{"gene":"TOMM70","run_date":"2026-06-10T10:51:55","timeline":{"discoveries":[{"year":2003,"finding":"Cytosolic chaperones Hsp90 and Hsp70 dock onto a specialized TPR domain in Tom70 at the outer mitochondrial membrane, delivering preproteins to the receptor for subsequent membrane translocation dependent on the Hsp90 ATPase. Disruption of chaperone/Tom70 recognition inhibits preprotein import into mitochondria. In mammals Hsp90 is used; in yeast Hsp70 is the primary partner.","method":"Co-immunoprecipitation, cross-linking, in vitro import assay, purified cytosolic fragment of Tom70","journal":"Cell","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — reconstituted interactions, in vitro import assays with chaperone docking, replicated across mammalian and yeast systems in one study","pmids":["12526792"],"is_preprint":false},{"year":1997,"finding":"The purified cytosolic domain of Tom70 preferentially binds preproteins with internal targeting signals (not N-terminal presequences), and a synthetic presequence peptide does not compete for Tom70 binding (unlike Tom20/Tom22), demonstrating distinct binding specificity among import receptors.","method":"Purified recombinant cytosolic receptor domains, in vitro preprotein binding assay, competition with synthetic presequence peptide","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — reconstituted in vitro binding with purified proteins; finding replicated in multiple independent studies","pmids":["9252394"],"is_preprint":false},{"year":1999,"finding":"Tom70 binds to multiple segments within internal-targeting-signal-containing preproteins (e.g., phosphate carrier) distributed throughout the mature protein, but does not efficiently bind presequence segments. Both charged and uncharged peptides serve as Tom70 binding sites, indicating charge is not a critical determinant of internal targeting sequences.","method":"Cellulose-bound peptide scans (SPOT synthesis), binding of purified cytosolic receptor domains to overlapping 13-mer peptides","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — systematic peptide-scan binding assay with purified protein; corroborates and extends prior in vitro reconstitution work","pmids":["10347216"],"is_preprint":false},{"year":2000,"finding":"A stably folded 25 kDa core domain in the middle portion of Tom70, containing two of its seven TPR motifs, is sufficient for binding non-cleavable and cleavable preproteins with internal targeting signals with the same specificity as full-length receptor. Competition studies showed at least one additional interaction site exists in full-length Tom70.","method":"Domain deletion/truncation, recombinant protein expression and purification, preprotein binding competition assay","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with purified protein fragments and competition assays; single lab but multiple orthogonal methods","pmids":["11054285"],"is_preprint":false},{"year":2006,"finding":"Hsp90 plays a role in import steps subsequent to Tom70 targeting: geldanamycin (N-terminal ATP-site inhibitor) had no effect on preprotein-Hsp90 interactions or Hsp90 docking onto Tom70 but impaired formation of preprotein import intermediates at the outer membrane, whereas novobiocin (C-terminal inhibitor) blocked Hsp90 cross-linking to preprotein and co-precipitation with Tom70.","method":"Hsp90 inhibitor treatment (geldanamycin, novobiocin), cross-linking, co-precipitation with purified cytosolic Tom70 fragment, in vitro import assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — in vitro import assays plus cross-linking and co-precipitation with inhibitor comparisons; multiple orthogonal methods, single lab","pmids":["16968702"],"is_preprint":false},{"year":2007,"finding":"Multiple Hsp40-related J-domain proteins (DJA1, DJA2, DJA4) specifically bind preproteins (via their C-terminal regions) and cooperate with Hsc70 and Hsp90 in Tom70-dependent mitochondrial import. DJA dominant-negative mutants lacking J-domains blocked Hsc70 binding to preprotein and impaired mitochondrial import. The Hsp90 cochaperones p23 and Aha1 also regulated Hsp90-preprotein interactions.","method":"Mass spectrometry identification of chaperone complexes, dominant-negative mutant expression, Hsc70 ATPase activation assays, in vitro import assay in HeLa cells","journal":"Molecular biology of the cell","confidence":"High","confidence_rationale":"Tier 2 / Moderate — MS interactome combined with functional dominant-negative experiments and import assays; single lab, multiple orthogonal methods","pmids":["17596514"],"is_preprint":false},{"year":2009,"finding":"Tom70 recognizes a set of presequence-containing precursor proteins whose mature regions are aggregate-prone; the receptor domain of Tom70 prevents aggregate formation of these substrates, maintaining their solubility for efficient transfer to downstream import machinery. Tom70 thus functions as a docking site for both cytosolic chaperones and aggregate-prone substrates.","method":"Proteome-wide in vitro import assay, aggregation prevention assay with purified Tom70 receptor domain","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — in vitro import with proteome-wide scope and direct aggregation prevention assay; multiple orthogonal methods","pmids":["19767391"],"is_preprint":false},{"year":2009,"finding":"Analytical ultracentrifugation and SAXS reveal that the cytosolic domain of Tom70 exists as an elongated monomer. Fluorescence anisotropy shows the monomer can simultaneously bind chaperone and precursor peptides; chaperone binding does not alter preprotein affinity or detectable shape change in the monomer. Molecular modeling indicates chaperone binding is incompatible with Tom70 dimer formation.","method":"Analytical ultracentrifugation, solution SAXS, fluorescence anisotropy, molecular modeling","journal":"Journal of molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — multiple biophysical techniques (AUC, SAXS, fluorescence anisotropy) in a single study establishing monomer state and functional binding","pmids":["19358854"],"is_preprint":false},{"year":2010,"finding":"Human Tom70 functions as a monomer; the cytosolic fragment exists in equilibrium between monomer and dimer. A point mutation at the predicted dimer interface increased monomeric fraction and significantly enhanced preprotein targeting, whereas chaperone docking was unchanged. Cross-linking of full-length Tom70 on mitochondrial membranes shows little evidence of homodimers, indicating monomers are the functional unit.","method":"Analytical ultracentrifugation, cross-linking, size-exclusion chromatography, multi-angle light scattering, site-directed mutagenesis, in vitro preprotein targeting assay","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — multiple biophysical methods plus mutagenesis and functional import assay; single lab","pmids":["20504278"],"is_preprint":false},{"year":2010,"finding":"Tom70 interacts with MAVS upon RNA virus infection and recruits TBK1/IRF3 to mitochondria via binding of Tom70's clamp domain (R192) to the C-terminal EEVD motif of Hsp90. Disruption of this interaction or mislocalization of Tom70 sharply impairs TBK1 and IRF3 activation. Tom70 acts as a critical adaptor linking MAVS to TBK1/IRF3.","method":"Co-immunoprecipitation, ectopic expression, siRNA knockdown, domain mutation (R192), reporter gene assay for IRF3-mediated gene expression","journal":"Cell research","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal co-IP with domain-specific mutation and functional reporter assays; single lab but multiple orthogonal methods","pmids":["20628368"],"is_preprint":false},{"year":2011,"finding":"Tom20 interacts with the TPR clamp domain of Tom70 via a conserved C-terminal DDVE motif, competing with the chaperones Hsc70 and Hsp90 for Tom70 binding. This interaction was detected by cross-linking of endogenous proteins on HeLa mitochondria, co-precipitation, and NMR titrations. The functional interaction may facilitate preprotein release from chaperones by competition, constituting a chaperone displacement mechanism.","method":"Protein cross-linking on mitochondria, co-precipitation, NMR titration, surface plasmon resonance, site-directed mutagenesis of TPR clamp domain and DDVE motif","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — reciprocal co-precipitation, cross-linking of endogenous proteins, NMR, SPR, and mutagenesis; multiple orthogonal methods in a single study","pmids":["21771790"],"is_preprint":false},{"year":2015,"finding":"Tom70 directly binds presequence peptides via a dedicated groove. A single point mutation M551R in this pocket reduces presequence binding affinity ten-fold and selectively impairs import of presequence-containing precursor Mdl1, but not the ADP/ATP carrier, demonstrating that Tom70 contributes to the presequence import pathway.","method":"Fluorescence binding assay with presequence peptides, site-directed mutagenesis (M551R), in vitro import assay","journal":"Biochimica et biophysica acta","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstituted binding with mutagenesis and functional import assay; single lab but rigorous mechanistic validation","pmids":["25958336"],"is_preprint":false},{"year":2016,"finding":"Cross-linking/mass spectrometry identified a novel region of contact between the C-terminal domain of Hsp90 and Tom70 beyond the canonical MEEVD/TPR interaction. A molecular model validated by SAXS and hydrogen/deuterium exchange indicates only one MEEVD motif within dimeric Hsp90 contacts Tom70. ITC confirmed the secondary interaction site affects preprotein import.","method":"Cross-linking/mass spectrometry, isothermal titration calorimetry, SAXS, hydrogen/deuterium exchange mass spectrometry, in vitro mitochondrial import assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — multiple orthogonal biophysical methods (XL-MS, ITC, SAXS, HDX-MS) and functional validation in a single study","pmids":["27402847"],"is_preprint":false},{"year":2018,"finding":"Many preproteins contain internal MTS-like signals (iMTS-Ls) in their mature regions that mediate binding to Tom70. Using Atp1 as model substrate, iMTS-Ls mediate Tom70 binding and can target proteins to mitochondria when presented at the N-terminus. Import of preproteins with high iMTS-L content is significantly impaired in the absence of Tom70, supporting a stepping-stone model where Tom70-mediated internal binding improves import efficiency.","method":"In silico prediction of iMTS-Ls, in vitro import assay with Tom70 deletion, N-terminal fusion targeting experiments, binding assay","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 1-2 / Moderate — computational prediction combined with functional in vitro import assays and direct binding experiments; single lab but multiple methods","pmids":["29382700"],"is_preprint":false},{"year":2018,"finding":"TOM70 clusters in distinct OMM foci that frequently overlap with ER-mitochondria contact sites. TOM70 depletion specifically impairs IP3-linked ER-to-mitochondria Ca2+ transfer by interacting with IP3 receptors (IP3R3) and favoring their functional recruitment close to mitochondria. Reduced constitutive Ca2+ transfer dampens mitochondrial respiration, affects bioenergetics, induces autophagy, and inhibits proliferation. TOM20 depletion did not reproduce this phenotype.","method":"Live-cell imaging/super-resolution microscopy for localization, siRNA knockdown, Ca2+ imaging, co-immunoprecipitation with IP3R3, mitochondrial respiration assay","journal":"Current biology : CB","confidence":"High","confidence_rationale":"Tier 2 / Moderate — direct localization linked to functional consequence, reciprocal co-IP with IP3R3, functional Ca2+ and respiration measurements; multiple orthogonal methods, single lab","pmids":["29395920"],"is_preprint":false},{"year":2021,"finding":"The PERK kinase promotes cristae formation by increasing TOM70-assisted mitochondrial import of MIC19 (a MICOS complex subunit). Cold stress/β-adrenergic stimulation activates PERK, which phosphorylates OGT; phosphorylated OGT O-GlcNAcylates TOM70 on Ser94, enhancing MIC19 protein import and promoting cristae formation and respiration. CK2α-mediated phosphorylation of TOM70 Ser94 opposes this by decreasing MIC19 import.","method":"In vivo and in vitro reconstitution, OGT glycosylation assay, site-directed mutagenesis (Ser94), in vitro mitochondrial import assay, cryo-EM of cristae, genetic epistasis with PERK/OGT/CK2α","journal":"Cell metabolism","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vivo and in vitro reconstitution with site-specific mutagenesis, identified PTM writer (OGT) and eraser (CK2α) with functional import readout","pmids":["33592173"],"is_preprint":false},{"year":2021,"finding":"Crystal structure of SARS-CoV-2 Orf9b in complex with the cytosolic segment of human TOM70 resolved to 2.2 Å. A central helical portion of Orf9b occupies the deep hydrophobic pocket of TOM70 C-terminal domain (CTD). The Orf9b dimer does not bind TOM70, but a monomeric C-peptide of Orf9b binds with nanomolar affinity (ITC). Orf9b binding to TOM70 CTD allosterically reduces Hsp90 EEVD binding to TOM70 NTD by ~29-fold, providing a structural mechanism for immune evasion.","method":"X-ray crystallography (2.2 Å), isothermal titration calorimetry, synthetic peptide binding assay","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 1 / Strong — high-resolution crystal structure combined with ITC quantification of binding affinities and allosteric effect; single study with multiple rigorous methods","pmids":["33990585"],"is_preprint":false},{"year":2021,"finding":"The predominant function of Tom70 in vivo is to recruit cytosolic chaperones to the outer mitochondrial membrane, rather than to serve as a mitochondrion-specifying targeting receptor. Tethering an unrelated chaperone-binding domain onto the mitochondrial surface complemented most defects caused by Tom70 deletion, including reduction of proteotoxicity of hydrophobic inner membrane proteins. The chaperone-binding activity protects the cytosol from mitoprotein-induced stress.","method":"In vivo high-content screens, in vitro import experiments, Tom70 deletion combined with heterologous chaperone-binding domain tethering, proteotoxicity assays","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic complementation with heterologous domain plus in vivo high-content screens and in vitro import; multiple orthogonal methods, robust mechanistic conclusion","pmids":["33826901"],"is_preprint":false},{"year":2021,"finding":"SARS-CoV-2 Orf9b binding to TOM70 inhibits Hsp90 recruitment to TOM70 and suppresses downstream chaperone-associated signaling. Orf9b Ser53 and TOM70 Glu477 are crucial residues for Orf9b-TOM70 association; the phosphomimetic Orf9b S53E shows drastically reduced TOM70 binding and does not inhibit Hsp90 recruitment, indicating phosphorylation regulates complex formation. A second binding site at the TOM70 N-terminal TPR domain was also identified.","method":"Site-directed mutagenesis, co-precipitation, chaperone recruitment assay, phosphomimetic variant analysis","journal":"International journal of molecular sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis and functional binding assays; single lab, single study","pmids":["34502139"],"is_preprint":false},{"year":2013,"finding":"Tom70 is essential for PINK1 import into mitochondria. Using a cell-free import system, PINK1 import was found to depend on Tom70 but not on Tom40 (the main import channel). PINK1 is not processed by the mitochondrial processing peptidase, indicating a unique import pathway that is independent of the TOM core complex but requires Tom70.","method":"Cell-free mitochondrial import assay, Tom70 knockdown, Tom40 knockdown/depletion, processing peptidase assay","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — cell-free import assay with specific receptor depletions; single lab, single study","pmids":["23472196"],"is_preprint":false},{"year":2006,"finding":"Mcl-1 interacts with the mitochondrial import receptor Tom70 via an internal EELD domain. A Tom70 antibody blocking Mcl-1-Tom70 interaction inhibits mitochondrial import of Mcl-1 in vitro. Tom70 knockdown significantly reduces Mcl-1 mitochondrial targeting; mutation of the EELD motif attenuates Tom70 binding and mitochondrial targeting.","method":"Co-immunoprecipitation, in vitro import assay with blocking antibody, siRNA knockdown, site-directed mutagenesis of EELD motif","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP with functional import assay and mutagenesis; single lab, multiple orthogonal methods","pmids":["16822835"],"is_preprint":false},{"year":2015,"finding":"Tom70 recruits IRF3 to mitochondria via Hsp90 upon Sendai virus infection, forming a dynamic complex Tom70/Hsp90/IRF3/Bax. Bax interacts specifically with IRF3 upon virus infection, and relocation of Bax to mitochondria via this complex induces cytochrome c leakage and apoptosis. IKK-i is essential for this apoptosis whereas TBK1 is dispensable.","method":"Co-immunoprecipitation, subcellular fractionation, cytochrome c release assay, siRNA knockdown, ectopic expression","journal":"Journal of virology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — co-IP-based complex identification with functional apoptosis readout; single lab, multiple methods","pmids":["25609812"],"is_preprint":false},{"year":2002,"finding":"Rat Tom70 (OM70) functions as a receptor for preproteins with internal targeting signals (ADP/ATP carrier, rTOM40) but not for cleavable presequence-containing proteins. Blue native PAGE and immunoprecipitation show OM70 is loosely associated with the ~400 kDa TOM complex containing rTOM22 and rTOM40. Yeast two-hybrid showed OM70 interacts with rTOM20 and rTOM22 through cytoplasmic domains. The N-terminal 66-residue region including a transmembrane domain and arginine cluster is sufficient for mitochondrial targeting.","method":"Antibody inhibition of import, blue native PAGE, immunoprecipitation, yeast two-hybrid, in organello import assay","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple complementary methods (BN-PAGE, co-IP, import inhibition, yeast two-hybrid); single lab","pmids":["11956321"],"is_preprint":false},{"year":2011,"finding":"Stoichiometry analysis revealed that one monomer of Tom70 interacts per dimer of the C-terminal domain of Hsp90 (containing the EEVD motif), with a KD of ~360 nM. This stoichiometry and thermodynamic profile differ from those of other TPR co-chaperones, indicating a distinct interaction mechanism between Tom70 and Hsp90.","method":"Isothermal titration calorimetry, size-exclusion chromatography, biophysical analysis","journal":"Archives of biochemistry and biophysics","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — rigorous biophysical quantification but single lab and single method (ITC)","pmids":["21781956"],"is_preprint":false},{"year":2007,"finding":"In yeast, Tom70 and its paralogue Tom71 are required for localization of the soluble F-box protein Mfb1 to mitochondria. Mfb1 interacts with Tom71 in vivo and binds to mitochondria through Tom70 in vitro. Cells lacking both Tom70 and Tom71 display aberrant mitochondrial morphology (short tubules and aggregates) similar to mfb1-null mutants, revealing an unexpected role for Tom70 in recruiting soluble proteins to the mitochondrial surface.","method":"In vivo co-immunoprecipitation (Mfb1-Tom71), in vitro mitochondrial binding assay, fluorescence microscopy of mitochondrial morphology, gene deletion","journal":"EMBO reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo co-IP and in vitro binding with genetic morphology phenotype; single lab, two orthogonal methods","pmids":["18007655"],"is_preprint":false},{"year":2022,"finding":"In budding yeast, Tom70 moonlights as a transcriptional regulator of mitochondrial protein genes, and this transcription-regulatory role is conserved in Drosophila. The dual roles in transcription and import allow cells to coordinate mitochondrial biogenesis without compromising cytosolic proteostasis. Age-related reduction of Tom70 is associated with loss of mitochondrial membrane potential, mtDNA, and mitochondrial proteins; Tom70 overexpression extends replicative lifespan.","method":"Genetic deletion and overexpression, transcriptional reporter assays, Drosophila genetic experiments, mitochondrial membrane potential and mtDNA measurements","journal":"eLife","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic experiments in two model organisms with transcriptional and physiological readouts; single lab","pmids":["35234609"],"is_preprint":false},{"year":2025,"finding":"The 2.04 Å crystal structure of unliganded human TOM70 cytosolic domain reveals two distinct conformations—open and closed—within the asymmetric unit. HDX-MS and MD simulations confirm these states in solution. Network analyses identify a continuum of motion linking the NTD (chaperone-binding) and CTD (preprotein-binding) via helices α7, α8, and α25. Orf9b engagement of the CTD interrupts this allosteric network, stabilizing a partially-closed intermediate and dampening NTD dynamics.","method":"X-ray crystallography (2.04 Å), hydrogen-deuterium exchange mass spectrometry, molecular dynamics simulations, principal component analysis, dynamical network analysis","journal":"Structure","confidence":"High","confidence_rationale":"Tier 1 / Moderate — high-resolution crystal structure combined with HDX-MS and MD simulations; multiple orthogonal methods in a single rigorous study","pmids":["41386227"],"is_preprint":false},{"year":2025,"finding":"The cytosolic chaperone PPID (cyclophilin 40/Cyp40) drives OMM insertion of TOM70 via its PPIase activity and C-terminal tetratricopeptide repeats, which show specificity towards TOM70 core and C-tail domains. This PPID-mediated TOM70 insertion regulates thermogenic/respiratory function in brown adipocytes and protects against diet-induced obesity in mice.","method":"In vitro reconstitution of OMM insertion, domain mutagenesis (PPIase activity mutation, TPR deletion), brown adipocyte functional assays, mouse obesity model","journal":"Nature cell biology","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution of insertion mechanism with domain-specific mutagenesis and in vivo physiological validation; multiple orthogonal methods","pmids":["39753947"],"is_preprint":false},{"year":2025,"finding":"In zebrafish, a missense mutation in tomm70 (affecting a conserved isoleucine corresponding to human TOMM70 p.Ile554Phe) impairs the interaction of Tomm70 with the ER sterol transporter Lam6, impairs mitochondrial transport to axons and dendrites, and causes demyelination of large-calibre spinal cord axons. These defects recapitulate features of hereditary spastic paraplegia.","method":"Zebrafish missense mutant model, co-immunoprecipitation (Tomm70-Lam6 interaction), fluorescence microscopy of mitochondrial axonal transport, electron microscopy of myelin","journal":"Disease models & mechanisms","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — animal model with co-IP-identified protein interaction and direct localization/morphology readouts; single lab","pmids":["40151845"],"is_preprint":false},{"year":2022,"finding":"ORF9b forms a complex with TOM70 that prevents full-length Hsp90 from binding to TOM70. The isolated C-terminal domain of Hsp90 is also blocked by ORF9b occupying TOM70. Biophysical characterization shows ORF9b homodimer has ~22 kDa and random coil conformation, while the ORF9b-TOM70 complex is folded and more thermally stable than free TOM70.","method":"SEC-MALS, circular dichroism, differential scanning calorimetry, protein-protein interaction assay (co-expression and co-purification), pull-down","journal":"Biochimie","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — biophysical characterization with multiple methods but single lab and no in-cell functional validation","pmids":["35643212"],"is_preprint":false},{"year":2025,"finding":"Using cryo-EM, 19F NMR, and ITC, Orf9b inhibits Hsp90 binding to Tom70 through a bipartite steric-blocking mechanism: the helix and intrinsically disordered tail of Orf9b sterically block two distinct structural units of Hsp90 from accessing Tom70. Orf9b primarily slows the association kinetics between Hsp90 and Tom70, rather than acting through allosteric conformational changes in Tom70.","method":"Cryo-electron microscopy, 19F NMR spectroscopy, isothermal titration calorimetry, kinetic binding analysis","journal":"bioRxiv","confidence":"High","confidence_rationale":"Tier 1 / Moderate — cryo-EM structure combined with NMR and ITC kinetic analysis; multiple rigorous orthogonal methods in a single study","pmids":["41332678"],"is_preprint":true},{"year":2025,"finding":"In yeast meiosis, Tom70 concentrates around the Gametogenesis-Uninherited Nuclear Compartment (GUNC) and tethers mitochondria to the nuclear envelope by recruiting the tethering protein Cnm1, independently of its canonical mitochondrial import function. Loss of Tom70 disrupts sequestration of nuclear pore complexes into the GUNC, and loss of Cnm1 partially phenocopies tom70Δ.","method":"Fluorescence live-cell imaging, gene deletion (tom70Δ, cnm1Δ), genetic epistasis, subcellular fractionation","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct localization imaging linked to functional nuclear inheritance readout with genetic epistasis; preprint, single lab","pmids":["41332789"],"is_preprint":true},{"year":2023,"finding":"ASFV protein p17 promotes mitophagy by facilitating the interaction of autophagy receptor SQSTM1 with TOMM70. Co-immunoprecipitation/mass spectrometry identified TOMM70 as a p17-interacting protein. The p17-TOMM70 interaction enhances SQSTM1 binding to TOMM70, leading to mitochondrial engulfment by autophagosomes and degradation of mitochondrial antiviral signaling proteins.","method":"Co-immunoprecipitation/mass spectrometry, co-immunoprecipitation, mitophagy assay (autophagosome engulfment, mitochondrial counts), siRNA knockdown","journal":"Virulence","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — MS-identified interaction followed by co-IP and functional mitophagy assays; single lab","pmids":["37442088"],"is_preprint":false},{"year":2014,"finding":"Tom70 downregulation in pathological hypertrophic hearts causes defective mitochondrial import of OPA1, triggering intracellular oxidative stress and pathological cardiac hypertrophy. Overexpression of Tom70 confers resistance to pro-hypertrophic insults. Tom70 thus acts as a molecular switch orchestrating hypertrophic stress and mitochondrial responses.","method":"siRNA knockdown and lentiviral overexpression in vivo/in vitro, mitochondrial import assay for OPA1, ROS measurement, echocardiography","journal":"Cell research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss- and gain-of-function with identified substrate (OPA1) and defined cellular phenotype; single lab","pmids":["25022898"],"is_preprint":false},{"year":2020,"finding":"De novo loss-of-function variants in TOMM70 (p.Thr607Ile, p.Ile554Phe) cause neurological impairment. In a Drosophila model replacing Tom70 with human TOMM70, both variants provided significantly less rescue of lethality than reference TOMM70. RNAi knockdown of Tom70 in the developing eye caused roughening and synaptic transmission defects rescued by reference but not variant TOMM70.","method":"CRISPR-Cas9 humanized Drosophila model, UAS-GAL4 rescue assay, RNAi knockdown, synaptic transmission electrophysiology","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vivo genetic rescue assay with multiple alleles in Drosophila model; single lab","pmids":["32356556"],"is_preprint":false},{"year":2017,"finding":"Tom70 governs the mitochondrial localization of MICU1 (mitochondrial Ca2+ uptake regulator). Tom70 knockdown reduces mitochondrial MICU1 content, worsens MI/R-induced mitochondrial Ca2+ overload, and exacerbates myocardial injury. Tom70 overexpression preserves mitochondrial MICU1, which is required for Tom70's cardioprotective effects.","method":"siRNA knockdown, lentiviral overexpression, mitochondrial fractionation, Ca2+ measurement, in vivo MI/R mouse model","journal":"Cell death & disease","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — loss- and gain-of-function with mitochondrial fractionation and Ca2+ measurement; single lab","pmids":["28703803"],"is_preprint":false},{"year":2024,"finding":"Proximity labeling (APEX2) shows that human TOMM70 and TOMM20 have differential association profiles with RNA-binding proteins (RBPs) and translation factors, with several RBPs (including SYNJ2BP) preferentially associating with TOMM20 over TOMM70. During translation stress (puromycin), RBP association increases specifically with TOMM20, suggesting TOMM70 does not share this role in preserving hemostasis during translation stress.","method":"APEX2-based proximity labeling, quantitative mass spectrometry, puromycin translation inhibition","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — proximity labeling proteomics with defined conditions; preprint, single lab, single method","pmids":["bio_10.1101_2024.10.25.620316"],"is_preprint":true}],"current_model":"TOMM70 is an outer mitochondrial membrane receptor composed of 11 TPR motifs organized into an N-terminal chaperone-binding domain and a C-terminal preprotein-binding domain; it functions primarily by recruiting cytosolic Hsp70/Hsc70 and Hsp90 (via the TPR clamp/EEVD interaction) to deliver hydrophobic, internally-targeted preproteins to the mitochondrial import machinery, with its import efficiency enhanced by O-GlcNAcylation at Ser94 (written by OGT downstream of PERK); it also mediates ER-mitochondria Ca2+ transfer via IP3R3, acts as an innate immune adaptor linking MAVS to TBK1/IRF3 through Hsp90 recruitment, and is subverted by SARS-CoV-2 Orf9b, which occupies the CTD pocket and allosterically suppresses Hsp90 docking to impair interferon signaling."},"narrative":{"mechanistic_narrative":"TOMM70 is a tetratricopeptide-repeat (TPR) receptor of the mitochondrial outer membrane whose principal function is to recruit cytosolic chaperones to the organelle surface and thereby deliver hydrophobic, internally-targeted preproteins into the import machinery [PMID:12526792, PMID:33826901]. Distinct from presequence receptors, its cytosolic domain preferentially binds internal targeting signals (iMTS-like segments) distributed throughout the mature regions of substrates rather than N-terminal presequences [PMID:9252394, PMID:10347216, PMID:29382700], and a folded core domain containing TPR motifs is sufficient for this internal-signal recognition [PMID:11054285]; the receptor also keeps aggregate-prone precursors soluble during transfer [PMID:19767391]. Chaperone docking occurs through the TPR clamp/EEVD interaction, in which a single MEEVD motif of dimeric Hsp90 engages the monomeric receptor [PMID:12526792, PMID:27402847, PMID:21781956], with Hsp70/Hsc70, Hsp40-family J-proteins, and Hsp90 cochaperones cooperating in import [PMID:17596514]; the functional receptor is a monomer, and chaperone binding is incompatible with dimerization [PMID:19358854, PMID:20504278]. The cytosolic domain interconverts between open and closed conformations linking the chaperone-binding N-terminal domain to the preprotein-binding C-terminal domain through an allosteric helical network [PMID:41386227], and competition by Tom20's C-terminal DDVE motif at the clamp provides a chaperone-displacement mechanism [PMID:21771790]. TOMM70 functions as an innate-immune adaptor, interacting with MAVS upon RNA-virus infection and recruiting TBK1/IRF3 to mitochondria via its clamp-domain (R192)-Hsp90 EEVD interaction [PMID:20628368]; SARS-CoV-2 Orf9b subverts this by occupying the CTD hydrophobic pocket and blocking Hsp90 docking to suppress interferon signaling [PMID:33990585, PMID:41332678]. The receptor additionally organizes ER-mitochondria contacts, recruiting IP3R3 to drive Ca2+ transfer that supports respiration [PMID:29395920], and its import activity is tuned by O-GlcNAcylation of Ser94 written by OGT downstream of PERK and opposed by CK2α phosphorylation [PMID:33592173]. De novo loss-of-function variants in TOMM70 (p.Thr607Ile, p.Ile554Phe) cause neurological impairment [PMID:32356556].","teleology":[{"year":1997,"claim":"Established that Tom70 is a functionally distinct import receptor, answering whether all receptors recognize the same targeting signal: it binds internal targeting signals, not N-terminal presequences.","evidence":"in vitro preprotein binding and presequence-peptide competition with purified cytosolic receptor domains","pmids":["9252394"],"confidence":"High","gaps":["Did not map the binding determinants within internal signals","Chaperone involvement in delivery not yet addressed"]},{"year":1999,"claim":"Defined the nature of Tom70 binding sites within substrates, showing internal targeting signals are dispersed and not charge-dependent.","evidence":"cellulose-bound peptide scans (SPOT) with purified receptor domains","pmids":["10347216"],"confidence":"High","gaps":["Structural basis of recognition not resolved","Did not address how multiple sites are engaged in vivo"]},{"year":2000,"claim":"Localized the substrate-binding activity to a discrete folded core domain, narrowing which TPR motifs carry recognition.","evidence":"domain truncation, recombinant fragment purification, competition binding assays","pmids":["11054285"],"confidence":"High","gaps":["Identity of the additional interaction site left open","Relation to chaperone-binding region not defined"]},{"year":2003,"claim":"Resolved how preproteins reach the receptor, establishing chaperone-assisted delivery: Hsp90/Hsp70 dock onto a specialized TPR domain and hand off preproteins for Hsp90-ATPase-dependent translocation.","evidence":"co-IP, cross-linking, in vitro import with purified cytosolic Tom70 fragment across mammalian and yeast systems","pmids":["12526792"],"confidence":"High","gaps":["Stoichiometry of the chaperone-receptor complex not defined","Step at which chaperones release substrate unclear"]},{"year":2006,"claim":"Dissected when Hsp90 acts during import, showing it operates at post-targeting steps via its C-terminal region rather than at the docking step.","evidence":"Hsp90 N- vs C-terminal inhibitor comparison, cross-linking, co-precipitation, in vitro import","pmids":["16968702"],"confidence":"High","gaps":["Mechanism of preprotein release into the translocase not resolved"]},{"year":2006,"claim":"Extended the substrate range to a regulatory protein, showing Mcl-1 uses an internal EELD motif for Tom70-dependent mitochondrial targeting.","evidence":"co-IP, blocking-antibody import assay, siRNA, EELD-motif mutagenesis","pmids":["16822835"],"confidence":"Medium","gaps":["Single lab","Functional consequence of Mcl-1 import for apoptosis not addressed here"]},{"year":2007,"claim":"Defined the broader chaperone network feeding the receptor, identifying DJA J-proteins and Hsp90 cochaperones (p23, Aha1) as cooperating factors.","evidence":"MS interactome, dominant-negative mutants, Hsc70 ATPase assays, in vitro import in HeLa","pmids":["17596514"],"confidence":"High","gaps":["Hierarchy/order of cochaperone action not fully ordered","Substrate selectivity of individual DJAs unresolved"]},{"year":2009,"claim":"Established the oligomeric state and simultaneous-binding capacity of the cytosolic domain, showing it is an elongated monomer binding chaperone and precursor at once.","evidence":"analytical ultracentrifugation, SAXS, fluorescence anisotropy, modeling","pmids":["19358854"],"confidence":"High","gaps":["In-membrane oligomeric state of full-length receptor not directly tested here"]},{"year":2009,"claim":"Reframed Tom70 as a solubility chaperone, showing its receptor domain prevents aggregation of presequence-containing aggregate-prone substrates.","evidence":"proteome-wide in vitro import and aggregation-prevention assays with purified receptor domain","pmids":["19767391"],"confidence":"High","gaps":["Did not quantify in vivo contribution relative to chaperone recruitment"]},{"year":2010,"claim":"Confirmed the monomer as the functional import unit in the human receptor, linking dimer disruption to enhanced targeting.","evidence":"AUC, cross-linking, SEC-MALS, dimer-interface mutagenesis, in vitro targeting","pmids":["20504278"],"confidence":"High","gaps":["Physiological regulation of monomer-dimer equilibrium unknown"]},{"year":2010,"claim":"Identified a non-import role, establishing Tom70 as an innate-immune adaptor that recruits TBK1/IRF3 to mitochondria downstream of MAVS via Hsp90.","evidence":"reciprocal co-IP, siRNA, R192 clamp mutation, IRF3 reporter assay","pmids":["20628368"],"confidence":"High","gaps":["How chaperone recruitment for import versus signaling is partitioned unclear"]},{"year":2011,"claim":"Defined a chaperone-displacement mechanism, showing Tom20's DDVE motif competes with chaperones at the TPR clamp to promote preprotein handoff.","evidence":"endogenous cross-linking, co-precipitation, NMR titration, SPR, mutagenesis","pmids":["21771790"],"confidence":"High","gaps":["Kinetics of handoff during active import not measured"]},{"year":2011,"claim":"Quantified the Hsp90-Tom70 interaction, establishing a 1 monomer:1 Hsp90-dimer stoichiometry distinct from other TPR cochaperones.","evidence":"ITC, SEC, biophysical analysis","pmids":["21781956"],"confidence":"Medium","gaps":["Single method (ITC)-dominated","Functional import consequence not tested in this study"]},{"year":2013,"claim":"Showed receptor specialization for an unusual substrate, establishing that PINK1 import requires Tom70 but bypasses the Tom40 channel and processing peptidase.","evidence":"cell-free import with Tom70 and Tom40 depletions, processing assay","pmids":["23472196"],"confidence":"Medium","gaps":["Single study","Translocation route for PINK1 beyond Tom70 unresolved"]},{"year":2014,"claim":"Linked Tom70 import function to organ physiology, showing its loss impairs OPA1 import and drives oxidative stress and cardiac hypertrophy.","evidence":"in vivo/in vitro knockdown and overexpression, OPA1 import assay, ROS, echocardiography","pmids":["25022898"],"confidence":"Medium","gaps":["Single lab","Direct vs indirect cause of hypertrophy not fully separated"]},{"year":2015,"claim":"Revealed that Tom70 also contributes to the presequence pathway, identifying a dedicated presequence-binding groove.","evidence":"fluorescence presequence-peptide binding, M551R mutagenesis, in vitro import","pmids":["25958336"],"confidence":"High","gaps":["Quantitative contribution to presequence import in vivo not defined"]},{"year":2015,"claim":"Expanded the immune-adaptor role to apoptosis, showing a Tom70/Hsp90/IRF3/Bax complex drives cytochrome c release via IKK-i.","evidence":"co-IP, fractionation, cytochrome c release, siRNA, ectopic expression","pmids":["25609812"],"confidence":"Medium","gaps":["Single lab","Trigger distinguishing pro-apoptotic vs pro-IFN outcomes unresolved"]},{"year":2016,"claim":"Refined the chaperone-receptor architecture, defining a secondary Hsp90 CTD-Tom70 contact beyond the canonical MEEVD/TPR site that affects import.","evidence":"XL-MS, ITC, SAXS, HDX-MS, in vitro import","pmids":["27402847"],"confidence":"High","gaps":["Role of secondary site in vivo not isolated"]},{"year":2017,"claim":"Connected the receptor to mitochondrial Ca2+ handling, showing Tom70 governs MICU1 localization and cardioprotection during ischemia/reperfusion.","evidence":"knockdown/overexpression, mitochondrial fractionation, Ca2+ measurement, MI/R mouse model","pmids":["28703803"],"confidence":"Medium","gaps":["Single lab","Whether MICU1 is a direct import substrate not established"]},{"year":2018,"claim":"Formalized the internal-signal recognition logic with the iMTS-L/stepping-stone model, showing internal MTS-like signals mediate Tom70 binding and improve import efficiency.","evidence":"iMTS-L prediction, in vitro import with Tom70 deletion, N-terminal fusion targeting, binding assays","pmids":["29382700"],"confidence":"High","gaps":["Predictive rules for which substrates strictly require Tom70 incomplete"]},{"year":2018,"claim":"Established a membrane-contact-site role, showing TOM70 recruits IP3R3 at ER-mitochondria junctions to sustain Ca2+ transfer and bioenergetics.","evidence":"super-resolution imaging, siRNA, Ca2+ imaging, IP3R3 co-IP, respiration assays","pmids":["29395920"],"confidence":"High","gaps":["Structural basis of TOM70-IP3R3 interaction not defined"]},{"year":2021,"claim":"Resolved the predominant in vivo function, demonstrating that chaperone recruitment (not mitochondrion-specifying targeting) is the core activity protecting the cytosol from mitoprotein stress.","evidence":"in vivo high-content screens, heterologous chaperone-binding domain tethering complementation, proteotoxicity assays","pmids":["33826901"],"confidence":"High","gaps":["Substrates strictly dependent on targeting specificity not enumerated"]},{"year":2021,"claim":"Identified post-translational tuning of import, showing PERK-OGT-driven O-GlcNAcylation of Ser94 enhances MIC19 import and cristae formation, opposed by CK2α.","evidence":"in vivo/in vitro reconstitution, OGT glycosylation assay, Ser94 mutagenesis, cristae cryo-EM, PERK/OGT/CK2α epistasis","pmids":["33592173"],"confidence":"High","gaps":["Generality of Ser94 modification across substrates beyond MIC19 unclear"]},{"year":2021,"claim":"Provided the structural mechanism of viral subversion, showing SARS-CoV-2 Orf9b occupies the CTD pocket and allosterically suppresses Hsp90 EEVD binding ~29-fold.","evidence":"2.2 Å crystal structure, ITC, synthetic peptide binding","pmids":["33990585"],"confidence":"High","gaps":["In-cell quantification of interferon suppression not in this study"]},{"year":2021,"claim":"Mapped the Orf9b-TOM70 interface and its phospho-regulation, identifying Orf9b Ser53 / TOM70 Glu477 as critical and a second NTD binding site.","evidence":"mutagenesis, co-precipitation, phosphomimetic (S53E) analysis, chaperone recruitment assay","pmids":["34502139"],"confidence":"Medium","gaps":["Single lab/single study","Physiological kinase for Orf9b S53 not identified"]},{"year":2022,"claim":"Biophysically characterized the Orf9b-TOM70 complex, confirming Orf9b blocks both full-length and isolated CTD Hsp90 and stabilizes TOM70.","evidence":"SEC-MALS, CD, DSC, co-expression/co-purification, pull-down","pmids":["35643212"],"confidence":"Medium","gaps":["No in-cell functional validation"]},{"year":2022,"claim":"Uncovered a moonlighting transcriptional role, showing Tom70 regulates mitochondrial-protein genes and influences replicative lifespan, conserved to Drosophila.","evidence":"yeast/Drosophila genetics, transcriptional reporters, membrane-potential/mtDNA measurements, lifespan assay","pmids":["35234609"],"confidence":"Medium","gaps":["Single lab","Mechanism by which an OMM receptor influences transcription unresolved"]},{"year":2023,"claim":"Showed viral exploitation for mitophagy, where ASFV p17 bridges SQSTM1 to TOMM70 to degrade antiviral signaling proteins.","evidence":"co-IP/MS, co-IP, mitophagy assays, siRNA","pmids":["37442088"],"confidence":"Medium","gaps":["Single lab","Whether endogenous mitophagy uses TOMM70 similarly unknown"]},{"year":2025,"claim":"Defined the conformational dynamics underlying allostery, showing open/closed states connect NTD and CTD and that Orf9b interrupts this network.","evidence":"2.04 Å crystal structure, HDX-MS, MD simulations, network analysis","pmids":["41386227"],"confidence":"High","gaps":["Functional import readout for conformational states not directly measured"]},{"year":2025,"claim":"Identified the biogenesis pathway of the receptor itself, showing PPID/Cyp40 drives TOM70 OMM insertion with physiological consequences for thermogenesis.","evidence":"in vitro insertion reconstitution, PPIase/TPR mutagenesis, brown adipocyte assays, mouse obesity model","pmids":["39753947"],"confidence":"High","gaps":["Whether other insertases contribute in parallel not resolved"]},{"year":2025,"claim":"Connected a specific human-mutation residue to disease mechanism in vivo, showing the Ile554-equivalent variant disrupts a Lam6 interaction and causes axonal/myelin defects resembling hereditary spastic paraplegia.","evidence":"zebrafish missense model, Tomm70-Lam6 co-IP, mitochondrial transport imaging, myelin EM","pmids":["40151845"],"confidence":"Medium","gaps":["Single lab","Mechanistic link between Lam6 loss and demyelination incomplete"]},{"year":2025,"claim":"Revealed a nuclear-tethering moonlighting function, showing Tom70 recruits Cnm1 to tether mitochondria to the nuclear envelope during yeast meiosis independent of import.","evidence":"live-cell imaging, tom70Δ/cnm1Δ deletion, genetic epistasis, fractionation (preprint)","pmids":["41332789"],"confidence":"Medium","gaps":["Preprint","Conservation in mammals not tested"]},{"year":null,"claim":"It remains unresolved how a single receptor partitions its activities among canonical chaperone-mediated import, ER/nuclear contact-site tethering, transcriptional regulation, and immune signaling, and what governs the switch between them.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model integrating import vs signaling vs tethering roles","Regulatory inputs (PTMs, partners) that select among functions not mapped","In vivo human disease mechanism only partially defined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[0,17]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,5,10,12]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,9,14]},{"term_id":"GO:0038024","term_label":"cargo receptor 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Recognizes and mediates the translocation of mitochondrial preproteins from the cytosol into the mitochondria in a chaperone dependent manner (PubMed:12526792, PubMed:35025629). Mediates TBK1 and IRF3 activation induced by MAVS in response to Sendai virus infection and promotes host antiviral responses during virus infection (PubMed:20628368, PubMed:25609812, PubMed:32728199). Upon Sendai virus infection, recruits HSP90AA1:IRF3:BAX in mitochondrion and the complex induces apoptosis (PubMed:25609812)","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/O94826/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/TOMM70","classification":"Not 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Disruption of chaperone/Tom70 recognition inhibits preprotein import into mitochondria. In mammals Hsp90 is used; in yeast Hsp70 is the primary partner.\",\n      \"method\": \"Co-immunoprecipitation, cross-linking, in vitro import assay, purified cytosolic fragment of Tom70\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — reconstituted interactions, in vitro import assays with chaperone docking, replicated across mammalian and yeast systems in one study\",\n      \"pmids\": [\"12526792\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1997,\n      \"finding\": \"The purified cytosolic domain of Tom70 preferentially binds preproteins with internal targeting signals (not N-terminal presequences), and a synthetic presequence peptide does not compete for Tom70 binding (unlike Tom20/Tom22), demonstrating distinct binding specificity among import receptors.\",\n      \"method\": \"Purified recombinant cytosolic receptor domains, in vitro preprotein binding assay, competition with synthetic presequence peptide\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — reconstituted in vitro binding with purified proteins; finding replicated in multiple independent studies\",\n      \"pmids\": [\"9252394\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"Tom70 binds to multiple segments within internal-targeting-signal-containing preproteins (e.g., phosphate carrier) distributed throughout the mature protein, but does not efficiently bind presequence segments. Both charged and uncharged peptides serve as Tom70 binding sites, indicating charge is not a critical determinant of internal targeting sequences.\",\n      \"method\": \"Cellulose-bound peptide scans (SPOT synthesis), binding of purified cytosolic receptor domains to overlapping 13-mer peptides\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — systematic peptide-scan binding assay with purified protein; corroborates and extends prior in vitro reconstitution work\",\n      \"pmids\": [\"10347216\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2000,\n      \"finding\": \"A stably folded 25 kDa core domain in the middle portion of Tom70, containing two of its seven TPR motifs, is sufficient for binding non-cleavable and cleavable preproteins with internal targeting signals with the same specificity as full-length receptor. Competition studies showed at least one additional interaction site exists in full-length Tom70.\",\n      \"method\": \"Domain deletion/truncation, recombinant protein expression and purification, preprotein binding competition assay\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with purified protein fragments and competition assays; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"11054285\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Hsp90 plays a role in import steps subsequent to Tom70 targeting: geldanamycin (N-terminal ATP-site inhibitor) had no effect on preprotein-Hsp90 interactions or Hsp90 docking onto Tom70 but impaired formation of preprotein import intermediates at the outer membrane, whereas novobiocin (C-terminal inhibitor) blocked Hsp90 cross-linking to preprotein and co-precipitation with Tom70.\",\n      \"method\": \"Hsp90 inhibitor treatment (geldanamycin, novobiocin), cross-linking, co-precipitation with purified cytosolic Tom70 fragment, in vitro import assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro import assays plus cross-linking and co-precipitation with inhibitor comparisons; multiple orthogonal methods, single lab\",\n      \"pmids\": [\"16968702\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Multiple Hsp40-related J-domain proteins (DJA1, DJA2, DJA4) specifically bind preproteins (via their C-terminal regions) and cooperate with Hsc70 and Hsp90 in Tom70-dependent mitochondrial import. DJA dominant-negative mutants lacking J-domains blocked Hsc70 binding to preprotein and impaired mitochondrial import. The Hsp90 cochaperones p23 and Aha1 also regulated Hsp90-preprotein interactions.\",\n      \"method\": \"Mass spectrometry identification of chaperone complexes, dominant-negative mutant expression, Hsc70 ATPase activation assays, in vitro import assay in HeLa cells\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — MS interactome combined with functional dominant-negative experiments and import assays; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"17596514\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Tom70 recognizes a set of presequence-containing precursor proteins whose mature regions are aggregate-prone; the receptor domain of Tom70 prevents aggregate formation of these substrates, maintaining their solubility for efficient transfer to downstream import machinery. Tom70 thus functions as a docking site for both cytosolic chaperones and aggregate-prone substrates.\",\n      \"method\": \"Proteome-wide in vitro import assay, aggregation prevention assay with purified Tom70 receptor domain\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — in vitro import with proteome-wide scope and direct aggregation prevention assay; multiple orthogonal methods\",\n      \"pmids\": [\"19767391\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Analytical ultracentrifugation and SAXS reveal that the cytosolic domain of Tom70 exists as an elongated monomer. Fluorescence anisotropy shows the monomer can simultaneously bind chaperone and precursor peptides; chaperone binding does not alter preprotein affinity or detectable shape change in the monomer. Molecular modeling indicates chaperone binding is incompatible with Tom70 dimer formation.\",\n      \"method\": \"Analytical ultracentrifugation, solution SAXS, fluorescence anisotropy, molecular modeling\",\n      \"journal\": \"Journal of molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — multiple biophysical techniques (AUC, SAXS, fluorescence anisotropy) in a single study establishing monomer state and functional binding\",\n      \"pmids\": [\"19358854\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Human Tom70 functions as a monomer; the cytosolic fragment exists in equilibrium between monomer and dimer. A point mutation at the predicted dimer interface increased monomeric fraction and significantly enhanced preprotein targeting, whereas chaperone docking was unchanged. Cross-linking of full-length Tom70 on mitochondrial membranes shows little evidence of homodimers, indicating monomers are the functional unit.\",\n      \"method\": \"Analytical ultracentrifugation, cross-linking, size-exclusion chromatography, multi-angle light scattering, site-directed mutagenesis, in vitro preprotein targeting assay\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — multiple biophysical methods plus mutagenesis and functional import assay; single lab\",\n      \"pmids\": [\"20504278\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Tom70 interacts with MAVS upon RNA virus infection and recruits TBK1/IRF3 to mitochondria via binding of Tom70's clamp domain (R192) to the C-terminal EEVD motif of Hsp90. Disruption of this interaction or mislocalization of Tom70 sharply impairs TBK1 and IRF3 activation. Tom70 acts as a critical adaptor linking MAVS to TBK1/IRF3.\",\n      \"method\": \"Co-immunoprecipitation, ectopic expression, siRNA knockdown, domain mutation (R192), reporter gene assay for IRF3-mediated gene expression\",\n      \"journal\": \"Cell research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal co-IP with domain-specific mutation and functional reporter assays; single lab but multiple orthogonal methods\",\n      \"pmids\": [\"20628368\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Tom20 interacts with the TPR clamp domain of Tom70 via a conserved C-terminal DDVE motif, competing with the chaperones Hsc70 and Hsp90 for Tom70 binding. This interaction was detected by cross-linking of endogenous proteins on HeLa mitochondria, co-precipitation, and NMR titrations. The functional interaction may facilitate preprotein release from chaperones by competition, constituting a chaperone displacement mechanism.\",\n      \"method\": \"Protein cross-linking on mitochondria, co-precipitation, NMR titration, surface plasmon resonance, site-directed mutagenesis of TPR clamp domain and DDVE motif\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — reciprocal co-precipitation, cross-linking of endogenous proteins, NMR, SPR, and mutagenesis; multiple orthogonal methods in a single study\",\n      \"pmids\": [\"21771790\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Tom70 directly binds presequence peptides via a dedicated groove. A single point mutation M551R in this pocket reduces presequence binding affinity ten-fold and selectively impairs import of presequence-containing precursor Mdl1, but not the ADP/ATP carrier, demonstrating that Tom70 contributes to the presequence import pathway.\",\n      \"method\": \"Fluorescence binding assay with presequence peptides, site-directed mutagenesis (M551R), in vitro import assay\",\n      \"journal\": \"Biochimica et biophysica acta\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstituted binding with mutagenesis and functional import assay; single lab but rigorous mechanistic validation\",\n      \"pmids\": [\"25958336\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Cross-linking/mass spectrometry identified a novel region of contact between the C-terminal domain of Hsp90 and Tom70 beyond the canonical MEEVD/TPR interaction. A molecular model validated by SAXS and hydrogen/deuterium exchange indicates only one MEEVD motif within dimeric Hsp90 contacts Tom70. ITC confirmed the secondary interaction site affects preprotein import.\",\n      \"method\": \"Cross-linking/mass spectrometry, isothermal titration calorimetry, SAXS, hydrogen/deuterium exchange mass spectrometry, in vitro mitochondrial import assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — multiple orthogonal biophysical methods (XL-MS, ITC, SAXS, HDX-MS) and functional validation in a single study\",\n      \"pmids\": [\"27402847\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Many preproteins contain internal MTS-like signals (iMTS-Ls) in their mature regions that mediate binding to Tom70. Using Atp1 as model substrate, iMTS-Ls mediate Tom70 binding and can target proteins to mitochondria when presented at the N-terminus. Import of preproteins with high iMTS-L content is significantly impaired in the absence of Tom70, supporting a stepping-stone model where Tom70-mediated internal binding improves import efficiency.\",\n      \"method\": \"In silico prediction of iMTS-Ls, in vitro import assay with Tom70 deletion, N-terminal fusion targeting experiments, binding assay\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Moderate — computational prediction combined with functional in vitro import assays and direct binding experiments; single lab but multiple methods\",\n      \"pmids\": [\"29382700\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"TOM70 clusters in distinct OMM foci that frequently overlap with ER-mitochondria contact sites. TOM70 depletion specifically impairs IP3-linked ER-to-mitochondria Ca2+ transfer by interacting with IP3 receptors (IP3R3) and favoring their functional recruitment close to mitochondria. Reduced constitutive Ca2+ transfer dampens mitochondrial respiration, affects bioenergetics, induces autophagy, and inhibits proliferation. TOM20 depletion did not reproduce this phenotype.\",\n      \"method\": \"Live-cell imaging/super-resolution microscopy for localization, siRNA knockdown, Ca2+ imaging, co-immunoprecipitation with IP3R3, mitochondrial respiration assay\",\n      \"journal\": \"Current biology : CB\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization linked to functional consequence, reciprocal co-IP with IP3R3, functional Ca2+ and respiration measurements; multiple orthogonal methods, single lab\",\n      \"pmids\": [\"29395920\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"The PERK kinase promotes cristae formation by increasing TOM70-assisted mitochondrial import of MIC19 (a MICOS complex subunit). Cold stress/β-adrenergic stimulation activates PERK, which phosphorylates OGT; phosphorylated OGT O-GlcNAcylates TOM70 on Ser94, enhancing MIC19 protein import and promoting cristae formation and respiration. CK2α-mediated phosphorylation of TOM70 Ser94 opposes this by decreasing MIC19 import.\",\n      \"method\": \"In vivo and in vitro reconstitution, OGT glycosylation assay, site-directed mutagenesis (Ser94), in vitro mitochondrial import assay, cryo-EM of cristae, genetic epistasis with PERK/OGT/CK2α\",\n      \"journal\": \"Cell metabolism\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vivo and in vitro reconstitution with site-specific mutagenesis, identified PTM writer (OGT) and eraser (CK2α) with functional import readout\",\n      \"pmids\": [\"33592173\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Crystal structure of SARS-CoV-2 Orf9b in complex with the cytosolic segment of human TOM70 resolved to 2.2 Å. A central helical portion of Orf9b occupies the deep hydrophobic pocket of TOM70 C-terminal domain (CTD). The Orf9b dimer does not bind TOM70, but a monomeric C-peptide of Orf9b binds with nanomolar affinity (ITC). Orf9b binding to TOM70 CTD allosterically reduces Hsp90 EEVD binding to TOM70 NTD by ~29-fold, providing a structural mechanism for immune evasion.\",\n      \"method\": \"X-ray crystallography (2.2 Å), isothermal titration calorimetry, synthetic peptide binding assay\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — high-resolution crystal structure combined with ITC quantification of binding affinities and allosteric effect; single study with multiple rigorous methods\",\n      \"pmids\": [\"33990585\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"The predominant function of Tom70 in vivo is to recruit cytosolic chaperones to the outer mitochondrial membrane, rather than to serve as a mitochondrion-specifying targeting receptor. Tethering an unrelated chaperone-binding domain onto the mitochondrial surface complemented most defects caused by Tom70 deletion, including reduction of proteotoxicity of hydrophobic inner membrane proteins. The chaperone-binding activity protects the cytosol from mitoprotein-induced stress.\",\n      \"method\": \"In vivo high-content screens, in vitro import experiments, Tom70 deletion combined with heterologous chaperone-binding domain tethering, proteotoxicity assays\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic complementation with heterologous domain plus in vivo high-content screens and in vitro import; multiple orthogonal methods, robust mechanistic conclusion\",\n      \"pmids\": [\"33826901\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"SARS-CoV-2 Orf9b binding to TOM70 inhibits Hsp90 recruitment to TOM70 and suppresses downstream chaperone-associated signaling. Orf9b Ser53 and TOM70 Glu477 are crucial residues for Orf9b-TOM70 association; the phosphomimetic Orf9b S53E shows drastically reduced TOM70 binding and does not inhibit Hsp90 recruitment, indicating phosphorylation regulates complex formation. A second binding site at the TOM70 N-terminal TPR domain was also identified.\",\n      \"method\": \"Site-directed mutagenesis, co-precipitation, chaperone recruitment assay, phosphomimetic variant analysis\",\n      \"journal\": \"International journal of molecular sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis and functional binding assays; single lab, single study\",\n      \"pmids\": [\"34502139\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Tom70 is essential for PINK1 import into mitochondria. Using a cell-free import system, PINK1 import was found to depend on Tom70 but not on Tom40 (the main import channel). PINK1 is not processed by the mitochondrial processing peptidase, indicating a unique import pathway that is independent of the TOM core complex but requires Tom70.\",\n      \"method\": \"Cell-free mitochondrial import assay, Tom70 knockdown, Tom40 knockdown/depletion, processing peptidase assay\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — cell-free import assay with specific receptor depletions; single lab, single study\",\n      \"pmids\": [\"23472196\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Mcl-1 interacts with the mitochondrial import receptor Tom70 via an internal EELD domain. A Tom70 antibody blocking Mcl-1-Tom70 interaction inhibits mitochondrial import of Mcl-1 in vitro. Tom70 knockdown significantly reduces Mcl-1 mitochondrial targeting; mutation of the EELD motif attenuates Tom70 binding and mitochondrial targeting.\",\n      \"method\": \"Co-immunoprecipitation, in vitro import assay with blocking antibody, siRNA knockdown, site-directed mutagenesis of EELD motif\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP with functional import assay and mutagenesis; single lab, multiple orthogonal methods\",\n      \"pmids\": [\"16822835\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"Tom70 recruits IRF3 to mitochondria via Hsp90 upon Sendai virus infection, forming a dynamic complex Tom70/Hsp90/IRF3/Bax. Bax interacts specifically with IRF3 upon virus infection, and relocation of Bax to mitochondria via this complex induces cytochrome c leakage and apoptosis. IKK-i is essential for this apoptosis whereas TBK1 is dispensable.\",\n      \"method\": \"Co-immunoprecipitation, subcellular fractionation, cytochrome c release assay, siRNA knockdown, ectopic expression\",\n      \"journal\": \"Journal of virology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — co-IP-based complex identification with functional apoptosis readout; single lab, multiple methods\",\n      \"pmids\": [\"25609812\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Rat Tom70 (OM70) functions as a receptor for preproteins with internal targeting signals (ADP/ATP carrier, rTOM40) but not for cleavable presequence-containing proteins. Blue native PAGE and immunoprecipitation show OM70 is loosely associated with the ~400 kDa TOM complex containing rTOM22 and rTOM40. Yeast two-hybrid showed OM70 interacts with rTOM20 and rTOM22 through cytoplasmic domains. The N-terminal 66-residue region including a transmembrane domain and arginine cluster is sufficient for mitochondrial targeting.\",\n      \"method\": \"Antibody inhibition of import, blue native PAGE, immunoprecipitation, yeast two-hybrid, in organello import assay\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple complementary methods (BN-PAGE, co-IP, import inhibition, yeast two-hybrid); single lab\",\n      \"pmids\": [\"11956321\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Stoichiometry analysis revealed that one monomer of Tom70 interacts per dimer of the C-terminal domain of Hsp90 (containing the EEVD motif), with a KD of ~360 nM. This stoichiometry and thermodynamic profile differ from those of other TPR co-chaperones, indicating a distinct interaction mechanism between Tom70 and Hsp90.\",\n      \"method\": \"Isothermal titration calorimetry, size-exclusion chromatography, biophysical analysis\",\n      \"journal\": \"Archives of biochemistry and biophysics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — rigorous biophysical quantification but single lab and single method (ITC)\",\n      \"pmids\": [\"21781956\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"In yeast, Tom70 and its paralogue Tom71 are required for localization of the soluble F-box protein Mfb1 to mitochondria. Mfb1 interacts with Tom71 in vivo and binds to mitochondria through Tom70 in vitro. Cells lacking both Tom70 and Tom71 display aberrant mitochondrial morphology (short tubules and aggregates) similar to mfb1-null mutants, revealing an unexpected role for Tom70 in recruiting soluble proteins to the mitochondrial surface.\",\n      \"method\": \"In vivo co-immunoprecipitation (Mfb1-Tom71), in vitro mitochondrial binding assay, fluorescence microscopy of mitochondrial morphology, gene deletion\",\n      \"journal\": \"EMBO reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo co-IP and in vitro binding with genetic morphology phenotype; single lab, two orthogonal methods\",\n      \"pmids\": [\"18007655\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"In budding yeast, Tom70 moonlights as a transcriptional regulator of mitochondrial protein genes, and this transcription-regulatory role is conserved in Drosophila. The dual roles in transcription and import allow cells to coordinate mitochondrial biogenesis without compromising cytosolic proteostasis. Age-related reduction of Tom70 is associated with loss of mitochondrial membrane potential, mtDNA, and mitochondrial proteins; Tom70 overexpression extends replicative lifespan.\",\n      \"method\": \"Genetic deletion and overexpression, transcriptional reporter assays, Drosophila genetic experiments, mitochondrial membrane potential and mtDNA measurements\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic experiments in two model organisms with transcriptional and physiological readouts; single lab\",\n      \"pmids\": [\"35234609\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"The 2.04 Å crystal structure of unliganded human TOM70 cytosolic domain reveals two distinct conformations—open and closed—within the asymmetric unit. HDX-MS and MD simulations confirm these states in solution. Network analyses identify a continuum of motion linking the NTD (chaperone-binding) and CTD (preprotein-binding) via helices α7, α8, and α25. Orf9b engagement of the CTD interrupts this allosteric network, stabilizing a partially-closed intermediate and dampening NTD dynamics.\",\n      \"method\": \"X-ray crystallography (2.04 Å), hydrogen-deuterium exchange mass spectrometry, molecular dynamics simulations, principal component analysis, dynamical network analysis\",\n      \"journal\": \"Structure\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — high-resolution crystal structure combined with HDX-MS and MD simulations; multiple orthogonal methods in a single rigorous study\",\n      \"pmids\": [\"41386227\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"The cytosolic chaperone PPID (cyclophilin 40/Cyp40) drives OMM insertion of TOM70 via its PPIase activity and C-terminal tetratricopeptide repeats, which show specificity towards TOM70 core and C-tail domains. This PPID-mediated TOM70 insertion regulates thermogenic/respiratory function in brown adipocytes and protects against diet-induced obesity in mice.\",\n      \"method\": \"In vitro reconstitution of OMM insertion, domain mutagenesis (PPIase activity mutation, TPR deletion), brown adipocyte functional assays, mouse obesity model\",\n      \"journal\": \"Nature cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution of insertion mechanism with domain-specific mutagenesis and in vivo physiological validation; multiple orthogonal methods\",\n      \"pmids\": [\"39753947\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In zebrafish, a missense mutation in tomm70 (affecting a conserved isoleucine corresponding to human TOMM70 p.Ile554Phe) impairs the interaction of Tomm70 with the ER sterol transporter Lam6, impairs mitochondrial transport to axons and dendrites, and causes demyelination of large-calibre spinal cord axons. These defects recapitulate features of hereditary spastic paraplegia.\",\n      \"method\": \"Zebrafish missense mutant model, co-immunoprecipitation (Tomm70-Lam6 interaction), fluorescence microscopy of mitochondrial axonal transport, electron microscopy of myelin\",\n      \"journal\": \"Disease models & mechanisms\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — animal model with co-IP-identified protein interaction and direct localization/morphology readouts; single lab\",\n      \"pmids\": [\"40151845\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"ORF9b forms a complex with TOM70 that prevents full-length Hsp90 from binding to TOM70. The isolated C-terminal domain of Hsp90 is also blocked by ORF9b occupying TOM70. Biophysical characterization shows ORF9b homodimer has ~22 kDa and random coil conformation, while the ORF9b-TOM70 complex is folded and more thermally stable than free TOM70.\",\n      \"method\": \"SEC-MALS, circular dichroism, differential scanning calorimetry, protein-protein interaction assay (co-expression and co-purification), pull-down\",\n      \"journal\": \"Biochimie\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — biophysical characterization with multiple methods but single lab and no in-cell functional validation\",\n      \"pmids\": [\"35643212\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Using cryo-EM, 19F NMR, and ITC, Orf9b inhibits Hsp90 binding to Tom70 through a bipartite steric-blocking mechanism: the helix and intrinsically disordered tail of Orf9b sterically block two distinct structural units of Hsp90 from accessing Tom70. Orf9b primarily slows the association kinetics between Hsp90 and Tom70, rather than acting through allosteric conformational changes in Tom70.\",\n      \"method\": \"Cryo-electron microscopy, 19F NMR spectroscopy, isothermal titration calorimetry, kinetic binding analysis\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — cryo-EM structure combined with NMR and ITC kinetic analysis; multiple rigorous orthogonal methods in a single study\",\n      \"pmids\": [\"41332678\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"In yeast meiosis, Tom70 concentrates around the Gametogenesis-Uninherited Nuclear Compartment (GUNC) and tethers mitochondria to the nuclear envelope by recruiting the tethering protein Cnm1, independently of its canonical mitochondrial import function. Loss of Tom70 disrupts sequestration of nuclear pore complexes into the GUNC, and loss of Cnm1 partially phenocopies tom70Δ.\",\n      \"method\": \"Fluorescence live-cell imaging, gene deletion (tom70Δ, cnm1Δ), genetic epistasis, subcellular fractionation\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization imaging linked to functional nuclear inheritance readout with genetic epistasis; preprint, single lab\",\n      \"pmids\": [\"41332789\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"ASFV protein p17 promotes mitophagy by facilitating the interaction of autophagy receptor SQSTM1 with TOMM70. Co-immunoprecipitation/mass spectrometry identified TOMM70 as a p17-interacting protein. The p17-TOMM70 interaction enhances SQSTM1 binding to TOMM70, leading to mitochondrial engulfment by autophagosomes and degradation of mitochondrial antiviral signaling proteins.\",\n      \"method\": \"Co-immunoprecipitation/mass spectrometry, co-immunoprecipitation, mitophagy assay (autophagosome engulfment, mitochondrial counts), siRNA knockdown\",\n      \"journal\": \"Virulence\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — MS-identified interaction followed by co-IP and functional mitophagy assays; single lab\",\n      \"pmids\": [\"37442088\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"Tom70 downregulation in pathological hypertrophic hearts causes defective mitochondrial import of OPA1, triggering intracellular oxidative stress and pathological cardiac hypertrophy. Overexpression of Tom70 confers resistance to pro-hypertrophic insults. Tom70 thus acts as a molecular switch orchestrating hypertrophic stress and mitochondrial responses.\",\n      \"method\": \"siRNA knockdown and lentiviral overexpression in vivo/in vitro, mitochondrial import assay for OPA1, ROS measurement, echocardiography\",\n      \"journal\": \"Cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss- and gain-of-function with identified substrate (OPA1) and defined cellular phenotype; single lab\",\n      \"pmids\": [\"25022898\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"De novo loss-of-function variants in TOMM70 (p.Thr607Ile, p.Ile554Phe) cause neurological impairment. In a Drosophila model replacing Tom70 with human TOMM70, both variants provided significantly less rescue of lethality than reference TOMM70. RNAi knockdown of Tom70 in the developing eye caused roughening and synaptic transmission defects rescued by reference but not variant TOMM70.\",\n      \"method\": \"CRISPR-Cas9 humanized Drosophila model, UAS-GAL4 rescue assay, RNAi knockdown, synaptic transmission electrophysiology\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vivo genetic rescue assay with multiple alleles in Drosophila model; single lab\",\n      \"pmids\": [\"32356556\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Tom70 governs the mitochondrial localization of MICU1 (mitochondrial Ca2+ uptake regulator). Tom70 knockdown reduces mitochondrial MICU1 content, worsens MI/R-induced mitochondrial Ca2+ overload, and exacerbates myocardial injury. Tom70 overexpression preserves mitochondrial MICU1, which is required for Tom70's cardioprotective effects.\",\n      \"method\": \"siRNA knockdown, lentiviral overexpression, mitochondrial fractionation, Ca2+ measurement, in vivo MI/R mouse model\",\n      \"journal\": \"Cell death & disease\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — loss- and gain-of-function with mitochondrial fractionation and Ca2+ measurement; single lab\",\n      \"pmids\": [\"28703803\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Proximity labeling (APEX2) shows that human TOMM70 and TOMM20 have differential association profiles with RNA-binding proteins (RBPs) and translation factors, with several RBPs (including SYNJ2BP) preferentially associating with TOMM20 over TOMM70. During translation stress (puromycin), RBP association increases specifically with TOMM20, suggesting TOMM70 does not share this role in preserving hemostasis during translation stress.\",\n      \"method\": \"APEX2-based proximity labeling, quantitative mass spectrometry, puromycin translation inhibition\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — proximity labeling proteomics with defined conditions; preprint, single lab, single method\",\n      \"pmids\": [\"bio_10.1101_2024.10.25.620316\"],\n      \"is_preprint\": true\n    }\n  ],\n  \"current_model\": \"TOMM70 is an outer mitochondrial membrane receptor composed of 11 TPR motifs organized into an N-terminal chaperone-binding domain and a C-terminal preprotein-binding domain; it functions primarily by recruiting cytosolic Hsp70/Hsc70 and Hsp90 (via the TPR clamp/EEVD interaction) to deliver hydrophobic, internally-targeted preproteins to the mitochondrial import machinery, with its import efficiency enhanced by O-GlcNAcylation at Ser94 (written by OGT downstream of PERK); it also mediates ER-mitochondria Ca2+ transfer via IP3R3, acts as an innate immune adaptor linking MAVS to TBK1/IRF3 through Hsp90 recruitment, and is subverted by SARS-CoV-2 Orf9b, which occupies the CTD pocket and allosterically suppresses Hsp90 docking to impair interferon signaling.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"TOMM70 is a tetratricopeptide-repeat (TPR) receptor of the mitochondrial outer membrane whose principal function is to recruit cytosolic chaperones to the organelle surface and thereby deliver hydrophobic, internally-targeted preproteins into the import machinery [#0, #17]. Distinct from presequence receptors, its cytosolic domain preferentially binds internal targeting signals (iMTS-like segments) distributed throughout the mature regions of substrates rather than N-terminal presequences [#1, #2, #13], and a folded core domain containing TPR motifs is sufficient for this internal-signal recognition [#3]; the receptor also keeps aggregate-prone precursors soluble during transfer [#6]. Chaperone docking occurs through the TPR clamp/EEVD interaction, in which a single MEEVD motif of dimeric Hsp90 engages the monomeric receptor [#0, #12, #23], with Hsp70/Hsc70, Hsp40-family J-proteins, and Hsp90 cochaperones cooperating in import [#5]; the functional receptor is a monomer, and chaperone binding is incompatible with dimerization [#7, #8]. The cytosolic domain interconverts between open and closed conformations linking the chaperone-binding N-terminal domain to the preprotein-binding C-terminal domain through an allosteric helical network [#26], and competition by Tom20's C-terminal DDVE motif at the clamp provides a chaperone-displacement mechanism [#10]. TOMM70 functions as an innate-immune adaptor, interacting with MAVS upon RNA-virus infection and recruiting TBK1/IRF3 to mitochondria via its clamp-domain (R192)-Hsp90 EEVD interaction [#9]; SARS-CoV-2 Orf9b subverts this by occupying the CTD hydrophobic pocket and blocking Hsp90 docking to suppress interferon signaling [#16, #30]. The receptor additionally organizes ER-mitochondria contacts, recruiting IP3R3 to drive Ca2+ transfer that supports respiration [#14], and its import activity is tuned by O-GlcNAcylation of Ser94 written by OGT downstream of PERK and opposed by CK2\\u03b1 phosphorylation [#15]. De novo loss-of-function variants in TOMM70 (p.Thr607Ile, p.Ile554Phe) cause neurological impairment [#34].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Established that Tom70 is a functionally distinct import receptor, answering whether all receptors recognize the same targeting signal: it binds internal targeting signals, not N-terminal presequences.\",\n      \"evidence\": \"in vitro preprotein binding and presequence-peptide competition with purified cytosolic receptor domains\",\n      \"pmids\": [\"9252394\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not map the binding determinants within internal signals\", \"Chaperone involvement in delivery not yet addressed\"]\n    },\n    {\n      \"year\": 1999,\n      \"claim\": \"Defined the nature of Tom70 binding sites within substrates, showing internal targeting signals are dispersed and not charge-dependent.\",\n      \"evidence\": \"cellulose-bound peptide scans (SPOT) with purified receptor domains\",\n      \"pmids\": [\"10347216\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of recognition not resolved\", \"Did not address how multiple sites are engaged in vivo\"]\n    },\n    {\n      \"year\": 2000,\n      \"claim\": \"Localized the substrate-binding activity to a discrete folded core domain, narrowing which TPR motifs carry recognition.\",\n      \"evidence\": \"domain truncation, recombinant fragment purification, competition binding assays\",\n      \"pmids\": [\"11054285\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the additional interaction site left open\", \"Relation to chaperone-binding region not defined\"]\n    },\n    {\n      \"year\": 2003,\n      \"claim\": \"Resolved how preproteins reach the receptor, establishing chaperone-assisted delivery: Hsp90/Hsp70 dock onto a specialized TPR domain and hand off preproteins for Hsp90-ATPase-dependent translocation.\",\n      \"evidence\": \"co-IP, cross-linking, in vitro import with purified cytosolic Tom70 fragment across mammalian and yeast systems\",\n      \"pmids\": [\"12526792\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry of the chaperone-receptor complex not defined\", \"Step at which chaperones release substrate unclear\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Dissected when Hsp90 acts during import, showing it operates at post-targeting steps via its C-terminal region rather than at the docking step.\",\n      \"evidence\": \"Hsp90 N- vs C-terminal inhibitor comparison, cross-linking, co-precipitation, in vitro import\",\n      \"pmids\": [\"16968702\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of preprotein release into the translocase not resolved\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Extended the substrate range to a regulatory protein, showing Mcl-1 uses an internal EELD motif for Tom70-dependent mitochondrial targeting.\",\n      \"evidence\": \"co-IP, blocking-antibody import assay, siRNA, EELD-motif mutagenesis\",\n      \"pmids\": [\"16822835\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Functional consequence of Mcl-1 import for apoptosis not addressed here\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Defined the broader chaperone network feeding the receptor, identifying DJA J-proteins and Hsp90 cochaperones (p23, Aha1) as cooperating factors.\",\n      \"evidence\": \"MS interactome, dominant-negative mutants, Hsc70 ATPase assays, in vitro import in HeLa\",\n      \"pmids\": [\"17596514\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Hierarchy/order of cochaperone action not fully ordered\", \"Substrate selectivity of individual DJAs unresolved\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Established the oligomeric state and simultaneous-binding capacity of the cytosolic domain, showing it is an elongated monomer binding chaperone and precursor at once.\",\n      \"evidence\": \"analytical ultracentrifugation, SAXS, fluorescence anisotropy, modeling\",\n      \"pmids\": [\"19358854\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In-membrane oligomeric state of full-length receptor not directly tested here\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Reframed Tom70 as a solubility chaperone, showing its receptor domain prevents aggregation of presequence-containing aggregate-prone substrates.\",\n      \"evidence\": \"proteome-wide in vitro import and aggregation-prevention assays with purified receptor domain\",\n      \"pmids\": [\"19767391\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not quantify in vivo contribution relative to chaperone recruitment\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Confirmed the monomer as the functional import unit in the human receptor, linking dimer disruption to enhanced targeting.\",\n      \"evidence\": \"AUC, cross-linking, SEC-MALS, dimer-interface mutagenesis, in vitro targeting\",\n      \"pmids\": [\"20504278\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Physiological regulation of monomer-dimer equilibrium unknown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Identified a non-import role, establishing Tom70 as an innate-immune adaptor that recruits TBK1/IRF3 to mitochondria downstream of MAVS via Hsp90.\",\n      \"evidence\": \"reciprocal co-IP, siRNA, R192 clamp mutation, IRF3 reporter assay\",\n      \"pmids\": [\"20628368\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How chaperone recruitment for import versus signaling is partitioned unclear\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Defined a chaperone-displacement mechanism, showing Tom20's DDVE motif competes with chaperones at the TPR clamp to promote preprotein handoff.\",\n      \"evidence\": \"endogenous cross-linking, co-precipitation, NMR titration, SPR, mutagenesis\",\n      \"pmids\": [\"21771790\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Kinetics of handoff during active import not measured\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Quantified the Hsp90-Tom70 interaction, establishing a 1 monomer:1 Hsp90-dimer stoichiometry distinct from other TPR cochaperones.\",\n      \"evidence\": \"ITC, SEC, biophysical analysis\",\n      \"pmids\": [\"21781956\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single method (ITC)-dominated\", \"Functional import consequence not tested in this study\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed receptor specialization for an unusual substrate, establishing that PINK1 import requires Tom70 but bypasses the Tom40 channel and processing peptidase.\",\n      \"evidence\": \"cell-free import with Tom70 and Tom40 depletions, processing assay\",\n      \"pmids\": [\"23472196\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single study\", \"Translocation route for PINK1 beyond Tom70 unresolved\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Linked Tom70 import function to organ physiology, showing its loss impairs OPA1 import and drives oxidative stress and cardiac hypertrophy.\",\n      \"evidence\": \"in vivo/in vitro knockdown and overexpression, OPA1 import assay, ROS, echocardiography\",\n      \"pmids\": [\"25022898\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Direct vs indirect cause of hypertrophy not fully separated\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Revealed that Tom70 also contributes to the presequence pathway, identifying a dedicated presequence-binding groove.\",\n      \"evidence\": \"fluorescence presequence-peptide binding, M551R mutagenesis, in vitro import\",\n      \"pmids\": [\"25958336\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Quantitative contribution to presequence import in vivo not defined\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Expanded the immune-adaptor role to apoptosis, showing a Tom70/Hsp90/IRF3/Bax complex drives cytochrome c release via IKK-i.\",\n      \"evidence\": \"co-IP, fractionation, cytochrome c release, siRNA, ectopic expression\",\n      \"pmids\": [\"25609812\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Trigger distinguishing pro-apoptotic vs pro-IFN outcomes unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Refined the chaperone-receptor architecture, defining a secondary Hsp90 CTD-Tom70 contact beyond the canonical MEEVD/TPR site that affects import.\",\n      \"evidence\": \"XL-MS, ITC, SAXS, HDX-MS, in vitro import\",\n      \"pmids\": [\"27402847\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Role of secondary site in vivo not isolated\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Connected the receptor to mitochondrial Ca2+ handling, showing Tom70 governs MICU1 localization and cardioprotection during ischemia/reperfusion.\",\n      \"evidence\": \"knockdown/overexpression, mitochondrial fractionation, Ca2+ measurement, MI/R mouse model\",\n      \"pmids\": [\"28703803\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Whether MICU1 is a direct import substrate not established\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Formalized the internal-signal recognition logic with the iMTS-L/stepping-stone model, showing internal MTS-like signals mediate Tom70 binding and improve import efficiency.\",\n      \"evidence\": \"iMTS-L prediction, in vitro import with Tom70 deletion, N-terminal fusion targeting, binding assays\",\n      \"pmids\": [\"29382700\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Predictive rules for which substrates strictly require Tom70 incomplete\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Established a membrane-contact-site role, showing TOM70 recruits IP3R3 at ER-mitochondria junctions to sustain Ca2+ transfer and bioenergetics.\",\n      \"evidence\": \"super-resolution imaging, siRNA, Ca2+ imaging, IP3R3 co-IP, respiration assays\",\n      \"pmids\": [\"29395920\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of TOM70-IP3R3 interaction not defined\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Resolved the predominant in vivo function, demonstrating that chaperone recruitment (not mitochondrion-specifying targeting) is the core activity protecting the cytosol from mitoprotein stress.\",\n      \"evidence\": \"in vivo high-content screens, heterologous chaperone-binding domain tethering complementation, proteotoxicity assays\",\n      \"pmids\": [\"33826901\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Substrates strictly dependent on targeting specificity not enumerated\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified post-translational tuning of import, showing PERK-OGT-driven O-GlcNAcylation of Ser94 enhances MIC19 import and cristae formation, opposed by CK2\\u03b1.\",\n      \"evidence\": \"in vivo/in vitro reconstitution, OGT glycosylation assay, Ser94 mutagenesis, cristae cryo-EM, PERK/OGT/CK2\\u03b1 epistasis\",\n      \"pmids\": [\"33592173\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Generality of Ser94 modification across substrates beyond MIC19 unclear\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Provided the structural mechanism of viral subversion, showing SARS-CoV-2 Orf9b occupies the CTD pocket and allosterically suppresses Hsp90 EEVD binding ~29-fold.\",\n      \"evidence\": \"2.2 \\u00c5 crystal structure, ITC, synthetic peptide binding\",\n      \"pmids\": [\"33990585\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In-cell quantification of interferon suppression not in this study\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Mapped the Orf9b-TOM70 interface and its phospho-regulation, identifying Orf9b Ser53 / TOM70 Glu477 as critical and a second NTD binding site.\",\n      \"evidence\": \"mutagenesis, co-precipitation, phosphomimetic (S53E) analysis, chaperone recruitment assay\",\n      \"pmids\": [\"34502139\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab/single study\", \"Physiological kinase for Orf9b S53 not identified\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Biophysically characterized the Orf9b-TOM70 complex, confirming Orf9b blocks both full-length and isolated CTD Hsp90 and stabilizes TOM70.\",\n      \"evidence\": \"SEC-MALS, CD, DSC, co-expression/co-purification, pull-down\",\n      \"pmids\": [\"35643212\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No in-cell functional validation\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Uncovered a moonlighting transcriptional role, showing Tom70 regulates mitochondrial-protein genes and influences replicative lifespan, conserved to Drosophila.\",\n      \"evidence\": \"yeast/Drosophila genetics, transcriptional reporters, membrane-potential/mtDNA measurements, lifespan assay\",\n      \"pmids\": [\"35234609\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Mechanism by which an OMM receptor influences transcription unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Showed viral exploitation for mitophagy, where ASFV p17 bridges SQSTM1 to TOMM70 to degrade antiviral signaling proteins.\",\n      \"evidence\": \"co-IP/MS, co-IP, mitophagy assays, siRNA\",\n      \"pmids\": [\"37442088\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Whether endogenous mitophagy uses TOMM70 similarly unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined the conformational dynamics underlying allostery, showing open/closed states connect NTD and CTD and that Orf9b interrupts this network.\",\n      \"evidence\": \"2.04 \\u00c5 crystal structure, HDX-MS, MD simulations, network analysis\",\n      \"pmids\": [\"41386227\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Functional import readout for conformational states not directly measured\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Identified the biogenesis pathway of the receptor itself, showing PPID/Cyp40 drives TOM70 OMM insertion with physiological consequences for thermogenesis.\",\n      \"evidence\": \"in vitro insertion reconstitution, PPIase/TPR mutagenesis, brown adipocyte assays, mouse obesity model\",\n      \"pmids\": [\"39753947\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether other insertases contribute in parallel not resolved\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Connected a specific human-mutation residue to disease mechanism in vivo, showing the Ile554-equivalent variant disrupts a Lam6 interaction and causes axonal/myelin defects resembling hereditary spastic paraplegia.\",\n      \"evidence\": \"zebrafish missense model, Tomm70-Lam6 co-IP, mitochondrial transport imaging, myelin EM\",\n      \"pmids\": [\"40151845\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Mechanistic link between Lam6 loss and demyelination incomplete\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed a nuclear-tethering moonlighting function, showing Tom70 recruits Cnm1 to tether mitochondria to the nuclear envelope during yeast meiosis independent of import.\",\n      \"evidence\": \"live-cell imaging, tom70\\u0394/cnm1\\u0394 deletion, genetic epistasis, fractionation (preprint)\",\n      \"pmids\": [\"41332789\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Preprint\", \"Conservation in mammals not tested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how a single receptor partitions its activities among canonical chaperone-mediated import, ER/nuclear contact-site tethering, transcriptional regulation, and immune signaling, and what governs the switch between them.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model integrating import vs signaling vs tethering roles\", \"Regulatory inputs (PTMs, partners) that select among functions not mapped\", \"In vivo human disease mechanism only partially defined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [0, 17]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 5, 10, 12]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 9, 14]},\n      {\"term_id\": \"GO:0038024\", \"supporting_discovery_ids\": [1, 2, 13]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005741\", \"supporting_discovery_ids\": [0, 14, 22]},\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [0, 14]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [0, 13, 17]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 6, 17]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [9, 16]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [15]}\n    ],\n    \"complexes\": [\n      \"TOM complex\"\n    ],\n    \"partners\": [\n      \"HSP90\",\n      \"HSC70\",\n      \"TOM20\",\n      \"MAVS\",\n      \"IP3R3\",\n      \"OGT\",\n      \"Orf9b (SARS-CoV-2)\",\n      \"PPID\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}