{"gene":"ACRV1","run_date":"2026-06-09T22:02:39","timeline":{"discoveries":[{"year":1990,"finding":"SP-10 (ACRV1) is an intra-acrosomal protein localized throughout the acrosome, specifically in a bilaminar array associated with the inner aspect of the outer acrosomal membrane and the outer aspect of the inner acrosomal membrane; after the acrosome reaction it remains displayed on the sperm head associated with the inner acrosomal membrane and equatorial segment.","method":"Light and electron microscopic immunocytochemistry with monoclonal antibody MHS-10; immunofluorescence on ejaculated sperm","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 2 / Strong — direct immunolocalization at EM resolution replicated across multiple subsequent studies","pmids":["2310816"],"is_preprint":false},{"year":1990,"finding":"SP-10 (ACRV1) encodes a 265-amino acid protein with a hydrophobic signal peptide at the N-terminus and a central region containing three types of amino acid repeats occurring 16 times; alternative splicing generates at least two SP-10 mRNAs (including one with a 57-bp in-frame deletion); the protein is unique with no homology to other known sequences.","method":"cDNA cloning, sequencing, and deduced amino acid analysis from human testis cDNA library; recombinant protein expression and immunoblotting","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 1 / Strong — direct sequencing plus recombinant expression with functional antibody validation, replicated by subsequent structural studies","pmids":["1693291"],"is_preprint":false},{"year":1992,"finding":"SP-10 heterogeneity (17.5–34 kDa peptides) results from endoproteolytic cleavage at five different peptide bonds (following arginine, serine, proline, glycine, and glutamic acid), consistent with action of a trypsin-like protease (possibly acrosin) and previously undescribed intra-acrosomal protease specificities.","method":"Purification by monoclonal antibody affinity chromatography, reverse-phase HPLC, and preparative gel electrophoresis; Edman degradation sequencing of eight SP-10 peptides","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 1 / Moderate — direct Edman sequencing of purified peptides identified cleavage sites; single lab but multiple peptides analyzed with rigorous biochemical fractionation","pmids":["1637938"],"is_preprint":false},{"year":1992,"finding":"SP-10 is a hydrophilic peripheral acrosomal membrane protein (not an integral membrane protein), associated with the acrosomal membranes via a TX-114-resistant anchor; a chaotropic salt (sodium thiocyanate) and pH extremes fully release this TX-114-resistant pool, whereas repeated TX-114 or 1.5 M NaCl washes do not.","method":"Triton X-114 phase partitioning, sequential chemical extractions (NaCl, sodium thiocyanate, pH 2.0 and 10.0), Western blotting","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 1 / Moderate — reconstitution-level biochemical fractionation with multiple orthogonal extraction conditions in single rigorous study","pmids":["1591355"],"is_preprint":false},{"year":1994,"finding":"A full-length ~45 kDa SP-10 precursor is present in testis and is proteolytically processed to 32–26 kDa peptides in testis and/or via alternative splicing; further processing to 25–18 kDa peptides occurs in the initial segment or caput epididymidis; no additional processing occurs during epididymal transit, ejaculation, or capacitation. After the acrosome reaction, SP-10 is concentrated on the inner acrosomal membrane of the equatorial segment and associated with hybrid vesicles.","method":"Western blot of testis, caput/cauda epididymal, ejaculated, and capacitated sperm extracts; electron microscopic immunocytochemistry with colloidal gold","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 1–2 / Moderate — multiple fractionation steps with EM-level localization, single lab, two orthogonal methods","pmids":["7888499"],"is_preprint":false},{"year":1996,"finding":"Anti-SP-10 antibodies inhibit bovine in vitro fertilization by reducing sperm-zona secondary binding and reducing the ability of capacitated spermatozoa to complete the acrosome reaction; they also reduce motility of capacitated (but not noncapacitated) spermatozoa.","method":"Bovine in vitro fertilization assay with monoclonal and polyclonal anti-SP-10 antibodies; indirect immunofluorescence; immunoblotting","journal":"Journal of reproduction and fertility","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional fertilization assay with multiple antibody types, single lab","pmids":["8882296"],"is_preprint":false},{"year":1999,"finding":"A 294-bp proximal promoter region (-266 to +28 bp) of the mouse SP-10 (Acrv1) gene is sufficient to direct round spermatid-specific transcription in vivo; the core promoter lacks a TATA box but contains a canonical initiator (Inr) element at the transcription start site; the -91/+28 fragment lacks promoter activity.","method":"Transgenic mouse reporter assays with GFP under control of defined SP-10 promoter deletion constructs; in situ hybridization for mRNA localization","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 2 / Strong — transgenic mouse functional promoter dissection replicated in subsequent studies","pmids":["10529272"],"is_preprint":false},{"year":2000,"finding":"SP-10 expressed on the equatorial region of acrosome-reacted sperm mediates sperm-oolemma binding in a beta-1 integrin-independent manner, but does not mediate sperm-zona binding.","method":"Monoclonal antibody inhibition assay using zona-free hamster egg penetration test (sperm-oolemma binding) and hemizona assay (sperm-zona binding); sperm-cultured cell binding assay using F9 cells with and without beta-1 integrins","journal":"Biology of reproduction","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional antibody inhibition with two orthogonal binding assays, single lab","pmids":["10775167"],"is_preprint":false},{"year":2003,"finding":"The SP-10 proximal promoter (-408/-92 region) functions as an insulator in somatic cells by blocking enhancer-promoter interactions in a position- and orientation-dependent manner; insulator activity maps to the -186/-135 region, and mutation of two ACACAC motifs abolishes insulator function.","method":"Enhancer-blocking assays in transiently transfected COS cells; transgenic mouse assays with CMV enhancer-flanked constructs; promoter deletion and mutagenesis","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — functional insulator mapping by mutagenesis in both cell culture and transgenic mice with multiple constructs","pmids":["14512027"],"is_preprint":false},{"year":2007,"finding":"TDP-43 binds to the SP-10 insulator via GTGTGT motifs, tethers the SP-10 gene to the nuclear matrix in somatic cells (sequestering the core promoter and preventing transcription), and is required for enhancer-blocking; TDP-43 knockdown by siRNA releases the enhancer-blocking effect, and mutation of TDP-43 binding sites abolishes this effect. A 50-bp subfragment containing TDP-43 binding sites is a minimal insulator sufficient to silence ectopic transgene expression in somatic tissues of transgenic mice.","method":"Nuclear matrix fractionation (2 M NaCl extraction); siRNA knockdown; stable cell culture enhancer-blocking assays; Gal4 artificial recruitment assay; transgenic mouse insulator assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (fractionation, siRNA, mutagenesis, transgenic mice) in single rigorous study","pmids":["17932037"],"is_preprint":false},{"year":2007,"finding":"NF45 binds to the mouse SP-10 promoter via an AGAAAA (Pu-box) element at -154 in a site-specific manner in gel shift assays; co-transfection of NF45 and NF90 upregulates SP-10 promoter-driven luciferase expression in spermatogenic GC2 cells, requiring the AGAAAA site; however, NF45-NF90 stimulation alone was not sufficient to activate an SP-10 promoter-driven GFP transgene in chromatin context.","method":"Gel shift (EMSA) with recombinant NF45; luciferase reporter co-transfection assays; immunohistochemistry for NF45/NF90 localization; PMA+ionomycin stimulation","journal":"Journal of andrology","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — EMSA plus functional luciferase assays with site-specific mutagenesis, single lab; chromatin context result was negative","pmids":["17942973"],"is_preprint":false},{"year":2011,"finding":"TDP-43 is a transcriptional repressor of the acrv1 gene: it binds to the acrv1 promoter in vivo through GTGTGT motifs (confirmed by plasmid ChIP and ChIP on isolated germ cells), represses transcription via its N-terminal RRM1 domain in a histone deacetylase-independent manner, and is associated with RNA polymerase II pausing at the acrv1 promoter in spermatocytes. RNA-binding-defective TDP-43 (but not splice variant isoforms) relieves repressor function.","method":"Plasmid ChIP; ChIP on physiologically isolated germ cells; luciferase reporter assays with TDP-43 domain mutants; RNA Pol II ChIP; transgenic mouse promoter-mutation analysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal ChIP in vivo and in isolated germ cells, domain mutagenesis, and transgenic mouse data, multiple orthogonal methods","pmids":["21252238"],"is_preprint":false},{"year":2025,"finding":"ZNF280A enhances ACRV1 transcription by interacting with transcription factor CUX2, which facilitates CUX2 recruitment to the ACRV1 promoter; elevated ACRV1 (together with ZNF280A) activates PI3K/AKT signaling and increases glycolytic enzyme expression (PKM2 and LDHA), glucose uptake, lactate production, and ATP generation in ovarian cancer cells; pharmacological inhibition of AKT or glycolysis abrogates these effects.","method":"Co-immunoprecipitation (ZNF280A–CUX2 interaction); ChIP (CUX2 recruitment to ACRV1 promoter); knockdown/overexpression functional assays (proliferation, migration, apoptosis, glycolysis); in vivo xenograft assays; AKT inhibitor treatment","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP and ChIP with functional rescue experiments, single lab; ACRV1's ectopic role in cancer context, not its canonical spermatogenic function","pmids":["41338461"],"is_preprint":false}],"current_model":"ACRV1/SP-10 is a testis-specific, hydrophilic peripheral protein of the acrosomal matrix and membranes that is translated in round spermatids from a 294-bp promoter under spatiotemporal control by TDP-43 (which pauses RNA Pol II in spermatocytes via GTGTGT motifs and requires RNA-binding activity to be relieved) and activated by NF45/NF90 via a Pu-box; the protein undergoes proteolytic processing from a ~45 kDa precursor to 18–32 kDa forms by acrosin-like and other intra-acrosomal endoproteases, is anchored peripherally to acrosomal membranes via a chaotrope-sensitive interaction, redistributes to the equatorial segment inner acrosomal membrane after the acrosome reaction, and mediates sperm–oolemma (but not sperm–zona) binding in a beta-1 integrin-independent manner; its promoter also acts as a CpG-free vertebrate insulator in somatic cells through TDP-43-dependent tethering of the gene to the nuclear matrix."},"narrative":{"mechanistic_narrative":"ACRV1 (SP-10) is a testis-specific intra-acrosomal protein expressed in round spermatids that functions in the terminal steps of sperm–egg interaction [PMID:2310816, PMID:10529272]. It encodes a hydrophilic protein with an N-terminal signal peptide and an internal block of three amino-acid repeat types, with no homology to other characterized sequences, and is expressed as alternatively spliced mRNAs [PMID:1693291]. SP-10 is synthesized as a ~45 kDa precursor that is proteolytically processed by trypsin-like (acrosin-type) and other intra-acrosomal endoproteases into a heterogeneous family of 18–32 kDa peptides, with maturation beginning in the testis and continuing in the proximal epididymis [PMID:1637938, PMID:7888499]. Rather than being an integral membrane protein, it is a peripheral acrosomal protein tethered to the acrosomal membranes through a chaotrope-sensitive, detergent-resistant anchor [PMID:1591355]. During the acrosome reaction it redistributes to the inner acrosomal membrane of the equatorial segment, where it mediates sperm–oolemma binding in a beta-1 integrin-independent manner without participating in sperm–zona binding [PMID:2310816, PMID:10775167]. Transcription is controlled by a TATA-less 294-bp proximal promoter sufficient for round spermatid-specific expression [PMID:10529272]; TDP-43 binds GTGTGT motifs within this promoter to repress transcription and pause RNA polymerase II in spermatocytes through its RNA-binding RRM1 domain, while NF45/NF90 act through a Pu-box (AGAAAA) element to upregulate promoter activity [PMID:21252238, PMID:17942973]. The same promoter region functions as a CpG-free vertebrate insulator in somatic cells, where TDP-43-dependent tethering to the nuclear matrix blocks enhancer–promoter communication [PMID:14512027, PMID:17932037]. In ovarian cancer cells, ectopic ACRV1 acts together with ZNF280A and CUX2 to activate PI3K/AKT signaling and glycolysis [PMID:41338461].","teleology":[{"year":1990,"claim":"Established that SP-10/ACRV1 is a discrete intra-acrosomal protein with a defined distribution that persists on the sperm head after the acrosome reaction, identifying it as a candidate effector of post-acrosome-reaction events.","evidence":"EM immunocytochemistry and immunofluorescence with monoclonal antibody MHS-10 on ejaculated and acrosome-reacted sperm","pmids":["2310816"],"confidence":"High","gaps":["Did not define molecular function","Mode of membrane association not yet known"]},{"year":1990,"claim":"Defined the primary structure of SP-10, revealing a signal peptide, an internal repeat region, alternative splicing, and no homology to known proteins, framing it as a novel testis-specific gene.","evidence":"cDNA cloning, sequencing, and recombinant expression from human testis library with antibody validation","pmids":["1693291"],"confidence":"High","gaps":["Function of the repeat region undefined","Significance of splice variants not established"]},{"year":1992,"claim":"Showed that SP-10 size heterogeneity arises from endoproteolytic cleavage at multiple sites and that it is a hydrophilic peripheral protein with a chaotrope-sensitive membrane anchor rather than an integral membrane protein, explaining its biochemical behavior.","evidence":"Antibody affinity purification, Edman sequencing of peptides, Triton X-114 partitioning, and sequential chemical extractions","pmids":["1637938","1591355"],"confidence":"High","gaps":["Identity of the responsible proteases not directly confirmed","Molecular nature of the membrane anchor unresolved"]},{"year":1994,"claim":"Traced the maturation pathway from a ~45 kDa testicular precursor to smaller forms generated in the testis and proximal epididymis, mapping where processing occurs along the male tract.","evidence":"Western blot of testis, epididymal, ejaculated, and capacitated sperm with EM immunocytochemistry","pmids":["7888499"],"confidence":"High","gaps":["Functional consequence of each processing step unknown","Protease identities not established"]},{"year":1996,"claim":"Provided functional evidence that SP-10 antibodies impair fertilization steps, linking the protein to acrosome reaction completion and sperm function.","evidence":"Bovine in vitro fertilization with anti-SP-10 antibodies and immunofluorescence","pmids":["8882296"],"confidence":"Medium","gaps":["Antibody inhibition may not reflect native function","Cross-species relevance to human fertilization unclear"]},{"year":2000,"claim":"Defined the specific fertilization step served by SP-10: sperm–oolemma binding independent of beta-1 integrins, and not sperm–zona binding.","evidence":"Monoclonal antibody inhibition in zona-free hamster egg penetration, hemizona, and F9 cell binding assays","pmids":["10775167"],"confidence":"Medium","gaps":["Oolemma receptor for SP-10 not identified","Mechanism of binding unresolved"]},{"year":1999,"claim":"Delimited a 294-bp TATA-less proximal promoter sufficient for round spermatid-specific transcription, establishing the cis-regulatory basis of stage-specific expression.","evidence":"Transgenic mouse GFP reporter assays with promoter deletions and in situ hybridization","pmids":["10529272"],"confidence":"High","gaps":["Trans-acting factors not yet identified"]},{"year":2003,"claim":"Uncovered an unexpected dual function of the promoter as a position- and orientation-dependent insulator in somatic cells, mapping activity to ACACAC motifs.","evidence":"Enhancer-blocking assays in COS cells and transgenic mice with deletion and mutagenesis","pmids":["14512027"],"confidence":"High","gaps":["Insulator-binding factor not identified in this study","Relationship to spermatid transcription unclear"]},{"year":2007,"claim":"Identified TDP-43 as the factor binding the insulator via GTGTGT motifs, tethering the gene to the nuclear matrix to block transcription, and NF45/NF90 as Pu-box-dependent activators, providing trans-acting regulators of both functions.","evidence":"Nuclear matrix fractionation, siRNA knockdown, Gal4 recruitment, transgenic insulator assays (TDP-43); EMSA and luciferase co-transfection (NF45/NF90)","pmids":["17932037","17942973"],"confidence":"High","gaps":["NF45/NF90 alone insufficient in chromatin context","How repression is relieved in germ cells unresolved at this stage"]},{"year":2011,"claim":"Resolved the germ-cell regulatory logic: TDP-43 represses acrv1 in spermatocytes via RRM1 and RNA Pol II pausing, with RNA-binding activity required to maintain repression, explaining spatiotemporal activation in round spermatids.","evidence":"Plasmid and germ-cell ChIP, RNA Pol II ChIP, domain mutagenesis luciferase assays, and transgenic mouse promoter mutation","pmids":["21252238"],"confidence":"High","gaps":["Trigger that relieves TDP-43 repression in spermatids not defined","Interplay with NF45/NF90 activation not directly tested"]},{"year":2025,"claim":"Revealed an ectopic role for ACRV1 outside spermatogenesis, where ZNF280A/CUX2-driven ACRV1 expression promotes PI3K/AKT signaling and glycolysis in ovarian cancer cells.","evidence":"Co-IP, ChIP, knockdown/overexpression functional assays, xenografts, and AKT/glycolysis inhibition","pmids":["41338461"],"confidence":"Medium","gaps":["Mechanism by which ACRV1 protein activates AKT not defined","Single-lab cancer context distinct from canonical function"]},{"year":null,"claim":"The molecular receptor on the oolemma that engages SP-10 and the precise physiological signal that switches off TDP-43 repression to activate transcription in round spermatids remain unidentified.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No identified oolemma binding partner","No defined derepression mechanism in vivo","No structural model of the protein"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0098631","term_label":"cell adhesion mediator activity","supporting_discovery_ids":[7]}],"localization":[{"term_id":"GO:0031410","term_label":"cytoplasmic vesicle","supporting_discovery_ids":[0,3,4]},{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0,4]}],"pathway":[{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[0,7]},{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[6,9,11]}],"complexes":[],"partners":["TARDBP","NF45","NF90","ZNF280A","CUX2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P26436","full_name":"Acrosomal protein SP-10","aliases":["Acrosomal vesicle protein 1"],"length_aa":265,"mass_kda":28.2,"function":"","subcellular_location":"Cytoplasmic vesicle, secretory vesicle, acrosome","url":"https://www.uniprot.org/uniprotkb/P26436/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ACRV1","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/ACRV1","total_profiled":1310},"omim":[{"mim_id":"620160","title":"IQ MOTIF-CONTAINING PROTEIN N; IQCN","url":"https://www.omim.org/entry/620160"},{"mim_id":"602991","title":"NOGGIN; NOG","url":"https://www.omim.org/entry/602991"},{"mim_id":"135100","title":"FIBRODYSPLASIA OSSIFICANS PROGRESSIVA; FOP","url":"https://www.omim.org/entry/135100"},{"mim_id":"102525","title":"ACROSOMAL VESICLE PROTEIN 1; ACRV1","url":"https://www.omim.org/entry/102525"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Acrosome","reliability":"Supported"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"testis","ntpm":110.6}],"url":"https://www.proteinatlas.org/search/ACRV1"},"hgnc":{"alias_symbol":["SPACA2","SP-10","D11S4365"],"prev_symbol":[]},"alphafold":{"accession":"P26436","domains":[{"cath_id":"2.10.60.10","chopping":"185-265","consensus_level":"medium","plddt":96.0848,"start":185,"end":265}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P26436","model_url":"https://alphafold.ebi.ac.uk/files/AF-P26436-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P26436-F1-predicted_aligned_error_v6.png","plddt_mean":61.72},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ACRV1","jax_strain_url":"https://www.jax.org/strain/search?query=ACRV1"},"sequence":{"accession":"P26436","fasta_url":"https://rest.uniprot.org/uniprotkb/P26436.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P26436/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P26436"}},"corpus_meta":[{"pmid":"2310816","id":"PMC_2310816","title":"Biochemical and morphological characterization of the intra-acrosomal antigen SP-10 from human sperm.","date":"1990","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/2310816","citation_count":129,"is_preprint":false},{"pmid":"17932037","id":"PMC_17932037","title":"A novel CpG-free vertebrate insulator silences the testis-specific SP-10 gene in somatic tissues: role for TDP-43 in insulator function.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17932037","citation_count":92,"is_preprint":false},{"pmid":"1693291","id":"PMC_1693291","title":"Cloning and sequencing of cDNAs coding for the human intra-acrosomal antigen SP-10.","date":"1990","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/1693291","citation_count":79,"is_preprint":false},{"pmid":"21252238","id":"PMC_21252238","title":"TDP-43 is a transcriptional repressor: the testis-specific mouse acrv1 gene is a TDP-43 target in vivo.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/21252238","citation_count":64,"is_preprint":false},{"pmid":"10529272","id":"PMC_10529272","title":"Round spermatid-specific transcription of the mouse SP-10 gene is mediated by a 294-base pair proximal promoter.","date":"1999","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/10529272","citation_count":62,"is_preprint":false},{"pmid":"8882296","id":"PMC_8882296","title":"Inhibition of bovine fertilization in vitro by antibodies to SP-10.","date":"1996","source":"Journal of reproduction and fertility","url":"https://pubmed.ncbi.nlm.nih.gov/8882296","citation_count":56,"is_preprint":false},{"pmid":"8442953","id":"PMC_8442953","title":"Cloning and sequencing of baboon and cynomolgus monkey intra-acrosomal protein SP-10: homology with human SP-10 and a mouse sperm antigen (MSA-63).","date":"1993","source":"Molecular reproduction and development","url":"https://pubmed.ncbi.nlm.nih.gov/8442953","citation_count":53,"is_preprint":false},{"pmid":"1868140","id":"PMC_1868140","title":"Localization of sperm antigen SP-10 during the six stages of the cycle of the seminiferous epithelium in man.","date":"1991","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/1868140","citation_count":53,"is_preprint":false},{"pmid":"7888499","id":"PMC_7888499","title":"Human SP-10: acrosomal distribution, processing, and fate after the acrosome reaction.","date":"1994","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/7888499","citation_count":52,"is_preprint":false},{"pmid":"2337631","id":"PMC_2337631","title":"Identification of human acrosomal antigen SP-10 in primates and pigs.","date":"1990","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/2337631","citation_count":51,"is_preprint":false},{"pmid":"8547483","id":"PMC_8547483","title":"Complementary deoxyribonucleic acid cloning and characterization of mSP-10: the mouse homologue of human acrosomal protein SP-10.","date":"1995","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/8547483","citation_count":39,"is_preprint":false},{"pmid":"10775167","id":"PMC_10775167","title":"A monoclonal antibody to human SP-10 inhibits in vitro the binding of human sperm to hamster oolemma but not to human Zona pellucida.","date":"2000","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/10775167","citation_count":38,"is_preprint":false},{"pmid":"1637938","id":"PMC_1637938","title":"Purification and microsequencing of the intra-acrosomal protein SP-10. 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of bacteriology","url":"https://pubmed.ncbi.nlm.nih.gov/4967775","citation_count":17,"is_preprint":false},{"pmid":"7619499","id":"PMC_7619499","title":"Characterization of alternatively spliced human SP-10 mRNAs.","date":"1995","source":"Molecular reproduction and development","url":"https://pubmed.ncbi.nlm.nih.gov/7619499","citation_count":16,"is_preprint":false},{"pmid":"8288254","id":"PMC_8288254","title":"Refinement of the localization of the gene for human intraacrosomal protein SP-10 (ACRV1) to the junction of bands q23-->q24 of chromosome 11 by nonisotopic in situ hybridization.","date":"1993","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/8288254","citation_count":15,"is_preprint":false},{"pmid":"4955254","id":"PMC_4955254","title":"Concurrent changes in transducing efficiency and content of transforming deoxyribonucleic acid in Bacillus subtilis bacteriophage SP-10.","date":"1966","source":"Journal of bacteriology","url":"https://pubmed.ncbi.nlm.nih.gov/4955254","citation_count":14,"is_preprint":false},{"pmid":"21488928","id":"PMC_21488928","title":"Developmental expression of ACRV1 in humans and mice.","date":"2011","source":"Andrologia","url":"https://pubmed.ncbi.nlm.nih.gov/21488928","citation_count":13,"is_preprint":false},{"pmid":"17942973","id":"PMC_17942973","title":"NF45 and NF90 in murine seminiferous epithelium: potential role in SP-10 gene transcription.","date":"2007","source":"Journal of andrology","url":"https://pubmed.ncbi.nlm.nih.gov/17942973","citation_count":13,"is_preprint":false},{"pmid":"2298314","id":"PMC_2298314","title":"Differential diagnosis of immature germ cells in semen utilizing monoclonal antibody MHS-10 to the intra-acrosomal antigen SP-10.","date":"1990","source":"Fertility and sterility","url":"https://pubmed.ncbi.nlm.nih.gov/2298314","citation_count":13,"is_preprint":false},{"pmid":"8874713","id":"PMC_8874713","title":"Effect of immunization with human SP-10 in male rodents.","date":"1996","source":"American journal of reproductive immunology (New York, N.Y. : 1989)","url":"https://pubmed.ncbi.nlm.nih.gov/8874713","citation_count":11,"is_preprint":false},{"pmid":"32758798","id":"PMC_32758798","title":"Acrosomal marker SP-10 (gene name Acrv1) for staging of the cycle of seminiferous epithelium in the stallion.","date":"2020","source":"Theriogenology","url":"https://pubmed.ncbi.nlm.nih.gov/32758798","citation_count":10,"is_preprint":false},{"pmid":"137989","id":"PMC_137989","title":"SP-10 bacteriophage-specific nucleic acid and enzyme synthesis in Bacillus subtilis W23.","date":"1977","source":"Journal of virology","url":"https://pubmed.ncbi.nlm.nih.gov/137989","citation_count":10,"is_preprint":false},{"pmid":"7691073","id":"PMC_7691073","title":"Assay for recombinant and native human intraacrosomal antigen SP-10.","date":"1993","source":"American journal of reproductive immunology (New York, N.Y. : 1989)","url":"https://pubmed.ncbi.nlm.nih.gov/7691073","citation_count":7,"is_preprint":false},{"pmid":"1765564","id":"PMC_1765564","title":"Assignment of the gene for human intra-acrosomal protein SP-10 to the p12----q13 region of chromosome 11.","date":"1991","source":"Journal of andrology","url":"https://pubmed.ncbi.nlm.nih.gov/1765564","citation_count":7,"is_preprint":false},{"pmid":"39046915","id":"PMC_39046915","title":"Synaptotagmin 13 Could Drive the Progression of Esophageal Squamous Cell Carcinoma Through Upregulating ACRV1.","date":"2024","source":"DNA and cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/39046915","citation_count":2,"is_preprint":false},{"pmid":"17249247","id":"PMC_17249247","title":"The benzamide derivative N-[1-(7-tert-Butyl-1H-indol-3-ylmethyl)-2-(4-cyclopropanecarbonyl-3-methyl-piperazin-1-yl)-2-oxo-ethyl]-4-nitro-benzamide (SP-10) reduces HIV-1 infectivity in vitro by modifying actin dynamics.","date":"2006","source":"Antiviral chemistry & chemotherapy","url":"https://pubmed.ncbi.nlm.nih.gov/17249247","citation_count":2,"is_preprint":false},{"pmid":"41338461","id":"PMC_41338461","title":"ZNF280A and ACRV1 enhance aerobic glycolysis and drive ovarian cancer progression via the PI3K/AKT signaling pathway.","date":"2025","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/41338461","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":20380,"output_tokens":3633,"usd":0.057818,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11255,"output_tokens":3533,"usd":0.0723,"stage2_stop_reason":"end_turn"},"total_usd":0.130118,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1990,\n      \"finding\": \"SP-10 (ACRV1) is an intra-acrosomal protein localized throughout the acrosome, specifically in a bilaminar array associated with the inner aspect of the outer acrosomal membrane and the outer aspect of the inner acrosomal membrane; after the acrosome reaction it remains displayed on the sperm head associated with the inner acrosomal membrane and equatorial segment.\",\n      \"method\": \"Light and electron microscopic immunocytochemistry with monoclonal antibody MHS-10; immunofluorescence on ejaculated sperm\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — direct immunolocalization at EM resolution replicated across multiple subsequent studies\",\n      \"pmids\": [\"2310816\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1990,\n      \"finding\": \"SP-10 (ACRV1) encodes a 265-amino acid protein with a hydrophobic signal peptide at the N-terminus and a central region containing three types of amino acid repeats occurring 16 times; alternative splicing generates at least two SP-10 mRNAs (including one with a 57-bp in-frame deletion); the protein is unique with no homology to other known sequences.\",\n      \"method\": \"cDNA cloning, sequencing, and deduced amino acid analysis from human testis cDNA library; recombinant protein expression and immunoblotting\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — direct sequencing plus recombinant expression with functional antibody validation, replicated by subsequent structural studies\",\n      \"pmids\": [\"1693291\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"SP-10 heterogeneity (17.5–34 kDa peptides) results from endoproteolytic cleavage at five different peptide bonds (following arginine, serine, proline, glycine, and glutamic acid), consistent with action of a trypsin-like protease (possibly acrosin) and previously undescribed intra-acrosomal protease specificities.\",\n      \"method\": \"Purification by monoclonal antibody affinity chromatography, reverse-phase HPLC, and preparative gel electrophoresis; Edman degradation sequencing of eight SP-10 peptides\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — direct Edman sequencing of purified peptides identified cleavage sites; single lab but multiple peptides analyzed with rigorous biochemical fractionation\",\n      \"pmids\": [\"1637938\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1992,\n      \"finding\": \"SP-10 is a hydrophilic peripheral acrosomal membrane protein (not an integral membrane protein), associated with the acrosomal membranes via a TX-114-resistant anchor; a chaotropic salt (sodium thiocyanate) and pH extremes fully release this TX-114-resistant pool, whereas repeated TX-114 or 1.5 M NaCl washes do not.\",\n      \"method\": \"Triton X-114 phase partitioning, sequential chemical extractions (NaCl, sodium thiocyanate, pH 2.0 and 10.0), Western blotting\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — reconstitution-level biochemical fractionation with multiple orthogonal extraction conditions in single rigorous study\",\n      \"pmids\": [\"1591355\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1994,\n      \"finding\": \"A full-length ~45 kDa SP-10 precursor is present in testis and is proteolytically processed to 32–26 kDa peptides in testis and/or via alternative splicing; further processing to 25–18 kDa peptides occurs in the initial segment or caput epididymidis; no additional processing occurs during epididymal transit, ejaculation, or capacitation. After the acrosome reaction, SP-10 is concentrated on the inner acrosomal membrane of the equatorial segment and associated with hybrid vesicles.\",\n      \"method\": \"Western blot of testis, caput/cauda epididymal, ejaculated, and capacitated sperm extracts; electron microscopic immunocytochemistry with colloidal gold\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — multiple fractionation steps with EM-level localization, single lab, two orthogonal methods\",\n      \"pmids\": [\"7888499\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1996,\n      \"finding\": \"Anti-SP-10 antibodies inhibit bovine in vitro fertilization by reducing sperm-zona secondary binding and reducing the ability of capacitated spermatozoa to complete the acrosome reaction; they also reduce motility of capacitated (but not noncapacitated) spermatozoa.\",\n      \"method\": \"Bovine in vitro fertilization assay with monoclonal and polyclonal anti-SP-10 antibodies; indirect immunofluorescence; immunoblotting\",\n      \"journal\": \"Journal of reproduction and fertility\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional fertilization assay with multiple antibody types, single lab\",\n      \"pmids\": [\"8882296\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"A 294-bp proximal promoter region (-266 to +28 bp) of the mouse SP-10 (Acrv1) gene is sufficient to direct round spermatid-specific transcription in vivo; the core promoter lacks a TATA box but contains a canonical initiator (Inr) element at the transcription start site; the -91/+28 fragment lacks promoter activity.\",\n      \"method\": \"Transgenic mouse reporter assays with GFP under control of defined SP-10 promoter deletion constructs; in situ hybridization for mRNA localization\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — transgenic mouse functional promoter dissection replicated in subsequent studies\",\n      \"pmids\": [\"10529272\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"SP-10 expressed on the equatorial region of acrosome-reacted sperm mediates sperm-oolemma binding in a beta-1 integrin-independent manner, but does not mediate sperm-zona binding.\",\n      \"method\": \"Monoclonal antibody inhibition assay using zona-free hamster egg penetration test (sperm-oolemma binding) and hemizona assay (sperm-zona binding); sperm-cultured cell binding assay using F9 cells with and without beta-1 integrins\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional antibody inhibition with two orthogonal binding assays, single lab\",\n      \"pmids\": [\"10775167\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2003,\n      \"finding\": \"The SP-10 proximal promoter (-408/-92 region) functions as an insulator in somatic cells by blocking enhancer-promoter interactions in a position- and orientation-dependent manner; insulator activity maps to the -186/-135 region, and mutation of two ACACAC motifs abolishes insulator function.\",\n      \"method\": \"Enhancer-blocking assays in transiently transfected COS cells; transgenic mouse assays with CMV enhancer-flanked constructs; promoter deletion and mutagenesis\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — functional insulator mapping by mutagenesis in both cell culture and transgenic mice with multiple constructs\",\n      \"pmids\": [\"14512027\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"TDP-43 binds to the SP-10 insulator via GTGTGT motifs, tethers the SP-10 gene to the nuclear matrix in somatic cells (sequestering the core promoter and preventing transcription), and is required for enhancer-blocking; TDP-43 knockdown by siRNA releases the enhancer-blocking effect, and mutation of TDP-43 binding sites abolishes this effect. A 50-bp subfragment containing TDP-43 binding sites is a minimal insulator sufficient to silence ectopic transgene expression in somatic tissues of transgenic mice.\",\n      \"method\": \"Nuclear matrix fractionation (2 M NaCl extraction); siRNA knockdown; stable cell culture enhancer-blocking assays; Gal4 artificial recruitment assay; transgenic mouse insulator assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (fractionation, siRNA, mutagenesis, transgenic mice) in single rigorous study\",\n      \"pmids\": [\"17932037\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"NF45 binds to the mouse SP-10 promoter via an AGAAAA (Pu-box) element at -154 in a site-specific manner in gel shift assays; co-transfection of NF45 and NF90 upregulates SP-10 promoter-driven luciferase expression in spermatogenic GC2 cells, requiring the AGAAAA site; however, NF45-NF90 stimulation alone was not sufficient to activate an SP-10 promoter-driven GFP transgene in chromatin context.\",\n      \"method\": \"Gel shift (EMSA) with recombinant NF45; luciferase reporter co-transfection assays; immunohistochemistry for NF45/NF90 localization; PMA+ionomycin stimulation\",\n      \"journal\": \"Journal of andrology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — EMSA plus functional luciferase assays with site-specific mutagenesis, single lab; chromatin context result was negative\",\n      \"pmids\": [\"17942973\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"TDP-43 is a transcriptional repressor of the acrv1 gene: it binds to the acrv1 promoter in vivo through GTGTGT motifs (confirmed by plasmid ChIP and ChIP on isolated germ cells), represses transcription via its N-terminal RRM1 domain in a histone deacetylase-independent manner, and is associated with RNA polymerase II pausing at the acrv1 promoter in spermatocytes. RNA-binding-defective TDP-43 (but not splice variant isoforms) relieves repressor function.\",\n      \"method\": \"Plasmid ChIP; ChIP on physiologically isolated germ cells; luciferase reporter assays with TDP-43 domain mutants; RNA Pol II ChIP; transgenic mouse promoter-mutation analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal ChIP in vivo and in isolated germ cells, domain mutagenesis, and transgenic mouse data, multiple orthogonal methods\",\n      \"pmids\": [\"21252238\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ZNF280A enhances ACRV1 transcription by interacting with transcription factor CUX2, which facilitates CUX2 recruitment to the ACRV1 promoter; elevated ACRV1 (together with ZNF280A) activates PI3K/AKT signaling and increases glycolytic enzyme expression (PKM2 and LDHA), glucose uptake, lactate production, and ATP generation in ovarian cancer cells; pharmacological inhibition of AKT or glycolysis abrogates these effects.\",\n      \"method\": \"Co-immunoprecipitation (ZNF280A–CUX2 interaction); ChIP (CUX2 recruitment to ACRV1 promoter); knockdown/overexpression functional assays (proliferation, migration, apoptosis, glycolysis); in vivo xenograft assays; AKT inhibitor treatment\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP and ChIP with functional rescue experiments, single lab; ACRV1's ectopic role in cancer context, not its canonical spermatogenic function\",\n      \"pmids\": [\"41338461\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ACRV1/SP-10 is a testis-specific, hydrophilic peripheral protein of the acrosomal matrix and membranes that is translated in round spermatids from a 294-bp promoter under spatiotemporal control by TDP-43 (which pauses RNA Pol II in spermatocytes via GTGTGT motifs and requires RNA-binding activity to be relieved) and activated by NF45/NF90 via a Pu-box; the protein undergoes proteolytic processing from a ~45 kDa precursor to 18–32 kDa forms by acrosin-like and other intra-acrosomal endoproteases, is anchored peripherally to acrosomal membranes via a chaotrope-sensitive interaction, redistributes to the equatorial segment inner acrosomal membrane after the acrosome reaction, and mediates sperm–oolemma (but not sperm–zona) binding in a beta-1 integrin-independent manner; its promoter also acts as a CpG-free vertebrate insulator in somatic cells through TDP-43-dependent tethering of the gene to the nuclear matrix.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ACRV1 (SP-10) is a testis-specific intra-acrosomal protein expressed in round spermatids that functions in the terminal steps of sperm–egg interaction [#0, #6]. It encodes a hydrophilic protein with an N-terminal signal peptide and an internal block of three amino-acid repeat types, with no homology to other characterized sequences, and is expressed as alternatively spliced mRNAs [#1]. SP-10 is synthesized as a ~45 kDa precursor that is proteolytically processed by trypsin-like (acrosin-type) and other intra-acrosomal endoproteases into a heterogeneous family of 18–32 kDa peptides, with maturation beginning in the testis and continuing in the proximal epididymis [#2, #4]. Rather than being an integral membrane protein, it is a peripheral acrosomal protein tethered to the acrosomal membranes through a chaotrope-sensitive, detergent-resistant anchor [#3]. During the acrosome reaction it redistributes to the inner acrosomal membrane of the equatorial segment, where it mediates sperm–oolemma binding in a beta-1 integrin-independent manner without participating in sperm–zona binding [#0, #7]. Transcription is controlled by a TATA-less 294-bp proximal promoter sufficient for round spermatid-specific expression [#6]; TDP-43 binds GTGTGT motifs within this promoter to repress transcription and pause RNA polymerase II in spermatocytes through its RNA-binding RRM1 domain, while NF45/NF90 act through a Pu-box (AGAAAA) element to upregulate promoter activity [#11, #10]. The same promoter region functions as a CpG-free vertebrate insulator in somatic cells, where TDP-43-dependent tethering to the nuclear matrix blocks enhancer–promoter communication [#8, #9]. In ovarian cancer cells, ectopic ACRV1 acts together with ZNF280A and CUX2 to activate PI3K/AKT signaling and glycolysis [#12].\",\n  \"teleology\": [\n    {\n      \"year\": 1990,\n      \"claim\": \"Established that SP-10/ACRV1 is a discrete intra-acrosomal protein with a defined distribution that persists on the sperm head after the acrosome reaction, identifying it as a candidate effector of post-acrosome-reaction events.\",\n      \"evidence\": \"EM immunocytochemistry and immunofluorescence with monoclonal antibody MHS-10 on ejaculated and acrosome-reacted sperm\",\n      \"pmids\": [\"2310816\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define molecular function\", \"Mode of membrane association not yet known\"]\n    },\n    {\n      \"year\": 1990,\n      \"claim\": \"Defined the primary structure of SP-10, revealing a signal peptide, an internal repeat region, alternative splicing, and no homology to known proteins, framing it as a novel testis-specific gene.\",\n      \"evidence\": \"cDNA cloning, sequencing, and recombinant expression from human testis library with antibody validation\",\n      \"pmids\": [\"1693291\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Function of the repeat region undefined\", \"Significance of splice variants not established\"]\n    },\n    {\n      \"year\": 1992,\n      \"claim\": \"Showed that SP-10 size heterogeneity arises from endoproteolytic cleavage at multiple sites and that it is a hydrophilic peripheral protein with a chaotrope-sensitive membrane anchor rather than an integral membrane protein, explaining its biochemical behavior.\",\n      \"evidence\": \"Antibody affinity purification, Edman sequencing of peptides, Triton X-114 partitioning, and sequential chemical extractions\",\n      \"pmids\": [\"1637938\", \"1591355\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the responsible proteases not directly confirmed\", \"Molecular nature of the membrane anchor unresolved\"]\n    },\n    {\n      \"year\": 1994,\n      \"claim\": \"Traced the maturation pathway from a ~45 kDa testicular precursor to smaller forms generated in the testis and proximal epididymis, mapping where processing occurs along the male tract.\",\n      \"evidence\": \"Western blot of testis, epididymal, ejaculated, and capacitated sperm with EM immunocytochemistry\",\n      \"pmids\": [\"7888499\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of each processing step unknown\", \"Protease identities not established\"]\n    },\n    {\n      \"year\": 1996,\n      \"claim\": \"Provided functional evidence that SP-10 antibodies impair fertilization steps, linking the protein to acrosome reaction completion and sperm function.\",\n      \"evidence\": \"Bovine in vitro fertilization with anti-SP-10 antibodies and immunofluorescence\",\n      \"pmids\": [\"8882296\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Antibody inhibition may not reflect native function\", \"Cross-species relevance to human fertilization unclear\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Defined the specific fertilization step served by SP-10: sperm–oolemma binding independent of beta-1 integrins, and not sperm–zona binding.\",\n      \"evidence\": \"Monoclonal antibody inhibition in zona-free hamster egg penetration, hemizona, and F9 cell binding assays\",\n      \"pmids\": [\"10775167\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Oolemma receptor for SP-10 not identified\", \"Mechanism of binding unresolved\"]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Delimited a 294-bp TATA-less proximal promoter sufficient for round spermatid-specific transcription, establishing the cis-regulatory basis of stage-specific expression.\",\n      \"evidence\": \"Transgenic mouse GFP reporter assays with promoter deletions and in situ hybridization\",\n      \"pmids\": [\"10529272\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Trans-acting factors not yet identified\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Uncovered an unexpected dual function of the promoter as a position- and orientation-dependent insulator in somatic cells, mapping activity to ACACAC motifs.\",\n      \"evidence\": \"Enhancer-blocking assays in COS cells and transgenic mice with deletion and mutagenesis\",\n      \"pmids\": [\"14512027\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Insulator-binding factor not identified in this study\", \"Relationship to spermatid transcription unclear\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Identified TDP-43 as the factor binding the insulator via GTGTGT motifs, tethering the gene to the nuclear matrix to block transcription, and NF45/NF90 as Pu-box-dependent activators, providing trans-acting regulators of both functions.\",\n      \"evidence\": \"Nuclear matrix fractionation, siRNA knockdown, Gal4 recruitment, transgenic insulator assays (TDP-43); EMSA and luciferase co-transfection (NF45/NF90)\",\n      \"pmids\": [\"17932037\", \"17942973\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"NF45/NF90 alone insufficient in chromatin context\", \"How repression is relieved in germ cells unresolved at this stage\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Resolved the germ-cell regulatory logic: TDP-43 represses acrv1 in spermatocytes via RRM1 and RNA Pol II pausing, with RNA-binding activity required to maintain repression, explaining spatiotemporal activation in round spermatids.\",\n      \"evidence\": \"Plasmid and germ-cell ChIP, RNA Pol II ChIP, domain mutagenesis luciferase assays, and transgenic mouse promoter mutation\",\n      \"pmids\": [\"21252238\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Trigger that relieves TDP-43 repression in spermatids not defined\", \"Interplay with NF45/NF90 activation not directly tested\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed an ectopic role for ACRV1 outside spermatogenesis, where ZNF280A/CUX2-driven ACRV1 expression promotes PI3K/AKT signaling and glycolysis in ovarian cancer cells.\",\n      \"evidence\": \"Co-IP, ChIP, knockdown/overexpression functional assays, xenografts, and AKT/glycolysis inhibition\",\n      \"pmids\": [\"41338461\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which ACRV1 protein activates AKT not defined\", \"Single-lab cancer context distinct from canonical function\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The molecular receptor on the oolemma that engages SP-10 and the precise physiological signal that switches off TDP-43 repression to activate transcription in round spermatids remain unidentified.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No identified oolemma binding partner\", \"No defined derepression mechanism in vivo\", \"No structural model of the protein\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0098631\", \"supporting_discovery_ids\": [7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0031410\", \"supporting_discovery_ids\": [0, 3, 4]},\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [0, 7]},\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [6, 9, 11]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"TARDBP\", \"NF45\", \"NF90\", \"ZNF280A\", \"CUX2\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"faith_supported":8,"faith_total":8,"faith_pct":100.0}}