{"gene":"RFX2","run_date":"2026-06-10T06:43:36","timeline":{"discoveries":[{"year":2004,"finding":"RFX2 was purified from rat testis nuclear extracts using the H1t TE1 promoter element (an X-box consensus sequence) as an affinity chromatography probe, identifying it as an 85 kDa protein that binds specifically to the TE1 element; polyclonal antibodies against RFX2 supershifted the low-mobility testis nuclear protein complex in EMSA. Co-expression of RFX2 with an H1t promoter/reporter vector activated the H1t promoter in GC-2spd germinal cells, and mutation of either TE1 or TE2 subelements repressed this activity.","method":"Affinity chromatography purification, EMSA with supershift, co-transfection reporter assay, site-directed mutagenesis of promoter elements","journal":"Journal of cellular biochemistry","confidence":"High","confidence_rationale":"Tier 1/2 / Strong — protein purified biochemically, binding confirmed by EMSA supershift, functional activation confirmed by reporter assay with mutagenesis, replicated across two independent papers (PMID:14743396 and PMID:15229132)","pmids":["14743396"],"is_preprint":false},{"year":2004,"finding":"Competitive band-shift assays and specific antisera showed that the H1t-60 CCTAGG palindrome (X-box) motif binds RFX family members; the testis-specific binding complex contains RFX2, probably as a homodimer, while somatic complexes contain RFX1 primarily as a heterodimer. Western blots confirmed RFX2 expression is greatly enhanced in adult testis and equally prominent in late pachytene spermatocytes and round spermatids.","method":"Competitive EMSA, antibody supershift, Western blot, immunohistochemistry","journal":"Biology of reproduction","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal EMSA with competition and supershift, Western blot, IHC; replicated in multiple subsequent papers","pmids":["15229132"],"is_preprint":false},{"year":2005,"finding":"RFX2 can bind independently to either the TE1 or TE2 X-box element of the H1t promoter to partially activate transcription; simultaneous mutation of both X-box elements is required to totally abolish RFX2-mediated reactivation, indicating that maximal promoter activation requires simultaneous occupancy of both elements.","method":"Transient co-transfection reporter assays with individual and double X-box mutations in GC-2spd cells","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean loss-of-function mutagenesis of promoter elements with reporter assay, single lab, single method","pmids":["15526285"],"is_preprint":false},{"year":2006,"finding":"RFX2 is most abundant in rat testis among tissues examined, is enriched in primary spermatocyte nuclei where H1t transcription is upregulated, and decreases in early spermatids where RFX1 levels increase and H1t transcription is downregulated; antibodies against RFX2 generate a shifted band in EMSA with H1t and testisin X-box probes using spermatocyte nuclear proteins.","method":"Western blot across tissues, EMSA with antibody supershift on spermatocyte nuclear extracts, subcellular fractionation","journal":"Journal of cellular biochemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct biochemical fractionation and EMSA, but single lab; functional consequence inferred rather than directly tested","pmids":["16676351"],"is_preprint":false},{"year":2008,"finding":"RFX2 occupies the H1t X-box in vivo in pachytene spermatocytes as shown by ChIP; transcription factor NF-Y binds the adjacent CCAAT-box and interacts directly or indirectly with RFX2; both the X-box and CCAAT-box are required for promoter activity; co-expression of RFX2 greatly enhances H1t promoter activity in GC-1spg cells.","method":"ChIP analysis, EMSA, Western blot, co-transfection reporter assay","journal":"Journal of cellular biochemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — in vivo ChIP plus EMSA plus functional reporter assay, multiple orthogonal methods in single lab, consistent with prior work","pmids":["18247329"],"is_preprint":false},{"year":2009,"finding":"The Rfx2 promoter contains a cluster of three MYB binding sites (MBS); A-MYB binds these sites as shown by electrophoretic gel-shift, ChIP, and co-transfection assays; Rfx2 expression is virtually eliminated in A-myb knockout testes, placing Rfx2 downstream of A-MYB in the spermatocyte transcriptional network. RFX2 also directly occupies and activates the Alf (TFIIA variant) promoter in vivo.","method":"EMSA, ChIP, co-transfection reporter assay, A-myb knockout mouse, immunohistology","journal":"BMC developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — three orthogonal methods (EMSA, ChIP, reporter assay) plus genetic loss-of-function (knockout mouse) confirming upstream regulation","pmids":["20003220"],"is_preprint":false},{"year":2011,"finding":"Morpholino knockdown of Rfx2 in Xenopus results in fewer or truncated cilia in ciliated tissues (neural tube, gastrocoel roof plate, epidermal MCCs, otic vesicles, kidneys) and causes cilia-defective embryonic phenotypes. Rfx2 is required for expression of several ciliogenic genes including TTC25, which is itself required for ciliogenesis, Hedgehog signaling, and left-right patterning.","method":"Morpholino knockdown in Xenopus, in situ hybridization, immunofluorescence for cilia markers","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function with specific cellular phenotype, target gene validation, replicated across multiple ciliated tissues and two independent papers (PMID:22227339 and PMID:22233545)","pmids":["22227339"],"is_preprint":false},{"year":2011,"finding":"Morpholino knockdown of Rfx2 in zebrafish Kupffer's Vesicle (ciliated organ of asymmetry) reduces KV cilia length and randomizes left-right asymmetry, including Nodal signaling gene expression (southpaw, lefty1, lefty2) and organ situs. Rfx2 is also required for ciliogenesis in zebrafish pronephric duct.","method":"Morpholino knockdown in zebrafish, immunofluorescence, in situ hybridization for asymmetry markers","journal":"Developmental biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — tissue-specific and whole-embryo knockdown with defined ciliary and signaling phenotypes, replicated by independent lab","pmids":["22233545"],"is_preprint":false},{"year":2014,"finding":"ChIP-seq and RNA-seq in Xenopus MCCs identified direct genomic targets of Rfx2, showing it coordinates gene expression programs for ciliogenesis, cilia function, and cell movement. Rfx2 cell-autonomously controls apical surface expansion in nascent MCCs, a previously unrecognized role for an RFX factor in cell movement.","method":"ChIP-seq, RNA-seq, morpholino knockdown with in vivo imaging, bioinformatics","journal":"eLife","confidence":"High","confidence_rationale":"Tier 2 / Strong — ChIP-seq plus RNA-seq plus in vivo cell biological validation with multiple orthogonal methods, single rigorous study","pmids":["24424412","25419512"],"is_preprint":false},{"year":2015,"finding":"Targeted knockout of Rfx2 in mice causes complete male sterility due to arrest of spermatid development just prior to elongation, with altered Golgi organization leading to failure of acrosomal cap formation from proacrosomal vesicles, and complete failure to form flagellar axoneme. RNA-seq and ChIP-seq identified 139 genes directly controlled by RFX2 during spermiogenesis, enriched for cilium function genes.","method":"Conditional knockout mouse, RNA-seq, ChIP-seq, electron and fluorescence microscopy","journal":"PLoS genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic knockout with specific cellular phenotype, whole-genome direct target identification by ChIP-seq and RNA-seq, replicated by independent labs (PMID:26162102 and PMID:26853561)","pmids":["26162102"],"is_preprint":false},{"year":2016,"finding":"Rfx2 knockout mice exhibit male sterility due to arrest of spermatogenesis at the early round spermatid step; Rfx2-null spermatids detach from seminiferous tubules forming multinucleated giant cells that undergo apoptosis, and flagellum formation is inhibited at its earliest stage. RNA-seq and ChIP-PCR identified numerous cilia-related and testis-specific genes directly regulated by RFX2.","method":"Knockout mouse, RNA-seq, ChIP-PCR, histology, immunofluorescence","journal":"Scientific reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic knockout with specific spermatid phenotype, ChIP-PCR confirming direct targets, replication of PMID:26162102 findings by independent lab","pmids":["26853561"],"is_preprint":false},{"year":2015,"finding":"A lacZ gene trap insertion into the first intron of Rfx2 creates a null allele (no Rfx2 mRNA detected); Rfx2gt/gt mice develop normally without neural tube or situs defects, but males are infertile due to a defect in spermatid maturation at or before the round/elongating spermatid stage.","method":"Gene trap null allele in mouse, RT-PCR, histology, beta-galactosidase reporter","journal":"Genesis","confidence":"High","confidence_rationale":"Tier 2 / Strong — null allele confirmed by absence of mRNA, specific spermatid arrest phenotype, consistent with two other knockout studies","pmids":["26248850"],"is_preprint":false},{"year":2023,"finding":"RFX2 binds to the PAF1 promoter (by ChIP-qPCR) and activates PAF1 transcription (by dual-luciferase assay) in spinal ependymoma cells. RFX2 knockdown reduces tumor stemness markers and sphere formation; PAF1 overexpression rescues these effects, placing RFX2 upstream of PAF1 in a stem cell-promoting axis.","method":"ChIP-qPCR, dual-luciferase reporter assay, siRNA knockdown, in vivo xenograft","journal":"Journal of neuro-oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus functional reporter assay plus rescue experiment, single lab, single study","pmids":["38057505"],"is_preprint":false},{"year":2025,"finding":"ACK1 interacts with RFX2 through its MHR domain (by co-immunoprecipitation and mass spectrometry) and competitively inhibits RFX2 ubiquitination by E3 ubiquitin ligase MIB1; ACK1 inhibition facilitates MIB1-mediated RFX2 ubiquitination and proteasomal degradation. RFX2 is a transcriptional suppressor of BNIP3 (by luciferase reporter and ChIP), so RFX2 degradation de-represses BNIP3 and activates PINK1/PARKIN-mediated mitophagy.","method":"Co-immunoprecipitation, mass spectrometry, ChIP, luciferase reporter assay, ubiquitination assay, in vitro and in vivo cell models","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (Co-IP/MS, ChIP, reporter, ubiquitination assay) in single lab, single study","pmids":["40715489"],"is_preprint":false},{"year":2025,"finding":"RFX2 binds the RASSF1 promoter and activates RASSF1 transcription (by dual-luciferase assay and ChIP) in lung adenocarcinoma cells; loss of RFX2 reduces RASSF1 expression, decreases YAP phosphorylation, and impairs Hippo pathway signaling, thereby promoting immune escape.","method":"ChIP, dual-luciferase reporter assay, RFX2 overexpression and siRNA knockdown, co-culture with CD8+ T cells, in vivo tumor model","journal":"Cell division","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP plus functional reporter plus rescue experiment, single lab, single study","pmids":["40069841"],"is_preprint":false},{"year":2025,"finding":"Depletion of Actl6a (SWI/SNF complex component) in zebrafish downregulates rfx2 at the transcriptional, chromatin accessibility, and SWI/SNF binding levels; overexpression of rfx2 mRNA partially rescues cilia disassembly and cystic kidney in actl6a mutants, placing rfx2 downstream of SWI/SNF complexes in cilia gene regulation.","method":"ATAC-seq, RNA-seq, CUT&RUN/ChIP, morpholino/CRISPR knockdown in zebrafish, mRNA rescue experiment","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple omics methods plus genetic rescue in zebrafish, preprint not yet peer reviewed","pmids":["bio_10.1101_2025.06.10.658863"],"is_preprint":true}],"current_model":"RFX2 is a winged-helix transcription factor that binds X-box DNA elements as a homodimer (in germ cells) or heterodimer (in somatic cells) to directly activate or repress target gene transcription; it is a master regulator of ciliogenesis across vertebrate tissues and of spermiogenesis (controlling >100 genes required for axoneme formation, acrosome biogenesis, and flagellum assembly), acts downstream of A-MYB in pachytene spermatocytes, cell-autonomously controls apical surface expansion in multi-ciliated cells, and in cancer contexts directly activates RASSF1/Hippo and PAF1 transcription or suppresses BNIP3 transcription; its stability is regulated by ACK1-competitive inhibition of MIB1-mediated ubiquitination, and its transcription is itself maintained by SWI/SNF chromatin remodeling complexes."},"narrative":{"mechanistic_narrative":"RFX2 is a winged-helix transcription factor that binds X-box DNA elements to direct the gene expression programs underlying ciliogenesis and spermiogenesis across vertebrates [PMID:14743396, PMID:22227339, PMID:26162102]. It was first purified from testis nuclear extracts as an X-box-binding protein that activates the H1t histone promoter, occupying both TE1 and TE2 X-box subelements for maximal activation [PMID:14743396, PMID:15526285]; the testis-specific X-box complex contains RFX2 (probably as a homodimer) whereas somatic complexes are dominated by RFX1 [PMID:15229132]. At target promoters RFX2 occupies the X-box in vivo and functions combinatorially with adjacent factors such as the CCAAT-binding NF-Y [PMID:18247329]. In the spermatocyte transcriptional hierarchy RFX2 acts downstream of A-MYB, which binds the Rfx2 promoter, and RFX2 in turn directly activates targets including the TFIIA variant Alf [PMID:20003220]. Genetic loss of Rfx2 causes male sterility through arrest of spermatid development, with disrupted Golgi-derived acrosome formation and complete failure of flagellar axoneme assembly, and RNA-seq/ChIP-seq define >100 directly bound spermiogenic and cilium-function genes [PMID:26162102, PMID:26853561, PMID:26248850]. In multiciliated and other ciliated tissues RFX2 is required for cilia formation and elongation, controls left-right asymmetry via ciliated organizer structures, coordinates ciliogenic gene programs, and cell-autonomously drives apical surface expansion in nascent multiciliated cells [PMID:22227339, PMID:22233545, PMID:24424412, PMID:25419512]. In cancer contexts RFX2 directly activates RASSF1 to sustain Hippo/YAP signaling and PAF1 to promote tumor stemness, and acts as a transcriptional suppressor of BNIP3; its protein level is set by competition between ACK1 and the E3 ligase MIB1 over RFX2 ubiquitination, linking RFX2 stability to BNIP3 de-repression and mitophagy [PMID:38057505, PMID:40715489, PMID:40069841].","teleology":[{"year":2004,"claim":"Established the biochemical identity of the testis X-box-binding activity and showed RFX2 is a functional transcriptional activator, answering what protein reads the X-box element in germ cells.","evidence":"Affinity purification on the H1t TE1 X-box, EMSA supershift, and co-transfection reporter assays with promoter mutagenesis in germinal cells","pmids":["14743396","15229132"],"confidence":"High","gaps":["Dimerization state inferred rather than structurally resolved","Did not define the full target gene repertoire"]},{"year":2005,"claim":"Defined the cis-architecture of RFX2 action, showing it can bind either X-box independently but requires occupancy of both for maximal promoter activation.","evidence":"Single and double X-box mutagenesis with reporter assays in GC-2spd cells","pmids":["15526285"],"confidence":"Medium","gaps":["Single lab, single promoter context","Cooperativity mechanism between elements not biochemically dissected"]},{"year":2008,"claim":"Demonstrated that RFX2 occupies its target X-box in vivo and acts combinatorially with the CCAAT-binding factor NF-Y, moving from in vitro binding to in vivo promoter occupancy.","evidence":"ChIP in pachytene spermatocytes, EMSA, and co-transfection reporter assays","pmids":["18247329"],"confidence":"High","gaps":["Direct vs indirect RFX2-NF-Y interaction not resolved","Limited to the H1t promoter"]},{"year":2009,"claim":"Placed RFX2 within the spermatocyte transcriptional hierarchy by identifying A-MYB as its upstream activator and Alf as a downstream RFX2 target.","evidence":"EMSA, ChIP, reporter assays, and A-myb knockout mice with immunohistology","pmids":["20003220"],"confidence":"High","gaps":["Other upstream regulators not surveyed","Full RFX2 target set not yet defined at this stage"]},{"year":2011,"claim":"Extended RFX2 function from germ cells to ciliogenesis, showing it is broadly required for cilia formation and for left-right patterning in vertebrate embryos.","evidence":"Morpholino knockdown in Xenopus and zebrafish with cilia immunofluorescence and asymmetry-marker in situ hybridization","pmids":["22227339","22233545"],"confidence":"High","gaps":["Morpholino knockdown not complemented by stable genetic null in these studies","Direct vs indirect regulation of ciliogenic targets not yet mapped genome-wide"]},{"year":2014,"claim":"Provided genome-wide direct targets in multiciliated cells and revealed an unexpected role in apical surface expansion and cell movement beyond classical ciliary gene control.","evidence":"ChIP-seq and RNA-seq in Xenopus MCCs with morpholino knockdown and in vivo imaging","pmids":["24424412","25419512"],"confidence":"High","gaps":["Mechanism linking RFX2 targets to apical surface expansion not fully defined","Cofactor requirements at MCC targets not mapped"]},{"year":2015,"claim":"Genetic knockout in mice established RFX2 as essential for spermiogenesis, defining its requirement for acrosome biogenesis and flagellar axoneme assembly and identifying its direct spermiogenic target set.","evidence":"Conditional and gene-trap knockout mice with RNA-seq, ChIP-seq, and electron/fluorescence microscopy","pmids":["26162102","26248850"],"confidence":"High","gaps":["Why neural tube and situs are spared in mouse nulls (unlike Xenopus/zebrafish knockdowns) unresolved","Cell-type-specific cofactors not identified"]},{"year":2016,"claim":"Independently confirmed the spermatid-arrest phenotype and direct cilia/testis target regulation, reinforcing RFX2 as the master spermiogenic ciliogenic regulator.","evidence":"Knockout mouse with RNA-seq, ChIP-PCR, histology, and immunofluorescence","pmids":["26853561"],"confidence":"High","gaps":["Pathway from RFX2 loss to multinucleated giant cell apoptosis not mechanistically traced"]},{"year":2023,"claim":"Identified a cancer role, with RFX2 directly activating PAF1 to promote tumor stemness in spinal ependymoma.","evidence":"ChIP-qPCR, dual-luciferase reporter, siRNA knockdown with rescue, and xenografts","pmids":["38057505"],"confidence":"Medium","gaps":["Single tumor type and single lab","Whether RFX2 acts as oncogene broadly across cancers not addressed"]},{"year":2025,"claim":"Expanded the cancer-context regulatory logic, showing RFX2 activates RASSF1/Hippo and suppresses BNIP3, and that its abundance is set by ACK1-MIB1 competition over ubiquitination.","evidence":"ChIP, dual-luciferase, Co-IP/mass spectrometry, ubiquitination assays, T-cell co-culture, and in vivo tumor models","pmids":["40715489","40069841"],"confidence":"Medium","gaps":["Activator vs suppressor switch determinants not defined","Single study per target; integration with germ-cell/ciliary functions unclear"]},{"year":2025,"claim":"Positioned rfx2 transcription itself downstream of SWI/SNF chromatin remodeling in cilia gene regulation.","evidence":"ATAC-seq, RNA-seq, CUT&RUN/ChIP, and mRNA rescue in zebrafish actl6a mutants (preprint)","pmids":["bio_10.1101_2025.06.10.658863"],"confidence":"Medium","gaps":["Preprint, not yet peer reviewed","Whether SWI/SNF directly binds the rfx2 locus in mammals untested"]},{"year":null,"claim":"How RFX2 selects between activator and repressor modes, and what cofactor/dimer-partner combinations distinguish its germ-cell, multiciliated-cell, and cancer programs, remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of RFX2 on X-box DNA in the corpus","Determinants of activation vs repression unknown","Tissue-specific dimerization partners largely uncharacterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[0,5,8,9,13,14]},{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[0,1,4,8]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0,3,4]}],"pathway":[{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[0,5,8,9]},{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[6,8,9]},{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[9,10,11]},{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[6,7,8]}],"complexes":[],"partners":["NFYA","AMYB","ACK1","MIB1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P48378","full_name":"DNA-binding protein RFX2","aliases":["Regulatory factor X 2"],"length_aa":723,"mass_kda":80.0,"function":"Transcription factor that acts as a key regulator of spermatogenesis. Acts by regulating expression of genes required for the haploid phase during spermiogenesis, such as genes required for cilium assembly and function (By similarity). Recognizes and binds the X-box, a regulatory motif with DNA sequence 5'-GTNRCC(0-3N)RGYAAC-3' present on promoters (PubMed:10330134). Probably activates transcription of the testis-specific histone gene H1-6 (By similarity)","subcellular_location":"Nucleus; Cytoplasm","url":"https://www.uniprot.org/uniprotkb/P48378/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/RFX2","classification":"Not Classified","n_dependent_lines":5,"n_total_lines":1208,"dependency_fraction":0.0041390728476821195},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/RFX2","total_profiled":1310},"omim":[{"mim_id":"620506","title":"INTRAFLAGELLAR TRANSPORT 46; IFT46","url":"https://www.omim.org/entry/620506"},{"mim_id":"619466","title":"CILIARY DYSKINESIA, PRIMARY, 47, AND LISSENCEPHALY; CILD47","url":"https://www.omim.org/entry/619466"},{"mim_id":"612659","title":"REGULATORY FACTOR X, 6; RFX6","url":"https://www.omim.org/entry/612659"},{"mim_id":"601990","title":"TUMOR PROTEIN p73; TP73","url":"https://www.omim.org/entry/601990"},{"mim_id":"601863","title":"REGULATORY FACTOR X, 5; RFX5","url":"https://www.omim.org/entry/601863"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"},{"location":"Golgi apparatus","reliability":"Approved"},{"location":"Primary cilium","reliability":"Additional"},{"location":"Basal body","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"testis","ntpm":55.3}],"url":"https://www.proteinatlas.org/search/RFX2"},"hgnc":{"alias_symbol":["FLJ14226"],"prev_symbol":[]},"alphafold":{"accession":"P48378","domains":[{"cath_id":"1.10.10.10","chopping":"173-277","consensus_level":"high","plddt":82.0887,"start":173,"end":277},{"cath_id":"-","chopping":"344-404_424-518","consensus_level":"medium","plddt":91.3919,"start":344,"end":518},{"cath_id":"1.10.490","chopping":"531-682","consensus_level":"high","plddt":89.4309,"start":531,"end":682}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P48378","model_url":"https://alphafold.ebi.ac.uk/files/AF-P48378-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P48378-F1-predicted_aligned_error_v6.png","plddt_mean":67.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=RFX2","jax_strain_url":"https://www.jax.org/strain/search?query=RFX2"},"sequence":{"accession":"P48378","fasta_url":"https://rest.uniprot.org/uniprotkb/P48378.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P48378/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P48378"}},"corpus_meta":[{"pmid":"24424412","id":"PMC_24424412","title":"Coordinated 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in the ciliated organ of asymmetry and an RFX2 transgene identifies a population of ciliated cells sufficient for fluid flow.","date":"2011","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/22233545","citation_count":46,"is_preprint":false},{"pmid":"19252121","id":"PMC_19252121","title":"Candida albicans RFX2 encodes a DNA binding protein involved in DNA damage responses, morphogenesis, and virulence.","date":"2009","source":"Eukaryotic cell","url":"https://pubmed.ncbi.nlm.nih.gov/19252121","citation_count":42,"is_preprint":false},{"pmid":"15229132","id":"PMC_15229132","title":"RFX2 is a potential transcriptional regulatory factor for histone H1t and other genes expressed during the meiotic phase of spermatogenesis.","date":"2004","source":"Biology of reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/15229132","citation_count":40,"is_preprint":false},{"pmid":"20003220","id":"PMC_20003220","title":"RFX2 is a candidate downstream amplifier of A-MYB regulation in 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genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34762273","citation_count":5,"is_preprint":false},{"pmid":"29277047","id":"PMC_29277047","title":"Association of the common SNPs in RNF212, STAG3 and RFX2 gene with male infertility with azoospermia in Chinese population.","date":"2017","source":"European journal of obstetrics, gynecology, and reproductive biology","url":"https://pubmed.ncbi.nlm.nih.gov/29277047","citation_count":5,"is_preprint":false},{"pmid":"38057505","id":"PMC_38057505","title":"RFX2 promotes tumor cell stemness through epigenetic regulation of PAF1 in spinal ependymoma.","date":"2023","source":"Journal of neuro-oncology","url":"https://pubmed.ncbi.nlm.nih.gov/38057505","citation_count":3,"is_preprint":false},{"pmid":"36922987","id":"PMC_36922987","title":"Molecular characteristics and transcriptional regulatory of spermatogenesis-related gene RFX2 in adult Banna mini-pig inbred line (BMI).","date":"2023","source":"Animal reproduction","url":"https://pubmed.ncbi.nlm.nih.gov/36922987","citation_count":2,"is_preprint":false},{"pmid":"40069841","id":"PMC_40069841","title":"RFX2 downregulates RASSF1 expression and YAP phosphorylation through Hippo signaling to promote immune escape in lung adenocarcinoma.","date":"2025","source":"Cell division","url":"https://pubmed.ncbi.nlm.nih.gov/40069841","citation_count":2,"is_preprint":false},{"pmid":"40715489","id":"PMC_40715489","title":"RFX2-BNIP3 axis-driven adaptive mitophagy promotes resistance to ACK1-targeted therapy in non-small cell lung cancer.","date":"2025","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/40715489","citation_count":1,"is_preprint":false},{"pmid":"35145545","id":"PMC_35145545","title":"The First Report of a Missense Variant in RFX2 Causing Non-Syndromic Tooth Agenesis in a Consanguineous Pakistani Family.","date":"2022","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/35145545","citation_count":1,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.06.10.658863","title":"Epigenetic regulation of cilia stability and kidney by the chromatin remodeling SWI/SNF complexes","date":"2025-06-14","source":"bioRxiv","url":"https://doi.org/10.1101/2025.06.10.658863","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13517,"output_tokens":4275,"usd":0.052338,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":12096,"output_tokens":3679,"usd":0.076228,"stage2_stop_reason":"end_turn"},"total_usd":0.128566,"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\": 2004,\n      \"finding\": \"RFX2 was purified from rat testis nuclear extracts using the H1t TE1 promoter element (an X-box consensus sequence) as an affinity chromatography probe, identifying it as an 85 kDa protein that binds specifically to the TE1 element; polyclonal antibodies against RFX2 supershifted the low-mobility testis nuclear protein complex in EMSA. Co-expression of RFX2 with an H1t promoter/reporter vector activated the H1t promoter in GC-2spd germinal cells, and mutation of either TE1 or TE2 subelements repressed this activity.\",\n      \"method\": \"Affinity chromatography purification, EMSA with supershift, co-transfection reporter assay, site-directed mutagenesis of promoter elements\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1/2 / Strong — protein purified biochemically, binding confirmed by EMSA supershift, functional activation confirmed by reporter assay with mutagenesis, replicated across two independent papers (PMID:14743396 and PMID:15229132)\",\n      \"pmids\": [\"14743396\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Competitive band-shift assays and specific antisera showed that the H1t-60 CCTAGG palindrome (X-box) motif binds RFX family members; the testis-specific binding complex contains RFX2, probably as a homodimer, while somatic complexes contain RFX1 primarily as a heterodimer. Western blots confirmed RFX2 expression is greatly enhanced in adult testis and equally prominent in late pachytene spermatocytes and round spermatids.\",\n      \"method\": \"Competitive EMSA, antibody supershift, Western blot, immunohistochemistry\",\n      \"journal\": \"Biology of reproduction\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal EMSA with competition and supershift, Western blot, IHC; replicated in multiple subsequent papers\",\n      \"pmids\": [\"15229132\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"RFX2 can bind independently to either the TE1 or TE2 X-box element of the H1t promoter to partially activate transcription; simultaneous mutation of both X-box elements is required to totally abolish RFX2-mediated reactivation, indicating that maximal promoter activation requires simultaneous occupancy of both elements.\",\n      \"method\": \"Transient co-transfection reporter assays with individual and double X-box mutations in GC-2spd cells\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean loss-of-function mutagenesis of promoter elements with reporter assay, single lab, single method\",\n      \"pmids\": [\"15526285\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"RFX2 is most abundant in rat testis among tissues examined, is enriched in primary spermatocyte nuclei where H1t transcription is upregulated, and decreases in early spermatids where RFX1 levels increase and H1t transcription is downregulated; antibodies against RFX2 generate a shifted band in EMSA with H1t and testisin X-box probes using spermatocyte nuclear proteins.\",\n      \"method\": \"Western blot across tissues, EMSA with antibody supershift on spermatocyte nuclear extracts, subcellular fractionation\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct biochemical fractionation and EMSA, but single lab; functional consequence inferred rather than directly tested\",\n      \"pmids\": [\"16676351\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"RFX2 occupies the H1t X-box in vivo in pachytene spermatocytes as shown by ChIP; transcription factor NF-Y binds the adjacent CCAAT-box and interacts directly or indirectly with RFX2; both the X-box and CCAAT-box are required for promoter activity; co-expression of RFX2 greatly enhances H1t promoter activity in GC-1spg cells.\",\n      \"method\": \"ChIP analysis, EMSA, Western blot, co-transfection reporter assay\",\n      \"journal\": \"Journal of cellular biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — in vivo ChIP plus EMSA plus functional reporter assay, multiple orthogonal methods in single lab, consistent with prior work\",\n      \"pmids\": [\"18247329\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The Rfx2 promoter contains a cluster of three MYB binding sites (MBS); A-MYB binds these sites as shown by electrophoretic gel-shift, ChIP, and co-transfection assays; Rfx2 expression is virtually eliminated in A-myb knockout testes, placing Rfx2 downstream of A-MYB in the spermatocyte transcriptional network. RFX2 also directly occupies and activates the Alf (TFIIA variant) promoter in vivo.\",\n      \"method\": \"EMSA, ChIP, co-transfection reporter assay, A-myb knockout mouse, immunohistology\",\n      \"journal\": \"BMC developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — three orthogonal methods (EMSA, ChIP, reporter assay) plus genetic loss-of-function (knockout mouse) confirming upstream regulation\",\n      \"pmids\": [\"20003220\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Morpholino knockdown of Rfx2 in Xenopus results in fewer or truncated cilia in ciliated tissues (neural tube, gastrocoel roof plate, epidermal MCCs, otic vesicles, kidneys) and causes cilia-defective embryonic phenotypes. Rfx2 is required for expression of several ciliogenic genes including TTC25, which is itself required for ciliogenesis, Hedgehog signaling, and left-right patterning.\",\n      \"method\": \"Morpholino knockdown in Xenopus, in situ hybridization, immunofluorescence for cilia markers\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function with specific cellular phenotype, target gene validation, replicated across multiple ciliated tissues and two independent papers (PMID:22227339 and PMID:22233545)\",\n      \"pmids\": [\"22227339\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Morpholino knockdown of Rfx2 in zebrafish Kupffer's Vesicle (ciliated organ of asymmetry) reduces KV cilia length and randomizes left-right asymmetry, including Nodal signaling gene expression (southpaw, lefty1, lefty2) and organ situs. Rfx2 is also required for ciliogenesis in zebrafish pronephric duct.\",\n      \"method\": \"Morpholino knockdown in zebrafish, immunofluorescence, in situ hybridization for asymmetry markers\",\n      \"journal\": \"Developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — tissue-specific and whole-embryo knockdown with defined ciliary and signaling phenotypes, replicated by independent lab\",\n      \"pmids\": [\"22233545\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"ChIP-seq and RNA-seq in Xenopus MCCs identified direct genomic targets of Rfx2, showing it coordinates gene expression programs for ciliogenesis, cilia function, and cell movement. Rfx2 cell-autonomously controls apical surface expansion in nascent MCCs, a previously unrecognized role for an RFX factor in cell movement.\",\n      \"method\": \"ChIP-seq, RNA-seq, morpholino knockdown with in vivo imaging, bioinformatics\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — ChIP-seq plus RNA-seq plus in vivo cell biological validation with multiple orthogonal methods, single rigorous study\",\n      \"pmids\": [\"24424412\", \"25419512\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Targeted knockout of Rfx2 in mice causes complete male sterility due to arrest of spermatid development just prior to elongation, with altered Golgi organization leading to failure of acrosomal cap formation from proacrosomal vesicles, and complete failure to form flagellar axoneme. RNA-seq and ChIP-seq identified 139 genes directly controlled by RFX2 during spermiogenesis, enriched for cilium function genes.\",\n      \"method\": \"Conditional knockout mouse, RNA-seq, ChIP-seq, electron and fluorescence microscopy\",\n      \"journal\": \"PLoS genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic knockout with specific cellular phenotype, whole-genome direct target identification by ChIP-seq and RNA-seq, replicated by independent labs (PMID:26162102 and PMID:26853561)\",\n      \"pmids\": [\"26162102\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Rfx2 knockout mice exhibit male sterility due to arrest of spermatogenesis at the early round spermatid step; Rfx2-null spermatids detach from seminiferous tubules forming multinucleated giant cells that undergo apoptosis, and flagellum formation is inhibited at its earliest stage. RNA-seq and ChIP-PCR identified numerous cilia-related and testis-specific genes directly regulated by RFX2.\",\n      \"method\": \"Knockout mouse, RNA-seq, ChIP-PCR, histology, immunofluorescence\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic knockout with specific spermatid phenotype, ChIP-PCR confirming direct targets, replication of PMID:26162102 findings by independent lab\",\n      \"pmids\": [\"26853561\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"A lacZ gene trap insertion into the first intron of Rfx2 creates a null allele (no Rfx2 mRNA detected); Rfx2gt/gt mice develop normally without neural tube or situs defects, but males are infertile due to a defect in spermatid maturation at or before the round/elongating spermatid stage.\",\n      \"method\": \"Gene trap null allele in mouse, RT-PCR, histology, beta-galactosidase reporter\",\n      \"journal\": \"Genesis\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — null allele confirmed by absence of mRNA, specific spermatid arrest phenotype, consistent with two other knockout studies\",\n      \"pmids\": [\"26248850\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"RFX2 binds to the PAF1 promoter (by ChIP-qPCR) and activates PAF1 transcription (by dual-luciferase assay) in spinal ependymoma cells. RFX2 knockdown reduces tumor stemness markers and sphere formation; PAF1 overexpression rescues these effects, placing RFX2 upstream of PAF1 in a stem cell-promoting axis.\",\n      \"method\": \"ChIP-qPCR, dual-luciferase reporter assay, siRNA knockdown, in vivo xenograft\",\n      \"journal\": \"Journal of neuro-oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus functional reporter assay plus rescue experiment, single lab, single study\",\n      \"pmids\": [\"38057505\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"ACK1 interacts with RFX2 through its MHR domain (by co-immunoprecipitation and mass spectrometry) and competitively inhibits RFX2 ubiquitination by E3 ubiquitin ligase MIB1; ACK1 inhibition facilitates MIB1-mediated RFX2 ubiquitination and proteasomal degradation. RFX2 is a transcriptional suppressor of BNIP3 (by luciferase reporter and ChIP), so RFX2 degradation de-represses BNIP3 and activates PINK1/PARKIN-mediated mitophagy.\",\n      \"method\": \"Co-immunoprecipitation, mass spectrometry, ChIP, luciferase reporter assay, ubiquitination assay, in vitro and in vivo cell models\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (Co-IP/MS, ChIP, reporter, ubiquitination assay) in single lab, single study\",\n      \"pmids\": [\"40715489\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"RFX2 binds the RASSF1 promoter and activates RASSF1 transcription (by dual-luciferase assay and ChIP) in lung adenocarcinoma cells; loss of RFX2 reduces RASSF1 expression, decreases YAP phosphorylation, and impairs Hippo pathway signaling, thereby promoting immune escape.\",\n      \"method\": \"ChIP, dual-luciferase reporter assay, RFX2 overexpression and siRNA knockdown, co-culture with CD8+ T cells, in vivo tumor model\",\n      \"journal\": \"Cell division\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP plus functional reporter plus rescue experiment, single lab, single study\",\n      \"pmids\": [\"40069841\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Depletion of Actl6a (SWI/SNF complex component) in zebrafish downregulates rfx2 at the transcriptional, chromatin accessibility, and SWI/SNF binding levels; overexpression of rfx2 mRNA partially rescues cilia disassembly and cystic kidney in actl6a mutants, placing rfx2 downstream of SWI/SNF complexes in cilia gene regulation.\",\n      \"method\": \"ATAC-seq, RNA-seq, CUT&RUN/ChIP, morpholino/CRISPR knockdown in zebrafish, mRNA rescue experiment\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple omics methods plus genetic rescue in zebrafish, preprint not yet peer reviewed\",\n      \"pmids\": [\"bio_10.1101_2025.06.10.658863\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"RFX2 is a winged-helix transcription factor that binds X-box DNA elements as a homodimer (in germ cells) or heterodimer (in somatic cells) to directly activate or repress target gene transcription; it is a master regulator of ciliogenesis across vertebrate tissues and of spermiogenesis (controlling >100 genes required for axoneme formation, acrosome biogenesis, and flagellum assembly), acts downstream of A-MYB in pachytene spermatocytes, cell-autonomously controls apical surface expansion in multi-ciliated cells, and in cancer contexts directly activates RASSF1/Hippo and PAF1 transcription or suppresses BNIP3 transcription; its stability is regulated by ACK1-competitive inhibition of MIB1-mediated ubiquitination, and its transcription is itself maintained by SWI/SNF chromatin remodeling complexes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"RFX2 is a winged-helix transcription factor that binds X-box DNA elements to direct the gene expression programs underlying ciliogenesis and spermiogenesis across vertebrates [#0, #6, #9]. It was first purified from testis nuclear extracts as an X-box-binding protein that activates the H1t histone promoter, occupying both TE1 and TE2 X-box subelements for maximal activation [#0, #2]; the testis-specific X-box complex contains RFX2 (probably as a homodimer) whereas somatic complexes are dominated by RFX1 [#1]. At target promoters RFX2 occupies the X-box in vivo and functions combinatorially with adjacent factors such as the CCAAT-binding NF-Y [#4]. In the spermatocyte transcriptional hierarchy RFX2 acts downstream of A-MYB, which binds the Rfx2 promoter, and RFX2 in turn directly activates targets including the TFIIA variant Alf [#5]. Genetic loss of Rfx2 causes male sterility through arrest of spermatid development, with disrupted Golgi-derived acrosome formation and complete failure of flagellar axoneme assembly, and RNA-seq/ChIP-seq define >100 directly bound spermiogenic and cilium-function genes [#9, #10, #11]. In multiciliated and other ciliated tissues RFX2 is required for cilia formation and elongation, controls left-right asymmetry via ciliated organizer structures, coordinates ciliogenic gene programs, and cell-autonomously drives apical surface expansion in nascent multiciliated cells [#6, #7, #8]. In cancer contexts RFX2 directly activates RASSF1 to sustain Hippo/YAP signaling and PAF1 to promote tumor stemness, and acts as a transcriptional suppressor of BNIP3; its protein level is set by competition between ACK1 and the E3 ligase MIB1 over RFX2 ubiquitination, linking RFX2 stability to BNIP3 de-repression and mitophagy [#12, #13, #14].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established the biochemical identity of the testis X-box-binding activity and showed RFX2 is a functional transcriptional activator, answering what protein reads the X-box element in germ cells.\",\n      \"evidence\": \"Affinity purification on the H1t TE1 X-box, EMSA supershift, and co-transfection reporter assays with promoter mutagenesis in germinal cells\",\n      \"pmids\": [\"14743396\", \"15229132\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Dimerization state inferred rather than structurally resolved\", \"Did not define the full target gene repertoire\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Defined the cis-architecture of RFX2 action, showing it can bind either X-box independently but requires occupancy of both for maximal promoter activation.\",\n      \"evidence\": \"Single and double X-box mutagenesis with reporter assays in GC-2spd cells\",\n      \"pmids\": [\"15526285\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab, single promoter context\", \"Cooperativity mechanism between elements not biochemically dissected\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Demonstrated that RFX2 occupies its target X-box in vivo and acts combinatorially with the CCAAT-binding factor NF-Y, moving from in vitro binding to in vivo promoter occupancy.\",\n      \"evidence\": \"ChIP in pachytene spermatocytes, EMSA, and co-transfection reporter assays\",\n      \"pmids\": [\"18247329\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct vs indirect RFX2-NF-Y interaction not resolved\", \"Limited to the H1t promoter\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Placed RFX2 within the spermatocyte transcriptional hierarchy by identifying A-MYB as its upstream activator and Alf as a downstream RFX2 target.\",\n      \"evidence\": \"EMSA, ChIP, reporter assays, and A-myb knockout mice with immunohistology\",\n      \"pmids\": [\"20003220\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Other upstream regulators not surveyed\", \"Full RFX2 target set not yet defined at this stage\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Extended RFX2 function from germ cells to ciliogenesis, showing it is broadly required for cilia formation and for left-right patterning in vertebrate embryos.\",\n      \"evidence\": \"Morpholino knockdown in Xenopus and zebrafish with cilia immunofluorescence and asymmetry-marker in situ hybridization\",\n      \"pmids\": [\"22227339\", \"22233545\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Morpholino knockdown not complemented by stable genetic null in these studies\", \"Direct vs indirect regulation of ciliogenic targets not yet mapped genome-wide\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Provided genome-wide direct targets in multiciliated cells and revealed an unexpected role in apical surface expansion and cell movement beyond classical ciliary gene control.\",\n      \"evidence\": \"ChIP-seq and RNA-seq in Xenopus MCCs with morpholino knockdown and in vivo imaging\",\n      \"pmids\": [\"24424412\", \"25419512\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism linking RFX2 targets to apical surface expansion not fully defined\", \"Cofactor requirements at MCC targets not mapped\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Genetic knockout in mice established RFX2 as essential for spermiogenesis, defining its requirement for acrosome biogenesis and flagellar axoneme assembly and identifying its direct spermiogenic target set.\",\n      \"evidence\": \"Conditional and gene-trap knockout mice with RNA-seq, ChIP-seq, and electron/fluorescence microscopy\",\n      \"pmids\": [\"26162102\", \"26248850\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Why neural tube and situs are spared in mouse nulls (unlike Xenopus/zebrafish knockdowns) unresolved\", \"Cell-type-specific cofactors not identified\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Independently confirmed the spermatid-arrest phenotype and direct cilia/testis target regulation, reinforcing RFX2 as the master spermiogenic ciliogenic regulator.\",\n      \"evidence\": \"Knockout mouse with RNA-seq, ChIP-PCR, histology, and immunofluorescence\",\n      \"pmids\": [\"26853561\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Pathway from RFX2 loss to multinucleated giant cell apoptosis not mechanistically traced\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Identified a cancer role, with RFX2 directly activating PAF1 to promote tumor stemness in spinal ependymoma.\",\n      \"evidence\": \"ChIP-qPCR, dual-luciferase reporter, siRNA knockdown with rescue, and xenografts\",\n      \"pmids\": [\"38057505\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single tumor type and single lab\", \"Whether RFX2 acts as oncogene broadly across cancers not addressed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Expanded the cancer-context regulatory logic, showing RFX2 activates RASSF1/Hippo and suppresses BNIP3, and that its abundance is set by ACK1-MIB1 competition over ubiquitination.\",\n      \"evidence\": \"ChIP, dual-luciferase, Co-IP/mass spectrometry, ubiquitination assays, T-cell co-culture, and in vivo tumor models\",\n      \"pmids\": [\"40715489\", \"40069841\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Activator vs suppressor switch determinants not defined\", \"Single study per target; integration with germ-cell/ciliary functions unclear\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Positioned rfx2 transcription itself downstream of SWI/SNF chromatin remodeling in cilia gene regulation.\",\n      \"evidence\": \"ATAC-seq, RNA-seq, CUT&RUN/ChIP, and mRNA rescue in zebrafish actl6a mutants (preprint)\",\n      \"pmids\": [\"bio_10.1101_2025.06.10.658863\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint, not yet peer reviewed\", \"Whether SWI/SNF directly binds the rfx2 locus in mammals untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How RFX2 selects between activator and repressor modes, and what cofactor/dimer-partner combinations distinguish its germ-cell, multiciliated-cell, and cancer programs, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of RFX2 on X-box DNA in the corpus\", \"Determinants of activation vs repression unknown\", \"Tissue-specific dimerization partners largely uncharacterized\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [0, 5, 8, 9, 13, 14]},\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [0, 1, 4, 8]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 3, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [0, 5, 8, 9]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [6, 8, 9]},\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [9, 10, 11]},\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [6, 7, 8]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"NFYA\", \"AMYB\", \"ACK1\", \"MIB1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}