{"gene":"RNPC3","run_date":"2026-06-10T06:43:37","timeline":{"discoveries":[{"year":2003,"finding":"RNPC3 encodes a protein with two RNA recognition motif (RRM) domains and two bipartite nuclear targeting sequences; GFP localization experiments demonstrated that the RNPC3 protein localizes to the cell nucleus.","method":"cDNA cloning, sequence analysis, GFP fusion localization imaging","journal":"Biochemical genetics","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — direct GFP localization experiment in single lab; domain identification by sequence analysis; no functional mutagenesis","pmids":["14974681"],"is_preprint":false},{"year":2018,"finding":"RNPC3 (encoding the U11/U12-65K protein) is an essential component of the U12-dependent (minor class) spliceosome; conditional knockout of Rnpc3 in adult mice caused increased retention of U12-type introns in intestinal epithelial cell transcripts, demonstrating that 65K is required for minor intron splicing in vivo.","method":"Conditional Rnpc3 knockout mouse model, RT-PCR for U12 intron retention in purified intestinal epithelial cells","journal":"RNA (New York, N.Y.)","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO with defined molecular phenotype (intron retention), direct splicing assay, replicated across multiple transcripts in a novel mouse model","pmids":["30254136"],"is_preprint":false},{"year":2018,"finding":"Loss of Rnpc3 in intestinal stem/progenitor cells leads to loss of phospho-ERK1/2 signaling, reduced proliferation, and increased apoptosis, placing U12-dependent splicing upstream of ERK signaling in intestinal homeostasis.","method":"Conditional Rnpc3 knockout mouse, immunostaining for phospho-ERK1/2, cell proliferation and death assays in intestinal crypts","journal":"RNA (New York, N.Y.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO mouse with defined cellular phenotype and pathway marker loss, single lab, correlative between ERK loss and Rnpc3 deficiency","pmids":["30254136"],"is_preprint":false},{"year":2018,"finding":"Homozygous Rnpc3 null mice die prior to blastocyst implantation, establishing that 65K/RNPC3-mediated U12 splicing is essential for the earliest stages of mammalian embryonic development.","method":"Germline Rnpc3 knockout mouse, developmental stage analysis","journal":"RNA (New York, N.Y.)","confidence":"High","confidence_rationale":"Tier 2 / Strong — germline KO with clear developmental arrest phenotype, rigorous genetic model","pmids":["30254136"],"is_preprint":false},{"year":2021,"finding":"RNPC3 is expressed in the developing forebrain, including the hypothalamus and Rathke's pouch (the pituitary anlage), in both mouse and human embryos; CRISPR/Cas9 knock-in of the p.Leu483Phe pathogenic variant in the Rnpc3 RRM2 domain in female mice reduced pituitary GH content, establishing a developmental role for RNPC3 in pituitary function.","method":"In situ hybridization on murine/human embryonic sections, CRISPR/Cas9 knock-in mouse model, pituitary GH content measurement","journal":"Genetics in medicine : official journal of the American College of Medical Genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — CRISPR knock-in model with defined endocrine phenotype and expression localization; single lab, specific RRM2 domain variant tested","pmids":["34906446"],"is_preprint":false},{"year":2024,"finding":"The minor spliceosomal 65K/RNPC3 protein physically interacts with ANKRD11, a cofactor of histone deacetylase 3 (HDAC3); in human cells, the ANKRD11 middle uncharacterized domain mediates the association of Hs65K with HDAC3. ANKRD11 acts as a bridging factor enabling synergistic chromatin co-binding of HDAC3 and Hs65K, and knockdown of ANKRD11 reduces their common chromatin binding and decreases H3K9 deacetylation at nearby loci, linking minor spliceosome activity to histone deacetylation and transcriptional regulation.","method":"Affinity purification from Drosophila lysates, CRISPR/Cas9 deletion strains, CUT&Tag chromatin binding assay, ANKRD11 knockdown with H3K9 deacetylation measurement, domain mapping","journal":"Advanced science (Weinheim, Baden-Wurttemberg, Germany)","confidence":"High","confidence_rationale":"Tier 2 / Strong — interaction identified by affinity purification, validated in human cells, domain mapped, functional chromatin assay (CUT&Tag) with loss-of-function confirmation, multiple orthogonal methods in single study","pmids":["38837887"],"is_preprint":false},{"year":2024,"finding":"Loss of 65K/RNPC3 in Drosophila (Dm65KΔ/Δ) caused reduced histone deacetylation at H3K9 and H4K5 in heads and neural-related defects, functionally linking the minor spliceosome component to histone deacetylase activity in vivo.","method":"CRISPR/Cas9 deletion in Drosophila, histone deacetylation assays, neural phenotype characterization","journal":"Advanced science (Weinheim, Baden-Wurttemberg, Germany)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo KO with defined biochemical and phenotypic readout; Drosophila ortholog model, single lab","pmids":["38837887"],"is_preprint":false},{"year":2025,"finding":"Conditional ablation of RNPC3 in activated B cells impaired germinal center (GC) B cell development, inhibited proliferation, and promoted apoptosis; mechanistically, RNPC3 deficiency caused accumulation of minor intron retention in minor intron-containing genes associated with cell proliferation and apoptosis, establishing that RNPC3-dependent minor intron splicing is required for the GC B cell response.","method":"Conditional B-cell-specific Rnpc3 knockout mice, flow cytometry for GC B cell populations, proliferation and apoptosis assays, minor intron retention analysis","journal":"European journal of immunology","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional KO with defined cellular phenotype (GC defect), direct minor intron retention assay linking molecular mechanism to immune phenotype, multiple orthogonal readouts","pmids":["40170400"],"is_preprint":false},{"year":2010,"finding":"RNPC3 protein acts as a molecular bridge promoting U11/U12 RNP (di-snRNP) complex formation within the minor spliceosome.","method":"Reported as established function in autoantibody clinical literature (referenced as prior mechanistic knowledge)","journal":"ACR open rheumatology","confidence":"Low","confidence_rationale":"Tier 4 / Weak — cited as background fact in a clinical autoantibody paper; no primary experiment described in this abstract; original experimental source not directly available in corpus","pmids":["41946577"],"is_preprint":false}],"current_model":"RNPC3 encodes the U11/U12-65K protein, an essential and unique component of the minor (U12-dependent) spliceosome that promotes U11/U12 di-snRNP complex formation and is required for excision of U12-type introns from a small subset of genes; it is indispensable for embryonic development, intestinal homeostasis, pituitary development, and germinal center B cell responses, and additionally interacts with ANKRD11 to couple minor spliceosome activity to HDAC3-mediated histone deacetylation and transcriptional regulation."},"narrative":{"mechanistic_narrative":"RNPC3 encodes the U11/U12-65K protein, an essential and unique component of the minor (U12-dependent) spliceosome required for excision of U12-type introns from a small subset of genes [PMID:30254136]. It is a nuclear protein containing two RNA recognition motifs and two bipartite nuclear targeting sequences [PMID:14974681], and functions as a molecular bridge promoting formation of the U11/U12 di-snRNP within the minor spliceosome [PMID:41946577]. Across mammalian tissues RNPC3-dependent minor intron splicing is developmentally indispensable: germline loss causes pre-implantation embryonic lethality [PMID:30254136], conditional ablation in intestinal epithelium increases U12-type intron retention with loss of phospho-ERK1/2 signaling, reduced proliferation, and increased apoptosis [PMID:30254136], a pathogenic RRM2-domain variant impairs pituitary growth-hormone content [PMID:34906446], and B-cell-specific ablation impairs germinal center responses through retention of minor introns in proliferation- and apoptosis-associated genes [PMID:40170400]. Beyond its splicing role, RNPC3 physically interacts with the HDAC3 cofactor ANKRD11, which bridges synergistic chromatin co-binding of RNPC3 and HDAC3 and couples minor spliceosome activity to H3K9 histone deacetylation and transcriptional regulation [PMID:38837887].","teleology":[{"year":2003,"claim":"Established the basic molecular identity and subcellular address of the RNPC3 protein, defining it as a nuclear RNA-binding protein.","evidence":"cDNA cloning, sequence analysis, and GFP fusion localization imaging","pmids":["14974681"],"confidence":"Medium","gaps":["No functional role in splicing demonstrated","RRM RNA targets not identified","No mutagenesis of nuclear targeting sequences"]},{"year":2010,"claim":"Framed RNPC3 mechanistically as a bridging factor for U11/U12 di-snRNP assembly within the minor spliceosome.","evidence":"Cited as established background in a clinical autoantibody report; no primary experiment in the available abstract","pmids":["41946577"],"confidence":"Low","gaps":["Original experimental source not present in corpus","No structural model of the bridging interaction provided here","RNA contacts mediating di-snRNP formation undefined"]},{"year":2018,"claim":"Demonstrated in vivo that RNPC3 is required for U12-type intron excision and that its loss is incompatible with early development, linking minor splicing to organismal viability and tissue homeostasis.","evidence":"Germline and conditional Rnpc3 knockout mice with RT-PCR intron retention assays, phospho-ERK1/2 immunostaining, and proliferation/apoptosis assays in intestinal epithelium","pmids":["30254136"],"confidence":"High","gaps":["Mechanistic link between intron retention and ERK signaling is correlative","Specific minor-intron-containing transcripts driving the phenotype not fully resolved","Does not address splicing-independent functions"]},{"year":2021,"claim":"Connected RNPC3 to pituitary and forebrain development and showed a disease-associated RRM2 variant produces a defined endocrine phenotype.","evidence":"In situ hybridization on mouse/human embryos and CRISPR/Cas9 p.Leu483Phe knock-in mice with pituitary GH content measurement","pmids":["34906446"],"confidence":"Medium","gaps":["Splicing defects underlying the GH phenotype not directly mapped","Single variant tested","Sex-specific effect mechanism unexplained"]},{"year":2024,"claim":"Uncovered a chromatin-coupled function: RNPC3 physically associates with ANKRD11/HDAC3 and links minor spliceosome activity to histone deacetylation and transcription.","evidence":"Affinity purification, CRISPR deletion strains, domain mapping, CUT&Tag, and ANKRD11 knockdown with H3K9 deacetylation readout, plus Drosophila 65K deletion with histone deacetylation and neural phenotyping","pmids":["38837887"],"confidence":"High","gaps":["Whether chromatin co-binding requires catalytic splicing activity is unresolved","Direct genomic targets co-regulated by RNPC3 and HDAC3 not enumerated","Mechanism by which a spliceosomal RRM protein engages chromatin undefined"]},{"year":2025,"claim":"Extended the requirement for RNPC3-dependent minor splicing to adaptive immunity, showing it sustains germinal center B cell proliferation and survival.","evidence":"B-cell-specific conditional Rnpc3 knockout mice with flow cytometry, proliferation/apoptosis assays, and minor intron retention analysis","pmids":["40170400"],"confidence":"High","gaps":["Individual causal minor-intron-containing genes not isolated","Relationship to the ANKRD11/HDAC3 axis in B cells untested","Effect on antibody affinity maturation outcome not addressed"]},{"year":null,"claim":"How RNPC3's role in di-snRNP assembly mechanistically integrates with its chromatin/HDAC3-coupled transcriptional function across tissues remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structure of the U11/U12-65K bridging interaction in the corpus","Whether splicing and chromatin functions are separable is untested","Tissue-specific minor-intron target sets driving distinct phenotypes not defined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003723","term_label":"RNA binding","supporting_discovery_ids":[0]},{"term_id":"GO:0140098","term_label":"catalytic activity, acting on RNA","supporting_discovery_ids":[1,8]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[1,7]},{"term_id":"R-HSA-4839726","term_label":"Chromatin organization","supporting_discovery_ids":[5]}],"complexes":["minor (U12-dependent) spliceosome","U11/U12 di-snRNP"],"partners":["ANKRD11","HDAC3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96LT9","full_name":"RNA-binding region-containing protein 3","aliases":["RNA-binding motif protein 40","RNA-binding protein 40","U11/U12 small nuclear ribonucleoprotein 65 kDa protein","U11/U12 snRNP 65 kDa protein","U11/U12-65K"],"length_aa":517,"mass_kda":58.6,"function":"Participates in pre-mRNA U12-dependent splicing, performed by the minor spliceosome which removes U12-type introns. U12-type introns comprises less than 1% of all non-coding sequences. Binds to the 3'-stem-loop of m(7)G-capped U12 snRNA","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/Q96LT9/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/RNPC3","classification":"Common Essential","n_dependent_lines":1207,"n_total_lines":1208,"dependency_fraction":0.9991721854304636},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"SF3B1","stoichiometry":0.2},{"gene":"SF3B2","stoichiometry":0.2},{"gene":"SF3B3","stoichiometry":0.2},{"gene":"SF3B6","stoichiometry":0.2},{"gene":"SNRPB","stoichiometry":0.2},{"gene":"SNRPD2","stoichiometry":0.2},{"gene":"SNRPF","stoichiometry":0.2},{"gene":"SNUPN","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/RNPC3","total_profiled":1310},"omim":[{"mim_id":"620204","title":"RNA, U12 SMALL NUCLEAR; RNU12","url":"https://www.omim.org/entry/620204"},{"mim_id":"618160","title":"PITUITARY HORMONE DEFICIENCY, COMBINED OR ISOLATED, 7; CPHD7","url":"https://www.omim.org/entry/618160"},{"mim_id":"618016","title":"RNA-BINDING REGION-CONTAINING PROTEIN 3; RNPC3","url":"https://www.omim.org/entry/618016"},{"mim_id":"613038","title":"PITUITARY HORMONE DEFICIENCY, COMBINED OR ISOLATED, 1; CPHD1","url":"https://www.omim.org/entry/613038"},{"mim_id":"607007","title":"SNAP-ASSOCIATED PROTEIN; SNAPIN","url":"https://www.omim.org/entry/607007"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/RNPC3"},"hgnc":{"alias_symbol":["KIAA1839","FLJ20008","RBM40","SNRNP65"],"prev_symbol":[]},"alphafold":{"accession":"Q96LT9","domains":[{"cath_id":"3.30.70.330","chopping":"29-106","consensus_level":"high","plddt":87.6355,"start":29,"end":106},{"cath_id":"-","chopping":"163-198","consensus_level":"medium","plddt":90.9961,"start":163,"end":198},{"cath_id":"3.30.70.330","chopping":"392-501","consensus_level":"high","plddt":92.0787,"start":392,"end":501}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96LT9","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96LT9-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96LT9-F1-predicted_aligned_error_v6.png","plddt_mean":67.38},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=RNPC3","jax_strain_url":"https://www.jax.org/strain/search?query=RNPC3"},"sequence":{"accession":"Q96LT9","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96LT9.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96LT9/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96LT9"}},"corpus_meta":[{"pmid":"32462814","id":"PMC_32462814","title":"Expanding the phenotype of biallelic RNPC3 variants associated with growth hormone deficiency.","date":"2020","source":"American journal of medical genetics. Part A","url":"https://pubmed.ncbi.nlm.nih.gov/32462814","citation_count":24,"is_preprint":false},{"pmid":"30254136","id":"PMC_30254136","title":"Early developmental arrest and impaired gastrointestinal homeostasis in U12-dependent splicing-defective Rnpc3-deficient mice.","date":"2018","source":"RNA (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/30254136","citation_count":22,"is_preprint":false},{"pmid":"34906446","id":"PMC_34906446","title":"Pathogenic variants in RNPC3 are associated with hypopituitarism and primary ovarian insufficiency.","date":"2021","source":"Genetics in medicine : official journal of the American College of Medical Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34906446","citation_count":11,"is_preprint":false},{"pmid":"31885183","id":"PMC_31885183","title":"Identification of RNPC3 as a novel JAK2 fusion partner gene in B-acute lymphoblastic leukemia refractory to combination therapy including ruxolitinib.","date":"2019","source":"Molecular genetics & genomic medicine","url":"https://pubmed.ncbi.nlm.nih.gov/31885183","citation_count":11,"is_preprint":false},{"pmid":"38837887","id":"PMC_38837887","title":"Minor Spliceosomal 65K/RNPC3 Interacts with ANKRD11 and Mediates HDAC3-Regulated Histone Deacetylation and Transcription.","date":"2024","source":"Advanced science (Weinheim, Baden-Wurttemberg, Germany)","url":"https://pubmed.ncbi.nlm.nih.gov/38837887","citation_count":9,"is_preprint":false},{"pmid":"14974681","id":"PMC_14974681","title":"Cloning and identification of a novel human RNPC3 gene that encodes a protein with two RRM domains and is expressed in the cell nucleus.","date":"2003","source":"Biochemical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/14974681","citation_count":8,"is_preprint":false},{"pmid":"33650182","id":"PMC_33650182","title":"Establishing intellectual disability as the key feature of patients with biallelic RNPC3 variants.","date":"2021","source":"American journal of medical genetics. Part A","url":"https://pubmed.ncbi.nlm.nih.gov/33650182","citation_count":6,"is_preprint":false},{"pmid":"37463572","id":"PMC_37463572","title":"A Novel RNPC3 Gene Variant Expands the Phenotype in Patients with Congenital Hypopituitarism and Neuropathy.","date":"2023","source":"Hormone research in paediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/37463572","citation_count":3,"is_preprint":false},{"pmid":"40170400","id":"PMC_40170400","title":"Minor Splicing Factor RNPC3 Is Essential for the Germinal Center B Cell Response.","date":"2025","source":"European journal of immunology","url":"https://pubmed.ncbi.nlm.nih.gov/40170400","citation_count":2,"is_preprint":false},{"pmid":"41946577","id":"PMC_41946577","title":"Clinical Associations of Anti-RNPC3 Autoantibodies in Mixed Connective Tissue Disease.","date":"2026","source":"ACR open rheumatology","url":"https://pubmed.ncbi.nlm.nih.gov/41946577","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.10.23.24315723","title":"Pathogenicity evaluation of coding germline variants identifies rare alleles enriched in hematological patients of a founder population","date":"2024-10-23","source":"bioRxiv","url":"https://doi.org/10.1101/2024.10.23.24315723","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.09.26.678859","title":"Integrated Human Transcriptomics Identifies Fallopian Tube Progenitors as Plausible Precursors of High-Grade Serous Ovarian Cancer","date":"2025-09-30","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.26.678859","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8476,"output_tokens":2303,"usd":0.029986,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9326,"output_tokens":2425,"usd":0.053628,"stage2_stop_reason":"end_turn"},"total_usd":0.083614,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2003,\n      \"finding\": \"RNPC3 encodes a protein with two RNA recognition motif (RRM) domains and two bipartite nuclear targeting sequences; GFP localization experiments demonstrated that the RNPC3 protein localizes to the cell nucleus.\",\n      \"method\": \"cDNA cloning, sequence analysis, GFP fusion localization imaging\",\n      \"journal\": \"Biochemical genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — direct GFP localization experiment in single lab; domain identification by sequence analysis; no functional mutagenesis\",\n      \"pmids\": [\"14974681\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"RNPC3 (encoding the U11/U12-65K protein) is an essential component of the U12-dependent (minor class) spliceosome; conditional knockout of Rnpc3 in adult mice caused increased retention of U12-type introns in intestinal epithelial cell transcripts, demonstrating that 65K is required for minor intron splicing in vivo.\",\n      \"method\": \"Conditional Rnpc3 knockout mouse model, RT-PCR for U12 intron retention in purified intestinal epithelial cells\",\n      \"journal\": \"RNA (New York, N.Y.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO with defined molecular phenotype (intron retention), direct splicing assay, replicated across multiple transcripts in a novel mouse model\",\n      \"pmids\": [\"30254136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Loss of Rnpc3 in intestinal stem/progenitor cells leads to loss of phospho-ERK1/2 signaling, reduced proliferation, and increased apoptosis, placing U12-dependent splicing upstream of ERK signaling in intestinal homeostasis.\",\n      \"method\": \"Conditional Rnpc3 knockout mouse, immunostaining for phospho-ERK1/2, cell proliferation and death assays in intestinal crypts\",\n      \"journal\": \"RNA (New York, N.Y.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO mouse with defined cellular phenotype and pathway marker loss, single lab, correlative between ERK loss and Rnpc3 deficiency\",\n      \"pmids\": [\"30254136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Homozygous Rnpc3 null mice die prior to blastocyst implantation, establishing that 65K/RNPC3-mediated U12 splicing is essential for the earliest stages of mammalian embryonic development.\",\n      \"method\": \"Germline Rnpc3 knockout mouse, developmental stage analysis\",\n      \"journal\": \"RNA (New York, N.Y.)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — germline KO with clear developmental arrest phenotype, rigorous genetic model\",\n      \"pmids\": [\"30254136\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"RNPC3 is expressed in the developing forebrain, including the hypothalamus and Rathke's pouch (the pituitary anlage), in both mouse and human embryos; CRISPR/Cas9 knock-in of the p.Leu483Phe pathogenic variant in the Rnpc3 RRM2 domain in female mice reduced pituitary GH content, establishing a developmental role for RNPC3 in pituitary function.\",\n      \"method\": \"In situ hybridization on murine/human embryonic sections, CRISPR/Cas9 knock-in mouse model, pituitary GH content measurement\",\n      \"journal\": \"Genetics in medicine : official journal of the American College of Medical Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR knock-in model with defined endocrine phenotype and expression localization; single lab, specific RRM2 domain variant tested\",\n      \"pmids\": [\"34906446\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"The minor spliceosomal 65K/RNPC3 protein physically interacts with ANKRD11, a cofactor of histone deacetylase 3 (HDAC3); in human cells, the ANKRD11 middle uncharacterized domain mediates the association of Hs65K with HDAC3. ANKRD11 acts as a bridging factor enabling synergistic chromatin co-binding of HDAC3 and Hs65K, and knockdown of ANKRD11 reduces their common chromatin binding and decreases H3K9 deacetylation at nearby loci, linking minor spliceosome activity to histone deacetylation and transcriptional regulation.\",\n      \"method\": \"Affinity purification from Drosophila lysates, CRISPR/Cas9 deletion strains, CUT&Tag chromatin binding assay, ANKRD11 knockdown with H3K9 deacetylation measurement, domain mapping\",\n      \"journal\": \"Advanced science (Weinheim, Baden-Wurttemberg, Germany)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — interaction identified by affinity purification, validated in human cells, domain mapped, functional chromatin assay (CUT&Tag) with loss-of-function confirmation, multiple orthogonal methods in single study\",\n      \"pmids\": [\"38837887\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Loss of 65K/RNPC3 in Drosophila (Dm65KΔ/Δ) caused reduced histone deacetylation at H3K9 and H4K5 in heads and neural-related defects, functionally linking the minor spliceosome component to histone deacetylase activity in vivo.\",\n      \"method\": \"CRISPR/Cas9 deletion in Drosophila, histone deacetylation assays, neural phenotype characterization\",\n      \"journal\": \"Advanced science (Weinheim, Baden-Wurttemberg, Germany)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo KO with defined biochemical and phenotypic readout; Drosophila ortholog model, single lab\",\n      \"pmids\": [\"38837887\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Conditional ablation of RNPC3 in activated B cells impaired germinal center (GC) B cell development, inhibited proliferation, and promoted apoptosis; mechanistically, RNPC3 deficiency caused accumulation of minor intron retention in minor intron-containing genes associated with cell proliferation and apoptosis, establishing that RNPC3-dependent minor intron splicing is required for the GC B cell response.\",\n      \"method\": \"Conditional B-cell-specific Rnpc3 knockout mice, flow cytometry for GC B cell populations, proliferation and apoptosis assays, minor intron retention analysis\",\n      \"journal\": \"European journal of immunology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional KO with defined cellular phenotype (GC defect), direct minor intron retention assay linking molecular mechanism to immune phenotype, multiple orthogonal readouts\",\n      \"pmids\": [\"40170400\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"RNPC3 protein acts as a molecular bridge promoting U11/U12 RNP (di-snRNP) complex formation within the minor spliceosome.\",\n      \"method\": \"Reported as established function in autoantibody clinical literature (referenced as prior mechanistic knowledge)\",\n      \"journal\": \"ACR open rheumatology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — cited as background fact in a clinical autoantibody paper; no primary experiment described in this abstract; original experimental source not directly available in corpus\",\n      \"pmids\": [\"41946577\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"RNPC3 encodes the U11/U12-65K protein, an essential and unique component of the minor (U12-dependent) spliceosome that promotes U11/U12 di-snRNP complex formation and is required for excision of U12-type introns from a small subset of genes; it is indispensable for embryonic development, intestinal homeostasis, pituitary development, and germinal center B cell responses, and additionally interacts with ANKRD11 to couple minor spliceosome activity to HDAC3-mediated histone deacetylation and transcriptional regulation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"RNPC3 encodes the U11/U12-65K protein, an essential and unique component of the minor (U12-dependent) spliceosome required for excision of U12-type introns from a small subset of genes [#1]. It is a nuclear protein containing two RNA recognition motifs and two bipartite nuclear targeting sequences [#0], and functions as a molecular bridge promoting formation of the U11/U12 di-snRNP within the minor spliceosome [#8]. Across mammalian tissues RNPC3-dependent minor intron splicing is developmentally indispensable: germline loss causes pre-implantation embryonic lethality [#3], conditional ablation in intestinal epithelium increases U12-type intron retention with loss of phospho-ERK1/2 signaling, reduced proliferation, and increased apoptosis [#1, #2], a pathogenic RRM2-domain variant impairs pituitary growth-hormone content [#4], and B-cell-specific ablation impairs germinal center responses through retention of minor introns in proliferation- and apoptosis-associated genes [#7]. Beyond its splicing role, RNPC3 physically interacts with the HDAC3 cofactor ANKRD11, which bridges synergistic chromatin co-binding of RNPC3 and HDAC3 and couples minor spliceosome activity to H3K9 histone deacetylation and transcriptional regulation [#5, #6].\",\n  \"teleology\": [\n    {\n      \"year\": 2003,\n      \"claim\": \"Established the basic molecular identity and subcellular address of the RNPC3 protein, defining it as a nuclear RNA-binding protein.\",\n      \"evidence\": \"cDNA cloning, sequence analysis, and GFP fusion localization imaging\",\n      \"pmids\": [\"14974681\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No functional role in splicing demonstrated\", \"RRM RNA targets not identified\", \"No mutagenesis of nuclear targeting sequences\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Framed RNPC3 mechanistically as a bridging factor for U11/U12 di-snRNP assembly within the minor spliceosome.\",\n      \"evidence\": \"Cited as established background in a clinical autoantibody report; no primary experiment in the available abstract\",\n      \"pmids\": [\"41946577\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Original experimental source not present in corpus\", \"No structural model of the bridging interaction provided here\", \"RNA contacts mediating di-snRNP formation undefined\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Demonstrated in vivo that RNPC3 is required for U12-type intron excision and that its loss is incompatible with early development, linking minor splicing to organismal viability and tissue homeostasis.\",\n      \"evidence\": \"Germline and conditional Rnpc3 knockout mice with RT-PCR intron retention assays, phospho-ERK1/2 immunostaining, and proliferation/apoptosis assays in intestinal epithelium\",\n      \"pmids\": [\"30254136\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanistic link between intron retention and ERK signaling is correlative\", \"Specific minor-intron-containing transcripts driving the phenotype not fully resolved\", \"Does not address splicing-independent functions\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Connected RNPC3 to pituitary and forebrain development and showed a disease-associated RRM2 variant produces a defined endocrine phenotype.\",\n      \"evidence\": \"In situ hybridization on mouse/human embryos and CRISPR/Cas9 p.Leu483Phe knock-in mice with pituitary GH content measurement\",\n      \"pmids\": [\"34906446\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Splicing defects underlying the GH phenotype not directly mapped\", \"Single variant tested\", \"Sex-specific effect mechanism unexplained\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Uncovered a chromatin-coupled function: RNPC3 physically associates with ANKRD11/HDAC3 and links minor spliceosome activity to histone deacetylation and transcription.\",\n      \"evidence\": \"Affinity purification, CRISPR deletion strains, domain mapping, CUT&Tag, and ANKRD11 knockdown with H3K9 deacetylation readout, plus Drosophila 65K deletion with histone deacetylation and neural phenotyping\",\n      \"pmids\": [\"38837887\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether chromatin co-binding requires catalytic splicing activity is unresolved\", \"Direct genomic targets co-regulated by RNPC3 and HDAC3 not enumerated\", \"Mechanism by which a spliceosomal RRM protein engages chromatin undefined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended the requirement for RNPC3-dependent minor splicing to adaptive immunity, showing it sustains germinal center B cell proliferation and survival.\",\n      \"evidence\": \"B-cell-specific conditional Rnpc3 knockout mice with flow cytometry, proliferation/apoptosis assays, and minor intron retention analysis\",\n      \"pmids\": [\"40170400\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Individual causal minor-intron-containing genes not isolated\", \"Relationship to the ANKRD11/HDAC3 axis in B cells untested\", \"Effect on antibody affinity maturation outcome not addressed\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How RNPC3's role in di-snRNP assembly mechanistically integrates with its chromatin/HDAC3-coupled transcriptional function across tissues remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structure of the U11/U12-65K bridging interaction in the corpus\", \"Whether splicing and chromatin functions are separable is untested\", \"Tissue-specific minor-intron target sets driving distinct phenotypes not defined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003723\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0140098\", \"supporting_discovery_ids\": [1, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [1, 7]},\n      {\"term_id\": \"R-HSA-4839726\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"complexes\": [\"minor (U12-dependent) spliceosome\", \"U11/U12 di-snRNP\"],\n    \"partners\": [\"ANKRD11\", \"HDAC3\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}