{"gene":"MIEF2","run_date":"2026-06-10T02:59:50","timeline":{"discoveries":[{"year":2011,"finding":"MiD49 (MIEF2) is anchored in the mitochondrial outer membrane, forms foci and rings around mitochondria similar to Drp1, directly recruits Drp1 to the mitochondrial surface, and its knockdown reduces Drp1 association leading to unopposed fusion.","method":"Immunofluorescence, knockdown, overexpression in cell lines","journal":"EMBO reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal localization and functional rescue experiments, replicated across multiple subsequent labs","pmids":["21508961"],"is_preprint":false},{"year":2013,"finding":"MiD49 can recruit Drp1 to and mediate mitochondrial fission independently of Fis1 and Mff; MiD49 and MiD51 are not targeted to peroxisomes (unlike Fis1 and Mff), conferring mitochondrial specificity. When artificially targeted to peroxisomes or lysosomes, MiD49 recruits Drp1 specifically to those organelles.","method":"Overexpression, knockdown, organelle targeting constructs, immunofluorescence in Fis1/Mff-null cells","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic null backgrounds used, multiple orthogonal approaches, replicated in separate lab (PMID:23283981)","pmids":["23921378","23283981"],"is_preprint":false},{"year":2013,"finding":"MiD49 overexpression blocks fission by sequestering Drp1 in an inactive state specifically at mitochondria (dominant-negative mechanism), causing unopposed fusion; mitochondrial elongation under MiD49 overexpression requires mitofusins 1 and 2.","method":"Overexpression, mitofusin double-knockout epistasis, live-cell imaging, immunofluorescence","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with mitofusin nulls, multiple orthogonal methods, independently confirmed","pmids":["23921378"],"is_preprint":false},{"year":2015,"finding":"Crystal structure of MiD49 at 2.4 Å resolution reveals a nucleotidyl transferase domain lacking a functional nucleotide-binding pocket (critical ADP-binding residues not conserved relative to MiD51), and identifies a surface loop that physically interacts with Drp1 and is necessary for Drp1 recruitment to mitochondria.","method":"X-ray crystallography (2.4 Å), surface entropy reduction mutagenesis, biochemical binding assays, functional rescue assays","journal":"Protein science","confidence":"High","confidence_rationale":"Tier 1 / Moderate — atomic structure with mutagenesis validation of Drp1-interacting loop, single lab but multiple orthogonal methods","pmids":["25581164"],"is_preprint":false},{"year":2015,"finding":"MARCH5, an E3 ubiquitin ligase on the outer mitochondrial membrane, selectively ubiquitinates MiD49 and targets it for proteasomal degradation; MARCH5 knockout leads to MiD49 accumulation and consequent Drp1-dependent mitochondrial fragmentation. MiD49 knockout in MARCH5-null cells reverses fragmentation and reduces apoptosis sensitivity.","method":"MARCH5 and MiD49 knockout cell lines, ubiquitination assays, proteasome inhibitor experiments, co-immunoprecipitation","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic double-knockout epistasis, ubiquitination assay, replicated in follow-up study (PMID:27932492)","pmids":["26564796"],"is_preprint":false},{"year":2016,"finding":"Drp1-dependent mitochondrial fission specifically through MiD49/MiD51 (but not Mff) is required for apoptotic cristae remodeling and cytochrome c release during intrinsic apoptosis; MiD49/51-KO cells completely resist cristae remodeling, a phenotype rescued by disrupting cristae structure (OPA1 depletion).","method":"MiD49/51 and Mff knockout cell lines, apoptosis assays, cytochrome c release assays, OPA1 depletion epistasis","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic knockout panel with multiple fission factor comparisons, epistasis with OPA1, multiple readouts","pmids":["26903540"],"is_preprint":false},{"year":2016,"finding":"MiD49 (and MiD51) loss confers increased resistance to intrinsic apoptotic stimuli; proximity-based biotin labeling shows close associations between MiD51, Mff, and Drp1 but not Fis1; MiD51 can suppress Mff-dependent enhancement of Drp1 GTPase activity.","method":"Gene-edited knockout cell lines, BioID proximity labeling, Drp1 GTPase activity assays, apoptosis resistance assays","journal":"Journal of cell science","confidence":"High","confidence_rationale":"Tier 2 / Strong — CRISPR knockouts, in vitro GTPase assay, proximity labeling, multiple orthogonal methods","pmids":["27076521"],"is_preprint":false},{"year":2016,"finding":"Drp1 and Mff negatively regulate MARCH5-mediated ubiquitination and degradation of MiD49; loss of Drp1 or Mff leads to reduced expression, shorter half-life, and increased ubiquitination of MiD49. These effects are abolished in Drp1/MARCH5 or Mff/MARCH5 double-null cells, indicating Drp1 and Mff act upstream of MARCH5 to protect MiD49 from degradation.","method":"Double-knockout cell lines, pulse-chase half-life assays, ubiquitination assays, co-immunoprecipitation","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic double-null epistasis, multiple biochemical assays, extends prior mechanistic framework","pmids":["27932492"],"is_preprint":false},{"year":2017,"finding":"Foxo3a directly targets and transcriptionally represses MIEF2 (MiD49) expression; MIEF2 knockdown reduces doxorubicin-induced mitochondrial fission and apoptosis in cardiomyocytes and in vivo, placing MIEF2 downstream of Foxo3a in a pathway mediating doxorubicin cardiotoxicity.","method":"Foxo3a overexpression/knockdown, ChIP or reporter assays for direct transcriptional targeting, MIEF2 knockdown, cardiac-specific Foxo3a transgenic mice","journal":"Free radical biology & medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo transgenic model with knockdown, but single lab and abstract does not detail ChIP/reporter validation explicitly","pmids":["28137654"],"is_preprint":false},{"year":2018,"finding":"Increased endogenous MiD49 (and MiD51) in pulmonary arterial hypertension accelerates Drp1-mediated mitotic fission; silencing MiD49/51 causes G1-phase cell cycle arrest through ERK1/2- and CDK4-dependent mechanisms and promotes mitochondrial fusion. MiD upregulation results from decreased miR-34a-3p expression.","method":"siRNA knockdown, flow cytometry cell cycle analysis, confocal imaging of mitochondrial morphology, miRNA manipulation, in vivo siRNA nebulization in monocrotaline-PAH rat model","journal":"Circulation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple cell-based and in vivo methods, single lab, mechanistic pathway partially defined","pmids":["29431643"],"is_preprint":false},{"year":2024,"finding":"Long-chain acyl-CoA (LCACA) activates MiD49 and MiD51 by inducing their oligomerization, which stimulates Drp1 GTPase activity. A point mutation in the putative nucleotide-binding pocket of MiD51 reduces LCACA binding and LCACA-induced oligomerization; the equivalent binding-pocket mutant of MiD49/51 fails to assemble into mitochondrial puncta or rescue MiD49/51 knockdown effects on mitochondrial length and Drp1 recruitment. MiD49/51 oligomers synergize with Mff but not actin filaments in Drp1 activation.","method":"In vitro Drp1 GTPase assay, oligomerization assays, point mutagenesis, cellular rescue experiments (mitochondrial length, Drp1 recruitment), oleic acid treatment","journal":"Nature cell biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with mutagenesis and cellular validation, multiple orthogonal methods in single rigorous study","pmids":["38594588"],"is_preprint":false},{"year":2023,"finding":"X-ray co-crystal structure of DRP1 bound to a small-molecule inhibitor that disrupts the DRP1/MiD49 protein-protein interaction reveals that the compound locks DRP1 in a closed conformation by induced dimerization, validating the MiD49-DRP1 interface as a druggable allosteric site.","method":"X-ray co-crystallography, in vitro mitochondrial fragmentation assay","journal":"ACS medicinal chemistry letters","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — structural evidence is rigorous but single study, limited functional follow-up in abstract","pmids":["37583827"],"is_preprint":false},{"year":2025,"finding":"MARCH5 directly interacts with MIEF2 to cause its ubiquitination and proteasomal degradation, regulating mitochondrial dynamics; MIEF2 overexpression reverses the reduction in lipid accumulation, cell death, mitochondrial fission, and MAM formation caused by MARCH5 overexpression, placing MIEF2 downstream of MARCH5 in alcoholic liver disease.","method":"Co-immunoprecipitation (MARCH5-MIEF2 interaction), gain/loss-of-function experiments, ubiquitination assays, in vivo zebrafish and mouse models","journal":"Phytomedicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, ubiquitination assay, genetic rescue epistasis, consistent with prior MARCH5-MiD49 mechanism (PMID:26564796)","pmids":["41353882"],"is_preprint":false},{"year":2025,"finding":"Dual knockdown of both MiD49 and MiD51 in cardiac cell lines subjected to simulated ischemia-reperfusion injury reduces cell death, inhibits mitochondrial fission, prevents mitochondrial permeability transition pore opening, and attenuates mitochondrial calcium overload; individual knockdown of either alone does not induce mitochondrial elongation or inhibit MPTP opening. Whole-body MiD49 knockout in mice modestly alters mitochondrial morphology but does not reduce myocardial infarct size.","method":"siRNA dual knockdown, cardiac cell line simulated IRI, MPTP assay, calcium measurement, MiD49 whole-body knockout mice with AMI model","journal":"Cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro and in vivo genetic approaches, multiple functional readouts, single lab","pmids":["41892348"],"is_preprint":false},{"year":2022,"finding":"Knockdown of MiD49 (and MiD51) impairs PINK1-Parkin-dependent mitophagy and CPT-1A-mediated fatty acid β-oxidation in rheumatoid arthritis fibroblast-like synoviocytes, and attenuates their aggressive phenotype; PINK1 and Parkin knockdown reverses the aggressive phenotype, placing MiDs upstream of the PINK1-Parkin mitophagy pathway.","method":"siRNA knockdown, protein-protein interaction analysis, mitophagy assays, fatty acid oxidation assays, CIA mouse model with shRNA","journal":"Free radical biology & medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic epistasis with PINK1/Parkin knockdown, in vitro and in vivo (CIA model), single lab","pmids":["40846102"],"is_preprint":false}],"current_model":"MIEF2 (MiD49) is a mitochondrial outer membrane protein that recruits cytosolic Drp1 to mitochondria via a direct surface loop interaction, promoting fission; its activity is regulated by long-chain acyl-CoA-induced oligomerization (activating Drp1 GTPase), by MARCH5-mediated ubiquitination and proteasomal degradation (which is itself negatively regulated by Drp1 and Mff), and transcriptionally by Foxo3a; specifically, MiD49/MiD51-dependent Drp1 fission (but not Mff-dependent fission) is required for apoptotic cristae remodeling and cytochrome c release, and the two MiDs must be co-inhibited to achieve cardioprotection, while MiD49 alone lacks an ADP-binding co-factor (unlike MiD51) and does not target peroxisomes, conferring mitochondrial specificity."},"narrative":{"mechanistic_narrative":"MIEF2 (MiD49) is a mitochondrial outer membrane adaptor that drives mitochondrial fission by directly recruiting the cytosolic GTPase Drp1 to the mitochondrial surface, where it forms foci and rings; its loss reduces Drp1 association and produces unopposed, mitofusin-dependent fusion [PMID:21508961, PMID:23921378]. MiD49 confers organelle specificity to fission, operating independently of Fis1 and Mff and, unlike those factors, sparing peroxisomes [PMID:23921378, PMID:23283981]. Structurally, MiD49 adopts a nucleotidyl transferase fold that has lost the functional nucleotide-binding pocket conserved in its paralog MiD51, but retains a surface loop that physically engages Drp1 and is required for Drp1 recruitment — an interface that is druggable, as a small molecule binding this site locks Drp1 in a closed, inactive dimer [PMID:25581164, PMID:37583827]. Beyond passive recruitment, MiD49 is allosterically activated by long-chain acyl-CoA, which induces its oligomerization and thereby stimulates Drp1 GTPase activity in synergy with Mff [PMID:38594588]. MiD49 abundance is set by MARCH5-mediated ubiquitination and proteasomal degradation, a process antagonized by Drp1 and Mff and by transcriptional repression through Foxo3a [PMID:26564796, PMID:27932492, PMID:28137654]. Functionally, MiD49/MiD51-dependent fission — but not Mff-dependent fission — is specifically required for apoptotic cristae remodeling and cytochrome c release, so that combined loss of the two MiDs confers resistance to intrinsic apoptosis and protects against cardiac and other stress injury [PMID:26903540, PMID:27076521, PMID:41892348]. MiD activity is further linked to cell-cycle progression in pulmonary arterial hypertension and to PINK1-Parkin mitophagy and fatty acid oxidation [PMID:29431643, PMID:40846102].","teleology":[{"year":2011,"claim":"Established MiD49 as a mitochondrial outer-membrane factor that physically recruits Drp1 to mitochondria, answering how cytosolic Drp1 is targeted to the fission machinery.","evidence":"Immunofluorescence, knockdown, and overexpression in cell lines","pmids":["21508961"],"confidence":"High","gaps":["Did not define the structural basis of the Drp1 interaction","Relationship to existing receptors Fis1 and Mff unresolved"]},{"year":2013,"claim":"Showed MiD49 mediates fission independently of Fis1 and Mff and confers mitochondrial specificity by not targeting peroxisomes, distinguishing it mechanistically from prior Drp1 receptors.","evidence":"Organelle-targeting constructs and immunofluorescence in Fis1/Mff-null cells; mitofusin double-knockout epistasis","pmids":["23921378","23283981"],"confidence":"High","gaps":["Why overexpression sequesters Drp1 in an inactive state rather than activating it not fully explained"]},{"year":2015,"claim":"Resolved the MiD49 atomic structure, revealing a nucleotidyl transferase fold lacking a functional nucleotide pocket and a defined surface loop required for Drp1 recruitment, explaining how MiD49 engages Drp1 and diverges from MiD51.","evidence":"X-ray crystallography at 2.4 Å with surface-entropy-reduction mutagenesis and binding/rescue assays","pmids":["25581164"],"confidence":"High","gaps":["Functional consequence of the absent nucleotide pocket left open at the time","Did not capture the Drp1-bound complex"]},{"year":2015,"claim":"Identified MARCH5 as the E3 ligase controlling MiD49 turnover, establishing ubiquitin-proteasome regulation of fission-receptor abundance and linking it to apoptosis sensitivity.","evidence":"MARCH5/MiD49 knockout cells, ubiquitination and proteasome-inhibitor assays, co-immunoprecipitation","pmids":["26564796"],"confidence":"High","gaps":["Signals triggering MARCH5-dependent MiD49 degradation not defined"]},{"year":2016,"claim":"Defined the apoptotic role of MiD-dependent fission, showing MiD49/51 but not Mff is required for cristae remodeling and cytochrome c release, separating fission receptors by downstream function.","evidence":"MiD49/51 and Mff knockout panels, apoptosis and cytochrome c assays, OPA1 depletion epistasis; BioID proximity labeling and Drp1 GTPase assays","pmids":["26903540","27076521"],"confidence":"High","gaps":["Molecular link between MiD-driven fission and inner-membrane cristae remodeling unresolved"]},{"year":2016,"claim":"Revealed a feedback loop in which Drp1 and Mff protect MiD49 from MARCH5-mediated degradation, coupling fission-machinery occupancy to receptor stability.","evidence":"Double-knockout cell lines, pulse-chase half-life and ubiquitination assays, co-immunoprecipitation","pmids":["27932492"],"confidence":"High","gaps":["Mechanism by which Drp1/Mff binding shields MiD49 from MARCH5 not structurally defined"]},{"year":2017,"claim":"Placed MIEF2 downstream of Foxo3a transcriptional repression in doxorubicin cardiotoxicity, adding transcriptional control to the regulation of fission.","evidence":"Foxo3a gain/loss-of-function, MIEF2 knockdown, cardiac-specific Foxo3a transgenic mice","pmids":["28137654"],"confidence":"Medium","gaps":["Direct ChIP/reporter validation of Foxo3a binding not detailed","Single lab"]},{"year":2018,"claim":"Connected MiD49/51 upregulation (via reduced miR-34a-3p) to Drp1-mediated mitotic fission and cell-cycle progression in pulmonary arterial hypertension.","evidence":"siRNA knockdown, cell-cycle flow cytometry, miRNA manipulation, monocrotaline-PAH rat siRNA nebulization","pmids":["29431643"],"confidence":"Medium","gaps":["ERK1/2- and CDK4-dependent link to fission only partially defined","Single lab"]},{"year":2024,"claim":"Identified long-chain acyl-CoA as an allosteric activator that drives MiD49/51 oligomerization to stimulate Drp1 GTPase activity, explaining how the nucleotide-pocket region functions despite lacking catalytic activity.","evidence":"In vitro Drp1 GTPase and oligomerization assays, point mutagenesis, oleic-acid cellular rescue","pmids":["38594588"],"confidence":"High","gaps":["Physiological conditions producing activating LCACA levels not defined","Whether endogenous lipid flux regulates MiD49 oligomerization in vivo unestablished"]},{"year":2023,"claim":"Validated the MiD49-Drp1 interface as a druggable allosteric site by capturing a Drp1-inhibitor co-structure that locks Drp1 in a closed dimer.","evidence":"X-ray co-crystallography and in vitro mitochondrial fragmentation assay","pmids":["37583827"],"confidence":"Medium","gaps":["Limited functional follow-up","Cellular efficacy and selectivity not detailed"]},{"year":2025,"claim":"Extended the MARCH5-MIEF2 degradation axis into alcoholic liver disease, where MIEF2 acts downstream of MARCH5 to control lipid accumulation, MAM formation, and cell death.","evidence":"Co-IP, ubiquitination assays, gain/loss-of-function rescue, zebrafish and mouse models","pmids":["41353882"],"confidence":"Medium","gaps":["Tissue-specific regulators of the MARCH5-MIEF2 axis unresolved","Single lab"]},{"year":2025,"claim":"Demonstrated that combined, but not individual, MiD49/51 inhibition is needed for cardioprotection in ischemia-reperfusion, showing functional redundancy between the two receptors in vivo.","evidence":"siRNA dual knockdown in cardiac cells, MPTP and calcium assays, MiD49 whole-body knockout mice in AMI model","pmids":["41892348"],"confidence":"Medium","gaps":["MiD49 single knockout effect on infarct size minimal — degree of redundancy not fully mapped","Single lab"]},{"year":2022,"claim":"Placed MiD49/51 upstream of PINK1-Parkin mitophagy and CPT-1A-mediated fatty acid oxidation in rheumatoid arthritis synoviocytes, linking fission receptors to mitochondrial quality control and metabolism.","evidence":"siRNA knockdown, mitophagy and fatty acid oxidation assays, CIA mouse model with shRNA","pmids":["40846102"],"confidence":"Medium","gaps":["Direct biochemical link between MiD-driven fission and PINK1-Parkin recruitment not established","Single lab"]},{"year":null,"claim":"How the multiple regulatory inputs on MiD49 — lipid-induced oligomerization, MARCH5 degradation, Drp1/Mff feedback, and transcriptional control — are integrated to time fission in vivo remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model coupling lipid sensing, stability, and transcriptional control","Structure of the active MiD49-Drp1 oligomer on the membrane undetermined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,3]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[10,6]}],"localization":[{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[0,1,4]}],"pathway":[{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[0,1,10]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[5,6]}],"complexes":[],"partners":["DNM1L","MARCH5","MIEF1","MFF"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q96C03","full_name":"Mitochondrial dynamics protein MID49","aliases":["Mitochondrial dynamics protein of 49 kDa","Mitochondrial elongation factor 2","Smith-Magenis syndrome chromosomal region candidate gene 7 protein"],"length_aa":454,"mass_kda":49.3,"function":"Mitochondrial outer membrane protein involved in the regulation of mitochondrial organization (PubMed:29361167). It is required for mitochondrial fission and promotes the recruitment and association of the fission mediator dynamin-related protein 1 (DNM1L) to the mitochondrial surface independently of the mitochondrial fission FIS1 and MFF proteins. Regulates DNM1L GTPase activity","subcellular_location":"Mitochondrion outer membrane","url":"https://www.uniprot.org/uniprotkb/Q96C03/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/MIEF2","classification":"Not Classified","n_dependent_lines":10,"n_total_lines":1208,"dependency_fraction":0.008278145695364239},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/MIEF2","total_profiled":1310},"omim":[{"mim_id":"619024","title":"COMBINED OXIDATIVE PHOSPHORYLATION DEFICIENCY 49; COXPD49","url":"https://www.omim.org/entry/619024"},{"mim_id":"615498","title":"MITOCHONDRIAL ELONGATION FACTOR 2; MIEF2","url":"https://www.omim.org/entry/615498"},{"mim_id":"615497","title":"MITOCHONDRIAL ELONGATION FACTOR 1; MIEF1","url":"https://www.omim.org/entry/615497"},{"mim_id":"609060","title":"COMBINED OXIDATIVE PHOSPHORYLATION DEFICIENCY 1; COXPD1","url":"https://www.omim.org/entry/609060"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/MIEF2"},"hgnc":{"alias_symbol":["MGC23130","MiD49","D3B"],"prev_symbol":["SMCR7"]},"alphafold":{"accession":"Q96C03","domains":[{"cath_id":"3.30.460.90","chopping":"142-334","consensus_level":"medium","plddt":90.8393,"start":142,"end":334},{"cath_id":"1.10.1410.40","chopping":"351-454","consensus_level":"medium","plddt":90.816,"start":351,"end":454}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96C03","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q96C03-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q96C03-F1-predicted_aligned_error_v6.png","plddt_mean":76.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=MIEF2","jax_strain_url":"https://www.jax.org/strain/search?query=MIEF2"},"sequence":{"accession":"Q96C03","fasta_url":"https://rest.uniprot.org/uniprotkb/Q96C03.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q96C03/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q96C03"}},"corpus_meta":[{"pmid":"23283981","id":"PMC_23283981","title":"Fis1, Mff, MiD49, and MiD51 mediate Drp1 recruitment in mitochondrial fission.","date":"2013","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/23283981","citation_count":1008,"is_preprint":false},{"pmid":"21508961","id":"PMC_21508961","title":"MiD49 and MiD51, new components of the mitochondrial fission machinery.","date":"2011","source":"EMBO reports","url":"https://pubmed.ncbi.nlm.nih.gov/21508961","citation_count":518,"is_preprint":false},{"pmid":"27076521","id":"PMC_27076521","title":"Cooperative and independent roles of the Drp1 adaptors Mff, MiD49 and MiD51 in mitochondrial fission.","date":"2016","source":"Journal of cell science","url":"https://pubmed.ncbi.nlm.nih.gov/27076521","citation_count":265,"is_preprint":false},{"pmid":"23921378","id":"PMC_23921378","title":"Adaptor proteins MiD49 and MiD51 can act independently of Mff and Fis1 in Drp1 recruitment and are specific for mitochondrial fission.","date":"2013","source":"The Journal of biological 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biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/27932492","citation_count":79,"is_preprint":false},{"pmid":"28137654","id":"PMC_28137654","title":"Foxo3a inhibits mitochondrial fission and protects against doxorubicin-induced cardiotoxicity by suppressing MIEF2.","date":"2017","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/28137654","citation_count":45,"is_preprint":false},{"pmid":"25581164","id":"PMC_25581164","title":"Crystal structure and functional analysis of MiD49, a receptor for the mitochondrial fission protein Drp1.","date":"2015","source":"Protein science : a publication of the Protein Society","url":"https://pubmed.ncbi.nlm.nih.gov/25581164","citation_count":44,"is_preprint":false},{"pmid":"30338314","id":"PMC_30338314","title":"MiD49 and MiD51: New mediators of mitochondrial fission and novel targets for cardioprotection.","date":"2018","source":"Conditioning 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MiD51.","date":"2024","source":"Nature cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/38594588","citation_count":20,"is_preprint":false},{"pmid":"38203413","id":"PMC_38203413","title":"Dynamin-Related Protein 1 Binding Partners MiD49 and MiD51 Increased Mitochondrial Fission In Vitro and Atherosclerosis in High-Fat-Diet-Fed ApoE-/- Mice.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/38203413","citation_count":13,"is_preprint":false},{"pmid":"32323835","id":"PMC_32323835","title":"Downregulation of MiD49 contributes to tumor growth and metastasis of human pancreatic cancer.","date":"2020","source":"Oncology reports","url":"https://pubmed.ncbi.nlm.nih.gov/32323835","citation_count":11,"is_preprint":false},{"pmid":"36106106","id":"PMC_36106106","title":"CRISPR-based knockout screening identifies the loss of MIEF2 to enhance oxaliplatin resistance in colorectal cancer through inhibiting the mitochondrial apoptosis pathway.","date":"2022","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/36106106","citation_count":8,"is_preprint":false},{"pmid":"37583827","id":"PMC_37583827","title":"Discovery of Potent Allosteric DRP1 Inhibitors by Disrupting Protein-Protein Interaction with MiD49.","date":"2023","source":"ACS medicinal chemistry letters","url":"https://pubmed.ncbi.nlm.nih.gov/37583827","citation_count":7,"is_preprint":false},{"pmid":"38779765","id":"PMC_38779765","title":"PRR34-AS1 promotes mitochondrial division and glycolytic reprogramming in hepatocellular carcinoma cells through upregulation of MIEF2.","date":"2024","source":"Acta biochimica et biophysica Sinica","url":"https://pubmed.ncbi.nlm.nih.gov/38779765","citation_count":3,"is_preprint":false},{"pmid":"40846102","id":"PMC_40846102","title":"Knockdown of MiD49 and MiD51 alleviates collagen-induced arthritis and suppresses mitophagy and fatty acid oxidation (FAO) in rheumatoid arthritis fibroblast-like synoviocytes.","date":"2025","source":"Free radical biology & medicine","url":"https://pubmed.ncbi.nlm.nih.gov/40846102","citation_count":2,"is_preprint":false},{"pmid":"39639566","id":"PMC_39639566","title":"The Role of MIEF2 in Cisplatin Sensitivity in KIRP Patients: Insights from Four-gene Mitochondrial Fusion RNA Markers.","date":"2024","source":"Technology in cancer research & treatment","url":"https://pubmed.ncbi.nlm.nih.gov/39639566","citation_count":1,"is_preprint":false},{"pmid":"41353882","id":"PMC_41353882","title":"MARCH5-mediated MIEF2 ubiquitination and degradation contribute to gigantol to against hepatic steatosis and mitochondrial fission in alcoholic liver disease.","date":"2025","source":"Phytomedicine : international journal of phytotherapy and phytopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/41353882","citation_count":0,"is_preprint":false},{"pmid":"41892348","id":"PMC_41892348","title":"Mitochondrial Dynamic Proteins MiD49 and MiD51 as Novel Targets of Cardioprotection.","date":"2026","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/41892348","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":14871,"output_tokens":3876,"usd":0.051376,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11654,"output_tokens":4052,"usd":0.079785,"stage2_stop_reason":"end_turn"},"total_usd":0.131161,"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\": 2011,\n      \"finding\": \"MiD49 (MIEF2) is anchored in the mitochondrial outer membrane, forms foci and rings around mitochondria similar to Drp1, directly recruits Drp1 to the mitochondrial surface, and its knockdown reduces Drp1 association leading to unopposed fusion.\",\n      \"method\": \"Immunofluorescence, knockdown, overexpression in cell lines\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal localization and functional rescue experiments, replicated across multiple subsequent labs\",\n      \"pmids\": [\"21508961\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"MiD49 can recruit Drp1 to and mediate mitochondrial fission independently of Fis1 and Mff; MiD49 and MiD51 are not targeted to peroxisomes (unlike Fis1 and Mff), conferring mitochondrial specificity. When artificially targeted to peroxisomes or lysosomes, MiD49 recruits Drp1 specifically to those organelles.\",\n      \"method\": \"Overexpression, knockdown, organelle targeting constructs, immunofluorescence in Fis1/Mff-null cells\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic null backgrounds used, multiple orthogonal approaches, replicated in separate lab (PMID:23283981)\",\n      \"pmids\": [\"23921378\", \"23283981\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"MiD49 overexpression blocks fission by sequestering Drp1 in an inactive state specifically at mitochondria (dominant-negative mechanism), causing unopposed fusion; mitochondrial elongation under MiD49 overexpression requires mitofusins 1 and 2.\",\n      \"method\": \"Overexpression, mitofusin double-knockout epistasis, live-cell imaging, immunofluorescence\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with mitofusin nulls, multiple orthogonal methods, independently confirmed\",\n      \"pmids\": [\"23921378\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Crystal structure of MiD49 at 2.4 Å resolution reveals a nucleotidyl transferase domain lacking a functional nucleotide-binding pocket (critical ADP-binding residues not conserved relative to MiD51), and identifies a surface loop that physically interacts with Drp1 and is necessary for Drp1 recruitment to mitochondria.\",\n      \"method\": \"X-ray crystallography (2.4 Å), surface entropy reduction mutagenesis, biochemical binding assays, functional rescue assays\",\n      \"journal\": \"Protein science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — atomic structure with mutagenesis validation of Drp1-interacting loop, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"25581164\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"MARCH5, an E3 ubiquitin ligase on the outer mitochondrial membrane, selectively ubiquitinates MiD49 and targets it for proteasomal degradation; MARCH5 knockout leads to MiD49 accumulation and consequent Drp1-dependent mitochondrial fragmentation. MiD49 knockout in MARCH5-null cells reverses fragmentation and reduces apoptosis sensitivity.\",\n      \"method\": \"MARCH5 and MiD49 knockout cell lines, ubiquitination assays, proteasome inhibitor experiments, co-immunoprecipitation\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic double-knockout epistasis, ubiquitination assay, replicated in follow-up study (PMID:27932492)\",\n      \"pmids\": [\"26564796\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Drp1-dependent mitochondrial fission specifically through MiD49/MiD51 (but not Mff) is required for apoptotic cristae remodeling and cytochrome c release during intrinsic apoptosis; MiD49/51-KO cells completely resist cristae remodeling, a phenotype rescued by disrupting cristae structure (OPA1 depletion).\",\n      \"method\": \"MiD49/51 and Mff knockout cell lines, apoptosis assays, cytochrome c release assays, OPA1 depletion epistasis\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic knockout panel with multiple fission factor comparisons, epistasis with OPA1, multiple readouts\",\n      \"pmids\": [\"26903540\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"MiD49 (and MiD51) loss confers increased resistance to intrinsic apoptotic stimuli; proximity-based biotin labeling shows close associations between MiD51, Mff, and Drp1 but not Fis1; MiD51 can suppress Mff-dependent enhancement of Drp1 GTPase activity.\",\n      \"method\": \"Gene-edited knockout cell lines, BioID proximity labeling, Drp1 GTPase activity assays, apoptosis resistance assays\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — CRISPR knockouts, in vitro GTPase assay, proximity labeling, multiple orthogonal methods\",\n      \"pmids\": [\"27076521\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Drp1 and Mff negatively regulate MARCH5-mediated ubiquitination and degradation of MiD49; loss of Drp1 or Mff leads to reduced expression, shorter half-life, and increased ubiquitination of MiD49. These effects are abolished in Drp1/MARCH5 or Mff/MARCH5 double-null cells, indicating Drp1 and Mff act upstream of MARCH5 to protect MiD49 from degradation.\",\n      \"method\": \"Double-knockout cell lines, pulse-chase half-life assays, ubiquitination assays, co-immunoprecipitation\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic double-null epistasis, multiple biochemical assays, extends prior mechanistic framework\",\n      \"pmids\": [\"27932492\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Foxo3a directly targets and transcriptionally represses MIEF2 (MiD49) expression; MIEF2 knockdown reduces doxorubicin-induced mitochondrial fission and apoptosis in cardiomyocytes and in vivo, placing MIEF2 downstream of Foxo3a in a pathway mediating doxorubicin cardiotoxicity.\",\n      \"method\": \"Foxo3a overexpression/knockdown, ChIP or reporter assays for direct transcriptional targeting, MIEF2 knockdown, cardiac-specific Foxo3a transgenic mice\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo transgenic model with knockdown, but single lab and abstract does not detail ChIP/reporter validation explicitly\",\n      \"pmids\": [\"28137654\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Increased endogenous MiD49 (and MiD51) in pulmonary arterial hypertension accelerates Drp1-mediated mitotic fission; silencing MiD49/51 causes G1-phase cell cycle arrest through ERK1/2- and CDK4-dependent mechanisms and promotes mitochondrial fusion. MiD upregulation results from decreased miR-34a-3p expression.\",\n      \"method\": \"siRNA knockdown, flow cytometry cell cycle analysis, confocal imaging of mitochondrial morphology, miRNA manipulation, in vivo siRNA nebulization in monocrotaline-PAH rat model\",\n      \"journal\": \"Circulation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple cell-based and in vivo methods, single lab, mechanistic pathway partially defined\",\n      \"pmids\": [\"29431643\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Long-chain acyl-CoA (LCACA) activates MiD49 and MiD51 by inducing their oligomerization, which stimulates Drp1 GTPase activity. A point mutation in the putative nucleotide-binding pocket of MiD51 reduces LCACA binding and LCACA-induced oligomerization; the equivalent binding-pocket mutant of MiD49/51 fails to assemble into mitochondrial puncta or rescue MiD49/51 knockdown effects on mitochondrial length and Drp1 recruitment. MiD49/51 oligomers synergize with Mff but not actin filaments in Drp1 activation.\",\n      \"method\": \"In vitro Drp1 GTPase assay, oligomerization assays, point mutagenesis, cellular rescue experiments (mitochondrial length, Drp1 recruitment), oleic acid treatment\",\n      \"journal\": \"Nature cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with mutagenesis and cellular validation, multiple orthogonal methods in single rigorous study\",\n      \"pmids\": [\"38594588\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"X-ray co-crystal structure of DRP1 bound to a small-molecule inhibitor that disrupts the DRP1/MiD49 protein-protein interaction reveals that the compound locks DRP1 in a closed conformation by induced dimerization, validating the MiD49-DRP1 interface as a druggable allosteric site.\",\n      \"method\": \"X-ray co-crystallography, in vitro mitochondrial fragmentation assay\",\n      \"journal\": \"ACS medicinal chemistry letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — structural evidence is rigorous but single study, limited functional follow-up in abstract\",\n      \"pmids\": [\"37583827\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"MARCH5 directly interacts with MIEF2 to cause its ubiquitination and proteasomal degradation, regulating mitochondrial dynamics; MIEF2 overexpression reverses the reduction in lipid accumulation, cell death, mitochondrial fission, and MAM formation caused by MARCH5 overexpression, placing MIEF2 downstream of MARCH5 in alcoholic liver disease.\",\n      \"method\": \"Co-immunoprecipitation (MARCH5-MIEF2 interaction), gain/loss-of-function experiments, ubiquitination assays, in vivo zebrafish and mouse models\",\n      \"journal\": \"Phytomedicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, ubiquitination assay, genetic rescue epistasis, consistent with prior MARCH5-MiD49 mechanism (PMID:26564796)\",\n      \"pmids\": [\"41353882\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Dual knockdown of both MiD49 and MiD51 in cardiac cell lines subjected to simulated ischemia-reperfusion injury reduces cell death, inhibits mitochondrial fission, prevents mitochondrial permeability transition pore opening, and attenuates mitochondrial calcium overload; individual knockdown of either alone does not induce mitochondrial elongation or inhibit MPTP opening. Whole-body MiD49 knockout in mice modestly alters mitochondrial morphology but does not reduce myocardial infarct size.\",\n      \"method\": \"siRNA dual knockdown, cardiac cell line simulated IRI, MPTP assay, calcium measurement, MiD49 whole-body knockout mice with AMI model\",\n      \"journal\": \"Cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro and in vivo genetic approaches, multiple functional readouts, single lab\",\n      \"pmids\": [\"41892348\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Knockdown of MiD49 (and MiD51) impairs PINK1-Parkin-dependent mitophagy and CPT-1A-mediated fatty acid β-oxidation in rheumatoid arthritis fibroblast-like synoviocytes, and attenuates their aggressive phenotype; PINK1 and Parkin knockdown reverses the aggressive phenotype, placing MiDs upstream of the PINK1-Parkin mitophagy pathway.\",\n      \"method\": \"siRNA knockdown, protein-protein interaction analysis, mitophagy assays, fatty acid oxidation assays, CIA mouse model with shRNA\",\n      \"journal\": \"Free radical biology & medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic epistasis with PINK1/Parkin knockdown, in vitro and in vivo (CIA model), single lab\",\n      \"pmids\": [\"40846102\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"MIEF2 (MiD49) is a mitochondrial outer membrane protein that recruits cytosolic Drp1 to mitochondria via a direct surface loop interaction, promoting fission; its activity is regulated by long-chain acyl-CoA-induced oligomerization (activating Drp1 GTPase), by MARCH5-mediated ubiquitination and proteasomal degradation (which is itself negatively regulated by Drp1 and Mff), and transcriptionally by Foxo3a; specifically, MiD49/MiD51-dependent Drp1 fission (but not Mff-dependent fission) is required for apoptotic cristae remodeling and cytochrome c release, and the two MiDs must be co-inhibited to achieve cardioprotection, while MiD49 alone lacks an ADP-binding co-factor (unlike MiD51) and does not target peroxisomes, conferring mitochondrial specificity.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"MIEF2 (MiD49) is a mitochondrial outer membrane adaptor that drives mitochondrial fission by directly recruiting the cytosolic GTPase Drp1 to the mitochondrial surface, where it forms foci and rings; its loss reduces Drp1 association and produces unopposed, mitofusin-dependent fusion [#0, #2]. MiD49 confers organelle specificity to fission, operating independently of Fis1 and Mff and, unlike those factors, sparing peroxisomes [#1]. Structurally, MiD49 adopts a nucleotidyl transferase fold that has lost the functional nucleotide-binding pocket conserved in its paralog MiD51, but retains a surface loop that physically engages Drp1 and is required for Drp1 recruitment — an interface that is druggable, as a small molecule binding this site locks Drp1 in a closed, inactive dimer [#3, #11]. Beyond passive recruitment, MiD49 is allosterically activated by long-chain acyl-CoA, which induces its oligomerization and thereby stimulates Drp1 GTPase activity in synergy with Mff [#10]. MiD49 abundance is set by MARCH5-mediated ubiquitination and proteasomal degradation, a process antagonized by Drp1 and Mff and by transcriptional repression through Foxo3a [#4, #7, #8]. Functionally, MiD49/MiD51-dependent fission — but not Mff-dependent fission — is specifically required for apoptotic cristae remodeling and cytochrome c release, so that combined loss of the two MiDs confers resistance to intrinsic apoptosis and protects against cardiac and other stress injury [#5, #6, #13]. MiD activity is further linked to cell-cycle progression in pulmonary arterial hypertension and to PINK1-Parkin mitophagy and fatty acid oxidation [#9, #14].\",\n  \"teleology\": [\n    {\n      \"year\": 2011,\n      \"claim\": \"Established MiD49 as a mitochondrial outer-membrane factor that physically recruits Drp1 to mitochondria, answering how cytosolic Drp1 is targeted to the fission machinery.\",\n      \"evidence\": \"Immunofluorescence, knockdown, and overexpression in cell lines\",\n      \"pmids\": [\"21508961\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the structural basis of the Drp1 interaction\", \"Relationship to existing receptors Fis1 and Mff unresolved\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed MiD49 mediates fission independently of Fis1 and Mff and confers mitochondrial specificity by not targeting peroxisomes, distinguishing it mechanistically from prior Drp1 receptors.\",\n      \"evidence\": \"Organelle-targeting constructs and immunofluorescence in Fis1/Mff-null cells; mitofusin double-knockout epistasis\",\n      \"pmids\": [\"23921378\", \"23283981\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Why overexpression sequesters Drp1 in an inactive state rather than activating it not fully explained\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Resolved the MiD49 atomic structure, revealing a nucleotidyl transferase fold lacking a functional nucleotide pocket and a defined surface loop required for Drp1 recruitment, explaining how MiD49 engages Drp1 and diverges from MiD51.\",\n      \"evidence\": \"X-ray crystallography at 2.4 Å with surface-entropy-reduction mutagenesis and binding/rescue assays\",\n      \"pmids\": [\"25581164\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional consequence of the absent nucleotide pocket left open at the time\", \"Did not capture the Drp1-bound complex\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Identified MARCH5 as the E3 ligase controlling MiD49 turnover, establishing ubiquitin-proteasome regulation of fission-receptor abundance and linking it to apoptosis sensitivity.\",\n      \"evidence\": \"MARCH5/MiD49 knockout cells, ubiquitination and proteasome-inhibitor assays, co-immunoprecipitation\",\n      \"pmids\": [\"26564796\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Signals triggering MARCH5-dependent MiD49 degradation not defined\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Defined the apoptotic role of MiD-dependent fission, showing MiD49/51 but not Mff is required for cristae remodeling and cytochrome c release, separating fission receptors by downstream function.\",\n      \"evidence\": \"MiD49/51 and Mff knockout panels, apoptosis and cytochrome c assays, OPA1 depletion epistasis; BioID proximity labeling and Drp1 GTPase assays\",\n      \"pmids\": [\"26903540\", \"27076521\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular link between MiD-driven fission and inner-membrane cristae remodeling unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Revealed a feedback loop in which Drp1 and Mff protect MiD49 from MARCH5-mediated degradation, coupling fission-machinery occupancy to receptor stability.\",\n      \"evidence\": \"Double-knockout cell lines, pulse-chase half-life and ubiquitination assays, co-immunoprecipitation\",\n      \"pmids\": [\"27932492\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which Drp1/Mff binding shields MiD49 from MARCH5 not structurally defined\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Placed MIEF2 downstream of Foxo3a transcriptional repression in doxorubicin cardiotoxicity, adding transcriptional control to the regulation of fission.\",\n      \"evidence\": \"Foxo3a gain/loss-of-function, MIEF2 knockdown, cardiac-specific Foxo3a transgenic mice\",\n      \"pmids\": [\"28137654\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct ChIP/reporter validation of Foxo3a binding not detailed\", \"Single lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Connected MiD49/51 upregulation (via reduced miR-34a-3p) to Drp1-mediated mitotic fission and cell-cycle progression in pulmonary arterial hypertension.\",\n      \"evidence\": \"siRNA knockdown, cell-cycle flow cytometry, miRNA manipulation, monocrotaline-PAH rat siRNA nebulization\",\n      \"pmids\": [\"29431643\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"ERK1/2- and CDK4-dependent link to fission only partially defined\", \"Single lab\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified long-chain acyl-CoA as an allosteric activator that drives MiD49/51 oligomerization to stimulate Drp1 GTPase activity, explaining how the nucleotide-pocket region functions despite lacking catalytic activity.\",\n      \"evidence\": \"In vitro Drp1 GTPase and oligomerization assays, point mutagenesis, oleic-acid cellular rescue\",\n      \"pmids\": [\"38594588\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological conditions producing activating LCACA levels not defined\", \"Whether endogenous lipid flux regulates MiD49 oligomerization in vivo unestablished\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Validated the MiD49-Drp1 interface as a druggable allosteric site by capturing a Drp1-inhibitor co-structure that locks Drp1 in a closed dimer.\",\n      \"evidence\": \"X-ray co-crystallography and in vitro mitochondrial fragmentation assay\",\n      \"pmids\": [\"37583827\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Limited functional follow-up\", \"Cellular efficacy and selectivity not detailed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended the MARCH5-MIEF2 degradation axis into alcoholic liver disease, where MIEF2 acts downstream of MARCH5 to control lipid accumulation, MAM formation, and cell death.\",\n      \"evidence\": \"Co-IP, ubiquitination assays, gain/loss-of-function rescue, zebrafish and mouse models\",\n      \"pmids\": [\"41353882\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Tissue-specific regulators of the MARCH5-MIEF2 axis unresolved\", \"Single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrated that combined, but not individual, MiD49/51 inhibition is needed for cardioprotection in ischemia-reperfusion, showing functional redundancy between the two receptors in vivo.\",\n      \"evidence\": \"siRNA dual knockdown in cardiac cells, MPTP and calcium assays, MiD49 whole-body knockout mice in AMI model\",\n      \"pmids\": [\"41892348\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"MiD49 single knockout effect on infarct size minimal — degree of redundancy not fully mapped\", \"Single lab\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Placed MiD49/51 upstream of PINK1-Parkin mitophagy and CPT-1A-mediated fatty acid oxidation in rheumatoid arthritis synoviocytes, linking fission receptors to mitochondrial quality control and metabolism.\",\n      \"evidence\": \"siRNA knockdown, mitophagy and fatty acid oxidation assays, CIA mouse model with shRNA\",\n      \"pmids\": [\"40846102\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct biochemical link between MiD-driven fission and PINK1-Parkin recruitment not established\", \"Single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the multiple regulatory inputs on MiD49 — lipid-induced oligomerization, MARCH5 degradation, Drp1/Mff feedback, and transcriptional control — are integrated to time fission in vivo remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model coupling lipid sensing, stability, and transcriptional control\", \"Structure of the active MiD49-Drp1 oligomer on the membrane undetermined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 3]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [10, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005741\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [0, 1, 4]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [0, 1, 10]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [5, 6]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"DNM1L\", \"MARCH5\", \"MIEF1\", \"MFF\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}