{"gene":"FMN1","run_date":"2026-06-09T23:54:44","timeline":{"discoveries":[{"year":1998,"finding":"The mouse Fmn (formin) gene produces abundant circular RNA transcripts in which downstream exons are joined to upstream exon acceptors (back-splicing). Gene-targeted deletion of exon 4 or exon 5 abolishes circular transcript production without eliminating linear RNA isoforms. Mice lacking circular Fmn transcripts exhibit variably penetrant renal agenesis, phenocopying other Fmn mutant alleles, suggesting the circular transcripts play a role in kidney development.","method":"RT-PCR, ribonuclease protection assay, gene-targeted homologous recombination (knockout mice), phenotypic analysis","journal":"Molecular medicine (Cambridge, Mass.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO with defined renal phenotype and two orthogonal RNA detection methods in single lab; functional link between circular transcripts and kidney development is correlative rather than mechanistically resolved","pmids":["9848078"],"is_preprint":false},{"year":1997,"finding":"The mouse Fmn (formin) gene spans ~400 kb, is composed of at least 24 exons, and produces differentially processed transcripts expressed in embryonic limb bud, adult brain, and kidney. Two novel exons were identified that are expressed in developing limb bud.","method":"Genomic library screening, clone characterization, microsatellite mapping, probe hybridization","journal":"Genomics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct genomic structural characterization in single lab with multiple overlapping clones; establishes gene architecture but limited functional mechanistic depth","pmids":["9119367"],"is_preprint":false},{"year":2010,"finding":"Homozygous 263-kb deletion of the human FMN1 gene causes oligosyndactyly, radio-ulnar synostosis, hearing loss, and renal defects—a phenotype identical to that of limb deformity (ld) mice—establishing that loss of FMN1 protein (in addition to disruption of GREM1 regulatory elements) contributes to the limb deformity/renal agenesis phenotype. A 1.7-Mb duplication encompassing both GREM1 and FMN1 was associated with Cenani-Lenz-like isolated oligosyndactyly.","method":"Array CGH (chromosomal imbalance detection), clinical phenotype characterization, comparison with mouse ld model","journal":"Journal of medical genetics","confidence":"Low","confidence_rationale":"Tier 3 / Weak — human genomic deletion mapping with phenotypic readout; no direct biochemical or cellular mechanism experiment performed on FMN1 protein itself","pmids":["20610440"],"is_preprint":false},{"year":2021,"finding":"FMN1 (formin 1) confers invasive mechanical fitness to glioblastoma cells. Mechanistically, FMN1 acts from the microtubule lattice to promote robust mechanical cohesion, leading to increased cell stiffness, higher mechanical forces on substrate, and stochastic migration. Ectopic FMN1 expression increased these fitness parameters in cancer and normal cell lines; FMN1 expression was induced by mechano-chemical signals and confirmed in patient glioblastoma samples.","method":"Live-cell imaging, traction force microscopy, atomic force microscopy, ectopic overexpression and loss-of-function, patient sample validation, mechanobiology assays","journal":"Developmental cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization to microtubule lattice with multiple orthogonal mechanobiological readouts in single lab; mechanism proposed (microtubule-based mechanical cohesion) supported by functional assays but not fully reconstituted in vitro","pmids":["34559979"],"is_preprint":false},{"year":2018,"finding":"FMN1 protein functions in the BMP antagonistic pathway during limb development. Genomic rearrangements of the GREM1-FMN1 locus, including FMN1 point mutations, cause Cenani-Lenz syndrome-like syndactyly, linking FMN1 loss-of-function to disrupted BMP signaling in limb patterning.","method":"Clinical genetics, mutation analysis, pathway analysis (WNT/BMP cross-talk review with genetic evidence)","journal":"American journal of medical genetics. Part A","confidence":"Low","confidence_rationale":"Tier 4 / Weak — pathway placement based on genetic/clinical data and literature review without direct biochemical experiment on FMN1 protein in BMP pathway","pmids":["30569497"],"is_preprint":false}],"current_model":"FMN1 (formin 1) is a formin-family protein whose loss in mice and humans causes limb deformities and renal aplasia; in glioblastoma cells, FMN1 localizes to the microtubule lattice and promotes mechanical cohesion, cell stiffness, and invasive motility, while the mouse Fmn locus also produces abundant circular RNA transcripts whose exon-specific deletion phenocopies renal agenesis, suggesting additional regulatory roles for the locus in kidney development."},"narrative":{"mechanistic_narrative":"FMN1 is a formin-family protein whose locus is essential for limb and kidney development and which contributes to cancer cell mechanics [PMID:9848078, PMID:34559979]. The mouse Fmn gene spans ~400 kb with at least 24 exons and produces differentially processed transcripts in embryonic limb bud, adult brain, and kidney, including abundant circular RNAs generated by back-splicing; gene-targeted deletion of exon 4 or 5 abolishes circular transcript production without eliminating linear isoforms and produces variably penetrant renal agenesis, implicating these circular transcripts in kidney development [PMID:9848078, PMID:9119367]. In glioblastoma cells, FMN1 protein localizes to the microtubule lattice and promotes mechanical cohesion, increasing cell stiffness, traction forces on substrate, and stochastic invasive migration; ectopic FMN1 raises these fitness parameters in both cancer and normal cells and its expression is induced by mechano-chemical signals [PMID:34559979]. In humans, homozygous deletion of FMN1 causes a limb deformity and renal phenotype identical to the mouse limb deformity (ld) model [PMID:20610440]. Beyond these findings, the biochemical actin- or microtubule-regulatory activity of the FMN1 protein has not been reconstituted in the available corpus.","teleology":[{"year":1997,"claim":"Establishing the architecture of the Fmn locus was the prerequisite for relating its transcripts to developmental phenotypes, defining a large multi-exon gene with tissue-specific isoforms.","evidence":"Genomic library screening, clone characterization, and probe hybridization mapping the mouse Fmn gene","pmids":["9119367"],"confidence":"Medium","gaps":["No protein product characterized functionally","Roles of individual isoforms not assigned","No molecular activity defined for the encoded protein"]},{"year":1998,"claim":"Whether the locus's non-linear transcripts had a developmental function was unknown; exon-specific deletion showed that circular Fmn RNAs are required for normal kidney development independent of linear mRNA.","evidence":"RT-PCR, ribonuclease protection, and exon 4/5 knockout mice with renal phenotyping","pmids":["9848078"],"confidence":"Medium","gaps":["Mechanism linking circular transcripts to kidney development is correlative","Molecular targets of the circular RNAs unidentified","Penetrance is variable"]},{"year":2010,"claim":"Whether the mouse phenotype translated to humans was open; a homozygous human FMN1 deletion reproduced the limb deformity/renal phenotype, establishing FMN1 loss as causally relevant in humans.","evidence":"Array CGH genomic deletion mapping with clinical phenotyping, compared to the ld mouse model","pmids":["20610440"],"confidence":"Low","gaps":["Deletion also disrupts GREM1 regulatory elements, confounding attribution to FMN1 alone","No biochemical or cellular experiment on FMN1 protein performed","Mechanism of developmental defect not resolved"]},{"year":2018,"claim":"To place FMN1 in a developmental signaling context, genetic evidence linked FMN1 loss-of-function and point mutations to disrupted BMP-antagonistic signaling in limb patterning.","evidence":"Clinical genetics and mutation analysis with pathway review of WNT/BMP cross-talk","pmids":["30569497"],"confidence":"Low","gaps":["Pathway placement is inferred from genetics, not direct biochemistry","No demonstration that FMN1 protein acts on BMP components","Locus-level confounding with GREM1 persists"]},{"year":2021,"claim":"The cell-biological function of FMN1 protein was undefined; mechanobiology in glioblastoma showed FMN1 acts from the microtubule lattice to confer mechanical cohesion and invasive fitness.","evidence":"Live-cell imaging, traction force and atomic force microscopy, gain/loss-of-function, and patient sample validation","pmids":["34559979"],"confidence":"Medium","gaps":["Microtubule-based mechanism not reconstituted in vitro","Direct molecular activity (actin nucleation, MT binding) not biochemically defined","Single-lab mechanism"]},{"year":null,"claim":"The biochemical activity of the FMN1 protein and how it bridges its microtubule-associated mechanical role with its developmental requirement in limb and kidney remain unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No in vitro reconstitution of FMN1 enzymatic/cytoskeletal activity","Mechanistic connection between circular RNA function and protein function unclear","Direct molecular partners of FMN1 not defined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[3]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[3]}],"pathway":[{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[0,1,2]}],"complexes":[],"partners":[],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q68DA7","full_name":"Formin-1","aliases":["Limb deformity protein homolog"],"length_aa":1419,"mass_kda":157.6,"function":"Plays a role in the formation of adherens junction and the polymerization of linear actin cables","subcellular_location":"Nucleus; Cytoplasm; Cell junction, adherens junction; Cell membrane","url":"https://www.uniprot.org/uniprotkb/Q68DA7/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/FMN1","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/FMN1","total_profiled":1310},"omim":[{"mim_id":"616288","title":"FORMIN-LIKE 3; FMNL3","url":"https://www.omim.org/entry/616288"},{"mim_id":"616285","title":"FORMIN-LIKE 2; FMNL2","url":"https://www.omim.org/entry/616285"},{"mim_id":"612941","title":"PRE-mRNA-PROCESSING FACTOR 40 HOMOLOG A; PRPF40A","url":"https://www.omim.org/entry/612941"},{"mim_id":"609691","title":"FORMIN HOMOLOGY-2 DOMAIN-CONTAINING PROTEIN 3; FHOD3","url":"https://www.omim.org/entry/609691"},{"mim_id":"609216","title":"SPIRE-TYPE ACTIN NUCLEATION FACTOR 1; SPIRE1","url":"https://www.omim.org/entry/609216"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"retina","ntpm":27.8}],"url":"https://www.proteinatlas.org/search/FMN1"},"hgnc":{"alias_symbol":["DKFZP686C2281","FLJ45135","MGC125288","MGC125289"],"prev_symbol":["LD","FMN"]},"alphafold":{"accession":"Q68DA7","domains":[{"cath_id":"1.20.58","chopping":"1049-1135","consensus_level":"medium","plddt":88.0889,"start":1049,"end":1135},{"cath_id":"1.20.58.2220","chopping":"1153-1390","consensus_level":"medium","plddt":93.4652,"start":1153,"end":1390}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q68DA7","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q68DA7-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q68DA7-F1-predicted_aligned_error_v6.png","plddt_mean":55.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=FMN1","jax_strain_url":"https://www.jax.org/strain/search?query=FMN1"},"sequence":{"accession":"Q68DA7","fasta_url":"https://rest.uniprot.org/uniprotkb/Q68DA7.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q68DA7/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q68DA7"}},"corpus_meta":[{"pmid":"1715579","id":"PMC_1715579","title":"Purification and characterization of the cytokine-induced macrophage nitric oxide synthase: an FAD- and FMN-containing flavoprotein.","date":"1991","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/1715579","citation_count":745,"is_preprint":false},{"pmid":"9237990","id":"PMC_9237990","title":"Three-dimensional structure of NADPH-cytochrome P450 reductase: prototype for FMN- and FAD-containing enzymes.","date":"1997","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/9237990","citation_count":661,"is_preprint":false},{"pmid":"10924135","id":"PMC_10924135","title":"Photochemical and mutational analysis of the FMN-binding domains of the plant blue light receptor, phototropin.","date":"2000","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10924135","citation_count":447,"is_preprint":false},{"pmid":"15808508","id":"PMC_15808508","title":"The speed of RNA transcription and metabolite binding kinetics operate an FMN riboswitch.","date":"2005","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/15808508","citation_count":386,"is_preprint":false},{"pmid":"2708380","id":"PMC_2708380","title":"Structural analysis of the FMN binding domain of NADPH-cytochrome P-450 oxidoreductase by site-directed mutagenesis.","date":"1989","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/2708380","citation_count":264,"is_preprint":false},{"pmid":"6778861","id":"PMC_6778861","title":"Separate roles for FMN and FAD in catalysis by liver microsomal NADPH-cytochrome P-450 reductase.","date":"1981","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/6778861","citation_count":262,"is_preprint":false},{"pmid":"8642604","id":"PMC_8642604","title":"Molecular recognition in the FMN-RNA aptamer complex.","date":"1996","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/8642604","citation_count":179,"is_preprint":false},{"pmid":"9514256","id":"PMC_9514256","title":"Covalent attachment of flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) to enzymes: the current state of affairs.","date":"1998","source":"Protein science : a publication of the Protein Society","url":"https://pubmed.ncbi.nlm.nih.gov/9514256","citation_count":162,"is_preprint":false},{"pmid":"6807985","id":"PMC_6807985","title":"Oxidation-reduction states of FMN and FAD in NADPH-cytochrome P-450 reductase during reduction by NADPH.","date":"1982","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/6807985","citation_count":120,"is_preprint":false},{"pmid":"20193654","id":"PMC_20193654","title":"The FMN-dependent two-component monooxygenase systems.","date":"2010","source":"Archives of biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/20193654","citation_count":114,"is_preprint":false},{"pmid":"9848078","id":"PMC_9848078","title":"The mouse formin (Fmn) gene: abundant circular RNA transcripts and gene-targeted deletion analysis.","date":"1998","source":"Molecular medicine (Cambridge, Mass.)","url":"https://pubmed.ncbi.nlm.nih.gov/9848078","citation_count":112,"is_preprint":false},{"pmid":"11020276","id":"PMC_11020276","title":"Crystal structure of FMN-dependent nitroreductase from Escherichia coli B: a prodrug-activating enzyme.","date":"2000","source":"Journal of medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11020276","citation_count":110,"is_preprint":false},{"pmid":"880288","id":"PMC_880288","title":"Purification and properties of the NADH and NADPH specific FMN oxidoreductases from Beneckea harveyi.","date":"1977","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/880288","citation_count":92,"is_preprint":false},{"pmid":"10461454","id":"PMC_10461454","title":"Photodynamic crosslinking of proteins. III. Kinetics of the FMN- and rose bengal-sensitized photooxidation and intermolecular crosslinking of model tyrosine-containing N-(2-hydroxypropyl)methacrylamide copolymers.","date":"1999","source":"Photochemistry and photobiology","url":"https://pubmed.ncbi.nlm.nih.gov/10461454","citation_count":88,"is_preprint":false},{"pmid":"9398151","id":"PMC_9398151","title":"Differential stabilization of the three FMN redox forms by tyrosine 94 and tryptophan 57 in flavodoxin from Anabaena and its influence on the redox potentials.","date":"1997","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9398151","citation_count":88,"is_preprint":false},{"pmid":"11112541","id":"PMC_11112541","title":"RNA-Catalyzed CoA, NAD, and FAD synthesis from phosphopantetheine, NMN, and FMN.","date":"2000","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11112541","citation_count":80,"is_preprint":false},{"pmid":"6086343","id":"PMC_6086343","title":"Content and localization of FMN, Fe-S clusters and nickel in the NAD-linked hydrogenase of Nocardia opaca 1b.","date":"1984","source":"European journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/6086343","citation_count":76,"is_preprint":false},{"pmid":"21730168","id":"PMC_21730168","title":"Structure and function of the interacting domains of Spire and Fmn-family formins.","date":"2011","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/21730168","citation_count":75,"is_preprint":false},{"pmid":"9030258","id":"PMC_9030258","title":"Bovine-heart NADH:ubiquinone oxidoreductase is a monomer with 8 Fe-S clusters and 2 FMN groups.","date":"1997","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/9030258","citation_count":69,"is_preprint":false},{"pmid":"21593602","id":"PMC_21593602","title":"The riboflavin analog roseoflavin targets an FMN-riboswitch and blocks Listeria monocytogenes growth, but also stimulates virulence gene-expression and infection.","date":"2011","source":"RNA biology","url":"https://pubmed.ncbi.nlm.nih.gov/21593602","citation_count":68,"is_preprint":false},{"pmid":"8910599","id":"PMC_8910599","title":"The B form of dihydroorotate dehydrogenase from Lactococcus lactis consists of two different subunits, encoded by the pyrDb and pyrK genes, and contains FMN, FAD, and [FeS] redox centers.","date":"1996","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8910599","citation_count":68,"is_preprint":false},{"pmid":"10734100","id":"PMC_10734100","title":"Dissecting the energetics of the apoflavodoxin-FMN complex.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10734100","citation_count":67,"is_preprint":false},{"pmid":"25661987","id":"PMC_25661987","title":"The ribB FMN riboswitch from Escherichia coli operates at the transcriptional and translational level and regulates riboflavin biosynthesis.","date":"2015","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/25661987","citation_count":65,"is_preprint":false},{"pmid":"15184374","id":"PMC_15184374","title":"Crystal structure and functional characterization of yeast YLR011wp, an enzyme with NAD(P)H-FMN and ferric iron reductase activities.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15184374","citation_count":63,"is_preprint":false},{"pmid":"22985396","id":"PMC_22985396","title":"Redox reactions of reduced flavin mononucleotide (FMN), riboflavin (RBF), and anthraquinone-2,6-disulfonate (AQDS) with ferrihydrite and lepidocrocite.","date":"2012","source":"Environmental science & technology","url":"https://pubmed.ncbi.nlm.nih.gov/22985396","citation_count":63,"is_preprint":false},{"pmid":"10887197","id":"PMC_10887197","title":"Molecular characterization of FMN1, the structural gene for the monofunctional flavokinase of Saccharomyces cerevisiae.","date":"2000","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10887197","citation_count":59,"is_preprint":false},{"pmid":"18245777","id":"PMC_18245777","title":"Mechanism and regulation of the Two-component FMN-dependent monooxygenase ActVA-ActVB from Streptomyces coelicolor.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18245777","citation_count":57,"is_preprint":false},{"pmid":"17897954","id":"PMC_17897954","title":"Old yellow enzymes, highly homologous FMN oxidoreductases with modulating roles in oxidative stress and programmed cell death in yeast.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17897954","citation_count":57,"is_preprint":false},{"pmid":"17902705","id":"PMC_17902705","title":"Obligatory intermolecular electron-transfer from FAD to FMN in dimeric P450BM-3.","date":"2007","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17902705","citation_count":56,"is_preprint":false},{"pmid":"32054832","id":"PMC_32054832","title":"FMN reduces Amyloid-β toxicity in yeast by regulating redox status and cellular metabolism.","date":"2020","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/32054832","citation_count":55,"is_preprint":false},{"pmid":"30873834","id":"PMC_30873834","title":"Energetics and Dynamics of Proton-Coupled Electron Transfer in the NADH/FMN Site of Respiratory Complex I.","date":"2019","source":"Journal of the American Chemical Society","url":"https://pubmed.ncbi.nlm.nih.gov/30873834","citation_count":55,"is_preprint":false},{"pmid":"8463285","id":"PMC_8463285","title":"Critical residues involved in FMN binding and catalytic activity in cytochrome P450BM-3.","date":"1993","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8463285","citation_count":54,"is_preprint":false},{"pmid":"2261478","id":"PMC_2261478","title":"Structure and oxidation-reduction behavior of 1-deaza-FMN flavodoxins: modulation of redox potentials in flavodoxins.","date":"1990","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/2261478","citation_count":54,"is_preprint":false},{"pmid":"1939279","id":"PMC_1939279","title":"Expression, purification, and properties of the flavoprotein domain of cytochrome P-450BM-3. Evidence for the importance of the amino-terminal region for FMN binding.","date":"1991","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/1939279","citation_count":52,"is_preprint":false},{"pmid":"19375431","id":"PMC_19375431","title":"Structure and mechanism of a eukaryotic FMN adenylyltransferase.","date":"2009","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/19375431","citation_count":49,"is_preprint":false},{"pmid":"859041","id":"PMC_859041","title":"NADH-FMN oxidoreductase activity and iron content of organs from riboflavin and iron-deficient rats.","date":"1977","source":"The Journal of nutrition","url":"https://pubmed.ncbi.nlm.nih.gov/859041","citation_count":49,"is_preprint":false},{"pmid":"11248234","id":"PMC_11248234","title":"Expression and mutagenesis of the NqrC subunit of the NQR respiratory Na(+) pump from Vibrio cholerae with covalently attached FMN.","date":"2001","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/11248234","citation_count":49,"is_preprint":false},{"pmid":"9727006","id":"PMC_9727006","title":"Purification and characterization of wild-type and mutant \"classical\" nitroreductases of Salmonella typhimurium. L33R mutation greatly diminishes binding of FMN to the nitroreductase of S. typhimurium.","date":"1998","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/9727006","citation_count":48,"is_preprint":false},{"pmid":"19290671","id":"PMC_19290671","title":"Regulation of FMN subdomain interactions and function in neuronal nitric oxide synthase.","date":"2009","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19290671","citation_count":47,"is_preprint":false},{"pmid":"16183635","id":"PMC_16183635","title":"An FMN hydrolase is fused to a riboflavin kinase homolog in plants.","date":"2005","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16183635","citation_count":45,"is_preprint":false},{"pmid":"15882995","id":"PMC_15882995","title":"Altered mechanism of the alkanesulfonate FMN reductase with the monooxygenase enzyme.","date":"2005","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/15882995","citation_count":45,"is_preprint":false},{"pmid":"29551348","id":"PMC_29551348","title":"Biosynthesis and Activity of Prenylated FMN Cofactors.","date":"2018","source":"Cell chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/29551348","citation_count":44,"is_preprint":false},{"pmid":"16752898","id":"PMC_16752898","title":"Characterization of a thermostable NADPH:FMN oxidoreductase from the mesophilic bacterium Bacillus subtilis.","date":"2006","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16752898","citation_count":43,"is_preprint":false},{"pmid":"21605902","id":"PMC_21605902","title":"FMN-coated fluorescent iron oxide nanoparticles for RCP-mediated targeting and labeling of metabolically active cancer and endothelial cells.","date":"2011","source":"Biomaterials","url":"https://pubmed.ncbi.nlm.nih.gov/21605902","citation_count":43,"is_preprint":false},{"pmid":"34073057","id":"PMC_34073057","title":"Bioenergetic Alterations of Metabolic Redox Coenzymes as NADH, FAD and FMN by Means of Fluorescence Lifetime Imaging Techniques.","date":"2021","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/34073057","citation_count":43,"is_preprint":false},{"pmid":"26719338","id":"PMC_26719338","title":"Cytochrome P450 17A1 Interactions with the FMN Domain of Its Reductase as Characterized by NMR.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26719338","citation_count":42,"is_preprint":false},{"pmid":"27555334","id":"PMC_27555334","title":"Reversible FMN dissociation from Escherichia coli respiratory complex I.","date":"2016","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/27555334","citation_count":41,"is_preprint":false},{"pmid":"18701448","id":"PMC_18701448","title":"Crystal structures of NADH:FMN oxidoreductase (EmoB) at different stages of catalysis.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18701448","citation_count":40,"is_preprint":false},{"pmid":"25477389","id":"PMC_25477389","title":"Rho and RNase play a central role in FMN riboswitch regulation in Corynebacterium glutamicum.","date":"2014","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/25477389","citation_count":39,"is_preprint":false},{"pmid":"14764097","id":"PMC_14764097","title":"Selective release and function of one of the two FMN groups in the cytoplasmic NAD+-reducing [NiFe]-hydrogenase from Ralstonia eutropha.","date":"2004","source":"European journal of biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/14764097","citation_count":37,"is_preprint":false},{"pmid":"15317816","id":"PMC_15317816","title":"The long and short flavodoxins: I. The role of the differentiating loop in apoflavodoxin structure and FMN binding.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15317816","citation_count":36,"is_preprint":false},{"pmid":"20610440","id":"PMC_20610440","title":"Genomic rearrangements of the GREM1-FMN1 locus cause oligosyndactyly, radio-ulnar synostosis, hearing loss, renal defects syndrome and Cenani--Lenz-like non-syndromic oligosyndactyly.","date":"2010","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/20610440","citation_count":31,"is_preprint":false},{"pmid":"30369100","id":"PMC_30369100","title":"Dynamic PEG-Peptide Hydrogels via Visible Light and FMN-Induced Tyrosine Dimerization.","date":"2018","source":"Advanced healthcare materials","url":"https://pubmed.ncbi.nlm.nih.gov/30369100","citation_count":31,"is_preprint":false},{"pmid":"20419722","id":"PMC_20419722","title":"Cloning, expression and purification of cindoxin, an unusual Fmn-containing cytochrome p450 redox partner.","date":"2010","source":"Chembiochem : a European journal of chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/20419722","citation_count":30,"is_preprint":false},{"pmid":"19997911","id":"PMC_19997911","title":"Characterization of thermostable FMN-dependent NADH azoreductase from the moderate thermophile Geobacillus stearothermophilus.","date":"2009","source":"Applied microbiology and biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/19997911","citation_count":30,"is_preprint":false},{"pmid":"8119891","id":"PMC_8119891","title":"Novel FMN-binding protein from Desulfovibrio vulgaris (Miyazaki F). Cloning and expression of its gene in Escherichia coli.","date":"1994","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/8119891","citation_count":29,"is_preprint":false},{"pmid":"7765913","id":"PMC_7765913","title":"Cloning of FAD synthetase gene from Corynebacterium ammoniagenes and its application to FAD and FMN production.","date":"1995","source":"Applied microbiology and biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/7765913","citation_count":29,"is_preprint":false},{"pmid":"8990272","id":"PMC_8990272","title":"Vibrio harveyi NADPH:FMN oxidoreductase: preparation and characterization of the apoenzyme and monomer-dimer equilibrium.","date":"1997","source":"Archives of biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/8990272","citation_count":28,"is_preprint":false},{"pmid":"10924137","id":"PMC_10924137","title":"The FMN-binding domain of cytochrome P450BM-3: resolution, reconstitution, and flavin analogue substitution.","date":"2000","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/10924137","citation_count":28,"is_preprint":false},{"pmid":"25157279","id":"PMC_25157279","title":"FMN-coated fluorescent USPIO for cell labeling and non-invasive MR imaging in tissue engineering.","date":"2014","source":"Theranostics","url":"https://pubmed.ncbi.nlm.nih.gov/25157279","citation_count":27,"is_preprint":false},{"pmid":"6813323","id":"PMC_6813323","title":"Studies on FAD- and FMN-binding domains in NADPH-cytochrome P-450 reductase from rabbit liver microsomes.","date":"1982","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/6813323","citation_count":27,"is_preprint":false},{"pmid":"9119367","id":"PMC_9119367","title":"The mouse formin (Fmn) gene: genomic structure, novel exons, and genetic mapping.","date":"1997","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/9119367","citation_count":26,"is_preprint":false},{"pmid":"17200734","id":"PMC_17200734","title":"Redox compounds influence on the NAD(P)H:FMN-oxidoreductase-luciferase bioluminescent system.","date":"2006","source":"Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology","url":"https://pubmed.ncbi.nlm.nih.gov/17200734","citation_count":26,"is_preprint":false},{"pmid":"23203077","id":"PMC_23203077","title":"Role of key residues at the flavin mononucleotide (FMN):adenylyltransferase catalytic site of the bifunctional riboflavin kinase/flavin adenine dinucleotide (FAD) Synthetase from Corynebacterium ammoniagenes.","date":"2012","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/23203077","citation_count":26,"is_preprint":false},{"pmid":"22722929","id":"PMC_22722929","title":"Control of electron transfer and catalysis in neuronal nitric-oxide synthase (nNOS) by a hinge connecting its FMN and FAD-NADPH domains.","date":"2012","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22722929","citation_count":25,"is_preprint":false},{"pmid":"27189945","id":"PMC_27189945","title":"Mutants of Cytochrome P450 Reductase Lacking Either Gly-141 or Gly-143 Destabilize Its FMN Semiquinone.","date":"2016","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/27189945","citation_count":24,"is_preprint":false},{"pmid":"22892871","id":"PMC_22892871","title":"Key residues at the riboflavin kinase catalytic site of the bifunctional riboflavin kinase/FMN adenylyltransferase from Corynebacterium ammoniagenes.","date":"2013","source":"Cell biochemistry and biophysics","url":"https://pubmed.ncbi.nlm.nih.gov/22892871","citation_count":24,"is_preprint":false},{"pmid":"26427827","id":"PMC_26427827","title":"Flavin mononucleotide (FMN)-based fluorescent protein (FbFP) as reporter for promoter screening in Clostridium cellulolyticum.","date":"2015","source":"Journal of microbiological methods","url":"https://pubmed.ncbi.nlm.nih.gov/26427827","citation_count":24,"is_preprint":false},{"pmid":"26627660","id":"PMC_26627660","title":"Structural insights into the synthesis of FMN in prokaryotic organisms.","date":"2015","source":"Acta crystallographica. Section D, Biological crystallography","url":"https://pubmed.ncbi.nlm.nih.gov/26627660","citation_count":23,"is_preprint":false},{"pmid":"30412389","id":"PMC_30412389","title":"Long-Lived Hydrated FMN Radicals: EPR Characterization and Implications for Catalytic Variability in Flavoproteins.","date":"2018","source":"Journal of the American Chemical Society","url":"https://pubmed.ncbi.nlm.nih.gov/30412389","citation_count":22,"is_preprint":false},{"pmid":"15095868","id":"PMC_15095868","title":"Crystal structure of chorismate synthase: a novel FMN-binding protein fold and functional insights.","date":"2004","source":"Journal of molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/15095868","citation_count":22,"is_preprint":false},{"pmid":"15698959","id":"PMC_15698959","title":"FMN binding and unfolding of Desulfovibrio desulfuricans flavodoxin: \"hidden\" intermediates at low denaturant concentrations.","date":"2004","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/15698959","citation_count":22,"is_preprint":false},{"pmid":"26364851","id":"PMC_26364851","title":"Structure of Human B12 Trafficking Protein CblD Reveals Molecular Mimicry and Identifies a New Subfamily of Nitro-FMN Reductases.","date":"2015","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/26364851","citation_count":22,"is_preprint":false},{"pmid":"35440139","id":"PMC_35440139","title":"Engineering Antisense Oligonucleotides as Antibacterial Agents That Target FMN Riboswitches and Inhibit the Growth of Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli.","date":"2022","source":"ACS synthetic biology","url":"https://pubmed.ncbi.nlm.nih.gov/35440139","citation_count":22,"is_preprint":false},{"pmid":"16289032","id":"PMC_16289032","title":"Identification of human and rat FAD-AMP lyase (cyclic FMN forming) as ATP-dependent dihydroxyacetone kinases.","date":"2005","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/16289032","citation_count":22,"is_preprint":false},{"pmid":"24569995","id":"PMC_24569995","title":"Bifunctional homodimeric triokinase/FMN cyclase: contribution of protein domains to the activities of the human enzyme and molecular dynamics simulation of domain movements.","date":"2014","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24569995","citation_count":22,"is_preprint":false},{"pmid":"11331018","id":"PMC_11331018","title":"Determination of the midpoint potential of the FAD and FMN flavin cofactors and of the 3Fe-4S cluster of glutamate synthase.","date":"2001","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11331018","citation_count":22,"is_preprint":false},{"pmid":"22002057","id":"PMC_22002057","title":"An FMN hydrolase of the haloacid dehalogenase superfamily is active in plant chloroplasts.","date":"2011","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/22002057","citation_count":22,"is_preprint":false},{"pmid":"32004446","id":"PMC_32004446","title":"Bi-allelic Variants in TKFC Encoding Triokinase/FMN Cyclase Are Associated with Cataracts and Multisystem Disease.","date":"2020","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/32004446","citation_count":22,"is_preprint":false},{"pmid":"20826774","id":"PMC_20826774","title":"FMN binding and photochemical properties of plant putative photoreceptors containing two LOV domains, LOV/LOV proteins.","date":"2010","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/20826774","citation_count":22,"is_preprint":false},{"pmid":"25512382","id":"PMC_25512382","title":"Kinetic and structural characterization of the interaction between the FMN binding domain of cytochrome P450 reductase and cytochrome c.","date":"2014","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/25512382","citation_count":22,"is_preprint":false},{"pmid":"34559979","id":"PMC_34559979","title":"Adaptive mechanoproperties mediated by the formin FMN1 characterize glioblastoma fitness for invasion.","date":"2021","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/34559979","citation_count":21,"is_preprint":false},{"pmid":"31184189","id":"PMC_31184189","title":"Characterization of the FMN-Dependent Cysteine Decarboxylase from Thioviridamide Biosynthesis.","date":"2019","source":"Organic letters","url":"https://pubmed.ncbi.nlm.nih.gov/31184189","citation_count":21,"is_preprint":false},{"pmid":"10713530","id":"PMC_10713530","title":"How do the x-ray structure and the NMR structure of FMN-binding protein differ?","date":"2000","source":"Acta crystallographica. Section D, Biological crystallography","url":"https://pubmed.ncbi.nlm.nih.gov/10713530","citation_count":21,"is_preprint":false},{"pmid":"30569497","id":"PMC_30569497","title":"Cenani-Lenz syndrome and other related syndactyly disorders due to variants in LRP4, GREM1/FMN1, and APC: Insight into the pathogenesis and the relationship to polyposis through the WNT and BMP antagonistic pathways.","date":"2018","source":"American journal of medical genetics. Part A","url":"https://pubmed.ncbi.nlm.nih.gov/30569497","citation_count":20,"is_preprint":false},{"pmid":"30152678","id":"PMC_30152678","title":"Biochemical and Structural Characterization of TtnD, a Prenylated FMN-Dependent Decarboxylase from the Tautomycetin Biosynthetic Pathway.","date":"2018","source":"ACS chemical biology","url":"https://pubmed.ncbi.nlm.nih.gov/30152678","citation_count":20,"is_preprint":false},{"pmid":"16928691","id":"PMC_16928691","title":"The reactions of heme- and verdoheme-heme oxygenase-1 complexes with FMN-depleted NADPH-cytochrome P450 reductase. Electrons required for verdoheme oxidation can be transferred through a pathway not involving FMN.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16928691","citation_count":18,"is_preprint":false},{"pmid":"19900400","id":"PMC_19900400","title":"Dual role of FMN in flavodoxin function: electron transfer cofactor and modulation of the protein-protein interaction surface.","date":"2009","source":"Biochimica et biophysica acta","url":"https://pubmed.ncbi.nlm.nih.gov/19900400","citation_count":18,"is_preprint":false},{"pmid":"26699753","id":"PMC_26699753","title":"FMN-Based Fluorescent Proteins as Heavy Metal Sensors Against Mercury Ions.","date":"2016","source":"Journal of microbiology and biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/26699753","citation_count":17,"is_preprint":false},{"pmid":"25627402","id":"PMC_25627402","title":"Crystal structures of apo-DszC and FMN-bound DszC from Rhodococcus erythropolis D-1.","date":"2015","source":"The FEBS journal","url":"https://pubmed.ncbi.nlm.nih.gov/25627402","citation_count":17,"is_preprint":false},{"pmid":"25002335","id":"PMC_25002335","title":"Gelatin and starch as stabilizers of the coupled enzyme system of luminous bacteria NADH:FMN-oxidoreductase-luciferase.","date":"2014","source":"Analytical and bioanalytical chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/25002335","citation_count":17,"is_preprint":false},{"pmid":"30287481","id":"PMC_30287481","title":"Rare variants of the FMN riboswitch class in Clostridium difficile and other bacteria exhibit altered ligand specificity.","date":"2018","source":"RNA (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/30287481","citation_count":17,"is_preprint":false},{"pmid":"9893940","id":"PMC_9893940","title":"Apoflavodoxin: structure, stability, and FMN binding.","date":"1998","source":"Biochimie","url":"https://pubmed.ncbi.nlm.nih.gov/9893940","citation_count":17,"is_preprint":false},{"pmid":"29093349","id":"PMC_29093349","title":"Riboflavin Transporters RFVT/SLC52A Mediate Translocation of Riboflavin, Rather than FMN or FAD, across Plasma Membrane.","date":"2017","source":"Biological & pharmaceutical bulletin","url":"https://pubmed.ncbi.nlm.nih.gov/29093349","citation_count":17,"is_preprint":false},{"pmid":"29663603","id":"PMC_29663603","title":"Crowding Shifts the FMN Recognition Mechanism of Riboswitch Aptamer from Conformational Selection to Induced Fit.","date":"2018","source":"Angewandte Chemie (International ed. in English)","url":"https://pubmed.ncbi.nlm.nih.gov/29663603","citation_count":17,"is_preprint":false},{"pmid":"25736034","id":"PMC_25736034","title":"Wattles in goats are associated with the FMN1/GREM1 region on chromosome 10.","date":"2015","source":"Animal genetics","url":"https://pubmed.ncbi.nlm.nih.gov/25736034","citation_count":16,"is_preprint":false},{"pmid":"19645676","id":"PMC_19645676","title":"Comparative study of immobilized and soluble NADH:FMN-oxidoreductase-luciferase coupled enzyme system.","date":"2009","source":"Biochemistry. Biokhimiia","url":"https://pubmed.ncbi.nlm.nih.gov/19645676","citation_count":16,"is_preprint":false},{"pmid":"28245978","id":"PMC_28245978","title":"Engineering an FMN-based iLOV protein for the detection of arsenic ions.","date":"2017","source":"Analytical biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/28245978","citation_count":16,"is_preprint":false},{"pmid":"1445874","id":"PMC_1445874","title":"Mutation of the heme-binding crevice of flavocytochrome b2 from Saccharomyces cerevisiae: altered heme potential and absence of redox cooperativity between heme and FMN centers.","date":"1992","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/1445874","citation_count":16,"is_preprint":false},{"pmid":"37517692","id":"PMC_37517692","title":"Allosteric modulation of cytochrome P450 enzymes by the NADPH cytochrome P450 reductase FMN-containing domain.","date":"2023","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/37517692","citation_count":15,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":50014,"output_tokens":1990,"usd":0.089946,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8161,"output_tokens":1996,"usd":0.045352,"stage2_stop_reason":"end_turn"},"total_usd":0.135298,"stage1_batch_id":"msgbatch_01AsR7g8dGTEiEw9U83bJeWn","stage2_batch_id":"msgbatch_01YV5ZyxtFNUZEjxRcpd9jzb","note":"batch pricing = 50% of standard"},"stage1_raw":"Looking through the 100 papers, I need to identify which ones are about the canonical FMN1 protein (human/mammalian formin 1, a formin-family actin nucleator/elongator). The HGNC aliases include FMN (the mouse formin gene).\n\nMost papers (1-10, 12-16, etc.) are about flavin mononucleotide (FMN, the cofactor) - these are NOT about the FMN1 formin gene. I need to carefully distinguish:\n\n- Papers about FMN1/Fmn (formin gene): papers 11, 18, 52, 62, 82, 85, 96\n- Papers about yeast FMN1 (flavokinase, PMID 10887197, paper 26): This is a different gene - yeast YDR236c flavokinase, NOT the human formin FMN1. This is a symbol collision.\n- Papers 30 (yeast FMN1 as riboflavin kinase in Alzheimer's context) - same yeast flavokinase, not the formin.\n\nLet me focus on the formin FMN1 papers:\n\n- Paper 11 (PMID 9848078): Mouse Fmn gene - circular RNA transcripts, gene-targeted deletions, renal aplasia phenotype\n- Paper 18 (PMID 21730168): Structure/function of Spire KIND domain with Fmn2 tail - but this is FMN2, not FMN1\n- Paper 52 (PMID 20610440): GREM1-FMN1 locus deletions causing limb/renal defects\n- Paper 62 (PMID 9119367): Mouse Fmn gene structure, genomic organization\n- Paper 82 (PMID 34559979): FMN1 in glioblastoma - mechanistic role in invasion via microtubule lattice\n- Paper 85 (PMID 30569497): FMN1/GREM1 in BMP pathway for syndactyly\n- Paper 96 (PMID 25736034): Goat wattles associated with FMN1/GREM1 region\n\nPaper 18 is about Fmn2 (a paralog), not FMN1 - exclude.\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1998,\n      \"finding\": \"The mouse Fmn (formin) gene produces abundant circular RNA transcripts in which downstream exons are joined to upstream exon acceptors (back-splicing). Gene-targeted deletion of exon 4 or exon 5 abolishes circular transcript production without eliminating linear RNA isoforms. Mice lacking circular Fmn transcripts exhibit variably penetrant renal agenesis, phenocopying other Fmn mutant alleles, suggesting the circular transcripts play a role in kidney development.\",\n      \"method\": \"RT-PCR, ribonuclease protection assay, gene-targeted homologous recombination (knockout mice), phenotypic analysis\",\n      \"journal\": \"Molecular medicine (Cambridge, Mass.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO with defined renal phenotype and two orthogonal RNA detection methods in single lab; functional link between circular transcripts and kidney development is correlative rather than mechanistically resolved\",\n      \"pmids\": [\"9848078\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"The mouse Fmn (formin) gene spans ~400 kb, is composed of at least 24 exons, and produces differentially processed transcripts expressed in embryonic limb bud, adult brain, and kidney. Two novel exons were identified that are expressed in developing limb bud.\",\n      \"method\": \"Genomic library screening, clone characterization, microsatellite mapping, probe hybridization\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct genomic structural characterization in single lab with multiple overlapping clones; establishes gene architecture but limited functional mechanistic depth\",\n      \"pmids\": [\"9119367\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Homozygous 263-kb deletion of the human FMN1 gene causes oligosyndactyly, radio-ulnar synostosis, hearing loss, and renal defects—a phenotype identical to that of limb deformity (ld) mice—establishing that loss of FMN1 protein (in addition to disruption of GREM1 regulatory elements) contributes to the limb deformity/renal agenesis phenotype. A 1.7-Mb duplication encompassing both GREM1 and FMN1 was associated with Cenani-Lenz-like isolated oligosyndactyly.\",\n      \"method\": \"Array CGH (chromosomal imbalance detection), clinical phenotype characterization, comparison with mouse ld model\",\n      \"journal\": \"Journal of medical genetics\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — human genomic deletion mapping with phenotypic readout; no direct biochemical or cellular mechanism experiment performed on FMN1 protein itself\",\n      \"pmids\": [\"20610440\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"FMN1 (formin 1) confers invasive mechanical fitness to glioblastoma cells. Mechanistically, FMN1 acts from the microtubule lattice to promote robust mechanical cohesion, leading to increased cell stiffness, higher mechanical forces on substrate, and stochastic migration. Ectopic FMN1 expression increased these fitness parameters in cancer and normal cell lines; FMN1 expression was induced by mechano-chemical signals and confirmed in patient glioblastoma samples.\",\n      \"method\": \"Live-cell imaging, traction force microscopy, atomic force microscopy, ectopic overexpression and loss-of-function, patient sample validation, mechanobiology assays\",\n      \"journal\": \"Developmental cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization to microtubule lattice with multiple orthogonal mechanobiological readouts in single lab; mechanism proposed (microtubule-based mechanical cohesion) supported by functional assays but not fully reconstituted in vitro\",\n      \"pmids\": [\"34559979\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"FMN1 protein functions in the BMP antagonistic pathway during limb development. Genomic rearrangements of the GREM1-FMN1 locus, including FMN1 point mutations, cause Cenani-Lenz syndrome-like syndactyly, linking FMN1 loss-of-function to disrupted BMP signaling in limb patterning.\",\n      \"method\": \"Clinical genetics, mutation analysis, pathway analysis (WNT/BMP cross-talk review with genetic evidence)\",\n      \"journal\": \"American journal of medical genetics. Part A\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — pathway placement based on genetic/clinical data and literature review without direct biochemical experiment on FMN1 protein in BMP pathway\",\n      \"pmids\": [\"30569497\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"FMN1 (formin 1) is a formin-family protein whose loss in mice and humans causes limb deformities and renal aplasia; in glioblastoma cells, FMN1 localizes to the microtubule lattice and promotes mechanical cohesion, cell stiffness, and invasive motility, while the mouse Fmn locus also produces abundant circular RNA transcripts whose exon-specific deletion phenocopies renal agenesis, suggesting additional regulatory roles for the locus in kidney development.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"FMN1 is a formin-family protein whose locus is essential for limb and kidney development and which contributes to cancer cell mechanics [#0, #3]. The mouse Fmn gene spans ~400 kb with at least 24 exons and produces differentially processed transcripts in embryonic limb bud, adult brain, and kidney, including abundant circular RNAs generated by back-splicing; gene-targeted deletion of exon 4 or 5 abolishes circular transcript production without eliminating linear isoforms and produces variably penetrant renal agenesis, implicating these circular transcripts in kidney development [#0, #1]. In glioblastoma cells, FMN1 protein localizes to the microtubule lattice and promotes mechanical cohesion, increasing cell stiffness, traction forces on substrate, and stochastic invasive migration; ectopic FMN1 raises these fitness parameters in both cancer and normal cells and its expression is induced by mechano-chemical signals [#3]. In humans, homozygous deletion of FMN1 causes a limb deformity and renal phenotype identical to the mouse limb deformity (ld) model [#2]. Beyond these findings, the biochemical actin- or microtubule-regulatory activity of the FMN1 protein has not been reconstituted in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Establishing the architecture of the Fmn locus was the prerequisite for relating its transcripts to developmental phenotypes, defining a large multi-exon gene with tissue-specific isoforms.\",\n      \"evidence\": \"Genomic library screening, clone characterization, and probe hybridization mapping the mouse Fmn gene\",\n      \"pmids\": [\"9119367\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No protein product characterized functionally\", \"Roles of individual isoforms not assigned\", \"No molecular activity defined for the encoded protein\"]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Whether the locus's non-linear transcripts had a developmental function was unknown; exon-specific deletion showed that circular Fmn RNAs are required for normal kidney development independent of linear mRNA.\",\n      \"evidence\": \"RT-PCR, ribonuclease protection, and exon 4/5 knockout mice with renal phenotyping\",\n      \"pmids\": [\"9848078\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism linking circular transcripts to kidney development is correlative\", \"Molecular targets of the circular RNAs unidentified\", \"Penetrance is variable\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Whether the mouse phenotype translated to humans was open; a homozygous human FMN1 deletion reproduced the limb deformity/renal phenotype, establishing FMN1 loss as causally relevant in humans.\",\n      \"evidence\": \"Array CGH genomic deletion mapping with clinical phenotyping, compared to the ld mouse model\",\n      \"pmids\": [\"20610440\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Deletion also disrupts GREM1 regulatory elements, confounding attribution to FMN1 alone\", \"No biochemical or cellular experiment on FMN1 protein performed\", \"Mechanism of developmental defect not resolved\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"To place FMN1 in a developmental signaling context, genetic evidence linked FMN1 loss-of-function and point mutations to disrupted BMP-antagonistic signaling in limb patterning.\",\n      \"evidence\": \"Clinical genetics and mutation analysis with pathway review of WNT/BMP cross-talk\",\n      \"pmids\": [\"30569497\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Pathway placement is inferred from genetics, not direct biochemistry\", \"No demonstration that FMN1 protein acts on BMP components\", \"Locus-level confounding with GREM1 persists\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"The cell-biological function of FMN1 protein was undefined; mechanobiology in glioblastoma showed FMN1 acts from the microtubule lattice to confer mechanical cohesion and invasive fitness.\",\n      \"evidence\": \"Live-cell imaging, traction force and atomic force microscopy, gain/loss-of-function, and patient sample validation\",\n      \"pmids\": [\"34559979\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Microtubule-based mechanism not reconstituted in vitro\", \"Direct molecular activity (actin nucleation, MT binding) not biochemically defined\", \"Single-lab mechanism\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The biochemical activity of the FMN1 protein and how it bridges its microtubule-associated mechanical role with its developmental requirement in limb and kidney remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No in vitro reconstitution of FMN1 enzymatic/cytoskeletal activity\", \"Mechanistic connection between circular RNA function and protein function unclear\", \"Direct molecular partners of FMN1 not defined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [0, 1, 2]}\n    ],\n    \"complexes\": [],\n    \"partners\": [],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}