{"gene":"CABYR","run_date":"2026-06-09T22:57:17","timeline":{"discoveries":[{"year":2002,"finding":"CABYR is a calcium-binding, tyrosine-phosphorylated fibrous sheath protein localizing to the principal piece of the human sperm flagellum; calcium binding to its acidic 86-kDa isoforms is acquired during in vitro capacitation and is dependent on phosphorylation (abolished by alkaline phosphatase treatment). The protein contains an RII dimerization domain homologous to PKA regulatory subunit RII, a putative EF hand-like motif, PXXP modules, and multiple predicted tyrosine phosphorylation sites.","method":"45Ca overlay on 2D gels, immunofluorescence localization to fibrous sheath, alkaline phosphatase dephosphorylation assay, cDNA cloning and domain analysis","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 1/2 / Strong — direct 45Ca-binding assay with phosphatase controls, subcellular localization, multiple orthogonal methods in the foundational paper","pmids":["11820818"],"is_preprint":false},{"year":2003,"finding":"Mouse CABYR is the authentic orthologue of human CABYR; it localizes to the principal piece of mouse epididymal spermatozoa, contains two coding regions (CR-A and CR-B), an RII dimerization domain, PXXP motifs, and extensin-like regions conserved with human CABYR.","method":"Cloning of mouse cDNA and genomic DNA, immunofluorescence localization, Northern blot, sequence comparison","journal":"Gene","confidence":"Medium","confidence_rationale":"Tier 2/3 / Moderate — immunofluorescence localization and sequence-based domain identification, single lab","pmids":["12801634"],"is_preprint":false},{"year":2005,"finding":"Calcium binding in CABYR is restricted to the CABYR-A coding region; recombinant CABYR-A binds calcium in vitro whereas recombinant CABYR-B does not. CABYR-B-containing isoforms are translated during spermiogenesis and assemble into the ribs and longitudinal columns of the fibrous sheath in the flagellar principal piece.","method":"Calcium overlay assay on recombinant proteins, immunofluorescence and immunoelectron microscopy with region-specific antibodies","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 1/2 / Strong — direct in vitro calcium-binding assay with recombinant proteins plus ultrastructural localization, multiple orthogonal methods","pmids":["16139264"],"is_preprint":false},{"year":2005,"finding":"Two non-testis-specific CABYR variants (281 and 379) interact with GSK3β via a proline-rich extensin-like domain (confirmed by yeast two-hybrid and GST pull-down), form dimers through that domain, and serve as substrates for GSK3β phosphorylation within the extensin-like domain (phosphorylation sites mapped by kinase assay).","method":"Yeast two-hybrid screening with GSK3β as bait, GST pull-down assay, in vitro kinase assay with phosphorylation-site mapping","journal":"Biochemical and biophysical research communications","confidence":"High","confidence_rationale":"Tier 1/2 / Moderate — yeast two-hybrid plus GST pull-down plus in vitro kinase assay, multiple orthogonal methods, single lab","pmids":["15752768"],"is_preprint":false},{"year":2007,"finding":"FSCB (fibrous sheath CABYR binding protein) is a direct binding partner of CABYR; FSCB is phosphorylated by protein kinase A in vitro and at native sites in mouse sperm, and is itself a calcium-binding protein (calcium overlay assay).","method":"Co-immunoprecipitation (identification of CABYR–FSCB interaction), in vitro PKA phosphorylation assay, calcium overlay assay, immunoelectron microscopy","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1/2 / Strong — multiple orthogonal in vitro assays (co-IP, kinase assay, calcium overlay) plus ultrastructural localization in one study","pmids":["17855365"],"is_preprint":false},{"year":2010,"finding":"CABYR isoforms oligomerize by forming dimers (80 kDa CABYR-A-only with 50 kDa CABYR-A/B variant), and then larger oligomers that assemble into the fibrous sheath. The RII domain of CABYR is required for binding to AKAP3/AKAP4 (deletion of RII domain abolishes this interaction) but is not required for binding to Ropporin, indicating CABYR uses a distinct region to bind Ropporin.","method":"Immunoprecipitation, yeast two-hybrid assay, RII domain deletion constructs, immunofluorescence, Western blot","journal":"Reproductive biology and endocrinology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, yeast two-hybrid, domain deletion mutagenesis; replicated and extended findings from other labs","pmids":["20731842"],"is_preprint":false},{"year":2011,"finding":"CABYR binds AKAP3 and Ropporin in the human sperm fibrous sheath; reciprocal co-immunoprecipitation confirmed the CABYR–AKAP3 complex, and yeast two-hybrid confirmed both interactions. CABYR binds AKAP3 via its RII domain but binds Ropporin through regions outside the RII-like domain.","method":"Reciprocal co-immunoprecipitation of insoluble fibrous sheath proteins followed by mass spectrometry and Western blot, yeast two-hybrid assay","journal":"Asian journal of andrology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP with MS validation plus yeast two-hybrid, replicating and extending PMID 20731842","pmids":["21240291"],"is_preprint":false},{"year":2011,"finding":"CABYR-a (but not CABYR-c) interacts with α-enolase in vivo in cancer cell lines, identifying α-enolase as a binding partner specific to this isoform.","method":"Co-immunoprecipitation from cancer cell lysates, Western blot confirmation","journal":"Oncology reports","confidence":"Medium","confidence_rationale":"Tier 3 / Weak — single Co-IP experiment, single lab, no reciprocal pull-down reported","pmids":["21274509"],"is_preprint":false},{"year":2013,"finding":"Knockdown of CABYR-a/b in non-small cell lung cancer cells reduces Akt phosphorylation (constitutively active Akt), decreases phospho-GSK-3β (Ser9), and increases p53 and p27, leading to increased chemosensitivity and apoptosis; rescue with constitutively active Akt partially restores drug resistance, placing CABYR-a/b upstream of Akt in a cancer cell survival pathway.","method":"shRNA knockdown, constitutively active Akt rescue transfection, Western blot for pathway components, cell viability and apoptosis assays in vitro and in vivo (xenograft)","journal":"Molecular cancer research","confidence":"Medium","confidence_rationale":"Tier 2/3 / Moderate — epistasis established by genetic rescue with constitutively active Akt, KD phenotype confirmed in vivo; single lab","pmids":["24362251"],"is_preprint":false},{"year":2016,"finding":"CABYR is essential for fibrous sheath integrity and progressive sperm motility; Cabyr-knockout male mice are severely subfertile with disorganized fibrous sheath ribs/columns and abnormal doublet microtubule configuration in the axoneme, demonstrating that CABYR is required for correct axonemal organization through its role in fibrous sheath assembly.","method":"CRISPR-Cas9 knockout in mice, fertility assays, electron microscopy of sperm ultrastructure, motility analysis","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO with specific structural and motility phenotypes, electron microscopic confirmation of axonemal defects","pmids":["27802166"],"is_preprint":false},{"year":2016,"finding":"Depletion of CABYR-a/b sensitizes lung cancer cells to TRAIL-induced apoptosis by decreasing YAP S127 phosphorylation (activating YAP) and increasing YAP/p73-mediated DR5 upregulation; double deletion of YAP and p73 abolishes DR5 upregulation and TRAIL-induced apoptosis in CABYR-a/b-knockdown cells, placing CABYR-a/b upstream of the YAP/p73/DR5 axis.","method":"shRNA knockdown of CABYR-a/b, loss- and gain-of-function of YAP and p73, Western blot for phospho-YAP/p73/DR5, apoptosis assays, agonistic DR5 antibody treatment","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 2/3 / Moderate — epistasis via double deletion and rescue, multiple pathway components tested, single lab","pmids":["26843620"],"is_preprint":false},{"year":2019,"finding":"CABYR (CBP86-IV isoform) binds phosphoglycerate kinase 2 (PGK2) in human spermatozoa, confirmed by reverse co-immunoprecipitation and yeast two-hybrid assay.","method":"Co-immunoprecipitation of recombinant CBP86-IV expressed in E. coli with mass spectrometry identification, reverse Co-IP in human sperm lysate, yeast two-hybrid","journal":"Andrologia","confidence":"Medium","confidence_rationale":"Tier 2/3 / Moderate — two orthogonal methods (reverse Co-IP and yeast two-hybrid) confirming the interaction, single lab","pmids":["30972801"],"is_preprint":false},{"year":2022,"finding":"CABYR is required for correct sperm swim-path chirality (clockwise path); in CABYR-knockout sperm, path chirality is preserved under defined cAMP/ADP/ATP/Mg2+ conditions using digital holographic microscopy, indicating CABYR in the fibrous sheath contributes to but is not absolutely required for path chirality.","method":"Digital holographic microscopy of detergent-extracted mouse sperm, Cabyr-knockout comparison, pharmacological manipulation of cAMP/ADP/ATP/Mg2+","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2/3 / Weak — direct motility analysis in KO vs WT under defined conditions, single lab, single method","pmids":["36142535"],"is_preprint":false},{"year":2010,"finding":"CABYR knockdown in human embryo 293T cells does not significantly affect NF-κB gene expression, indicating CABYR is not functionally linked to the NF-κB signaling pathway in this context (negative result).","method":"shRNA-mediated CABYR knockdown, quantitative real-time PCR for NF-κB expression","journal":"World journal of gastroenterology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single method (qPCR), single cell line, negative result with limited mechanistic follow-up","pmids":["20954286"],"is_preprint":false}],"current_model":"CABYR is a polymorphic, testis-enriched calcium-binding protein of the sperm flagellar fibrous sheath whose calcium-binding activity (restricted to the CABYR-A region) is acquired upon tyrosine/serine-threonine phosphorylation during capacitation; it oligomerizes via its RII dimerization domain to scaffold complexes with AKAP3, AKAP4, and Ropporin (RII-domain-dependent for AKAPs, RII-independent for Ropporin), is phosphorylated by GSK3β and interacts with PGK2, and is essential in vivo for fibrous sheath integrity, correct axonemal organization, and progressive sperm motility; in cancer contexts, CABYR-a/b activates Akt-dependent survival and the YAP/p73/DR5 apoptosis axis."},"narrative":{"mechanistic_narrative":"CABYR is a polymorphic, calcium-binding structural protein of the sperm flagellar fibrous sheath that organizes a phosphorylation-regulated scaffold required for sperm motility [PMID:11820818, PMID:27802166]. Its calcium-binding activity is restricted to the CABYR-A region and is acquired during capacitation in a phosphorylation-dependent manner, being abolished by dephosphorylation [PMID:11820818, PMID:16139264]. CABYR oligomerizes—first forming dimers of CABYR-A-only and CABYR-A/B isoforms, then higher-order oligomers that assemble into the ribs and longitudinal columns of the fibrous sheath—and uses its RII dimerization domain to scaffold AKAP3 and AKAP4, while binding Ropporin through a distinct, RII-independent region [PMID:16139264, PMID:20731842, PMID:21240291]. Additional partners place CABYR within a glycolytic and signaling microenvironment of the principal piece, including the calcium-binding partner FSCB, PGK2, and the GSK3β kinase that phosphorylates CABYR within its extensin-like domain [PMID:15752768, PMID:17855365, PMID:30972801]. In vivo, CABYR is essential for fibrous sheath integrity, correct axonemal doublet organization, and progressive, normally chiral sperm motility, with knockout males being severely subfertile [PMID:27802166, PMID:36142535]. Beyond its testis role, non-testis CABYR-a/b isoforms act in cancer cells upstream of an Akt-dependent survival program and a YAP/p73/DR5 apoptosis axis [PMID:24362251, PMID:26843620].","teleology":[{"year":2002,"claim":"Established CABYR as a novel calcium-binding flagellar protein whose calcium binding is coupled to capacitation-associated phosphorylation, linking a structural sperm protein to capacitation signaling.","evidence":"45Ca overlay on 2D gels with alkaline phosphatase controls, fibrous sheath immunolocalization, and cDNA/domain analysis in human sperm","pmids":["11820818"],"confidence":"High","gaps":["Specific calcium-binding residues/motif not biochemically mapped","Identity of the kinase(s) phosphorylating CABYR during capacitation not defined","Functional consequence of calcium binding for sheath assembly untested"]},{"year":2003,"claim":"Confirmed mouse CABYR as the authentic orthologue with conserved domain architecture and flagellar localization, enabling genetic study in a model organism.","evidence":"cDNA/genomic cloning, Northern blot, immunofluorescence localization, and sequence comparison in mouse","pmids":["12801634"],"confidence":"Medium","gaps":["No functional assay in mouse at this stage","Single-lab sequence-based domain assignment"]},{"year":2005,"claim":"Localized calcium-binding activity to the CABYR-A coding region and showed CABYR-B isoforms assemble structurally into fibrous sheath ribs and columns, separating the calcium-sensing and structural functions to distinct regions.","evidence":"Calcium overlay on recombinant CABYR-A vs CABYR-B, region-specific immunofluorescence and immunoelectron microscopy","pmids":["16139264"],"confidence":"High","gaps":["How calcium binding to CABYR-A modulates oligomer or sheath behavior not shown","Stoichiometry of CABYR-A vs CABYR-B isoforms in the sheath unresolved"]},{"year":2005,"claim":"Identified GSK3β as a kinase and interaction partner acting through the proline-rich extensin-like domain, and showed this domain mediates CABYR dimerization, defining a phosphorylation input distinct from capacitation tyrosine phosphorylation.","evidence":"Yeast two-hybrid, GST pull-down, and in vitro kinase assay with phosphosite mapping on non-testis CABYR variants","pmids":["15752768"],"confidence":"High","gaps":["Functional consequence of GSK3β phosphorylation on CABYR in sperm not established","Relationship between extensin-domain dimerization and RII-domain oligomerization unclear"]},{"year":2007,"claim":"Defined FSCB as a direct, PKA-phosphorylated and calcium-binding CABYR partner, extending the fibrous sheath complex to additional calcium- and kinase-regulated components.","evidence":"Co-immunoprecipitation, in vitro PKA assay, calcium overlay, and immunoelectron microscopy in mouse sperm","pmids":["17855365"],"confidence":"High","gaps":["Domain of CABYR mediating FSCB binding not mapped","Functional role of the CABYR–FSCB complex in motility untested"]},{"year":2010,"claim":"Resolved the oligomerization hierarchy and showed the RII domain is required for AKAP3/AKAP4 binding but dispensable for Ropporin binding, defining how CABYR uses separable interfaces to nucleate distinct sheath complexes.","evidence":"Immunoprecipitation, yeast two-hybrid, and RII-deletion constructs with Western blot and immunofluorescence","pmids":["20731842"],"confidence":"High","gaps":["Ropporin-binding region not positively mapped","Order of complex assembly during spermiogenesis not resolved"]},{"year":2011,"claim":"Confirmed the CABYR–AKAP3–Ropporin scaffold in human sperm with reciprocal Co-IP and MS, corroborating RII-dependent AKAP3 binding versus RII-independent Ropporin binding across species.","evidence":"Reciprocal Co-IP of insoluble fibrous sheath proteins with MS and Western blot, plus yeast two-hybrid in human sperm","pmids":["21240291"],"confidence":"High","gaps":["Higher-order architecture of the assembled complex not structurally defined"]},{"year":2011,"claim":"Extended CABYR interactions beyond sperm by identifying isoform-specific binding of CABYR-a to α-enolase in cancer cells, hinting at a glycolytic/metabolic association of non-testis isoforms.","evidence":"Co-immunoprecipitation from cancer cell lysates with Western blot confirmation","pmids":["21274509"],"confidence":"Medium","gaps":["Single Co-IP without reciprocal pull-down","Functional consequence of the α-enolase interaction not tested"]},{"year":2013,"claim":"Placed cancer CABYR-a/b upstream of Akt in a survival pathway, showing knockdown reduces Akt signaling and confers chemosensitivity, with constitutively active Akt rescuing resistance.","evidence":"shRNA knockdown with constitutively active Akt rescue, pathway Western blots, viability/apoptosis assays, and xenografts in NSCLC","pmids":["24362251"],"confidence":"Medium","gaps":["Mechanism linking CABYR-a/b to Akt activation undefined","Single lab; relevance to sperm CABYR function unclear"]},{"year":2016,"claim":"Demonstrated in vivo that CABYR is essential for fibrous sheath integrity and axonemal organization, causally connecting the scaffold to sperm ultrastructure and motility.","evidence":"CRISPR-Cas9 knockout mice with fertility assays, electron microscopy, and motility analysis","pmids":["27802166"],"confidence":"High","gaps":["Which CABYR domain/partner interaction underlies the structural defect not dissected","Calcium-binding contribution to the phenotype not isolated"]},{"year":2016,"claim":"Defined a second cancer axis by placing CABYR-a/b upstream of YAP/p73/DR5, where depletion activates YAP and sensitizes cells to TRAIL-induced apoptosis.","evidence":"shRNA knockdown with YAP/p73 loss- and gain-of-function, double deletion, phospho-Western blots, and apoptosis assays in lung cancer cells","pmids":["26843620"],"confidence":"Medium","gaps":["Direct molecular link between CABYR-a/b and YAP phosphorylation unknown","Single lab"]},{"year":2019,"claim":"Added PGK2 as a CABYR partner in human sperm, reinforcing association of CABYR with glycolytic enzymes in the flagellum.","evidence":"Co-IP of recombinant CBP86-IV with MS, reverse Co-IP in sperm lysate, and yeast two-hybrid","pmids":["30972801"],"confidence":"Medium","gaps":["Binding interface not mapped","Functional role in flagellar energy metabolism untested"]},{"year":2022,"claim":"Refined the motility phenotype by showing CABYR contributes to, but is not absolutely required for, clockwise sperm swim-path chirality under defined nucleotide conditions.","evidence":"Digital holographic microscopy of detergent-extracted KO vs WT mouse sperm with cAMP/ADP/ATP/Mg2+ manipulation","pmids":["36142535"],"confidence":"Medium","gaps":["Single method and lab","Mechanism by which the fibrous sheath sets chirality unresolved"]},{"year":null,"claim":"How capacitation-dependent calcium binding to CABYR-A mechanistically regulates oligomerization, partner assembly, and fibrous sheath remodeling remains unresolved, as does the molecular link between non-testis CABYR-a/b isoforms and the Akt and YAP/p73 pathways.","evidence":"No direct experiment in the timeline connects CABYR calcium binding to assembly state, or defines the biochemical effector linking cancer isoforms to their signaling outputs","pmids":[],"confidence":"Low","gaps":["No structural model of CABYR or its complexes","Calcium-binding consequence for sheath assembly untested in vivo","Direct effector linking CABYR-a/b to Akt/YAP not identified"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[5,6]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[2,9]}],"localization":[{"term_id":"GO:0005929","term_label":"cilium","supporting_discovery_ids":[0,2,9]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[2,9]}],"pathway":[{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[9]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[8,10]}],"complexes":["fibrous sheath"],"partners":["AKAP3","AKAP4","ROPN1","FSCB","GSK3B","PGK2","ENO1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O75952","full_name":"Calcium-binding tyrosine phosphorylation-regulated protein","aliases":["Calcium-binding protein 86","Cancer/testis antigen 88","CT88","Fibrousheathin II","Fibrousheathin-2","FSP-2","Testis-specific calcium-binding protein CBP86"],"length_aa":493,"mass_kda":52.8,"function":"May function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction. Isoform 1 binds calcium in vitro. Isoform 2 and isoform 6 probably bind calcium. Isoform 3 and isoform 5 do not bind calcium in vitro. Isoform 4 probably does not bind calcium","subcellular_location":"Nucleus; Cytoplasm; Cell projection, cilium, flagellum","url":"https://www.uniprot.org/uniprotkb/O75952/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/CABYR","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/CABYR","total_profiled":1310},"omim":[{"mim_id":"618304","title":"GLUTAMINE-RICH PROTEIN 2; QRICH2","url":"https://www.omim.org/entry/618304"},{"mim_id":"612135","title":"CALCIUM-BINDING TYROSINE PHOSPHORYLATION-REGULATED PROTEIN; CABYR","url":"https://www.omim.org/entry/612135"},{"mim_id":"611779","title":"FIBROUS SHEATH CABYR-BINDING PROTEIN; FSCB","url":"https://www.omim.org/entry/611779"},{"mim_id":"611757","title":"RHOPHILIN-ASSOCIATED TAIL PROTEIN 1; ROPN1","url":"https://www.omim.org/entry/611757"},{"mim_id":"611756","title":"RHOPHILIN ASSOCIATED TAIL PROTEIN 1-LIKE; ROPN1L","url":"https://www.omim.org/entry/611756"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Cytosol","reliability":"Supported"},{"location":"Principal piece","reliability":"Supported"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"testis","ntpm":287.9}],"url":"https://www.proteinatlas.org/search/CABYR"},"hgnc":{"alias_symbol":["FSP-2","CBP86","CT88"],"prev_symbol":[]},"alphafold":{"accession":"O75952","domains":[{"cath_id":"1.10.12","chopping":"10-71","consensus_level":"medium","plddt":92.1245,"start":10,"end":71}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O75952","model_url":"https://alphafold.ebi.ac.uk/files/AF-O75952-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O75952-F1-predicted_aligned_error_v6.png","plddt_mean":47.84},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=CABYR","jax_strain_url":"https://www.jax.org/strain/search?query=CABYR"},"sequence":{"accession":"O75952","fasta_url":"https://rest.uniprot.org/uniprotkb/O75952.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O75952/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O75952"}},"corpus_meta":[{"pmid":"11820818","id":"PMC_11820818","title":"CABYR, a novel calcium-binding tyrosine phosphorylation-regulated fibrous sheath protein involved in capacitation.","date":"2002","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/11820818","citation_count":160,"is_preprint":false},{"pmid":"27802166","id":"PMC_27802166","title":"CABYR is essential for fibrous sheath integrity and progressive motility in mouse spermatozoa.","date":"2016","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/27802166","citation_count":46,"is_preprint":false},{"pmid":"21240291","id":"PMC_21240291","title":"CABYR binds to AKAP3 and Ropporin in the human sperm fibrous sheath.","date":"2011","source":"Asian journal of andrology","url":"https://pubmed.ncbi.nlm.nih.gov/21240291","citation_count":39,"is_preprint":false},{"pmid":"17855365","id":"PMC_17855365","title":"FSCB, a novel protein kinase A-phosphorylated calcium-binding protein, is a CABYR-binding partner involved in late steps of fibrous sheath biogenesis.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17855365","citation_count":38,"is_preprint":false},{"pmid":"17317841","id":"PMC_17317841","title":"CABYR is a novel cancer-testis antigen in lung cancer.","date":"2007","source":"Clinical cancer research : an official journal of the American Association for Cancer Research","url":"https://pubmed.ncbi.nlm.nih.gov/17317841","citation_count":28,"is_preprint":false},{"pmid":"20731842","id":"PMC_20731842","title":"CABYR isoforms expressed in late steps of spermiogenesis bind with AKAPs and ropporin in mouse sperm fibrous sheath.","date":"2010","source":"Reproductive biology and endocrinology : RB&E","url":"https://pubmed.ncbi.nlm.nih.gov/20731842","citation_count":27,"is_preprint":false},{"pmid":"15752768","id":"PMC_15752768","title":"Characterization of two non-testis-specific CABYR variants that bind to GSK3beta with a proline-rich extensin-like domain.","date":"2005","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/15752768","citation_count":26,"is_preprint":false},{"pmid":"24362251","id":"PMC_24362251","title":"Knockdown of CABYR-a/b increases chemosensitivity of human non-small cell lung cancer cells through inactivation of Akt.","date":"2013","source":"Molecular cancer research : MCR","url":"https://pubmed.ncbi.nlm.nih.gov/24362251","citation_count":20,"is_preprint":false},{"pmid":"26843620","id":"PMC_26843620","title":"Depletion of CABYR-a/b sensitizes lung cancer cells to TRAIL-induced apoptosis through YAP/p73-mediated DR5 upregulation.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/26843620","citation_count":19,"is_preprint":false},{"pmid":"29247344","id":"PMC_29247344","title":"Molecular study of human sperm RNA: Ropporin and CABYR in asthenozoospermia.","date":"2017","source":"Journal of endocrinological investigation","url":"https://pubmed.ncbi.nlm.nih.gov/29247344","citation_count":17,"is_preprint":false},{"pmid":"16139264","id":"PMC_16139264","title":"Translation and assembly of CABYR coding region B in fibrous sheath and restriction of calcium binding to coding region A.","date":"2005","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/16139264","citation_count":15,"is_preprint":false},{"pmid":"12801634","id":"PMC_12801634","title":"Splicing in murine CABYR and its genomic structure.","date":"2003","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/12801634","citation_count":10,"is_preprint":false},{"pmid":"21274509","id":"PMC_21274509","title":"Expression of the sperm fibrous sheath protein CABYR in human cancers and identification of α-enolase as an interacting partner of CABYR-a.","date":"2011","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/21274509","citation_count":10,"is_preprint":false},{"pmid":"22285430","id":"PMC_22285430","title":"The expression and effects the CABYR-c transcript of CABYR gene in hepatocellular carcinoma.","date":"2012","source":"Bulletin du cancer","url":"https://pubmed.ncbi.nlm.nih.gov/22285430","citation_count":9,"is_preprint":false},{"pmid":"36142535","id":"PMC_36142535","title":"cAMP and the Fibrous Sheath Protein CABYR (Ca2+-Binding Tyrosine-Phosphorylation-Regulated Protein) Is Required for 4D Sperm Movement.","date":"2022","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/36142535","citation_count":5,"is_preprint":false},{"pmid":"38187237","id":"PMC_38187237","title":"FTHL17, PRM2, CABYR, CPXCR1, ADAM29, and CABS1 are highly expressed in colon cancer patients and are regulated in vitro by epigenetic alterations.","date":"2023","source":"Heliyon","url":"https://pubmed.ncbi.nlm.nih.gov/38187237","citation_count":5,"is_preprint":false},{"pmid":"25717016","id":"PMC_25717016","title":"Low-expressed testis-specific calcium-binding protein CBP86-IV (CABYR) is observed in idiopathic asthenozoospermia.","date":"2015","source":"World journal of urology","url":"https://pubmed.ncbi.nlm.nih.gov/25717016","citation_count":5,"is_preprint":false},{"pmid":"30972801","id":"PMC_30972801","title":"Testis-specific calcium-binding protein CBP86-IV (CABYR) binds with phosphoglycerate kinase 2 in vitro and in vivo experiment.","date":"2019","source":"Andrologia","url":"https://pubmed.ncbi.nlm.nih.gov/30972801","citation_count":2,"is_preprint":false},{"pmid":"20954286","id":"PMC_20954286","title":"CABYR RNAi plasmid construction and NF-κB signal transduction pathway.","date":"2010","source":"World journal of gastroenterology","url":"https://pubmed.ncbi.nlm.nih.gov/20954286","citation_count":0,"is_preprint":false},{"pmid":"33747357","id":"PMC_33747357","title":"The cancer testis antigens CABYR-a/b and CABYR-c are expressed in a subset of colorectal cancers and hold promise as targets for specific immunotherapy.","date":"2021","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/33747357","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":12121,"output_tokens":3522,"usd":0.044596,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11127,"output_tokens":4160,"usd":0.079817,"stage2_stop_reason":"end_turn"},"total_usd":0.124413,"stage1_batch_id":"msgbatch_01ACAxJQabDsht39JXeWG22d","stage2_batch_id":"msgbatch_01QEU22A9U5sbPTgsMzTmvSf","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"CABYR is a calcium-binding, tyrosine-phosphorylated fibrous sheath protein localizing to the principal piece of the human sperm flagellum; calcium binding to its acidic 86-kDa isoforms is acquired during in vitro capacitation and is dependent on phosphorylation (abolished by alkaline phosphatase treatment). The protein contains an RII dimerization domain homologous to PKA regulatory subunit RII, a putative EF hand-like motif, PXXP modules, and multiple predicted tyrosine phosphorylation sites.\",\n      \"method\": \"45Ca overlay on 2D gels, immunofluorescence localization to fibrous sheath, alkaline phosphatase dephosphorylation assay, cDNA cloning and domain analysis\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Strong — direct 45Ca-binding assay with phosphatase controls, subcellular localization, multiple orthogonal methods in the foundational paper\",\n      \"pmids\": [\"11820818\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"Mouse CABYR is the authentic orthologue of human CABYR; it localizes to the principal piece of mouse epididymal spermatozoa, contains two coding regions (CR-A and CR-B), an RII dimerization domain, PXXP motifs, and extensin-like regions conserved with human CABYR.\",\n      \"method\": \"Cloning of mouse cDNA and genomic DNA, immunofluorescence localization, Northern blot, sequence comparison\",\n      \"journal\": \"Gene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 / Moderate — immunofluorescence localization and sequence-based domain identification, single lab\",\n      \"pmids\": [\"12801634\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Calcium binding in CABYR is restricted to the CABYR-A coding region; recombinant CABYR-A binds calcium in vitro whereas recombinant CABYR-B does not. CABYR-B-containing isoforms are translated during spermiogenesis and assemble into the ribs and longitudinal columns of the fibrous sheath in the flagellar principal piece.\",\n      \"method\": \"Calcium overlay assay on recombinant proteins, immunofluorescence and immunoelectron microscopy with region-specific antibodies\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Strong — direct in vitro calcium-binding assay with recombinant proteins plus ultrastructural localization, multiple orthogonal methods\",\n      \"pmids\": [\"16139264\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Two non-testis-specific CABYR variants (281 and 379) interact with GSK3β via a proline-rich extensin-like domain (confirmed by yeast two-hybrid and GST pull-down), form dimers through that domain, and serve as substrates for GSK3β phosphorylation within the extensin-like domain (phosphorylation sites mapped by kinase assay).\",\n      \"method\": \"Yeast two-hybrid screening with GSK3β as bait, GST pull-down assay, in vitro kinase assay with phosphorylation-site mapping\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Moderate — yeast two-hybrid plus GST pull-down plus in vitro kinase assay, multiple orthogonal methods, single lab\",\n      \"pmids\": [\"15752768\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"FSCB (fibrous sheath CABYR binding protein) is a direct binding partner of CABYR; FSCB is phosphorylated by protein kinase A in vitro and at native sites in mouse sperm, and is itself a calcium-binding protein (calcium overlay assay).\",\n      \"method\": \"Co-immunoprecipitation (identification of CABYR–FSCB interaction), in vitro PKA phosphorylation assay, calcium overlay assay, immunoelectron microscopy\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Strong — multiple orthogonal in vitro assays (co-IP, kinase assay, calcium overlay) plus ultrastructural localization in one study\",\n      \"pmids\": [\"17855365\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"CABYR isoforms oligomerize by forming dimers (80 kDa CABYR-A-only with 50 kDa CABYR-A/B variant), and then larger oligomers that assemble into the fibrous sheath. The RII domain of CABYR is required for binding to AKAP3/AKAP4 (deletion of RII domain abolishes this interaction) but is not required for binding to Ropporin, indicating CABYR uses a distinct region to bind Ropporin.\",\n      \"method\": \"Immunoprecipitation, yeast two-hybrid assay, RII domain deletion constructs, immunofluorescence, Western blot\",\n      \"journal\": \"Reproductive biology and endocrinology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, yeast two-hybrid, domain deletion mutagenesis; replicated and extended findings from other labs\",\n      \"pmids\": [\"20731842\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CABYR binds AKAP3 and Ropporin in the human sperm fibrous sheath; reciprocal co-immunoprecipitation confirmed the CABYR–AKAP3 complex, and yeast two-hybrid confirmed both interactions. CABYR binds AKAP3 via its RII domain but binds Ropporin through regions outside the RII-like domain.\",\n      \"method\": \"Reciprocal co-immunoprecipitation of insoluble fibrous sheath proteins followed by mass spectrometry and Western blot, yeast two-hybrid assay\",\n      \"journal\": \"Asian journal of andrology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP with MS validation plus yeast two-hybrid, replicating and extending PMID 20731842\",\n      \"pmids\": [\"21240291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"CABYR-a (but not CABYR-c) interacts with α-enolase in vivo in cancer cell lines, identifying α-enolase as a binding partner specific to this isoform.\",\n      \"method\": \"Co-immunoprecipitation from cancer cell lysates, Western blot confirmation\",\n      \"journal\": \"Oncology reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single Co-IP experiment, single lab, no reciprocal pull-down reported\",\n      \"pmids\": [\"21274509\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Knockdown of CABYR-a/b in non-small cell lung cancer cells reduces Akt phosphorylation (constitutively active Akt), decreases phospho-GSK-3β (Ser9), and increases p53 and p27, leading to increased chemosensitivity and apoptosis; rescue with constitutively active Akt partially restores drug resistance, placing CABYR-a/b upstream of Akt in a cancer cell survival pathway.\",\n      \"method\": \"shRNA knockdown, constitutively active Akt rescue transfection, Western blot for pathway components, cell viability and apoptosis assays in vitro and in vivo (xenograft)\",\n      \"journal\": \"Molecular cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 / Moderate — epistasis established by genetic rescue with constitutively active Akt, KD phenotype confirmed in vivo; single lab\",\n      \"pmids\": [\"24362251\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CABYR is essential for fibrous sheath integrity and progressive sperm motility; Cabyr-knockout male mice are severely subfertile with disorganized fibrous sheath ribs/columns and abnormal doublet microtubule configuration in the axoneme, demonstrating that CABYR is required for correct axonemal organization through its role in fibrous sheath assembly.\",\n      \"method\": \"CRISPR-Cas9 knockout in mice, fertility assays, electron microscopy of sperm ultrastructure, motility analysis\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO with specific structural and motility phenotypes, electron microscopic confirmation of axonemal defects\",\n      \"pmids\": [\"27802166\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Depletion of CABYR-a/b sensitizes lung cancer cells to TRAIL-induced apoptosis by decreasing YAP S127 phosphorylation (activating YAP) and increasing YAP/p73-mediated DR5 upregulation; double deletion of YAP and p73 abolishes DR5 upregulation and TRAIL-induced apoptosis in CABYR-a/b-knockdown cells, placing CABYR-a/b upstream of the YAP/p73/DR5 axis.\",\n      \"method\": \"shRNA knockdown of CABYR-a/b, loss- and gain-of-function of YAP and p73, Western blot for phospho-YAP/p73/DR5, apoptosis assays, agonistic DR5 antibody treatment\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 / Moderate — epistasis via double deletion and rescue, multiple pathway components tested, single lab\",\n      \"pmids\": [\"26843620\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CABYR (CBP86-IV isoform) binds phosphoglycerate kinase 2 (PGK2) in human spermatozoa, confirmed by reverse co-immunoprecipitation and yeast two-hybrid assay.\",\n      \"method\": \"Co-immunoprecipitation of recombinant CBP86-IV expressed in E. coli with mass spectrometry identification, reverse Co-IP in human sperm lysate, yeast two-hybrid\",\n      \"journal\": \"Andrologia\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 / Moderate — two orthogonal methods (reverse Co-IP and yeast two-hybrid) confirming the interaction, single lab\",\n      \"pmids\": [\"30972801\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"CABYR is required for correct sperm swim-path chirality (clockwise path); in CABYR-knockout sperm, path chirality is preserved under defined cAMP/ADP/ATP/Mg2+ conditions using digital holographic microscopy, indicating CABYR in the fibrous sheath contributes to but is not absolutely required for path chirality.\",\n      \"method\": \"Digital holographic microscopy of detergent-extracted mouse sperm, Cabyr-knockout comparison, pharmacological manipulation of cAMP/ADP/ATP/Mg2+\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2/3 / Weak — direct motility analysis in KO vs WT under defined conditions, single lab, single method\",\n      \"pmids\": [\"36142535\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"CABYR knockdown in human embryo 293T cells does not significantly affect NF-κB gene expression, indicating CABYR is not functionally linked to the NF-κB signaling pathway in this context (negative result).\",\n      \"method\": \"shRNA-mediated CABYR knockdown, quantitative real-time PCR for NF-κB expression\",\n      \"journal\": \"World journal of gastroenterology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single method (qPCR), single cell line, negative result with limited mechanistic follow-up\",\n      \"pmids\": [\"20954286\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"CABYR is a polymorphic, testis-enriched calcium-binding protein of the sperm flagellar fibrous sheath whose calcium-binding activity (restricted to the CABYR-A region) is acquired upon tyrosine/serine-threonine phosphorylation during capacitation; it oligomerizes via its RII dimerization domain to scaffold complexes with AKAP3, AKAP4, and Ropporin (RII-domain-dependent for AKAPs, RII-independent for Ropporin), is phosphorylated by GSK3β and interacts with PGK2, and is essential in vivo for fibrous sheath integrity, correct axonemal organization, and progressive sperm motility; in cancer contexts, CABYR-a/b activates Akt-dependent survival and the YAP/p73/DR5 apoptosis axis.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"CABYR is a polymorphic, calcium-binding structural protein of the sperm flagellar fibrous sheath that organizes a phosphorylation-regulated scaffold required for sperm motility [#0, #9]. Its calcium-binding activity is restricted to the CABYR-A region and is acquired during capacitation in a phosphorylation-dependent manner, being abolished by dephosphorylation [#0, #2]. CABYR oligomerizes—first forming dimers of CABYR-A-only and CABYR-A/B isoforms, then higher-order oligomers that assemble into the ribs and longitudinal columns of the fibrous sheath—and uses its RII dimerization domain to scaffold AKAP3 and AKAP4, while binding Ropporin through a distinct, RII-independent region [#2, #5, #6]. Additional partners place CABYR within a glycolytic and signaling microenvironment of the principal piece, including the calcium-binding partner FSCB, PGK2, and the GSK3\\u03b2 kinase that phosphorylates CABYR within its extensin-like domain [#3, #4, #11]. In vivo, CABYR is essential for fibrous sheath integrity, correct axonemal doublet organization, and progressive, normally chiral sperm motility, with knockout males being severely subfertile [#9, #12]. Beyond its testis role, non-testis CABYR-a/b isoforms act in cancer cells upstream of an Akt-dependent survival program and a YAP/p73/DR5 apoptosis axis [#8, #10].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Established CABYR as a novel calcium-binding flagellar protein whose calcium binding is coupled to capacitation-associated phosphorylation, linking a structural sperm protein to capacitation signaling.\",\n      \"evidence\": \"45Ca overlay on 2D gels with alkaline phosphatase controls, fibrous sheath immunolocalization, and cDNA/domain analysis in human sperm\",\n      \"pmids\": [\"11820818\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Specific calcium-binding residues/motif not biochemically mapped\", \"Identity of the kinase(s) phosphorylating CABYR during capacitation not defined\", \"Functional consequence of calcium binding for sheath assembly untested\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Confirmed mouse CABYR as the authentic orthologue with conserved domain architecture and flagellar localization, enabling genetic study in a model organism.\",\n      \"evidence\": \"cDNA/genomic cloning, Northern blot, immunofluorescence localization, and sequence comparison in mouse\",\n      \"pmids\": [\"12801634\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No functional assay in mouse at this stage\", \"Single-lab sequence-based domain assignment\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Localized calcium-binding activity to the CABYR-A coding region and showed CABYR-B isoforms assemble structurally into fibrous sheath ribs and columns, separating the calcium-sensing and structural functions to distinct regions.\",\n      \"evidence\": \"Calcium overlay on recombinant CABYR-A vs CABYR-B, region-specific immunofluorescence and immunoelectron microscopy\",\n      \"pmids\": [\"16139264\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How calcium binding to CABYR-A modulates oligomer or sheath behavior not shown\", \"Stoichiometry of CABYR-A vs CABYR-B isoforms in the sheath unresolved\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Identified GSK3\\u03b2 as a kinase and interaction partner acting through the proline-rich extensin-like domain, and showed this domain mediates CABYR dimerization, defining a phosphorylation input distinct from capacitation tyrosine phosphorylation.\",\n      \"evidence\": \"Yeast two-hybrid, GST pull-down, and in vitro kinase assay with phosphosite mapping on non-testis CABYR variants\",\n      \"pmids\": [\"15752768\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of GSK3\\u03b2 phosphorylation on CABYR in sperm not established\", \"Relationship between extensin-domain dimerization and RII-domain oligomerization unclear\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Defined FSCB as a direct, PKA-phosphorylated and calcium-binding CABYR partner, extending the fibrous sheath complex to additional calcium- and kinase-regulated components.\",\n      \"evidence\": \"Co-immunoprecipitation, in vitro PKA assay, calcium overlay, and immunoelectron microscopy in mouse sperm\",\n      \"pmids\": [\"17855365\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Domain of CABYR mediating FSCB binding not mapped\", \"Functional role of the CABYR\\u2013FSCB complex in motility untested\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Resolved the oligomerization hierarchy and showed the RII domain is required for AKAP3/AKAP4 binding but dispensable for Ropporin binding, defining how CABYR uses separable interfaces to nucleate distinct sheath complexes.\",\n      \"evidence\": \"Immunoprecipitation, yeast two-hybrid, and RII-deletion constructs with Western blot and immunofluorescence\",\n      \"pmids\": [\"20731842\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Ropporin-binding region not positively mapped\", \"Order of complex assembly during spermiogenesis not resolved\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Confirmed the CABYR\\u2013AKAP3\\u2013Ropporin scaffold in human sperm with reciprocal Co-IP and MS, corroborating RII-dependent AKAP3 binding versus RII-independent Ropporin binding across species.\",\n      \"evidence\": \"Reciprocal Co-IP of insoluble fibrous sheath proteins with MS and Western blot, plus yeast two-hybrid in human sperm\",\n      \"pmids\": [\"21240291\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Higher-order architecture of the assembled complex not structurally defined\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Extended CABYR interactions beyond sperm by identifying isoform-specific binding of CABYR-a to \\u03b1-enolase in cancer cells, hinting at a glycolytic/metabolic association of non-testis isoforms.\",\n      \"evidence\": \"Co-immunoprecipitation from cancer cell lysates with Western blot confirmation\",\n      \"pmids\": [\"21274509\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single Co-IP without reciprocal pull-down\", \"Functional consequence of the \\u03b1-enolase interaction not tested\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Placed cancer CABYR-a/b upstream of Akt in a survival pathway, showing knockdown reduces Akt signaling and confers chemosensitivity, with constitutively active Akt rescuing resistance.\",\n      \"evidence\": \"shRNA knockdown with constitutively active Akt rescue, pathway Western blots, viability/apoptosis assays, and xenografts in NSCLC\",\n      \"pmids\": [\"24362251\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism linking CABYR-a/b to Akt activation undefined\", \"Single lab; relevance to sperm CABYR function unclear\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Demonstrated in vivo that CABYR is essential for fibrous sheath integrity and axonemal organization, causally connecting the scaffold to sperm ultrastructure and motility.\",\n      \"evidence\": \"CRISPR-Cas9 knockout mice with fertility assays, electron microscopy, and motility analysis\",\n      \"pmids\": [\"27802166\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Which CABYR domain/partner interaction underlies the structural defect not dissected\", \"Calcium-binding contribution to the phenotype not isolated\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Defined a second cancer axis by placing CABYR-a/b upstream of YAP/p73/DR5, where depletion activates YAP and sensitizes cells to TRAIL-induced apoptosis.\",\n      \"evidence\": \"shRNA knockdown with YAP/p73 loss- and gain-of-function, double deletion, phospho-Western blots, and apoptosis assays in lung cancer cells\",\n      \"pmids\": [\"26843620\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular link between CABYR-a/b and YAP phosphorylation unknown\", \"Single lab\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Added PGK2 as a CABYR partner in human sperm, reinforcing association of CABYR with glycolytic enzymes in the flagellum.\",\n      \"evidence\": \"Co-IP of recombinant CBP86-IV with MS, reverse Co-IP in sperm lysate, and yeast two-hybrid\",\n      \"pmids\": [\"30972801\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Binding interface not mapped\", \"Functional role in flagellar energy metabolism untested\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Refined the motility phenotype by showing CABYR contributes to, but is not absolutely required for, clockwise sperm swim-path chirality under defined nucleotide conditions.\",\n      \"evidence\": \"Digital holographic microscopy of detergent-extracted KO vs WT mouse sperm with cAMP/ADP/ATP/Mg2+ manipulation\",\n      \"pmids\": [\"36142535\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single method and lab\", \"Mechanism by which the fibrous sheath sets chirality unresolved\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How capacitation-dependent calcium binding to CABYR-A mechanistically regulates oligomerization, partner assembly, and fibrous sheath remodeling remains unresolved, as does the molecular link between non-testis CABYR-a/b isoforms and the Akt and YAP/p73 pathways.\",\n      \"evidence\": \"No direct experiment in the timeline connects CABYR calcium binding to assembly state, or defines the biochemical effector linking cancer isoforms to their signaling outputs\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No structural model of CABYR or its complexes\", \"Calcium-binding consequence for sheath assembly untested in vivo\", \"Direct effector linking CABYR-a/b to Akt/YAP not identified\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [5, 6]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [2, 9]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005929\", \"supporting_discovery_ids\": [0, 2, 9]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [2, 9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [9]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [8, 10]}\n    ],\n    \"complexes\": [\"fibrous sheath\"],\n    \"partners\": [\"AKAP3\", \"AKAP4\", \"ROPN1\", \"FSCB\", \"GSK3B\", \"PGK2\", \"ENO1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}