic nuclear migration analysis","journal":"Cellular and molecular life sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo genetic model plus promoter activity assay, single lab","pmids":["25352170"],"is_preprint":false},{"year":2019,"finding":"CCDC42 interacts with ODF2 (and ODF1) in the formation of the spermatid cytoskeleton. CCDC42 localizes to the manchette, head-to-tail coupling apparatus (HTCA), and sperm tail in spermatids, and also to the centrosome in somatic cells.","method":"Co-immunoprecipitation (CCDC42 with ODF2 and ODF1), immunofluorescence in spermatids and somatic cells","journal":"Frontiers in cell and developmental biology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single Co-IP/pulldown, single lab, limited mechanistic follow-up","pmids":["31475146"],"is_preprint":false},{"year":2013,"finding":"Odf2/Cenexin transcription is repressed in cycling cells but upregulated in quiescent cells. C/EBPα, c-Jun, and the JNK pathway activator MEKK1 can enhance Odf2 transcription in cycling cells. Neither Rfx3, Foxj1, nor other predicted transcription factors activate Odf2 transcription.","method":"Promoter-reporter (luciferase) assays, co-expression of transcription factors, qRT-PCR","journal":"Biochimica et biophysica acta","confidence":"Low","confidence_rationale":"Tier 3 / Weak — reporter assay, single lab, no ChIP confirmation","pmids":["23458833"],"is_preprint":false},{"year":2022,"finding":"FOXA1 is a transcriptional activator of Odf2/Cenexin. FOXA1 binds the Odf2 promoter (confirmed by ChIP), its knockdown decreases ODF2 protein levels and impairs primary cilia formation.","method":"Reporter gene assay, qRT-PCR, Western blot, ChIP, siRNA knockdown of FOXA1 with cilia formation assay","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP validation plus functional knockdown phenotype, multiple orthogonal methods, single lab","pmids":["36509813"],"is_preprint":false},{"year":2023,"finding":"ODF2 negatively regulates CP110 levels at centrioles/basal bodies to control primary cilia formation. Knockdown of ODF2 increases CP110 levels, while ODF2 overexpression alone is insufficient to promote ciliogenesis. Co-expression of ODF2 with HYLS1 produces tube-like structures, suggesting ODF2 acts as a scaffold for NEURL4 or HYLS1 to mediate CP110 degradation.","method":"siRNA knockdown of ODF2, overexpression experiments, rapamycin-mediated dimerization for targeted centriolar recruitment, immunofluorescence for CP110 levels and cilia","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss- and gain-of-function combined with protein recruitment assay, single lab, multiple experimental approaches","pmids":["37681926"],"is_preprint":false},{"year":2025,"finding":"In Xenopus, Odf2 localizes to the basal foot of basal bodies in multiciliated cells (MCCs). Morpholino-mediated knockdown of Odf2 impairs basal foot morphogenesis, reduces microtubule nucleation rate from basal bodies, causes cilia disorientation and reduced beating. Additionally, Odf2 is required for MCC motility and homotypic repulsion prior to surface emergence, with reduced migration speed altering MCC spacing.","method":"Morpholino knockdown in Xenopus embryo epidermis, electron microscopy, live imaging of basal body polarization and cilia beating, mathematical simulation of MCC spacing","journal":"Developmental biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo morpholino knockdown with EM and live imaging in ortholog model, single lab","pmids":["39864486"],"is_preprint":false}],"current_model":"ODF2/Cenexin is a scaffolding protein of the mother centriole distal and subdistal appendages (and their basal body equivalents, transition fibers and basal feet) that is essential for primary cilia formation, coordinated ciliary beating, centrosome cohesion, and spindle integrity: it interacts with ODF1 via leucine zippers in sperm outer dense fibers; its Cenexin1 splice variant localizes to somatic centrosomes via a 42-aa exon 3b extension, recruits Plk1 through Cdc2-phosphorylated S796, and promotes ciliogenesis through Rab8a and Chibby; distinct N-terminal domains specify subdistal versus distal appendage assembly; Odf2 acts upstream of trichoplein–ninein and Cep128 in hierarchical SDA assembly; it restrains centrosomal β-catenin to prevent premature centrosome splitting; it negatively regulates CP110 levels to license cilia formation; it is phosphorylated at S76 by Tssk4 in sperm; and its transcription is activated by FOXA1 and by the JNK pathway in a cell-cycle-dependent manner."},"narrative":{"mechanistic_narrative":"ODF2/Cenexin is a scaffolding protein of the mother centriole distal and subdistal appendages that is essential for the assembly of these structures and for primary cilia formation [PMID:15852003, PMID:24189274]. Loss of Odf2 eliminates both appendage types and completely abolishes ciliogenesis, and these defects are rescued by re-expression [PMID:15852003]; distinct N-terminal versus core domains specify subdistal (basal foot) versus distal (transition fiber) appendage assembly, with transition fibers licensing ciliogenesis and subdistal appendages stabilizing centrosomal microtubules [PMID:24189274]. In ciliated epithelia, the C-terminal region of Odf2 is specifically required to build the basal foot, whose loss disrupts polarized basal body alignment and coordinated ciliary beating without affecting planar cell polarity [PMID:22265411, PMID:39864486]. The Cenexin1 splice variant, distinguished by a 42-aa exon-3b extension that targets it to somatic centrosomes, is the isoform competent for ciliogenesis: it engages GTP-loaded Rab8a and recruits Chibby to appendages, and a Cdc2-phosphorylated S796 motif recruits Plk1 to promote pericentrin/gamma-tubulin loading and bipolar spindle formation [PMID:19386263, PMID:18171590, PMID:23343771]. Odf2 sits atop a hierarchical appendage-assembly pathway, acting upstream of trichoplein–ninein and of Cep128 to organize subdistal appendage components and centriolar microtubule anchoring [PMID:21325031, PMID:30623524]. It further maintains centrosome cohesion by restricting centrosomal β-catenin to prevent premature splitting and tripolar spindles [PMID:30257984], and negatively regulates CP110 levels to license cilia formation, acting as a scaffold for HYLS1 [PMID:37681926]. In sperm, ODF2 is a structural component of the outer dense fibers, interacting with ODF1 through its leucine zippers and phosphorylated at S76 by Tssk4 [PMID:9045620, PMID:26961893]. Odf2 transcription is activated by FOXA1, which is required for ciliogenesis, and by the JNK pathway in a cell-cycle-dependent manner [PMID:36509813, PMID:23458833].","teleology":[{"year":1997,"claim":"Established ODF2's original identity as a structural subunit of the sperm outer dense fibers, defining the leucine-zipper interaction that anchors it to ODF1.","evidence":"Yeast two-hybrid with leucine-to-alanine mutagenesis and immunoelectron microscopy in sperm","pmids":["9045620"],"confidence":"High","gaps":["Did not address any centrosomal or ciliary role","Stoichiometry and architecture of the ODF1–ODF2 fiber not resolved"]},{"year":2004,"claim":"Showed ODF2 self-associates into fibrillar structures and co-sediments with microtubules, but not via direct tubulin binding, implying its microtubule association is bridged by partner proteins.","evidence":"GFP-fusion imaging plus in vitro microtubule cosedimentation/coprecipitation","pmids":["15340007"],"confidence":"Medium","gaps":["Bridging factor not identified at this stage","In vitro biochemistry not linked to a cellular function"]},{"year":2005,"claim":"Defined ODF2 as indispensable for mother centriole distal/subdistal appendage formation and for primary ciliogenesis, moving it from a sperm structural protein to a core centriole appendage organizer.","evidence":"Odf2−/− F9 knockout cells with EM, immunofluorescence, and rescue","pmids":["15852003"],"confidence":"High","gaps":["Did not separate distal from subdistal appendage requirements","Molecular partners mediating appendage assembly unknown"]},{"year":2008,"claim":"Identified the Cenexin-specific 42-aa exon-3b peptide as the determinant for centrosome/cilia targeting, distinguishing the somatic isoform's localization from sperm ODF2 and showing targeting is dynein-independent.","evidence":"GFP-tagged deletion construct series in NIH3T3 cells with dynein inhibition","pmids":["18171590"],"confidence":"Medium","gaps":["The docking receptor recognizing the exon-3b peptide not identified","Functional consequence of differential targeting not tested here"]},{"year":2009,"claim":"Resolved isoform-specific function: hCenexin1 (not hODF2) localizes to centrosomes and recruits Plk1 via a Cdc2-phosphorylated S796 motif for bipolar spindle formation, while earlier recruiting ninein to promote ciliogenesis.","evidence":"ODF2 vs Cenexin1 constructs, S796A phospho-mutant, Co-IP, spindle/cilia phenotyping","pmids":["19386263"],"confidence":"High","gaps":["Did not establish how Plk1 activity feeds back on appendage assembly","Temporal switch between cilia and spindle functions not mechanistically dissected"]},{"year":2011,"claim":"Placed Odf2 upstream of trichoplein and ninein in a hierarchical subdistal appendage assembly pathway controlling centrosomal microtubule anchoring.","evidence":"Co-IP and sequential siRNA epistasis with microtubule anchoring assays","pmids":["21325031"],"confidence":"Medium","gaps":["Direct versus indirect Odf2–trichoplein binding not resolved","Single lab, no in vivo validation"]},{"year":2012,"claim":"Demonstrated in vivo that Odf2 builds the basal foot in ciliated epithelia, with the C-terminal exon-6/7 region specifically required, and that basal feet enforce polarized basal body alignment and coordinated beating.","evidence":"Conditional Odf2 ΔEx6,7 knockout mice with EM, IF, and tracheal ciliary beating assays","pmids":["22265411"],"confidence":"High","gaps":["How the basal foot mechanically directs beating polarity not resolved","Distinction from PCP machinery defined phenotypically but not molecularly"]},{"year":2013,"claim":"Mapped distinct ODF2 domains to distinct appendage types (aa 188–806 for transition fibers/ciliogenesis; aa 1–59 additionally for basal feet) and confirmed Cenexin1, not ODF2, supports ciliogenesis through Rab8a-GTP binding and Chibby recruitment.","evidence":"Domain-deletion KO rescue in F9 cells with EM; Rab8a Co-IP and Chibby recruitment assays in odf2−/− cells","pmids":["24189274","23343771"],"confidence":"High","gaps":["How the same scaffold partitions into structurally distinct appendages not explained","Whether axonemal ODF2 has any function unknown"]},{"year":2016,"claim":"Identified Tssk4 as the kinase phosphorylating ODF2 at S76 in sperm, adding a post-translational regulatory layer to its outer dense fiber role.","evidence":"Co-IP, point mutagenesis, phospho-specific antibody and LC-MS/MS in mouse sperm","pmids":["26961893"],"confidence":"Medium","gaps":["Functional consequence of S76 phosphorylation for fiber assembly not established","Single lab"]},{"year":2018,"claim":"Revealed a centrosome-cohesion function: ODF2 restrains centrosomal β-catenin to prevent premature centrosome splitting and tripolar spindles.","evidence":"siRNA depletion with centrosome-number, β-catenin, and spindle imaging","pmids":["30257984"],"confidence":"Medium","gaps":["Mechanism by which ODF2 limits β-catenin not defined","Single loss-of-function method"]},{"year":2019,"claim":"Extended the assembly hierarchy by showing Cep128 binds Odf2 and acts downstream to retain subdistal appendage components and stabilize centriolar microtubules.","evidence":"SR-SIM, Co-IP, and hierarchical siRNA knockdown of SDA components","pmids":["30623524"],"confidence":"Medium","gaps":["Direct binding interface not mapped","Order relative to trichoplein–ninein not fully reconciled"]},{"year":2022,"claim":"Defined a transcriptional input: FOXA1 binds the Odf2 promoter and is required for ODF2 expression and primary cilia formation, linking upstream gene regulation to ciliogenesis.","evidence":"ChIP, reporter assay, qRT-PCR, Western blot, and FOXA1 knockdown with cilia assay","pmids":["36509813"],"confidence":"Medium","gaps":["Whether FOXA1 control is cell-type restricted unknown","Relationship to cell-cycle-dependent JNK regulation not integrated"]},{"year":2023,"claim":"Showed ODF2 negatively regulates centriolar CP110 to license ciliogenesis and acts as a scaffold for HYLS1/NEURL4, indicating ODF2 controls cilia not only structurally but by modulating cilia-suppressor turnover.","evidence":"siRNA knockdown, overexpression, and rapamycin-induced centriolar recruitment with CP110/cilia imaging","pmids":["37681926"],"confidence":"Medium","gaps":["Whether ODF2 directly promotes CP110 degradation not demonstrated","ODF2 overexpression alone insufficient, implying additional rate-limiting factors"]},{"year":2025,"claim":"Confirmed conservation of Odf2 basal-foot function in Xenopus multiciliated cells and uncovered an unexpected role in pre-emergence cell motility and homotypic repulsion that sets MCC spacing.","evidence":"Morpholino knockdown in Xenopus epidermis with EM, live imaging, and spacing simulation","pmids":["39864486"],"confidence":"Medium","gaps":["Mechanism linking Odf2 to MCC migration unclear","Morpholino specificity not orthogonally validated"]},{"year":null,"claim":"How a single scaffold is partitioned into structurally distinct distal versus subdistal appendages, and how its appendage, centrosome-cohesion, CP110-regulatory, and sperm outer-dense-fiber functions are coordinated, remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of ODF2 within appendages","Direct enzymatic activity (if any) undefined","Integration of transcriptional, phospho, and scaffolding regulation not unified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[2,0,4]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[3,8,16]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[5,6]}],"localization":[{"term_id":"GO:0005815","term_label":"microtubule organizing center","supporting_discovery_ids":[0,3,4,7]},{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[0,1,8,17]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[2,5]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,4,1]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[3,11]}],"complexes":["mother centriole distal appendage (transition fibers)","mother centriole subdistal appendage (basal foot)","sperm outer dense fibers"],"partners":["ODF1","PLK1","RAB8A","CHIBBY","TRICHOPLEIN","CEP128","TSSK4","CCDC42"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q5BJF6","full_name":"Outer dense fiber protein 2","aliases":["Cenexin","Outer dense fiber of sperm tails protein 2"],"length_aa":829,"mass_kda":95.4,"function":"Seems to be a major component of sperm tail outer dense fibers (ODF). ODFs are filamentous structures located on the outside of the axoneme in the midpiece and principal piece of the mammalian sperm tail and may help to maintain the passive elastic structures and elastic recoil of the sperm tail. May have a modulating influence on sperm motility. Functions as a general scaffold protein that is specifically localized at the distal/subdistal appendages of mother centrioles. Component of the centrosome matrix required for the localization of PLK1 and NIN to the centrosomes. Required for the formation and/or maintenance of normal CETN1 assembly","subcellular_location":"Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Cell projection, cilium; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriole; Cytoplasm, cytoskeleton, spindle pole; Cell projection, cilium, flagellum","url":"https://www.uniprot.org/uniprotkb/Q5BJF6/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ODF2","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ODF2","total_profiled":1310},"omim":[{"mim_id":"620850","title":"SPERMATOGENIC FAILURE 94; SPGF94","url":"https://www.omim.org/entry/620850"},{"mim_id":"620667","title":"CENTROSOMAL PROTEIN, 128-KD; CEP128","url":"https://www.omim.org/entry/620667"},{"mim_id":"620496","title":"BASAL BODY ORIENTATION FACTOR 1; BBOF1","url":"https://www.omim.org/entry/620496"},{"mim_id":"620130","title":"OUTER DENSE FIBER OF SPERM TAILS 2-LIKE PROTEIN; ODF2L","url":"https://www.omim.org/entry/620130"},{"mim_id":"619829","title":"COILED-COIL DOMAIN-CONTAINING PROTEIN 146; CCDC146","url":"https://www.omim.org/entry/619829"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Primary cilium","reliability":"Supported"},{"location":"Centrosome","reliability":"Supported"},{"location":"Basal body","reliability":"Supported"},{"location":"Connecting piece","reliability":"Supported"},{"location":"Vesicles","reliability":"Additional"},{"location":"Microtubules","reliability":"Additional"},{"location":"Calyx","reliability":"Additional"},{"location":"Mid piece","reliability":"Additional"},{"location":"Principal piece","reliability":"Additional"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"testis","ntpm":292.3}],"url":"https://www.proteinatlas.org/search/ODF2"},"hgnc":{"alias_symbol":["ODF84","CT134"],"prev_symbol":[]},"alphafold":{"accession":"Q5BJF6","domains":[{"cath_id":"1.20.5","chopping":"126-240","consensus_level":"high","plddt":84.5459,"start":126,"end":240},{"cath_id":"1.20.5","chopping":"516-558","consensus_level":"medium","plddt":76.7665,"start":516,"end":558}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5BJF6","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5BJF6-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5BJF6-F1-predicted_aligned_error_v6.png","plddt_mean":78.06},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ODF2","jax_strain_url":"https://www.jax.org/strain/search?query=ODF2"},"sequence":{"accession":"Q5BJF6","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5BJF6.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5BJF6/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5BJF6"}},"corpus_meta":[{"pmid":"15852003","id":"PMC_15852003","title":"Odf2-deficient mother centrioles lack distal/subdistal appendages and the ability to generate primary cilia.","date":"2005","source":"Nature cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/15852003","citation_count":249,"is_preprint":false},{"pmid":"22265411","id":"PMC_22265411","title":"Coordinated ciliary beating requires Odf2-mediated polarization of basal bodies via basal feet.","date":"2012","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/22265411","citation_count":179,"is_preprint":false},{"pmid":"9045620","id":"PMC_9045620","title":"Interactional cloning of the 84-kDa major outer dense fiber protein Odf84. Leucine zippers mediate associations of Odf84 and Odf27.","date":"1997","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9045620","citation_count":86,"is_preprint":false},{"pmid":"19386263","id":"PMC_19386263","title":"Plk1-dependent and -independent roles of an ODF2 splice variant, hCenexin1, at the centrosome of somatic cells.","date":"2009","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/19386263","citation_count":75,"is_preprint":false},{"pmid":"24189274","id":"PMC_24189274","title":"Two appendages homologous between basal bodies and centrioles are formed using distinct Odf2 domains.","date":"2013","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/24189274","citation_count":73,"is_preprint":false},{"pmid":"15340007","id":"PMC_15340007","title":"Outer dense fibre protein 2 (ODF2) is a self-interacting centrosomal protein with affinity for microtubules.","date":"2004","source":"Journal of cell 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targeting of the genes ODF2 and UBQLN3 in spermatozoa of patients with oligoasthenozoospermia.","date":"2021","source":"Andrology","url":"https://pubmed.ncbi.nlm.nih.gov/33784796","citation_count":21,"is_preprint":false},{"pmid":"30257984","id":"PMC_30257984","title":"ODF2 maintains centrosome cohesion by restricting β-catenin accumulation.","date":"2018","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/30257984","citation_count":15,"is_preprint":false},{"pmid":"10072582","id":"PMC_10072582","title":"Human outer dense fiber gene, ODF2, localizes to chromosome 9q34.","date":"1998","source":"Cytogenetics and cell genetics","url":"https://pubmed.ncbi.nlm.nih.gov/10072582","citation_count":11,"is_preprint":false},{"pmid":"19756757","id":"PMC_19756757","title":"Mouse Odf2 localizes to centrosomes and basal bodies in adult tissues and to the photoreceptor primary cilium.","date":"2009","source":"Cell and tissue 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In Odf2−/− mouse F9 cells, both distal and subdistal appendages disappear from mother centrioles, and primary cilia formation is completely suppressed; these defects are rescued by exogenous Odf2 expression.\",\n      \"method\": \"Knockout cell line (Odf2−/− F9 cells), immunofluorescence, ultrathin-section electron microscopy, rescue by exogenous expression\",\n      \"journal\": \"Nature cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Strong — genetic KO with defined structural and functional phenotype, rescue experiment, electron microscopy, replicated in subsequent studies\",\n      \"pmids\": [\"15852003\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Odf2 is required for basal foot formation on basal bodies of ciliated epithelia; loss of basal feet disrupts polarized alignment of basal bodies and coordinated ciliary beating, without affecting planar cell polarity or ciliogenesis per se. The C-terminal region of Odf2 (encoded by exons 6–7) is specifically required for basal foot formation.\",\n      \"method\": \"Conditional knockout mice (Odf2 ΔEx6,7/ΔEx6,7), phenotypic analysis of tracheal cilia beating, electron microscopy, immunofluorescence\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo knockout mouse model with multiple orthogonal readouts (EM, IF, ciliary beating assay, PCP analysis), independently consistent with prior work\",\n      \"pmids\": [\"22265411\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"ODF2 (Odf84) interacts with the outer dense fiber protein ODF1 (Odf27) via leucine zippers; all leucine residues in the upstream leucine zipper of ODF2 are required for this interaction. ODF2 contains two C-terminal leucine zippers and localizes to outer dense fibers by fluorescence and immunoelectron microscopy.\",\n      \"method\": \"Yeast two-hybrid screen using Odf27 leucine zipper as bait, leucine-to-alanine mutagenesis, immunofluorescence, immunoelectron microscopy\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — yeast two-hybrid plus mutagenesis defining essential residues, immunolocalization; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"9045620\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The hCenexin1 splice variant (but not hODF2 itself) localizes to somatic centrosomes via its variant-specific C-terminal extension. The C-terminal extension contains a Cdc2-phosphorylated S796 motif that recruits Plk1; this Plk1 interaction is required for proper recruitment of pericentrin and gamma-tubulin and for bipolar spindle formation. Earlier in the cell cycle, hCenexin1 recruits ninein and promotes primary cilia formation independently of Plk1.\",\n      \"method\": \"Expression of hODF2 vs. hCenexin1 constructs and deletion mutants in cells, Co-IP/interaction assays, immunofluorescence, phospho-mutant analysis (S796A), spindle phenotype analysis\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction assays, phospho-mutant rescue, multiple functional readouts (spindle formation, cilia, ninein/pericentrin recruitment) in single study\",\n      \"pmids\": [\"19386263\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Distinct domains of ODF2/cenexin are required for different appendage types: amino acids 188–806 are required for ciliogenesis and transition fiber (distal appendage) formation, whereas aa 1–59 combined with aa 188–806 are additionally required for basal foot (subdistal appendage) formation. Transition fibers/distal appendages are required for ciliogenesis, while subdistal appendages stabilize centrosomal microtubules.\",\n      \"method\": \"Odf2-knockout F9 cells rescued with Odf2 deletion constructs, electron microscopy, immunofluorescence, microtubule stability assays\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Strong — domain-deletion mapping in KO rescue system, EM validation, multiple constructs tested with structural and functional readouts\",\n      \"pmids\": [\"24189274\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"ODF2 is a self-interacting protein that forms fibrillar structures in vivo and associates with microtubules in vitro (microtubule cosedimentation and coprecipitation). However, direct interaction with tubulin alone was not detected, suggesting the microtubule association is mediated by additional proteins.\",\n      \"method\": \"GFP-fusion expression in mammalian cells, in vitro microtubule cosedimentation, coprecipitation assay\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro coprecipitation and cosedimentation plus cell imaging, single lab, negative result for direct tubulin binding noted\",\n      \"pmids\": [\"15340007\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Trichoplein binds both Odf2 and ninein at the centrosome. Odf2 depletion inhibits trichoplein recruitment to the mother centriole subdistal region, whereas ninein depletion does not, placing Odf2 upstream of trichoplein in the hierarchical assembly. Trichoplein depletion abolishes ninein but not Odf2 recruitment, and depletion of each impairs microtubule anchoring at the centrosome.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, immunocytochemistry, microtubule anchoring assay\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus genetic epistasis via sequential knockdowns, single lab\",\n      \"pmids\": [\"21325031\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"A peptide of 42 amino acids specific to the Cenexin isoform (encoded by exon 3b) is necessary for targeting ODF2/Cenexin to the centrosome and primary cilia. The C-terminal coiled-coil region of ODF2 also contributes to centrosomal/ciliary targeting, presumably via self-association. Centrosomal targeting does not depend on dynein-mediated transport.\",\n      \"method\": \"Series of GFP-tagged deletion constructs transfected into NIH3T3 cells, immunofluorescence localization, dynein inhibition experiment\",\n      \"journal\": \"European journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — multiple deletion constructs with localization readouts, single lab\",\n      \"pmids\": [\"18171590\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Cenexin1 (ODF2 isoform 9), but not ODF2, is necessary and sufficient for primary cilia assembly in odf2−/− cells. Cenexin1 interacts with GTP-loaded Rab8a and localizes to distal/subdistal appendages, facilitating recruitment of the centriolar component Chibby, which is important for ciliogenesis. ODF2 localizes along the ciliary axoneme but does not support ciliogenesis.\",\n      \"method\": \"Rescue experiments in odf2−/− cells expressing ODF2 or Cenexin1, Co-IP (Rab8a interaction), immunofluorescence, Chibby recruitment assay\",\n      \"journal\": \"Cell cycle\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO rescue combined with Co-IP for Rab8a interaction, single lab\",\n      \"pmids\": [\"23343771\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Testis-specific serine/threonine kinase 4 (Tssk4) phosphorylates ODF2 at serine 76. The C-terminal region (aa 214–638) of Odf2 is required for its association with Tssk4. Phosphorylation at S76 was confirmed in vivo in mouse sperm by phospho-specific antibody and LC-MS/MS.\",\n      \"method\": \"Co-immunoprecipitation (Tssk4–Odf2 interaction), Ser/Thr/Lys-to-Ala point mutagenesis, in vivo phosphorylation confirmed by phospho-specific antibody and LC-MS/MS\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro/in vivo phosphorylation site identified by mutagenesis and mass spectrometry, single lab\",\n      \"pmids\": [\"26961893\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Cep128 associates with Odf2 (confirmed by co-immunoprecipitation) and is required for subdistal appendage (SDA) assembly downstream of Odf2. Cep128 knockdown causes dissociation of SDA components (centriolin, Ndel1, ninein, Cep170) from the centriole while Odf2 and distal appendage components remain; Cep128 KD also decreases centriolar microtubule stability.\",\n      \"method\": \"Super-resolution structured illumination microscopy (SR-SIM), co-immunoprecipitation, siRNA knockdown, immunofluorescence\",\n      \"journal\": \"Genes to cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus hierarchical knockdown epistasis with multiple SDA component readouts, single lab\",\n      \"pmids\": [\"30623524\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"ODF2 maintains centrosome cohesion by restricting β-catenin accumulation at the centrosome. Depletion of ODF2 causes premature centrosome splitting and formation of tripolar spindles, associated with elevated centrosomal β-catenin levels.\",\n      \"method\": \"siRNA depletion of ODF2 in cultured cells, immunofluorescence for centrosome number and β-catenin localization, spindle analysis\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss-of-function with defined structural/molecular phenotype, single lab, single main method\",\n      \"pmids\": [\"30257984\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Transcription factor Pax6 directly regulates Odf2 gene activity. In Pax6-deficient cortex (Sey/Sey mutant), mother centriole appendages are lost, RGCs fail to form primary cilia and detach from the ventricular surface, impairing interkinetic nuclear migration. Mechanistically, Pax6 acts upstream of Odf2 to control centriole maturation in cortical progenitors.\",\n      \"method\": \"Pax6-deficient mouse mutant (Sey/Sey), promoter reporter assay for Odf2 transcription, immunofluorescence of centrosomal appendages and cilia, interkinetic nuclear migration analysis\",\n      \"journal\": \"Cellular and molecular life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo genetic model plus promoter activity assay, single lab\",\n      \"pmids\": [\"25352170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CCDC42 interacts with ODF2 (and ODF1) in the formation of the spermatid cytoskeleton. CCDC42 localizes to the manchette, head-to-tail coupling apparatus (HTCA), and sperm tail in spermatids, and also to the centrosome in somatic cells.\",\n      \"method\": \"Co-immunoprecipitation (CCDC42 with ODF2 and ODF1), immunofluorescence in spermatids and somatic cells\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP/pulldown, single lab, limited mechanistic follow-up\",\n      \"pmids\": [\"31475146\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Odf2/Cenexin transcription is repressed in cycling cells but upregulated in quiescent cells. C/EBPα, c-Jun, and the JNK pathway activator MEKK1 can enhance Odf2 transcription in cycling cells. Neither Rfx3, Foxj1, nor other predicted transcription factors activate Odf2 transcription.\",\n      \"method\": \"Promoter-reporter (luciferase) assays, co-expression of transcription factors, qRT-PCR\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — reporter assay, single lab, no ChIP confirmation\",\n      \"pmids\": [\"23458833\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"FOXA1 is a transcriptional activator of Odf2/Cenexin. FOXA1 binds the Odf2 promoter (confirmed by ChIP), its knockdown decreases ODF2 protein levels and impairs primary cilia formation.\",\n      \"method\": \"Reporter gene assay, qRT-PCR, Western blot, ChIP, siRNA knockdown of FOXA1 with cilia formation assay\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP validation plus functional knockdown phenotype, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"36509813\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"ODF2 negatively regulates CP110 levels at centrioles/basal bodies to control primary cilia formation. Knockdown of ODF2 increases CP110 levels, while ODF2 overexpression alone is insufficient to promote ciliogenesis. Co-expression of ODF2 with HYLS1 produces tube-like structures, suggesting ODF2 acts as a scaffold for NEURL4 or HYLS1 to mediate CP110 degradation.\",\n      \"method\": \"siRNA knockdown of ODF2, overexpression experiments, rapamycin-mediated dimerization for targeted centriolar recruitment, immunofluorescence for CP110 levels and cilia\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss- and gain-of-function combined with protein recruitment assay, single lab, multiple experimental approaches\",\n      \"pmids\": [\"37681926\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In Xenopus, Odf2 localizes to the basal foot of basal bodies in multiciliated cells (MCCs). Morpholino-mediated knockdown of Odf2 impairs basal foot morphogenesis, reduces microtubule nucleation rate from basal bodies, causes cilia disorientation and reduced beating. Additionally, Odf2 is required for MCC motility and homotypic repulsion prior to surface emergence, with reduced migration speed altering MCC spacing.\",\n      \"method\": \"Morpholino knockdown in Xenopus embryo epidermis, electron microscopy, live imaging of basal body polarization and cilia beating, mathematical simulation of MCC spacing\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo morpholino knockdown with EM and live imaging in ortholog model, single lab\",\n      \"pmids\": [\"39864486\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ODF2/Cenexin is a scaffolding protein of the mother centriole distal and subdistal appendages (and their basal body equivalents, transition fibers and basal feet) that is essential for primary cilia formation, coordinated ciliary beating, centrosome cohesion, and spindle integrity: it interacts with ODF1 via leucine zippers in sperm outer dense fibers; its Cenexin1 splice variant localizes to somatic centrosomes via a 42-aa exon 3b extension, recruits Plk1 through Cdc2-phosphorylated S796, and promotes ciliogenesis through Rab8a and Chibby; distinct N-terminal domains specify subdistal versus distal appendage assembly; Odf2 acts upstream of trichoplein–ninein and Cep128 in hierarchical SDA assembly; it restrains centrosomal β-catenin to prevent premature centrosome splitting; it negatively regulates CP110 levels to license cilia formation; it is phosphorylated at S76 by Tssk4 in sperm; and its transcription is activated by FOXA1 and by the JNK pathway in a cell-cycle-dependent manner.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ODF2/Cenexin is a scaffolding protein of the mother centriole distal and subdistal appendages that is essential for the assembly of these structures and for primary cilia formation [#0, #4]. Loss of Odf2 eliminates both appendage types and completely abolishes ciliogenesis, and these defects are rescued by re-expression [#0]; distinct N-terminal versus core domains specify subdistal (basal foot) versus distal (transition fiber) appendage assembly, with transition fibers licensing ciliogenesis and subdistal appendages stabilizing centrosomal microtubules [#4]. In ciliated epithelia, the C-terminal region of Odf2 is specifically required to build the basal foot, whose loss disrupts polarized basal body alignment and coordinated ciliary beating without affecting planar cell polarity [#1, #17]. The Cenexin1 splice variant, distinguished by a 42-aa exon-3b extension that targets it to somatic centrosomes, is the isoform competent for ciliogenesis: it engages GTP-loaded Rab8a and recruits Chibby to appendages, and a Cdc2-phosphorylated S796 motif recruits Plk1 to promote pericentrin/gamma-tubulin loading and bipolar spindle formation [#3, #7, #8]. Odf2 sits atop a hierarchical appendage-assembly pathway, acting upstream of trichoplein\\u2013ninein and of Cep128 to organize subdistal appendage components and centriolar microtubule anchoring [#6, #10]. It further maintains centrosome cohesion by restricting centrosomal \\u03b2-catenin to prevent premature splitting and tripolar spindles [#11], and negatively regulates CP110 levels to license cilia formation, acting as a scaffold for HYLS1 [#16]. In sperm, ODF2 is a structural component of the outer dense fibers, interacting with ODF1 through its leucine zippers and phosphorylated at S76 by Tssk4 [#2, #9]. Odf2 transcription is activated by FOXA1, which is required for ciliogenesis, and by the JNK pathway in a cell-cycle-dependent manner [#15, #14].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Established ODF2's original identity as a structural subunit of the sperm outer dense fibers, defining the leucine-zipper interaction that anchors it to ODF1.\",\n      \"evidence\": \"Yeast two-hybrid with leucine-to-alanine mutagenesis and immunoelectron microscopy in sperm\",\n      \"pmids\": [\"9045620\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address any centrosomal or ciliary role\", \"Stoichiometry and architecture of the ODF1\\u2013ODF2 fiber not resolved\"]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Showed ODF2 self-associates into fibrillar structures and co-sediments with microtubules, but not via direct tubulin binding, implying its microtubule association is bridged by partner proteins.\",\n      \"evidence\": \"GFP-fusion imaging plus in vitro microtubule cosedimentation/coprecipitation\",\n      \"pmids\": [\"15340007\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Bridging factor not identified at this stage\", \"In vitro biochemistry not linked to a cellular function\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Defined ODF2 as indispensable for mother centriole distal/subdistal appendage formation and for primary ciliogenesis, moving it from a sperm structural protein to a core centriole appendage organizer.\",\n      \"evidence\": \"Odf2\\u2212/\\u2212 F9 knockout cells with EM, immunofluorescence, and rescue\",\n      \"pmids\": [\"15852003\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not separate distal from subdistal appendage requirements\", \"Molecular partners mediating appendage assembly unknown\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Identified the Cenexin-specific 42-aa exon-3b peptide as the determinant for centrosome/cilia targeting, distinguishing the somatic isoform's localization from sperm ODF2 and showing targeting is dynein-independent.\",\n      \"evidence\": \"GFP-tagged deletion construct series in NIH3T3 cells with dynein inhibition\",\n      \"pmids\": [\"18171590\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"The docking receptor recognizing the exon-3b peptide not identified\", \"Functional consequence of differential targeting not tested here\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Resolved isoform-specific function: hCenexin1 (not hODF2) localizes to centrosomes and recruits Plk1 via a Cdc2-phosphorylated S796 motif for bipolar spindle formation, while earlier recruiting ninein to promote ciliogenesis.\",\n      \"evidence\": \"ODF2 vs Cenexin1 constructs, S796A phospho-mutant, Co-IP, spindle/cilia phenotyping\",\n      \"pmids\": [\"19386263\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish how Plk1 activity feeds back on appendage assembly\", \"Temporal switch between cilia and spindle functions not mechanistically dissected\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Placed Odf2 upstream of trichoplein and ninein in a hierarchical subdistal appendage assembly pathway controlling centrosomal microtubule anchoring.\",\n      \"evidence\": \"Co-IP and sequential siRNA epistasis with microtubule anchoring assays\",\n      \"pmids\": [\"21325031\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct versus indirect Odf2\\u2013trichoplein binding not resolved\", \"Single lab, no in vivo validation\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Demonstrated in vivo that Odf2 builds the basal foot in ciliated epithelia, with the C-terminal exon-6/7 region specifically required, and that basal feet enforce polarized basal body alignment and coordinated beating.\",\n      \"evidence\": \"Conditional Odf2 \\u0394Ex6,7 knockout mice with EM, IF, and tracheal ciliary beating assays\",\n      \"pmids\": [\"22265411\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the basal foot mechanically directs beating polarity not resolved\", \"Distinction from PCP machinery defined phenotypically but not molecularly\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Mapped distinct ODF2 domains to distinct appendage types (aa 188\\u2013806 for transition fibers/ciliogenesis; aa 1\\u201359 additionally for basal feet) and confirmed Cenexin1, not ODF2, supports ciliogenesis through Rab8a-GTP binding and Chibby recruitment.\",\n      \"evidence\": \"Domain-deletion KO rescue in F9 cells with EM; Rab8a Co-IP and Chibby recruitment assays in odf2\\u2212/\\u2212 cells\",\n      \"pmids\": [\"24189274\", \"23343771\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the same scaffold partitions into structurally distinct appendages not explained\", \"Whether axonemal ODF2 has any function unknown\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Identified Tssk4 as the kinase phosphorylating ODF2 at S76 in sperm, adding a post-translational regulatory layer to its outer dense fiber role.\",\n      \"evidence\": \"Co-IP, point mutagenesis, phospho-specific antibody and LC-MS/MS in mouse sperm\",\n      \"pmids\": [\"26961893\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of S76 phosphorylation for fiber assembly not established\", \"Single lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Revealed a centrosome-cohesion function: ODF2 restrains centrosomal \\u03b2-catenin to prevent premature centrosome splitting and tripolar spindles.\",\n      \"evidence\": \"siRNA depletion with centrosome-number, \\u03b2-catenin, and spindle imaging\",\n      \"pmids\": [\"30257984\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which ODF2 limits \\u03b2-catenin not defined\", \"Single loss-of-function method\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Extended the assembly hierarchy by showing Cep128 binds Odf2 and acts downstream to retain subdistal appendage components and stabilize centriolar microtubules.\",\n      \"evidence\": \"SR-SIM, Co-IP, and hierarchical siRNA knockdown of SDA components\",\n      \"pmids\": [\"30623524\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding interface not mapped\", \"Order relative to trichoplein\\u2013ninein not fully reconciled\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined a transcriptional input: FOXA1 binds the Odf2 promoter and is required for ODF2 expression and primary cilia formation, linking upstream gene regulation to ciliogenesis.\",\n      \"evidence\": \"ChIP, reporter assay, qRT-PCR, Western blot, and FOXA1 knockdown with cilia assay\",\n      \"pmids\": [\"36509813\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether FOXA1 control is cell-type restricted unknown\", \"Relationship to cell-cycle-dependent JNK regulation not integrated\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showed ODF2 negatively regulates centriolar CP110 to license ciliogenesis and acts as a scaffold for HYLS1/NEURL4, indicating ODF2 controls cilia not only structurally but by modulating cilia-suppressor turnover.\",\n      \"evidence\": \"siRNA knockdown, overexpression, and rapamycin-induced centriolar recruitment with CP110/cilia imaging\",\n      \"pmids\": [\"37681926\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether ODF2 directly promotes CP110 degradation not demonstrated\", \"ODF2 overexpression alone insufficient, implying additional rate-limiting factors\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Confirmed conservation of Odf2 basal-foot function in Xenopus multiciliated cells and uncovered an unexpected role in pre-emergence cell motility and homotypic repulsion that sets MCC spacing.\",\n      \"evidence\": \"Morpholino knockdown in Xenopus epidermis with EM, live imaging, and spacing simulation\",\n      \"pmids\": [\"39864486\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism linking Odf2 to MCC migration unclear\", \"Morpholino specificity not orthogonally validated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How a single scaffold is partitioned into structurally distinct distal versus subdistal appendages, and how its appendage, centrosome-cohesion, CP110-regulatory, and sperm outer-dense-fiber functions are coordinated, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of ODF2 within appendages\", \"Direct enzymatic activity (if any) undefined\", \"Integration of transcriptional, phospho, and scaffolding regulation not unified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [2, 0, 4]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [3, 8, 16]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [5, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005815\", \"supporting_discovery_ids\": [0, 3, 4, 7]},\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [0, 1, 8, 17]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [2, 5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 4, 1]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [3, 11]}\n    ],\n    \"complexes\": [\n      \"mother centriole distal appendage (transition fibers)\",\n      \"mother centriole subdistal appendage (basal foot)\",\n      \"sperm outer dense fibers\"\n    ],\n    \"partners\": [\n      \"ODF1\",\n      \"Plk1\",\n      \"Rab8a\",\n      \"Chibby\",\n      \"trichoplein\",\n      \"Cep128\",\n      \"Tssk4\",\n      \"CCDC42\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":8,"faith_pct":100.0}}