{"gene":"MFN1","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2003,"finding":"Mfn1 and Mfn2 are essential mediators of mitochondrial outer membrane fusion in vertebrates. Loss of Mfn1 causes severe mitochondrial fragmentation due to reduction in fusion. Mfn1 and Mfn2 form homotypic and heterotypic complexes, and homotypic Mfn1 complexes are functional for fusion. Mfn1-deficient embryonic fibroblasts show loss of membrane potential in a subset of mitochondria.","method":"Knockout mouse generation, embryonic fibroblast live imaging, complementation/rescue assays, co-immunoprecipitation","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, genetic KO with defined cellular phenotype, rescue experiments; replicated across multiple cell types and in vivo","pmids":["12527753"],"is_preprint":false},{"year":2007,"finding":"Mfn1 forms heterooligomeric complexes with Mfn2, including complexes in trans between adjacent mitochondria. Wild-type Mfn1 can complement CMT2A disease mutants of Mfn2 through these heterooligomeric complexes, whereas wild-type Mfn2 cannot. This highlights a unique functional role for Mfn1-Mfn2 heterocomplexes in mitochondrial fusion.","method":"Co-immunoprecipitation, complementation rescue assays in Mfn-null fibroblasts, fluorescence microscopy","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, genetic complementation with multiple disease alleles, single lab with multiple orthogonal methods","pmids":["17296794"],"is_preprint":false},{"year":2017,"finding":"Crystal structures of engineered human MFN1 (GTPase domain + helical domain) reveal: (1) the helical domain is composed of elements from widely dispersed sequence regions and resembles the 'neck' of bacterial dynamin-like protein; (2) GTP binding induces conformational changes that promote GTPase domain dimerization in the transition state; (3) disruption of GTPase domain dimerization abolishes fusogenic activity; (4) a conserved aspartate residue affects mitochondrial elongation, likely through GTP-loading-dependent domain rearrangement.","method":"X-ray crystallography, site-directed mutagenesis, functional fusion assay in cells","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure with mutagenesis and functional validation, multiple orthogonal methods in a single rigorous study","pmids":["28114303"],"is_preprint":false},{"year":2010,"finding":"MFN1 associates with IPS-1 (MAVS) on the mitochondrial outer membrane and positively regulates RLR-mediated antiviral innate immune responses. Knockdown of MFN1 abrogates virus-induced redistribution of IPS-1 into speckle-like aggregates and abolishes interferon production.","method":"siRNA knockdown, immunofluorescence microscopy, interferon production assays, co-immunoprecipitation","journal":"PLoS pathogens","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP binding evidence plus functional KD phenotype, single lab with two orthogonal methods","pmids":["20661427"],"is_preprint":false},{"year":2014,"finding":"Under glucose starvation, MFN1 associates with the deacetylase HDAC6, leading to MFN1 deacetylation and activation, promoting mitochondrial fusion. HDAC6 or MFN1 deficiency prevents glucose deprivation-induced mitochondrial fusion. Failure to fuse causes excessive mitochondrial ROS and oxidative damage. An acetylation-resistant MFN1 mutant suppresses this oxidative damage. In fasting mice, skeletal muscle mitochondria undergo dramatic fusion that is abrogated in HDAC6-knockout mice.","method":"Co-immunoprecipitation, site-directed mutagenesis (acetylation-resistant mutant), HDAC6 KO mouse model, live-cell imaging, ROS measurement","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — Co-IP, acetylation-resistant mutagenesis, in vivo KO validation, multiple orthogonal methods in one study","pmids":["25271058"],"is_preprint":false},{"year":2014,"finding":"MARCH5 (E3 ubiquitin ligase) binds MFN1, ubiquitylates it, and mediates its degradation under mitochondrial stress conditions. Acetylation of MFN1 at K491 promotes its interaction with MARCH5 and subsequent ubiquitylation; an acetylation-deficient K491R mutant shows weak interaction with MARCH5 and reduced ubiquitylation. Fine-tuned MFN1 levels maintained by MARCH5-dependent quality control are essential for cell survival under stress.","method":"Co-immunoprecipitation, site-directed mutagenesis (K491R, K491Q), ubiquitylation assay, MARCH5 KO MEFs","journal":"Cell death & disease","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — mutagenesis of acetylation site, Co-IP, KO cell lines, multiple orthogonal methods","pmids":["24722297"],"is_preprint":false},{"year":2017,"finding":"SIRT1 deacetylase promotes MFN1 protein stability and mitochondrial elongation. The acetyltransferase TIP60 acetylates MFN1 in vitro, and co-expression of SIRT1 abolishes this acetylation. SIRT1 knockdown reduces MFN1 levels whereas SIRT1 overexpression increases MFN1, and hypoxia induces accumulation of both SIRT1 and MFN1 alongside mitochondrial elongation.","method":"In vitro acetylation assay, siRNA knockdown, overexpression, western blot, nicotinamide inhibitor treatment","journal":"Cellular signalling","confidence":"Medium","confidence_rationale":"Tier 1–2 / Moderate — in vitro acetylation assay with SIRT1/TIP60, cellular KD/OE, single lab","pmids":["28669827"],"is_preprint":false},{"year":2016,"finding":"Liver-specific deletion of Mfn1 (Mfn1LKO) leads to a highly fragmented mitochondrial network in hepatocytes, coupled with enhanced mitochondrial respiration capacity and preference for lipid oxidation. Mfn1LKO mice are protected against high-fat diet-induced insulin resistance, and Mfn1 deficiency increases complex I abundance and sensitizes animals to metformin's hypoglycemic effect.","method":"Conditional liver-specific KO mouse, mitochondrial morphology imaging, oxygen consumption measurement, glucose tolerance tests, metabolic phenotyping","journal":"Diabetes","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional tissue-specific KO with metabolic phenotyping, in vivo model, multiple functional readouts","pmids":["27613809"],"is_preprint":false},{"year":2017,"finding":"Rapid proteasomal degradation of SLC25A46 leads to increased stability and oligomerization of MFN1 and MFN2 on mitochondria, promoting mitochondrial hyperfusion. SLC25A46 acts as a regulator of MFN1/2 oligomerization; decreased SLC25A46 expression stabilizes mitofusins and drives hyperfusion independently of mitophagy or apoptosis.","method":"siRNA knockdown, western blot, MitoTracker imaging, ubiquitylation assay","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — KD phenotype with biochemical validation, single lab, multiple cell biology readouts","pmids":["28057766"],"is_preprint":false},{"year":2009,"finding":"The C. elegans BCL-2-like protein CED-9 physically interacts with FZO-1 (the C. elegans Mfn1/2 homologue) in vivo and promotes complete mitochondrial fusion (outer and inner membrane) in a manner dependent on FZO-1 and EAT-3 (Opa1 homologue). The ability of CED-9 to interact with FZO-1 is important for its pro-fusion activity.","method":"Co-immunoprecipitation in vivo (C. elegans), genetic epistasis, fluorescence microscopy of mitochondrial morphology","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus genetic epistasis in C. elegans ortholog, single lab","pmids":["19704021"],"is_preprint":false},{"year":2021,"finding":"STING1 promotes ferroptosis by binding MFN1/2 at the mitochondria to trigger mitochondrial fusion, leading to ROS production and lipid peroxidation. Erastin (ferroptosis inducer) causes STING1 accumulation at mitochondria where it binds MFN1/2. Genetic depletion of STING1 or MFN1/2 reduces ferroptosis sensitivity.","method":"Co-immunoprecipitation, siRNA knockdown, xenograft mouse model, lipid peroxidation and ROS assays","journal":"Frontiers in cell and developmental biology","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP binding, KD functional phenotype, in vivo xenograft, single lab","pmids":["34195205"],"is_preprint":false},{"year":2022,"finding":"FUNDC2 interacts via its amino-terminal region with the GTPase domain of MFN1, inhibiting MFN1 GTPase activity and thus suppressing outer mitochondrial membrane fusion. Loss of FUNDC2 leads to mitochondrial elongation, decreased mitochondrial respiration, and reprogrammed cellular metabolism.","method":"Co-immunoprecipitation, domain mapping, GTPase activity assay, siRNA/KO, mitochondrial morphology imaging, metabolic profiling","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — Co-IP with domain mapping, direct enzymatic inhibition assay, KO with multiple functional readouts in single rigorous study","pmids":["35710796"],"is_preprint":false},{"year":2022,"finding":"MFN1 and MFN2 promote physical clustering between mitochondria and peroxisomes. MFNs are enriched at the mitochondria-peroxisome interface, and overexpression of MFNs induces co-clustering of peroxisomes with mitochondria. A truncated MFN2 lacking the transmembrane region inhibits mitochondria-peroxisome tethering.","method":"Proximity labeling (BioID), fluorescence microscopy, overexpression and dominant-negative constructs, organelle co-clustering quantification","journal":"Communications biology","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — proximity labeling plus imaging with dominant-negative approach, single lab","pmids":["35523862"],"is_preprint":false},{"year":2016,"finding":"MARCH5-mediated ubiquitylation of MFN1 is triggered by tributyltin (TBT) exposure in iPSCs, leading to MFN1 degradation and mitochondrial fragmentation. Knockdown of MARCH5 abolishes TBT-induced MFN1 reduction, establishing MARCH5 as the E3 ligase responsible for MFN1 degradation under this toxic stress.","method":"siRNA knockdown of MARCH5, western blot, MitoTracker imaging, ATP measurement","journal":"Toxicology in vitro","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — MARCH5 KD rescues MFN1 levels, single lab, single method for the interaction","pmids":["27133438"],"is_preprint":false},{"year":2022,"finding":"MFN1 interacts with BAK at the mitochondrial outer membrane in tamoxifen-resistant breast cancer cells, restraining BAK activation and cytochrome c release. Elevated MFN1 also interacts with MFN2 to enhance outer membrane fusion, and interacts with OPA1 (whose oligomerization is reduced), thereby reshaping cristae. Knockdown or pharmacological inhibition of MFN1 restores BAK oligomerization, cytochrome c release, and caspase activation, reversing tamoxifen resistance.","method":"Co-immunoprecipitation, siRNA knockdown, pharmacological inhibition, cytochrome c release assay, caspase activity, in vivo xenograft","journal":"Cancer letters","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP for MFN1-BAK and MFN1-MFN2, functional KD/inhibition with multiple apoptosis readouts, single lab","pmids":["38583647"],"is_preprint":false},{"year":2022,"finding":"βIIPKC (protein kinase C beta II) accumulates on the mitochondrial outer membrane, interacts with MFN1, and phosphorylates MFN1 at serine 86. Disrupting Mfn1-βIIPKC interaction with the antagonistic peptide SAMβA attenuates neuronal injury following subarachnoid hemorrhage, preserves mitochondrial biogenesis, and increases Sirt3 activity and downstream antioxidant enzyme activity.","method":"Co-immunoprecipitation, peptide antagonist (SAMβA, βIIV5-3), western blot, in vivo rat SAH model, Sirt3 siRNA knockdown","journal":"Translational stroke research","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP plus targeted peptide disruption with functional readouts, in vivo validation, single lab","pmids":["35192161"],"is_preprint":false},{"year":2024,"finding":"REEP5 (ER tubule-shaping protein) physically interacts with MFN1/2 to mediate mitochondrial 'hitchhiking' on tubular ER along microtubules. REEP5 depletion reduces ER-mitochondria tethering and causes perinuclear clustering of mitochondria. Forced irreversible REEP5-MFN1/2 interaction causes mitochondrial hyperfusion. Disruption of MFN2-REEP5 interaction modulates mitochondrial ROS production.","method":"Co-immunoprecipitation, rapamycin-induced dimerization (chemogenetic), siRNA knockdown, live imaging, ROS measurement","journal":"The Journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, chemogenetic forced dimerization, KD phenotype with functional ROS readout, single lab","pmids":["39133213"],"is_preprint":false},{"year":2024,"finding":"Endogenous interactome mapping of MFN1-HA (CRISPR-Cas9 tagged) by HA-affinity isolation and mass spectrometry identified novel ER and endosomal partners of MFN1. RAB5C was validated as an endosomal modulator of mitochondrial homeostasis that interacts with MFN1. Nutrient deprivation modulates MFN1 interactors.","method":"CRISPR-Cas9 endogenous tagging, affinity isolation-mass spectrometry, validation by co-IP","journal":"Autophagy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — endogenous affinity-MS interactome with Co-IP validation, single lab, novel partners partially validated","pmids":["39675054"],"is_preprint":false},{"year":2023,"finding":"In a CMT2A mouse model (MFN2 R94Q mutation), imbalanced MFN1/MFN2 ratio causes retinal degeneration via P62/LC3B-mediated mitophagy/autophagy. Transgenic MFN1 augmentation in MFN2-R94Q mice rescues vision and retinal morphology by restoring MFN1/MFN2 homeostasis and shifting from Parkin-independent to PINK1-dependent mitophagy.","method":"Transgenic mouse model, retinal function testing (ERG), immunofluorescence, western blot, mitophagy pathway analysis","journal":"iScience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo transgenic rescue with multiple functional readouts, single lab","pmids":["36936780"],"is_preprint":false},{"year":2024,"finding":"Parkin, upon cadmium-induced mitochondrial translocation, mediates ubiquitin-dependent degradation of MFN1 in Leydig cells, causing mitochondrial fusion disorder and suppressing testosterone synthesis. Testicular-specific Parkin knockdown prevents MFN1 degradation and mitigates testosterone decline.","method":"In vivo mouse model, testicular-specific Parkin knockdown, MFN1 overexpression, ubiquitylation assay, testosterone measurement","journal":"Journal of hazardous materials","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — tissue-specific KD plus overexpression rescue, functional steroidogenesis readout, single lab","pmids":["38555669"],"is_preprint":false},{"year":2023,"finding":"In cardiac I/R injury, decreased immunoproteasome subunit β2i expression leads to increased E3 ligase Parkin protein, promoting ubiquitin-dependent degradation of MFN1/2 and causing excessive mitochondrial fission. β2i knockout exacerbates MFN1/2 loss and fission, while β2i overexpression via rAAV9 ameliorates cardiac I/R injury.","method":"β2i KO mice, rAAV9-β2i overexpression, western blot, mitochondrial morphology imaging, cardiac function measurement","journal":"Cellular and molecular life sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO and OE rescue in vivo, mechanistic pathway dissection, single lab","pmids":["37501008"],"is_preprint":false},{"year":2022,"finding":"Mfn1 and Mfn2 double knockout in β-cells reduces mitochondrial length, glucose-induced mitochondrial polarization, ATP synthesis, and cytosolic/mitochondrial Ca2+ increases, establishing that mitochondrial fusion is required for glucose-stimulated insulin secretion but not for incretin signaling.","method":"β-cell-selective conditional double KO mice, glucose tolerance testing, mitochondrial imaging, Ca2+ measurements, ATP assay, EPAC-camps sensor","journal":"Diabetes","confidence":"High","confidence_rationale":"Tier 2 / Strong — conditional tissue-specific double KO with multiple orthogonal functional readouts including live Ca2+ imaging and metabolic sensors","pmids":["35472764"],"is_preprint":false},{"year":2025,"finding":"KDM6B histone demethylase promotes H3K27me3 demethylation at the MFN1 promoter, increasing MFN1 transcription. KDM6B knockdown increases H3K27me3 enrichment at the MFN1 promoter, reduces MFN1 expression, promotes mitophagy, and suppresses macrophage apoptosis in sepsis-induced ALI.","method":"Chromatin immunoprecipitation (ChIP), siRNA knockdown, western blot, flow cytometry, in vivo CLP mouse model","journal":"Scientific reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP demonstrates direct promoter occupancy with functional KD phenotype, single lab","pmids":["41361208"],"is_preprint":false},{"year":2025,"finding":"Time-resolved tmFRET measurements of Mfn1 (GTPase domain + HB1) reveal that the GDP-bound state adopts an open conformation (GTPase and HB1 domains far apart) matching the crystal structure. GTP binding favors the open state, the transition state (GDP+Pi) shows an equilibrium between open and closed states rather than a single closed conformation, and the nucleotide-free state is conformationally distinct from either nucleotide-bound state. This reveals an unexpected conformational reversal in a single catalytic cycle and a heterogeneous transition-state ensemble.","method":"Time-resolved transition metal ion FRET (tmFRET), incorporation of fluorescent noncanonical amino acid, fluorescence lifetime measurements, engineered Mfn1 construct","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — novel structural/biophysical method with rigorous distance measurements, single lab preprint not yet peer-reviewed","pmids":[],"is_preprint":true},{"year":2025,"finding":"MFN1 mediates a type of dynamic tubulation ('pull-outs') characterized by lateral extrusion from pre-existing mitochondrial tubules. Pull-outs are distinct from tip elongation and are modulated by MFN1 and DRP1. They depend on mitochondrial actin polymerization, are stimulated by conditions favoring oxidative phosphorylation, and are required to increase mitochondrial connectivity and respiratory activity.","method":"Live-cell fluorescence microscopy, MFN1 perturbation (knockdown/knockout), mitochondrial morphology quantification, respiratory activity measurement","journal":"bioRxiv","confidence":"Low","confidence_rationale":"Tier 2–3 / Weak — live imaging with MFN1 perturbation, preprint not yet peer-reviewed, single lab","pmids":[],"is_preprint":true}],"current_model":"MFN1 is a dynamin-related GTPase embedded in the mitochondrial outer membrane that drives organelle fusion through GTP-hydrolysis-dependent GTPase domain dimerization and conformational rearrangement of its helical domain; it forms both homotypic and heterotypic complexes with MFN2, associates with IPS-1/MAVS to regulate antiviral signaling, is post-translationally regulated by acetylation (written by TIP60, erased by SIRT1/HDAC6) and ubiquitylation (by MARCH5, Parkin, and HRD1), and is required for glucose-stimulated insulin secretion, adaptive metabolic responses, and protection of mitochondrial membrane potential, with its activity additionally modulated by binding partners including FUNDC2 (inhibitor), STING1, REEP5, and βIIPKC."},"narrative":{"mechanistic_narrative":"MFN1 is a dynamin-related GTPase of the mitochondrial outer membrane that drives organelle fusion and thereby controls mitochondrial network connectivity, bioenergetics, and stress responses [PMID:12527753]. Together with MFN2 it forms both homotypic and heterotypic complexes, including trans complexes between adjacent mitochondria; homotypic MFN1 complexes are fusion-competent, and MFN1 can uniquely complement CMT2A-causing MFN2 mutants [PMID:12527753, PMID:17296794]. Fusion is powered by a defined catalytic mechanism: GTP binding promotes GTPase-domain dimerization in the transition state with rearrangement of a helical 'neck' domain, and disruption of this dimerization abolishes fusogenic activity [PMID:28114303]. MFN1 levels and activity are tightly tuned by post-translational control — acetylation by TIP60 opposed by the deacetylases SIRT1 and HDAC6 governs stability and activation, while ubiquitylation by the E3 ligases MARCH5 and Parkin drives stress-induced degradation; acetylation at K491 itself licenses MARCH5 binding, coupling the two layers of regulation [PMID:25271058, PMID:24722297, PMID:28669827, PMID:38555669]. Its fusogenic output is further modulated by direct partners including FUNDC2, which binds the GTPase domain and inhibits GTPase activity [PMID:35710796], and the ER tubule protein REEP5, which engages MFN1/2 to position mitochondria along the ER [PMID:39133213]. Through this fusion activity MFN1 supports tissue-level physiology, being required for glucose-stimulated insulin secretion in β-cells and shaping hepatic metabolic flexibility [PMID:35472764, PMID:27613809], and it intersects with cell-death and immune programs by associating with MAVS/IPS-1 to enable antiviral signaling and with BAK to restrain apoptosis [PMID:20661427, PMID:38583647].","teleology":[{"year":2003,"claim":"Established that MFN1 is an essential, non-redundant mediator of mitochondrial outer membrane fusion whose loss fragments the network and compromises membrane potential.","evidence":"Knockout mouse fibroblasts with live imaging, rescue assays, and co-immunoprecipitation","pmids":["12527753"],"confidence":"High","gaps":["Did not resolve the catalytic mechanism of fusion","Relative contributions of MFN1 vs MFN2 to fusion left unresolved"]},{"year":2007,"claim":"Showed MFN1-MFN2 heterooligomers form in trans between mitochondria and confer a unique ability to complement disease mutants, defining a functional asymmetry between the two mitofusins.","evidence":"Co-IP and genetic complementation of CMT2A alleles in Mfn-null fibroblasts","pmids":["17296794"],"confidence":"High","gaps":["Structural basis of trans complex formation not defined","Why MFN1 but not MFN2 complements mutants left mechanistically open"]},{"year":2009,"claim":"Linked the mitofusin (FZO-1 ortholog) to a BCL-2-family pro-fusion partner, suggesting cross-talk between apoptotic machinery and fusion.","evidence":"In vivo Co-IP and genetic epistasis in C. elegans","pmids":["19704021"],"confidence":"Medium","gaps":["Mammalian MFN1 equivalent of CED-9 interaction not established here","Direct vs indirect interaction not resolved"]},{"year":2010,"claim":"Extended MFN1 function beyond fusion to innate immunity by showing it organizes MAVS/IPS-1 for antiviral interferon signaling.","evidence":"siRNA knockdown, immunofluorescence of IPS-1 aggregates, interferon assays, Co-IP","pmids":["20661427"],"confidence":"Medium","gaps":["Whether the signaling role depends on fusion activity unclear","Direct binding interface with MAVS not mapped"]},{"year":2014,"claim":"Defined acetylation/deacetylation as a dynamic switch controlling MFN1 activity and stability under metabolic stress.","evidence":"Co-IP, acetylation-resistant and K491 mutants, ubiquitylation assays, HDAC6- and MARCH5-KO models","pmids":["25271058","24722297"],"confidence":"High","gaps":["Full set of acetylated lysines not enumerated","How acetylation alters GTPase activity mechanistically unresolved"]},{"year":2016,"claim":"Showed tissue-specific MFN1 loss reprograms hepatic metabolism, demonstrating that fusion state tunes respiration and substrate preference.","evidence":"Liver-specific conditional KO mice with metabolic phenotyping and respirometry","pmids":["27613809"],"confidence":"High","gaps":["Molecular link between fragmentation and complex I abundance not defined","Liver-autonomous vs systemic effects not fully separated"]},{"year":2017,"claim":"Provided the structural and biochemical basis for fusion, showing GTP-driven GTPase-domain dimerization through a dynamin-like architecture is required for fusogenic activity, and identified SIRT1/TIP60 as a stability axis.","evidence":"X-ray crystallography with mutagenesis and cellular fusion assays; in vitro acetylation assays with SIRT1/TIP60","pmids":["28114303","28669827"],"confidence":"High","gaps":["Full-length, membrane-embedded conformational cycle not captured","Coordination of dimerization with membrane merger unresolved"]},{"year":2017,"claim":"Identified SLC25A46 turnover as an upstream regulator of mitofusin oligomerization and hyperfusion.","evidence":"siRNA knockdown, western blot, MitoTracker imaging, ubiquitylation assay","pmids":["28057766"],"confidence":"Medium","gaps":["Direct vs indirect regulation of MFN1 oligomers unclear","Whether SLC25A46 binds MFN1 directly not shown"]},{"year":2022,"claim":"Resolved a direct inhibitory mechanism by showing FUNDC2 binds the GTPase domain and suppresses MFN1 enzymatic activity, defining an endogenous brake on fusion.","evidence":"Co-IP with domain mapping, GTPase activity assay, KO with metabolic readouts","pmids":["35710796"],"confidence":"High","gaps":["Whether FUNDC2 acts on GTP loading or dimerization step not specified","Regulation of FUNDC2-MFN1 binding in vivo not defined"]},{"year":2022,"claim":"Broadened MFN1 roles into organelle tethering, beta-cell physiology, apoptosis control, ferroptosis, and kinase signaling, showing fusion output is decoded by multiple downstream programs.","evidence":"BioID/imaging (peroxisome clustering), beta-cell conditional double KO with Ca2+/ATP readouts, Co-IP/inhibition (BAK, MFN2, OPA1), STING1 ferroptosis assays, betaIIPKC phosphorylation and peptide disruption","pmids":["35523862","35472764","38583647","34195205","35192161"],"confidence":"Medium","gaps":["Causal dependence of each phenotype on fusion vs scaffolding not always separated","Several interactions rest on single-lab Co-IP","S86 phosphorylation effect on GTPase activity not measured directly"]},{"year":2024,"claim":"Mapped ubiquitin-dependent degradation by Parkin and immunoproteasome-controlled Parkin levels as physiological determinants of MFN1 turnover, and used endogenous interactome mapping to reveal ER/endosomal partners and REEP5-mediated ER-coupled positioning.","evidence":"Tissue-specific KD/OE in vivo (Parkin, beta2i), ubiquitylation assays, CRISPR endogenous tagging with affinity-MS, chemogenetic REEP5-MFN1 dimerization","pmids":["38555669","37501008","39675054","39133213"],"confidence":"Medium","gaps":["Direct Parkin ubiquitylation sites on MFN1 not mapped here","Functional roles of newly identified endosomal partners largely unvalidated"]},{"year":2025,"claim":"Began to resolve transcriptional control (KDM6B/H3K27me3 at the MFN1 promoter) and the real-time conformational cycle of the catalytic core, refining the structural model toward a heterogeneous transition-state ensemble.","evidence":"ChIP and KD in a sepsis ALI model; time-resolved tmFRET on engineered Mfn1 (preprint)","pmids":["41361208"],"confidence":"Medium","gaps":["tmFRET findings are preprint and from engineered constructs","Conformational cycle not linked to membrane fusion in cells"]},{"year":null,"claim":"How the GTPase conformational cycle is mechanically coupled to outer-membrane merger, and how the many regulatory inputs (acetylation, ubiquitylation, phosphorylation, partner binding) are integrated to set fusion rate in vivo, remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No reconstituted full-length fusion mechanism in the corpus","Hierarchy and cross-talk among PTMs and inhibitory partners not integrated","Membrane-merger step downstream of GTPase dimerization undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003924","term_label":"GTPase activity","supporting_discovery_ids":[2,11]},{"term_id":"GO:0140657","term_label":"ATP-dependent activity","supporting_discovery_ids":[2]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[3,16,12]}],"localization":[{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[0,7,21]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,2,24]},{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[7,21]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[3]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[14,10]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[5,19]}],"complexes":[],"partners":["MFN2","MAVS","FUNDC2","MARCH5","REEP5","BAK","STING1","HDAC6"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8IWA4","full_name":"Mitofusin-1","aliases":["Fzo homolog","Transmembrane GTPase MFN1"],"length_aa":741,"mass_kda":84.2,"function":"Mitochondrial outer membrane GTPase that mediates mitochondrial clustering and fusion (PubMed:12475957, PubMed:12759376, PubMed:27920125, PubMed:28114303). Membrane clustering requires GTPase activity (PubMed:27920125). It may involve a major rearrangement of the coiled coil domains (PubMed:27920125, PubMed:28114303). Mitochondria are highly dynamic organelles, and their morphology is determined by the equilibrium between mitochondrial fusion and fission events (PubMed:12475957, PubMed:12759376). Overexpression induces the formation of mitochondrial networks (in vitro) (PubMed:12759376). Has low GTPase activity (PubMed:27920125, PubMed:28114303)","subcellular_location":"Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q8IWA4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MFN1","classification":"Not Classified","n_dependent_lines":14,"n_total_lines":1208,"dependency_fraction":0.011589403973509934},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000171109","cell_line_id":"CID000818","localizations":[{"compartment":"mitochondria","grade":3}],"interactors":[{"gene":"MFN2","stoichiometry":4.0},{"gene":"SYAP1","stoichiometry":0.2},{"gene":"PSMC6","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID000818","total_profiled":1310},"omim":[{"mim_id":"620739","title":"RCC1-LIKE PROTEIN; RCC1L","url":"https://www.omim.org/entry/620739"},{"mim_id":"618817","title":"TRANSMEMBRANE PROTEIN 11; TMEM11","url":"https://www.omim.org/entry/618817"},{"mim_id":"618802","title":"tRNA-HISTIDINE GUANYLYLTRANSFERASE 1-LIKE PROTEIN; THG1L","url":"https://www.omim.org/entry/618802"},{"mim_id":"617081","title":"OMA1 ZINC METALLOPEPTIDASE; OMA1","url":"https://www.omim.org/entry/617081"},{"mim_id":"616636","title":"IMMUNODEFICIENCY 44; IMD44","url":"https://www.omim.org/entry/616636"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Mitochondria","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/MFN1"},"hgnc":{"alias_symbol":["FLJ20693"],"prev_symbol":[]},"alphafold":{"accession":"Q8IWA4","domains":[{"cath_id":"3.40.50.300","chopping":"76-308","consensus_level":"medium","plddt":87.6817,"start":76,"end":308},{"cath_id":"-","chopping":"378-536_617-695","consensus_level":"medium","plddt":80.909,"start":378,"end":695}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8IWA4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8IWA4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8IWA4-F1-predicted_aligned_error_v6.png","plddt_mean":81.19},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MFN1","jax_strain_url":"https://www.jax.org/strain/search?query=MFN1"},"sequence":{"accession":"Q8IWA4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8IWA4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8IWA4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8IWA4"}},"corpus_meta":[{"pmid":"12527753","id":"PMC_12527753","title":"Mitofusins Mfn1 and Mfn2 coordinately regulate mitochondrial fusion and are essential for embryonic development.","date":"2003","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/12527753","citation_count":2109,"is_preprint":false},{"pmid":"17296794","id":"PMC_17296794","title":"Complementation between mouse Mfn1 and Mfn2 protects mitochondrial fusion defects caused by CMT2A disease mutations.","date":"2007","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/17296794","citation_count":285,"is_preprint":false},{"pmid":"28114303","id":"PMC_28114303","title":"MFN1 structures reveal nucleotide-triggered dimerization critical for mitochondrial fusion.","date":"2017","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/28114303","citation_count":265,"is_preprint":false},{"pmid":"20661427","id":"PMC_20661427","title":"Virus-infection or 5'ppp-RNA activates antiviral signal through redistribution of IPS-1 mediated by MFN1.","date":"2010","source":"PLoS pathogens","url":"https://pubmed.ncbi.nlm.nih.gov/20661427","citation_count":154,"is_preprint":false},{"pmid":"34195205","id":"PMC_34195205","title":"STING1 Promotes Ferroptosis Through MFN1/2-Dependent Mitochondrial Fusion.","date":"2021","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/34195205","citation_count":147,"is_preprint":false},{"pmid":"31819189","id":"PMC_31819189","title":"MFN1-dependent alteration of mitochondrial dynamics drives hepatocellular carcinoma metastasis by glucose metabolic reprogramming.","date":"2019","source":"British journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/31819189","citation_count":132,"is_preprint":false},{"pmid":"33667993","id":"PMC_33667993","title":"The lncRNA Malat1 regulates microvascular function after myocardial infarction in mice via miR-26b-5p/Mfn1 axis-mediated mitochondrial dynamics.","date":"2021","source":"Redox biology","url":"https://pubmed.ncbi.nlm.nih.gov/33667993","citation_count":126,"is_preprint":false},{"pmid":"25271058","id":"PMC_25271058","title":"MFN1 deacetylation activates adaptive mitochondrial fusion and protects metabolically challenged mitochondria.","date":"2014","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/25271058","citation_count":124,"is_preprint":false},{"pmid":"24722297","id":"PMC_24722297","title":"MARCH5-mediated quality control on acetylated Mfn1 facilitates mitochondrial homeostasis and cell survival.","date":"2014","source":"Cell death & disease","url":"https://pubmed.ncbi.nlm.nih.gov/24722297","citation_count":112,"is_preprint":false},{"pmid":"31938072","id":"PMC_31938072","title":"Denervation drives skeletal muscle atrophy and induces mitochondrial dysfunction, mitophagy and apoptosis via miR-142a-5p/MFN1 axis.","date":"2020","source":"Theranostics","url":"https://pubmed.ncbi.nlm.nih.gov/31938072","citation_count":111,"is_preprint":false},{"pmid":"31947947","id":"PMC_31947947","title":"Mitochondrial Fusion Via OPA1 and MFN1 Supports Liver Tumor Cell Metabolism and Growth.","date":"2020","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/31947947","citation_count":90,"is_preprint":false},{"pmid":"19704021","id":"PMC_19704021","title":"The BCL-2-like protein CED-9 of C. elegans promotes FZO-1/Mfn1,2- and EAT-3/Opa1-dependent mitochondrial fusion.","date":"2009","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/19704021","citation_count":88,"is_preprint":false},{"pmid":"27613809","id":"PMC_27613809","title":"Mfn1 Deficiency in the Liver Protects Against Diet-Induced Insulin Resistance and Enhances the Hypoglycemic Effect of Metformin.","date":"2016","source":"Diabetes","url":"https://pubmed.ncbi.nlm.nih.gov/27613809","citation_count":69,"is_preprint":false},{"pmid":"28057766","id":"PMC_28057766","title":"Rapid degradation of mutant SLC25A46 by the ubiquitin-proteasome system results in MFN1/2-mediated hyperfusion of mitochondria.","date":"2017","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/28057766","citation_count":68,"is_preprint":false},{"pmid":"35710796","id":"PMC_35710796","title":"FUNDC2 promotes liver tumorigenesis by inhibiting MFN1-mediated mitochondrial fusion.","date":"2022","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/35710796","citation_count":66,"is_preprint":false},{"pmid":"32802180","id":"PMC_32802180","title":"Lentinan-functionalized Selenium Nanoparticles target Tumor Cell Mitochondria via TLR4/TRAF3/MFN1 pathway.","date":"2020","source":"Theranostics","url":"https://pubmed.ncbi.nlm.nih.gov/32802180","citation_count":63,"is_preprint":false},{"pmid":"28669827","id":"PMC_28669827","title":"Mitochondria elongation is mediated through SIRT1-mediated MFN1 stabilization.","date":"2017","source":"Cellular signalling","url":"https://pubmed.ncbi.nlm.nih.gov/28669827","citation_count":50,"is_preprint":false},{"pmid":"28803425","id":"PMC_28803425","title":"Frameshift Mutations in Repeat Sequences of ANK3, HACD4, TCP10L, TP53BP1, MFN1, LCMT2, RNMT, TRMT6, METTL8 and METTL16 Genes in Colon Cancers.","date":"2017","source":"Pathology oncology research : POR","url":"https://pubmed.ncbi.nlm.nih.gov/28803425","citation_count":47,"is_preprint":false},{"pmid":"35523862","id":"PMC_35523862","title":"The MFN1 and MFN2 mitofusins promote clustering between mitochondria and peroxisomes.","date":"2022","source":"Communications biology","url":"https://pubmed.ncbi.nlm.nih.gov/35523862","citation_count":44,"is_preprint":false},{"pmid":"32072917","id":"PMC_32072917","title":"Apoptotic Effects of Melittin on 4T1 Breast Cancer Cell Line is associated with Up Regulation of Mfn1 and Drp1 mRNA Expression.","date":"2020","source":"Anti-cancer agents in medicinal chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/32072917","citation_count":40,"is_preprint":false},{"pmid":"28112198","id":"PMC_28112198","title":"Chlorpyrifos inhibits neural induction via Mfn1-mediated mitochondrial dysfunction in human induced pluripotent stem cells.","date":"2017","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/28112198","citation_count":38,"is_preprint":false},{"pmid":"38082266","id":"PMC_38082266","title":"Empagliflozin targets Mfn1 and Opa1 to attenuate microglia-mediated neuroinflammation in retinal ischemia and reperfusion injury.","date":"2023","source":"Journal of neuroinflammation","url":"https://pubmed.ncbi.nlm.nih.gov/38082266","citation_count":34,"is_preprint":false},{"pmid":"32330448","id":"PMC_32330448","title":"MFN2 Plays a Distinct Role from MFN1 in Regulating Spermatogonial Differentiation.","date":"2020","source":"Stem cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/32330448","citation_count":34,"is_preprint":false},{"pmid":"31867811","id":"PMC_31867811","title":"Resveratrol attenuates cerebral ischaemia reperfusion injury via modulating mitochondrial dynamics homeostasis and activating AMPK-Mfn1 pathway.","date":"2019","source":"International journal of experimental pathology","url":"https://pubmed.ncbi.nlm.nih.gov/31867811","citation_count":33,"is_preprint":false},{"pmid":"35472764","id":"PMC_35472764","title":"Mitofusins Mfn1 and Mfn2 Are Required to Preserve Glucose- but Not Incretin-Stimulated β-Cell Connectivity and Insulin Secretion.","date":"2022","source":"Diabetes","url":"https://pubmed.ncbi.nlm.nih.gov/35472764","citation_count":28,"is_preprint":false},{"pmid":"24824927","id":"PMC_24824927","title":"MicroRNA-19b targets Mfn1 to inhibit Mfn1-induced apoptosis in osteosarcoma cells.","date":"2014","source":"Neoplasma","url":"https://pubmed.ncbi.nlm.nih.gov/24824927","citation_count":28,"is_preprint":false},{"pmid":"33347533","id":"PMC_33347533","title":"miR-20b suppresses mitochondrial dysfunction-mediated apoptosis to alleviate hyperoxia-induced acute lung injury by directly targeting MFN1 and MFN2.","date":"2021","source":"Acta biochimica et biophysica Sinica","url":"https://pubmed.ncbi.nlm.nih.gov/33347533","citation_count":28,"is_preprint":false},{"pmid":"35306433","id":"PMC_35306433","title":"Baicalein suppresses high glucose-induced inflammation and apoptosis in trophoblasts by targeting the miRNA-17-5p-Mfn1/2-NF-κB pathway.","date":"2022","source":"Placenta","url":"https://pubmed.ncbi.nlm.nih.gov/35306433","citation_count":24,"is_preprint":false},{"pmid":"38555669","id":"PMC_38555669","title":"Environmental cadmium inhibits testicular testosterone synthesis via Parkin-dependent MFN1 degradation.","date":"2024","source":"Journal of hazardous materials","url":"https://pubmed.ncbi.nlm.nih.gov/38555669","citation_count":22,"is_preprint":false},{"pmid":"39465252","id":"PMC_39465252","title":"IRF1-mediated upregulation of PARP12 promotes cartilage degradation by inhibiting PINK1/Parkin dependent mitophagy through ISG15 attenuating ubiquitylation and SUMOylation of MFN1/2.","date":"2024","source":"Bone research","url":"https://pubmed.ncbi.nlm.nih.gov/39465252","citation_count":21,"is_preprint":false},{"pmid":"30518710","id":"PMC_30518710","title":"5-Fluorouracil inhibits neural differentiation via Mfn1/2 reduction in human induced pluripotent stem cells.","date":"2018","source":"The Journal of toxicological sciences","url":"https://pubmed.ncbi.nlm.nih.gov/30518710","citation_count":21,"is_preprint":false},{"pmid":"35090998","id":"PMC_35090998","title":"Lanthanum decreased VAPB-PTPP51, BAP31-FIS1, and MFN2-MFN1 expression of mitochondria-associated membranes and induced abnormal autophagy in rat hippocampus.","date":"2022","source":"Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association","url":"https://pubmed.ncbi.nlm.nih.gov/35090998","citation_count":20,"is_preprint":false},{"pmid":"22245982","id":"PMC_22245982","title":"High expression of Mfn1 promotes early development of bovine SCNT embryos: improvement of mitochondrial membrane potential and oxidative metabolism.","date":"2012","source":"Mitochondrion","url":"https://pubmed.ncbi.nlm.nih.gov/22245982","citation_count":20,"is_preprint":false},{"pmid":"27133438","id":"PMC_27133438","title":"Tributyltin induces mitochondrial fission through Mfn1 degradation in human induced pluripotent stem cells.","date":"2016","source":"Toxicology in vitro : an international journal published in association with BIBRA","url":"https://pubmed.ncbi.nlm.nih.gov/27133438","citation_count":20,"is_preprint":false},{"pmid":"29382326","id":"PMC_29382326","title":"Study on the inhibition of Mfn1 by plant-derived miR5338 mediating the treatment of BPH with rape bee pollen.","date":"2018","source":"BMC complementary and alternative medicine","url":"https://pubmed.ncbi.nlm.nih.gov/29382326","citation_count":20,"is_preprint":false},{"pmid":"31781352","id":"PMC_31781352","title":"Inhibition of cAMP/PKA Pathway Protects Optic Nerve Head Astrocytes against Oxidative Stress by Akt/Bax Phosphorylation-Mediated Mfn1/2 Oligomerization.","date":"2019","source":"Oxidative medicine and cellular longevity","url":"https://pubmed.ncbi.nlm.nih.gov/31781352","citation_count":19,"is_preprint":false},{"pmid":"38463181","id":"PMC_38463181","title":"A detailed review of pharmacology of MFN1 (mitofusion-1)-mediated mitochondrial dynamics: Implications for cellular health and diseases.","date":"2024","source":"Saudi pharmaceutical journal : SPJ : the official publication of the Saudi Pharmaceutical Society","url":"https://pubmed.ncbi.nlm.nih.gov/38463181","citation_count":18,"is_preprint":false},{"pmid":"36670935","id":"PMC_36670935","title":"Genipin Attenuates Diabetic Cognitive Impairment by Reducing Lipid Accumulation and Promoting Mitochondrial Fusion via FABP4/Mfn1 Signaling in Microglia.","date":"2022","source":"Antioxidants (Basel, Switzerland)","url":"https://pubmed.ncbi.nlm.nih.gov/36670935","citation_count":18,"is_preprint":false},{"pmid":"29787809","id":"PMC_29787809","title":"EET enhances renal function in obese mice resulting in restoration of HO-1-Mfn1/2 signaling, and decrease in hypertension through inhibition of sodium chloride co-transporter.","date":"2018","source":"Prostaglandins & other lipid mediators","url":"https://pubmed.ncbi.nlm.nih.gov/29787809","citation_count":18,"is_preprint":false},{"pmid":"37501008","id":"PMC_37501008","title":"The immunoproteasome subunit β2i ameliorates myocardial ischemia/reperfusion injury by regulating Parkin-Mfn1/2-mediated mitochondrial fusion.","date":"2023","source":"Cellular and molecular life sciences : CMLS","url":"https://pubmed.ncbi.nlm.nih.gov/37501008","citation_count":16,"is_preprint":false},{"pmid":"35496076","id":"PMC_35496076","title":"Protodioscin Induces Mitochondrial Apoptosis of Human Hepatocellular Carcinoma Cells Through Eliciting ER Stress-Mediated IP3R Targeting Mfn1/Bak Expression.","date":"2022","source":"Journal of hepatocellular carcinoma","url":"https://pubmed.ncbi.nlm.nih.gov/35496076","citation_count":16,"is_preprint":false},{"pmid":"38583647","id":"PMC_38583647","title":"Inhibition of MFN1 restores tamoxifen-induced apoptosis in resistant cells by disrupting aberrant mitochondrial fusion dynamics.","date":"2024","source":"Cancer letters","url":"https://pubmed.ncbi.nlm.nih.gov/38583647","citation_count":11,"is_preprint":false},{"pmid":"35192161","id":"PMC_35192161","title":"The Mfn1-βIIPKC Interaction Regulates Mitochondrial Dysfunction via Sirt3 Following Experimental Subarachnoid Hemorrhage.","date":"2022","source":"Translational stroke research","url":"https://pubmed.ncbi.nlm.nih.gov/35192161","citation_count":11,"is_preprint":false},{"pmid":"39133213","id":"PMC_39133213","title":"Dynamic interaction of REEP5-MFN1/2 enables mitochondrial hitchhiking on tubular ER.","date":"2024","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/39133213","citation_count":11,"is_preprint":false},{"pmid":"34163214","id":"PMC_34163214","title":"Mitochondrial Dynamics Related Genes -MFN1, MFN2 and DRP1 Polymorphisms are Associated with Risk of Lung Cancer.","date":"2021","source":"Pharmacogenomics and personalized medicine","url":"https://pubmed.ncbi.nlm.nih.gov/34163214","citation_count":11,"is_preprint":false},{"pmid":"35686354","id":"PMC_35686354","title":"Mitoquinone mitigates paraquat-induced A549 lung epithelial cell injury by promoting MFN1/MFN2-mediated mitochondrial fusion.","date":"2022","source":"Journal of biochemical and molecular toxicology","url":"https://pubmed.ncbi.nlm.nih.gov/35686354","citation_count":11,"is_preprint":false},{"pmid":"39675054","id":"PMC_39675054","title":"Endogenous interactomes of MFN1 and MFN2 provide novel insights into interorganelle communication and autophagy.","date":"2024","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/39675054","citation_count":10,"is_preprint":false},{"pmid":"32249375","id":"PMC_32249375","title":"Silibinin treatment results in reducing OPA1&MFN1 genes expression in a rat model hepatic ischemia-reperfusion.","date":"2020","source":"Molecular biology reports","url":"https://pubmed.ncbi.nlm.nih.gov/32249375","citation_count":10,"is_preprint":false},{"pmid":"34425738","id":"PMC_34425738","title":"Associations between OPA1, MFN1, and MFN2 polymorphisms and primary open angle glaucoma in Polish participants of European ancestry.","date":"2021","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34425738","citation_count":9,"is_preprint":false},{"pmid":"36936780","id":"PMC_36936780","title":"MFN1 augmentation prevents retinal degeneration in a Charcot-Marie-Tooth type 2A mouse model.","date":"2023","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/36936780","citation_count":8,"is_preprint":false},{"pmid":"26682159","id":"PMC_26682159","title":"Correlation between polymorphisms in the MFN1 gene and myopia in Chinese population.","date":"2015","source":"International journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/26682159","citation_count":8,"is_preprint":false},{"pmid":"31466503","id":"PMC_31466503","title":"Pretreatment of bone mesenchymal stem cells with miR181-c facilitates craniofacial defect reconstruction via activating AMPK-Mfn1 signaling pathways.","date":"2019","source":"Journal of receptor and signal transduction research","url":"https://pubmed.ncbi.nlm.nih.gov/31466503","citation_count":7,"is_preprint":false},{"pmid":"34864096","id":"PMC_34864096","title":"The relationship between MFN1 copy number variation and growth traits of beef cattle.","date":"2021","source":"Gene","url":"https://pubmed.ncbi.nlm.nih.gov/34864096","citation_count":6,"is_preprint":false},{"pmid":"37254890","id":"PMC_37254890","title":"LncRNA gadd7 promotes mitochondrial membrane potential decrease and apoptosis of alveolar type II epithelial cells by positively regulating MFN1 in an in vitro model of hyperoxia-induced acute lung injury.","date":"2023","source":"European journal of histochemistry : EJH","url":"https://pubmed.ncbi.nlm.nih.gov/37254890","citation_count":6,"is_preprint":false},{"pmid":"39697097","id":"PMC_39697097","title":"Senolysis by GLS1 Inhibition Ameliorates Kidney Aging by Inducing Excessive mPTP Opening Through MFN1.","date":"2025","source":"The journals of gerontology. Series A, Biological sciences and medical sciences","url":"https://pubmed.ncbi.nlm.nih.gov/39697097","citation_count":5,"is_preprint":false},{"pmid":"31609634","id":"PMC_31609634","title":"Gemini-Based Lipoplexes Complement the Mitochondrial Phenotype in MFN1-Knockout Mouse Embryonic Fibroblasts.","date":"2019","source":"Molecular pharmaceutics","url":"https://pubmed.ncbi.nlm.nih.gov/31609634","citation_count":5,"is_preprint":false},{"pmid":"40643535","id":"PMC_40643535","title":"Regulation of Mitochondrial Metabolism by Mfn1 Gene Encoding Mitofusin Affects Cellular Proliferation and Histone Modification.","date":"2025","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/40643535","citation_count":3,"is_preprint":false},{"pmid":"38173217","id":"PMC_38173217","title":"Quercetin Promotes the Repair of Mitochondrial Function in H9c2 Cells Through the miR-92a-3p/Mfn1 Axis.","date":"2024","source":"Current pharmaceutical biotechnology","url":"https://pubmed.ncbi.nlm.nih.gov/38173217","citation_count":3,"is_preprint":false},{"pmid":"39739772","id":"PMC_39739772","title":"Loss of Mfn1 but not Mfn2 enhances adipogenesis.","date":"2024","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/39739772","citation_count":2,"is_preprint":false},{"pmid":"36438475","id":"PMC_36438475","title":"Erratum: Lentinan-functionalized Selenium Nanoparticles target Tumor Cell Mitochondria via TLR4/TRAF3/MFN1 pathway: Erratum.","date":"2022","source":"Theranostics","url":"https://pubmed.ncbi.nlm.nih.gov/36438475","citation_count":2,"is_preprint":false},{"pmid":"41361208","id":"PMC_41361208","title":"KDM6B induces demethylation of H3K27me3 in MFN1 to modulate aberrant mitophagy in sepsis-induced acute lung injury.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/41361208","citation_count":1,"is_preprint":false},{"pmid":"40714924","id":"PMC_40714924","title":"LncRNA FENDRR Inhibits Mitochondrial Apoptosis via TET2-Mediated DNA Demethylation of MFN1 in NSCPO.","date":"2025","source":"Oral diseases","url":"https://pubmed.ncbi.nlm.nih.gov/40714924","citation_count":0,"is_preprint":false},{"pmid":"35730364","id":"PMC_35730364","title":"Mitochondrial dysfunction caused by targeted deletion of Mfn1 does not result in telomere shortening in oocytes.","date":"2022","source":"Zygote (Cambridge, England)","url":"https://pubmed.ncbi.nlm.nih.gov/35730364","citation_count":0,"is_preprint":false},{"pmid":"41078489","id":"PMC_41078489","title":"Chronic stress-induced downregulation of MFN1 contributes to fatty liver in chickens.","date":"2025","source":"Frontiers in veterinary science","url":"https://pubmed.ncbi.nlm.nih.gov/41078489","citation_count":0,"is_preprint":false},{"pmid":"41892266","id":"PMC_41892266","title":"Effect of Hydroxyapatite Nanoparticles on the Ultrastructure, Developmental Competence, and Expression of ZP3, MFN1, and NPM2 in Vitrified Bovine GV Oocytes.","date":"2026","source":"Biology","url":"https://pubmed.ncbi.nlm.nih.gov/41892266","citation_count":0,"is_preprint":false},{"pmid":"41240162","id":"PMC_41240162","title":"MYC affects mitochondrial function in IgA nephropathy by promoting the degradation of MFN1 through HRD1.","date":"2025","source":"Immunologic research","url":"https://pubmed.ncbi.nlm.nih.gov/41240162","citation_count":0,"is_preprint":false},{"pmid":"42180857","id":"PMC_42180857","title":"MTFR2 regulated the proliferation, apoptosis, migration, and invasion of endometrial cancer cells through the Drp1/MFN1 signaling pathway mediated mitochondrial fission.","date":"2026","source":"Translational cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/42180857","citation_count":0,"is_preprint":false},{"pmid":"42049406","id":"PMC_42049406","title":"Exercise Stimulates PINK-1, PARKIN, MFN-1, and ATG-3 Genes Expression Despite High-fat Diet: Tissue-specific Responses.","date":"2026","source":"In vivo (Athens, Greece)","url":"https://pubmed.ncbi.nlm.nih.gov/42049406","citation_count":0,"is_preprint":false},{"pmid":"33082914","id":"PMC_33082914","title":"Corrigendum to \"Inhibition of cAMP/PKA Pathway Protects Optic Nerve Head Astrocytes against Oxidative Stress by Akt/Bax Phosphorylation-Mediated Mfn1/2 Oligomerization\".","date":"2020","source":"Oxidative medicine and cellular longevity","url":"https://pubmed.ncbi.nlm.nih.gov/33082914","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.10.08.681278","title":"Time-resolved tmFRET reveals GTP-coupled conformational changes in Mfn1","date":"2025-10-09","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.08.681278","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.10.27.684912","title":"Systems modeling of mitochondrial dynamics in different exercise regimes","date":"2025-10-28","source":"bioRxiv","url":"https://doi.org/10.1101/2025.10.27.684912","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.11.25.690431","title":"Mitochondrial pull-outs are a distinct type of dynamic tubulation events regulated by mitochondrial activity","date":"2025-11-28","source":"bioRxiv","url":"https://doi.org/10.1101/2025.11.25.690431","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.09.26.678759","title":"Non-coding exon splicing orchestrates tissue-specific expression of two functionally distinct mitochondrial isoforms of Mitofusin 2","date":"2025-09-27","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.26.678759","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.09.11.675564","title":"Human Platelet-derived Lysates and Extracellular Vesicles Restore Mitochondrial Function and Redox Balance in Neuronal Models","date":"2025-09-16","source":"bioRxiv","url":"https://doi.org/10.1101/2025.09.11.675564","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.05.21.655403","title":"Mitochondrial fusion controls the development of specialized mitochondrial structure and metabolism in rod photoreceptor cells","date":"2025-05-26","source":"bioRxiv","url":"https://doi.org/10.1101/2025.05.21.655403","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.02.11.637688","title":"Disruption of Mitochondrial Dynamics and Stasis Leads to Liver Injury and Tumorigenesis","date":"2025-02-12","source":"bioRxiv","url":"https://doi.org/10.1101/2025.02.11.637688","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.04.03.647131","title":"Disease-causing MFN2 mutants impair mitochondrial fission dynamics by distinct DRP1 dysregulation","date":"2025-04-04","source":"bioRxiv","url":"https://doi.org/10.1101/2025.04.03.647131","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.01.29.635508","title":"Time-dependent Mitochondrial Remodeling in Experimental Atrial Fibrillation and Potential Therapeutic Relevance","date":"2025-02-01","source":"bioRxiv","url":"https://doi.org/10.1101/2025.01.29.635508","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.09.10.612286","title":"Identification and Validation of Mitophagy-Related Genes in Diabetic Retinopathy","date":"2024-09-14","source":"bioRxiv","url":"https://doi.org/10.1101/2024.09.10.612286","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.10.16.617081","title":"Voluntary Exercise Attenuates Tumor Growth in a Preclinical Model of Castration-Resistant Prostate Cancer","date":"2024-10-18","source":"bioRxiv","url":"https://doi.org/10.1101/2024.10.16.617081","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.07.23.604769","title":"PA28γ promotes the malignant progression of tumor by elevating mitochondrial function via C1QBP","date":"2024-07-23","source":"bioRxiv","url":"https://doi.org/10.1101/2024.07.23.604769","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.11.28.625892","title":"Isoliquiritigenin attenuated cognitive impairment, cerebral tau phosphorylation and oxidative stress in a streptozotocin-induced mouse model of Alzheimer’s disease","date":"2024-11-28","source":"bioRxiv","url":"https://doi.org/10.1101/2024.11.28.625892","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":45188,"output_tokens":6445,"usd":0.11612,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":15450,"output_tokens":4129,"usd":0.090237,"stage2_stop_reason":"end_turn"},"total_usd":0.206357,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2003,\n      \"finding\": \"Mfn1 and Mfn2 are essential mediators of mitochondrial outer membrane fusion in vertebrates. Loss of Mfn1 causes severe mitochondrial fragmentation due to reduction in fusion. Mfn1 and Mfn2 form homotypic and heterotypic complexes, and homotypic Mfn1 complexes are functional for fusion. Mfn1-deficient embryonic fibroblasts show loss of membrane potential in a subset of mitochondria.\",\n      \"method\": \"Knockout mouse generation, embryonic fibroblast live imaging, complementation/rescue assays, co-immunoprecipitation\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, genetic KO with defined cellular phenotype, rescue experiments; replicated across multiple cell types and in vivo\",\n      \"pmids\": [\"12527753\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Mfn1 forms heterooligomeric complexes with Mfn2, including complexes in trans between adjacent mitochondria. Wild-type Mfn1 can complement CMT2A disease mutants of Mfn2 through these heterooligomeric complexes, whereas wild-type Mfn2 cannot. This highlights a unique functional role for Mfn1-Mfn2 heterocomplexes in mitochondrial fusion.\",\n      \"method\": \"Co-immunoprecipitation, complementation rescue assays in Mfn-null fibroblasts, fluorescence microscopy\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, genetic complementation with multiple disease alleles, single lab with multiple orthogonal methods\",\n      \"pmids\": [\"17296794\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Crystal structures of engineered human MFN1 (GTPase domain + helical domain) reveal: (1) the helical domain is composed of elements from widely dispersed sequence regions and resembles the 'neck' of bacterial dynamin-like protein; (2) GTP binding induces conformational changes that promote GTPase domain dimerization in the transition state; (3) disruption of GTPase domain dimerization abolishes fusogenic activity; (4) a conserved aspartate residue affects mitochondrial elongation, likely through GTP-loading-dependent domain rearrangement.\",\n      \"method\": \"X-ray crystallography, site-directed mutagenesis, functional fusion assay in cells\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure with mutagenesis and functional validation, multiple orthogonal methods in a single rigorous study\",\n      \"pmids\": [\"28114303\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"MFN1 associates with IPS-1 (MAVS) on the mitochondrial outer membrane and positively regulates RLR-mediated antiviral innate immune responses. Knockdown of MFN1 abrogates virus-induced redistribution of IPS-1 into speckle-like aggregates and abolishes interferon production.\",\n      \"method\": \"siRNA knockdown, immunofluorescence microscopy, interferon production assays, co-immunoprecipitation\",\n      \"journal\": \"PLoS pathogens\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP binding evidence plus functional KD phenotype, single lab with two orthogonal methods\",\n      \"pmids\": [\"20661427\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Under glucose starvation, MFN1 associates with the deacetylase HDAC6, leading to MFN1 deacetylation and activation, promoting mitochondrial fusion. HDAC6 or MFN1 deficiency prevents glucose deprivation-induced mitochondrial fusion. Failure to fuse causes excessive mitochondrial ROS and oxidative damage. An acetylation-resistant MFN1 mutant suppresses this oxidative damage. In fasting mice, skeletal muscle mitochondria undergo dramatic fusion that is abrogated in HDAC6-knockout mice.\",\n      \"method\": \"Co-immunoprecipitation, site-directed mutagenesis (acetylation-resistant mutant), HDAC6 KO mouse model, live-cell imaging, ROS measurement\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — Co-IP, acetylation-resistant mutagenesis, in vivo KO validation, multiple orthogonal methods in one study\",\n      \"pmids\": [\"25271058\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"MARCH5 (E3 ubiquitin ligase) binds MFN1, ubiquitylates it, and mediates its degradation under mitochondrial stress conditions. Acetylation of MFN1 at K491 promotes its interaction with MARCH5 and subsequent ubiquitylation; an acetylation-deficient K491R mutant shows weak interaction with MARCH5 and reduced ubiquitylation. Fine-tuned MFN1 levels maintained by MARCH5-dependent quality control are essential for cell survival under stress.\",\n      \"method\": \"Co-immunoprecipitation, site-directed mutagenesis (K491R, K491Q), ubiquitylation assay, MARCH5 KO MEFs\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — mutagenesis of acetylation site, Co-IP, KO cell lines, multiple orthogonal methods\",\n      \"pmids\": [\"24722297\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"SIRT1 deacetylase promotes MFN1 protein stability and mitochondrial elongation. The acetyltransferase TIP60 acetylates MFN1 in vitro, and co-expression of SIRT1 abolishes this acetylation. SIRT1 knockdown reduces MFN1 levels whereas SIRT1 overexpression increases MFN1, and hypoxia induces accumulation of both SIRT1 and MFN1 alongside mitochondrial elongation.\",\n      \"method\": \"In vitro acetylation assay, siRNA knockdown, overexpression, western blot, nicotinamide inhibitor treatment\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — in vitro acetylation assay with SIRT1/TIP60, cellular KD/OE, single lab\",\n      \"pmids\": [\"28669827\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Liver-specific deletion of Mfn1 (Mfn1LKO) leads to a highly fragmented mitochondrial network in hepatocytes, coupled with enhanced mitochondrial respiration capacity and preference for lipid oxidation. Mfn1LKO mice are protected against high-fat diet-induced insulin resistance, and Mfn1 deficiency increases complex I abundance and sensitizes animals to metformin's hypoglycemic effect.\",\n      \"method\": \"Conditional liver-specific KO mouse, mitochondrial morphology imaging, oxygen consumption measurement, glucose tolerance tests, metabolic phenotyping\",\n      \"journal\": \"Diabetes\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional tissue-specific KO with metabolic phenotyping, in vivo model, multiple functional readouts\",\n      \"pmids\": [\"27613809\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Rapid proteasomal degradation of SLC25A46 leads to increased stability and oligomerization of MFN1 and MFN2 on mitochondria, promoting mitochondrial hyperfusion. SLC25A46 acts as a regulator of MFN1/2 oligomerization; decreased SLC25A46 expression stabilizes mitofusins and drives hyperfusion independently of mitophagy or apoptosis.\",\n      \"method\": \"siRNA knockdown, western blot, MitoTracker imaging, ubiquitylation assay\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — KD phenotype with biochemical validation, single lab, multiple cell biology readouts\",\n      \"pmids\": [\"28057766\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The C. elegans BCL-2-like protein CED-9 physically interacts with FZO-1 (the C. elegans Mfn1/2 homologue) in vivo and promotes complete mitochondrial fusion (outer and inner membrane) in a manner dependent on FZO-1 and EAT-3 (Opa1 homologue). The ability of CED-9 to interact with FZO-1 is important for its pro-fusion activity.\",\n      \"method\": \"Co-immunoprecipitation in vivo (C. elegans), genetic epistasis, fluorescence microscopy of mitochondrial morphology\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus genetic epistasis in C. elegans ortholog, single lab\",\n      \"pmids\": [\"19704021\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"STING1 promotes ferroptosis by binding MFN1/2 at the mitochondria to trigger mitochondrial fusion, leading to ROS production and lipid peroxidation. Erastin (ferroptosis inducer) causes STING1 accumulation at mitochondria where it binds MFN1/2. Genetic depletion of STING1 or MFN1/2 reduces ferroptosis sensitivity.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, xenograft mouse model, lipid peroxidation and ROS assays\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP binding, KD functional phenotype, in vivo xenograft, single lab\",\n      \"pmids\": [\"34195205\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"FUNDC2 interacts via its amino-terminal region with the GTPase domain of MFN1, inhibiting MFN1 GTPase activity and thus suppressing outer mitochondrial membrane fusion. Loss of FUNDC2 leads to mitochondrial elongation, decreased mitochondrial respiration, and reprogrammed cellular metabolism.\",\n      \"method\": \"Co-immunoprecipitation, domain mapping, GTPase activity assay, siRNA/KO, mitochondrial morphology imaging, metabolic profiling\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — Co-IP with domain mapping, direct enzymatic inhibition assay, KO with multiple functional readouts in single rigorous study\",\n      \"pmids\": [\"35710796\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"MFN1 and MFN2 promote physical clustering between mitochondria and peroxisomes. MFNs are enriched at the mitochondria-peroxisome interface, and overexpression of MFNs induces co-clustering of peroxisomes with mitochondria. A truncated MFN2 lacking the transmembrane region inhibits mitochondria-peroxisome tethering.\",\n      \"method\": \"Proximity labeling (BioID), fluorescence microscopy, overexpression and dominant-negative constructs, organelle co-clustering quantification\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — proximity labeling plus imaging with dominant-negative approach, single lab\",\n      \"pmids\": [\"35523862\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MARCH5-mediated ubiquitylation of MFN1 is triggered by tributyltin (TBT) exposure in iPSCs, leading to MFN1 degradation and mitochondrial fragmentation. Knockdown of MARCH5 abolishes TBT-induced MFN1 reduction, establishing MARCH5 as the E3 ligase responsible for MFN1 degradation under this toxic stress.\",\n      \"method\": \"siRNA knockdown of MARCH5, western blot, MitoTracker imaging, ATP measurement\",\n      \"journal\": \"Toxicology in vitro\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — MARCH5 KD rescues MFN1 levels, single lab, single method for the interaction\",\n      \"pmids\": [\"27133438\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"MFN1 interacts with BAK at the mitochondrial outer membrane in tamoxifen-resistant breast cancer cells, restraining BAK activation and cytochrome c release. Elevated MFN1 also interacts with MFN2 to enhance outer membrane fusion, and interacts with OPA1 (whose oligomerization is reduced), thereby reshaping cristae. Knockdown or pharmacological inhibition of MFN1 restores BAK oligomerization, cytochrome c release, and caspase activation, reversing tamoxifen resistance.\",\n      \"method\": \"Co-immunoprecipitation, siRNA knockdown, pharmacological inhibition, cytochrome c release assay, caspase activity, in vivo xenograft\",\n      \"journal\": \"Cancer letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP for MFN1-BAK and MFN1-MFN2, functional KD/inhibition with multiple apoptosis readouts, single lab\",\n      \"pmids\": [\"38583647\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"βIIPKC (protein kinase C beta II) accumulates on the mitochondrial outer membrane, interacts with MFN1, and phosphorylates MFN1 at serine 86. Disrupting Mfn1-βIIPKC interaction with the antagonistic peptide SAMβA attenuates neuronal injury following subarachnoid hemorrhage, preserves mitochondrial biogenesis, and increases Sirt3 activity and downstream antioxidant enzyme activity.\",\n      \"method\": \"Co-immunoprecipitation, peptide antagonist (SAMβA, βIIV5-3), western blot, in vivo rat SAH model, Sirt3 siRNA knockdown\",\n      \"journal\": \"Translational stroke research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP plus targeted peptide disruption with functional readouts, in vivo validation, single lab\",\n      \"pmids\": [\"35192161\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"REEP5 (ER tubule-shaping protein) physically interacts with MFN1/2 to mediate mitochondrial 'hitchhiking' on tubular ER along microtubules. REEP5 depletion reduces ER-mitochondria tethering and causes perinuclear clustering of mitochondria. Forced irreversible REEP5-MFN1/2 interaction causes mitochondrial hyperfusion. Disruption of MFN2-REEP5 interaction modulates mitochondrial ROS production.\",\n      \"method\": \"Co-immunoprecipitation, rapamycin-induced dimerization (chemogenetic), siRNA knockdown, live imaging, ROS measurement\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, chemogenetic forced dimerization, KD phenotype with functional ROS readout, single lab\",\n      \"pmids\": [\"39133213\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Endogenous interactome mapping of MFN1-HA (CRISPR-Cas9 tagged) by HA-affinity isolation and mass spectrometry identified novel ER and endosomal partners of MFN1. RAB5C was validated as an endosomal modulator of mitochondrial homeostasis that interacts with MFN1. Nutrient deprivation modulates MFN1 interactors.\",\n      \"method\": \"CRISPR-Cas9 endogenous tagging, affinity isolation-mass spectrometry, validation by co-IP\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — endogenous affinity-MS interactome with Co-IP validation, single lab, novel partners partially validated\",\n      \"pmids\": [\"39675054\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In a CMT2A mouse model (MFN2 R94Q mutation), imbalanced MFN1/MFN2 ratio causes retinal degeneration via P62/LC3B-mediated mitophagy/autophagy. Transgenic MFN1 augmentation in MFN2-R94Q mice rescues vision and retinal morphology by restoring MFN1/MFN2 homeostasis and shifting from Parkin-independent to PINK1-dependent mitophagy.\",\n      \"method\": \"Transgenic mouse model, retinal function testing (ERG), immunofluorescence, western blot, mitophagy pathway analysis\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo transgenic rescue with multiple functional readouts, single lab\",\n      \"pmids\": [\"36936780\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Parkin, upon cadmium-induced mitochondrial translocation, mediates ubiquitin-dependent degradation of MFN1 in Leydig cells, causing mitochondrial fusion disorder and suppressing testosterone synthesis. Testicular-specific Parkin knockdown prevents MFN1 degradation and mitigates testosterone decline.\",\n      \"method\": \"In vivo mouse model, testicular-specific Parkin knockdown, MFN1 overexpression, ubiquitylation assay, testosterone measurement\",\n      \"journal\": \"Journal of hazardous materials\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — tissue-specific KD plus overexpression rescue, functional steroidogenesis readout, single lab\",\n      \"pmids\": [\"38555669\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In cardiac I/R injury, decreased immunoproteasome subunit β2i expression leads to increased E3 ligase Parkin protein, promoting ubiquitin-dependent degradation of MFN1/2 and causing excessive mitochondrial fission. β2i knockout exacerbates MFN1/2 loss and fission, while β2i overexpression via rAAV9 ameliorates cardiac I/R injury.\",\n      \"method\": \"β2i KO mice, rAAV9-β2i overexpression, western blot, mitochondrial morphology imaging, cardiac function measurement\",\n      \"journal\": \"Cellular and molecular life sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO and OE rescue in vivo, mechanistic pathway dissection, single lab\",\n      \"pmids\": [\"37501008\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Mfn1 and Mfn2 double knockout in β-cells reduces mitochondrial length, glucose-induced mitochondrial polarization, ATP synthesis, and cytosolic/mitochondrial Ca2+ increases, establishing that mitochondrial fusion is required for glucose-stimulated insulin secretion but not for incretin signaling.\",\n      \"method\": \"β-cell-selective conditional double KO mice, glucose tolerance testing, mitochondrial imaging, Ca2+ measurements, ATP assay, EPAC-camps sensor\",\n      \"journal\": \"Diabetes\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — conditional tissue-specific double KO with multiple orthogonal functional readouts including live Ca2+ imaging and metabolic sensors\",\n      \"pmids\": [\"35472764\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"KDM6B histone demethylase promotes H3K27me3 demethylation at the MFN1 promoter, increasing MFN1 transcription. KDM6B knockdown increases H3K27me3 enrichment at the MFN1 promoter, reduces MFN1 expression, promotes mitophagy, and suppresses macrophage apoptosis in sepsis-induced ALI.\",\n      \"method\": \"Chromatin immunoprecipitation (ChIP), siRNA knockdown, western blot, flow cytometry, in vivo CLP mouse model\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP demonstrates direct promoter occupancy with functional KD phenotype, single lab\",\n      \"pmids\": [\"41361208\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Time-resolved tmFRET measurements of Mfn1 (GTPase domain + HB1) reveal that the GDP-bound state adopts an open conformation (GTPase and HB1 domains far apart) matching the crystal structure. GTP binding favors the open state, the transition state (GDP+Pi) shows an equilibrium between open and closed states rather than a single closed conformation, and the nucleotide-free state is conformationally distinct from either nucleotide-bound state. This reveals an unexpected conformational reversal in a single catalytic cycle and a heterogeneous transition-state ensemble.\",\n      \"method\": \"Time-resolved transition metal ion FRET (tmFRET), incorporation of fluorescent noncanonical amino acid, fluorescence lifetime measurements, engineered Mfn1 construct\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — novel structural/biophysical method with rigorous distance measurements, single lab preprint not yet peer-reviewed\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"MFN1 mediates a type of dynamic tubulation ('pull-outs') characterized by lateral extrusion from pre-existing mitochondrial tubules. Pull-outs are distinct from tip elongation and are modulated by MFN1 and DRP1. They depend on mitochondrial actin polymerization, are stimulated by conditions favoring oxidative phosphorylation, and are required to increase mitochondrial connectivity and respiratory activity.\",\n      \"method\": \"Live-cell fluorescence microscopy, MFN1 perturbation (knockdown/knockout), mitochondrial morphology quantification, respiratory activity measurement\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 2–3 / Weak — live imaging with MFN1 perturbation, preprint not yet peer-reviewed, single lab\",\n      \"pmids\": [],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"MFN1 is a dynamin-related GTPase embedded in the mitochondrial outer membrane that drives organelle fusion through GTP-hydrolysis-dependent GTPase domain dimerization and conformational rearrangement of its helical domain; it forms both homotypic and heterotypic complexes with MFN2, associates with IPS-1/MAVS to regulate antiviral signaling, is post-translationally regulated by acetylation (written by TIP60, erased by SIRT1/HDAC6) and ubiquitylation (by MARCH5, Parkin, and HRD1), and is required for glucose-stimulated insulin secretion, adaptive metabolic responses, and protection of mitochondrial membrane potential, with its activity additionally modulated by binding partners including FUNDC2 (inhibitor), STING1, REEP5, and βIIPKC.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MFN1 is a dynamin-related GTPase of the mitochondrial outer membrane that drives organelle fusion and thereby controls mitochondrial network connectivity, bioenergetics, and stress responses [#0]. Together with MFN2 it forms both homotypic and heterotypic complexes, including trans complexes between adjacent mitochondria; homotypic MFN1 complexes are fusion-competent, and MFN1 can uniquely complement CMT2A-causing MFN2 mutants [#0, #1]. Fusion is powered by a defined catalytic mechanism: GTP binding promotes GTPase-domain dimerization in the transition state with rearrangement of a helical 'neck' domain, and disruption of this dimerization abolishes fusogenic activity [#2]. MFN1 levels and activity are tightly tuned by post-translational control \\u2014 acetylation by TIP60 opposed by the deacetylases SIRT1 and HDAC6 governs stability and activation, while ubiquitylation by the E3 ligases MARCH5 and Parkin drives stress-induced degradation; acetylation at K491 itself licenses MARCH5 binding, coupling the two layers of regulation [#4, #5, #6, #19]. Its fusogenic output is further modulated by direct partners including FUNDC2, which binds the GTPase domain and inhibits GTPase activity [#11], and the ER tubule protein REEP5, which engages MFN1/2 to position mitochondria along the ER [#16]. Through this fusion activity MFN1 supports tissue-level physiology, being required for glucose-stimulated insulin secretion in \\u03b2-cells and shaping hepatic metabolic flexibility [#21, #7], and it intersects with cell-death and immune programs by associating with MAVS/IPS-1 to enable antiviral signaling and with BAK to restrain apoptosis [#3, #14].\"\n,\n  \"teleology\": [\n    {\n      \"year\": 2003,\n      \"claim\": \"Established that MFN1 is an essential, non-redundant mediator of mitochondrial outer membrane fusion whose loss fragments the network and compromises membrane potential.\",\n      \"evidence\": \"Knockout mouse fibroblasts with live imaging, rescue assays, and co-immunoprecipitation\",\n      \"pmids\": [\"12527753\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve the catalytic mechanism of fusion\", \"Relative contributions of MFN1 vs MFN2 to fusion left unresolved\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Showed MFN1-MFN2 heterooligomers form in trans between mitochondria and confer a unique ability to complement disease mutants, defining a functional asymmetry between the two mitofusins.\",\n      \"evidence\": \"Co-IP and genetic complementation of CMT2A alleles in Mfn-null fibroblasts\",\n      \"pmids\": [\"17296794\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of trans complex formation not defined\", \"Why MFN1 but not MFN2 complements mutants left mechanistically open\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Linked the mitofusin (FZO-1 ortholog) to a BCL-2-family pro-fusion partner, suggesting cross-talk between apoptotic machinery and fusion.\",\n      \"evidence\": \"In vivo Co-IP and genetic epistasis in C. elegans\",\n      \"pmids\": [\"19704021\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mammalian MFN1 equivalent of CED-9 interaction not established here\", \"Direct vs indirect interaction not resolved\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Extended MFN1 function beyond fusion to innate immunity by showing it organizes MAVS/IPS-1 for antiviral interferon signaling.\",\n      \"evidence\": \"siRNA knockdown, immunofluorescence of IPS-1 aggregates, interferon assays, Co-IP\",\n      \"pmids\": [\"20661427\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether the signaling role depends on fusion activity unclear\", \"Direct binding interface with MAVS not mapped\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Defined acetylation/deacetylation as a dynamic switch controlling MFN1 activity and stability under metabolic stress.\",\n      \"evidence\": \"Co-IP, acetylation-resistant and K491 mutants, ubiquitylation assays, HDAC6- and MARCH5-KO models\",\n      \"pmids\": [\"25271058\", \"24722297\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full set of acetylated lysines not enumerated\", \"How acetylation alters GTPase activity mechanistically unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Showed tissue-specific MFN1 loss reprograms hepatic metabolism, demonstrating that fusion state tunes respiration and substrate preference.\",\n      \"evidence\": \"Liver-specific conditional KO mice with metabolic phenotyping and respirometry\",\n      \"pmids\": [\"27613809\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular link between fragmentation and complex I abundance not defined\", \"Liver-autonomous vs systemic effects not fully separated\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Provided the structural and biochemical basis for fusion, showing GTP-driven GTPase-domain dimerization through a dynamin-like architecture is required for fusogenic activity, and identified SIRT1/TIP60 as a stability axis.\",\n      \"evidence\": \"X-ray crystallography with mutagenesis and cellular fusion assays; in vitro acetylation assays with SIRT1/TIP60\",\n      \"pmids\": [\"28114303\", \"28669827\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Full-length, membrane-embedded conformational cycle not captured\", \"Coordination of dimerization with membrane merger unresolved\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Identified SLC25A46 turnover as an upstream regulator of mitofusin oligomerization and hyperfusion.\",\n      \"evidence\": \"siRNA knockdown, western blot, MitoTracker imaging, ubiquitylation assay\",\n      \"pmids\": [\"28057766\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct vs indirect regulation of MFN1 oligomers unclear\", \"Whether SLC25A46 binds MFN1 directly not shown\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Resolved a direct inhibitory mechanism by showing FUNDC2 binds the GTPase domain and suppresses MFN1 enzymatic activity, defining an endogenous brake on fusion.\",\n      \"evidence\": \"Co-IP with domain mapping, GTPase activity assay, KO with metabolic readouts\",\n      \"pmids\": [\"35710796\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether FUNDC2 acts on GTP loading or dimerization step not specified\", \"Regulation of FUNDC2-MFN1 binding in vivo not defined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Broadened MFN1 roles into organelle tethering, beta-cell physiology, apoptosis control, ferroptosis, and kinase signaling, showing fusion output is decoded by multiple downstream programs.\",\n      \"evidence\": \"BioID/imaging (peroxisome clustering), beta-cell conditional double KO with Ca2+/ATP readouts, Co-IP/inhibition (BAK, MFN2, OPA1), STING1 ferroptosis assays, betaIIPKC phosphorylation and peptide disruption\",\n      \"pmids\": [\"35523862\", \"35472764\", \"38583647\", \"34195205\", \"35192161\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Causal dependence of each phenotype on fusion vs scaffolding not always separated\", \"Several interactions rest on single-lab Co-IP\", \"S86 phosphorylation effect on GTPase activity not measured directly\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Mapped ubiquitin-dependent degradation by Parkin and immunoproteasome-controlled Parkin levels as physiological determinants of MFN1 turnover, and used endogenous interactome mapping to reveal ER/endosomal partners and REEP5-mediated ER-coupled positioning.\",\n      \"evidence\": \"Tissue-specific KD/OE in vivo (Parkin, beta2i), ubiquitylation assays, CRISPR endogenous tagging with affinity-MS, chemogenetic REEP5-MFN1 dimerization\",\n      \"pmids\": [\"38555669\", \"37501008\", \"39675054\", \"39133213\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct Parkin ubiquitylation sites on MFN1 not mapped here\", \"Functional roles of newly identified endosomal partners largely unvalidated\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Began to resolve transcriptional control (KDM6B/H3K27me3 at the MFN1 promoter) and the real-time conformational cycle of the catalytic core, refining the structural model toward a heterogeneous transition-state ensemble.\",\n      \"evidence\": \"ChIP and KD in a sepsis ALI model; time-resolved tmFRET on engineered Mfn1 (preprint)\",\n      \"pmids\": [\"41361208\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"tmFRET findings are preprint and from engineered constructs\", \"Conformational cycle not linked to membrane fusion in cells\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the GTPase conformational cycle is mechanically coupled to outer-membrane merger, and how the many regulatory inputs (acetylation, ubiquitylation, phosphorylation, partner binding) are integrated to set fusion rate in vivo, remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No reconstituted full-length fusion mechanism in the corpus\", \"Hierarchy and cross-talk among PTMs and inhibitory partners not integrated\", \"Membrane-merger step downstream of GTPase dimerization undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003924\", \"supporting_discovery_ids\": [2, 11]},\n      {\"term_id\": \"GO:0140657\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [3, 16, 12]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005741\", \"supporting_discovery_ids\": [0, 3, 11]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [0, 7, 21]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 2, 24]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [7, 21]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [3]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [14, 10]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [5, 19]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"MFN2\", \"MAVS\", \"FUNDC2\", \"MARCH5\", \"REEP5\", \"BAK\", \"STING1\", \"HDAC6\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}