{"gene":"UQCRC1","run_date":"2026-06-10T10:51:56","timeline":{"discoveries":[{"year":2021,"finding":"UQCRC1 physically associates with cytochrome c (cyt-c), and UQCRC1 deficiency increases cytochrome c in the cytoplasmic fraction and activates the caspase cascade, leading to neuronal apoptosis; depleting cyt-c or expressing anti-apoptotic p35 ameliorates UQCRC1-deficiency-mediated neurodegeneration.","method":"Co-immunoprecipitation/association assay, cellular fractionation, genetic rescue experiments in Drosophila and human neuronal cell lines, caspase activity assays","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal association established, multiple orthogonal methods (co-IP, fractionation, genetic epistasis with cyt-c depletion and p35 rescue), validated in two model systems","pmids":["34551295"],"is_preprint":false},{"year":2020,"finding":"UQCRC1 overexpression in pancreatic cancer cells increases mitochondrial oxidative phosphorylation (OXPHOS) and ATP production; the overproduced ATP is released extracellularly via the pannexin 1 channel and acts as an autocrine/paracrine agent to promote cell proliferation through the ATP/P2Y2-RTK/AKT signaling axis.","method":"Extracellular flux analysis, RNA-Seq, UQCRC1 knockdown/overexpression in PANC-1 and CFPAC-1 cells, in vivo mouse transplant models, ATP release blockage experiments","journal":"Theranostics","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (extracellular flux, genetic KD/OE, in vivo models, pathway inhibition), single lab with strong mechanistic follow-up","pmids":["32089737"],"is_preprint":false},{"year":2019,"finding":"Homozygous knockout of UQCRC1 causes embryonic lethality in mice; heterozygous loss decreases complex III formation, complex III activity, and ATP content in the brain, worsens neurological outcome after ischemia, reduces mitochondrial membrane potential, increases free radicals, and impairs learning and memory.","method":"Knockout/heterozygous mouse model, biochemical complex III activity assays, ATP measurement, mitochondrial membrane potential assay, ROS detection, behavioral testing (Barnes maze, novel object recognition), brain ischemia models","journal":"Cellular and molecular life sciences : CMLS","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean KO/heterozygous mouse model with multiple orthogonal functional readouts (complex III activity, ATP, MMP, ROS, behavior, ischemia tolerance)","pmids":["30666338"],"is_preprint":false},{"year":2020,"finding":"Mutant UQCRC1 (p.Tyr314Ser, p.Ile311Leu) causes neurite degeneration and mitochondrial respiratory chain complex III dysfunction in SH-SY5Y dopaminergic cells; knock-in Drosophila and mouse models show age-dependent locomotor defects, dopaminergic neuronal loss, peripheral neuropathy, impaired complex III activity, and aberrant mitochondrial ultrastructures in nigral neurons.","method":"CRISPR/Cas9 knock-in in SH-SY5Y cells, Drosophila knock-in model, mouse knock-in model, respiratory chain complex III activity assay, electron microscopy, behavioral testing, levodopa rescue experiment","journal":"Brain : a journal of neurology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple model systems (human cell line, Drosophila, mouse), multiple orthogonal methods (enzymatic assay, EM, behavior, pharmacological rescue)","pmids":["33141179"],"is_preprint":false},{"year":2021,"finding":"Neuronal knockdown of uqcrc1 in Drosophila causes age-dependent dopaminergic neuron reduction and locomotor decline; lethality of uqcrc1-KO is rescued by neuronal UQCRC1 expression but not by the disease-causing variant (p.Tyr314Ser), establishing the variant as loss-of-function pathogenic.","method":"Drosophila neuron-specific RNAi knockdown, genetic rescue with wild-type vs. mutant UQCRC1, dopaminergic neuron counting, locomotor assays","journal":"Cell reports","confidence":"High","confidence_rationale":"Tier 2 / Strong — clean genetic epistasis with rescue experiments using wild-type vs. disease variant, multiple phenotypic readouts","pmids":["34551295"],"is_preprint":false},{"year":2019,"finding":"Oxidation of Trp395 in UQCRC1 (identified in a cardiotoxin myodegeneration model) causes large structural changes in mitochondrial complex III; molecular dynamics simulation shows decreased plasticity of the complex due to cross-talk among matrix-facing and intermembrane space subunits, impairing electron flow from cytochrome c.","method":"Proteomic identification of oxidized proteins from muscle biopsies, molecular dynamics simulation of oxidized vs. non-oxidized complex III","journal":"Scientific reports","confidence":"Low","confidence_rationale":"Tier 4 / Weak — molecular dynamics simulation with proteomic correlation only; no in vitro enzymatic reconstitution or mutagenesis to validate structural predictions","pmids":["31337785"],"is_preprint":false},{"year":2021,"finding":"PCSK9 mediates oxLDL-induced pyroptosis of vascular endothelial cells by inhibiting UQCRC1 expression, leading to mitochondrial membrane potential collapse, increased ROS generation, and mitochondrial dysfunction; PCSK9 silencing reverses UQCRC1 suppression and the associated mitochondrial damage.","method":"siRNA knockdown of PCSK9 and UQCRC1, lentiviral PCSK9 overexpression, ROS probe assay, JC-1 mitochondrial membrane potential staining, western blot, RT-qPCR in HUVECs","journal":"International journal of molecular medicine","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, multiple methods (KD, OE, ROS, MMP), but pathway placement is associative with UQCRC1 acting downstream of PCSK9","pmids":["33576442"],"is_preprint":false},{"year":2020,"finding":"FGF21 inhibits oxLDL-induced HUVEC pyroptosis through a TET2-UQCRC1-ROS pathway: FGF21 upregulates TET2, which upregulates UQCRC1 expression; UQCRC1 silencing aggravates pyroptosis and impairs mitochondrial function and increases ROS production.","method":"siRNA knockdown of UQCRC1 and TET2, FGF21 treatment, ROS measurement, mitochondrial function assays, western blot in HUVECs","journal":"DNA and cell biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, multiple methods (KD, functional assays), pathway ordering established by genetic intervention","pmids":["32101022"],"is_preprint":false},{"year":2020,"finding":"Melatonin prevents endothelial cell pyroptosis by upregulating TET2 to inhibit methylation of the UQCRC1 promoter, thereby increasing UQCRC1 expression, improving mitochondrial function, and reducing oxidative stress.","method":"Melatonin treatment of HUVECs, TET2 upregulation assay, UQCRC1 methylation analysis, mitochondrial function assays, NLRP3/caspase-1/IL-1β expression","journal":"Biochemistry and cell biology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — single lab, multiple methods including methylation analysis and functional mitochondrial readouts, but no direct methylation writer/eraser mutagenesis","pmids":["33332241"],"is_preprint":false},{"year":2022,"finding":"UQCRC1 overexpression in pancreatic cancer cells inhibits NK cell cytotoxicity and chemotaxis via elevated extracellular ATP and its metabolite adenosine acting through P2Y11R and A2AR receptors; mechanistically, the UQCRC1/eATP axis reduces CCL5 chemokine expression in cancer cells and shifts the balance of activating receptor DNAM-1 vs. inhibitory receptor CD96 on NK cells toward exhaustion.","method":"UQCRC1 knockdown/overexpression in PC cells, NK cell cytotoxicity assays, NK cell chemotaxis assays, adoptive NK cell therapy in subcutaneous mouse model, CIBERSORTx analysis, P2Y11R/A2AR receptor blocking experiments, CCL5 expression analysis","journal":"Frontiers in oncology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — single lab, multiple orthogonal methods (in vitro functional assays, in vivo mouse model, receptor blocking), mechanistic pathway defined","pmids":["35769718"],"is_preprint":false},{"year":2016,"finding":"Knockdown of Uqcrc1 in mouse spermatocytes (GC2 cells) decreases mitochondrial membrane potential and induces apoptosis, establishing that UQCRC1 is required for mitochondrial membrane potential maintenance and cell survival in spermatocytes.","method":"siRNA knockdown of Uqcrc1 in GC2 cells, flow cytometry for mitochondrial membrane potential and apoptosis, ATP measurement","journal":"Environmental toxicology and pharmacology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — clean loss-of-function with defined cellular phenotype, single lab, single cell type","pmids":["27525561"],"is_preprint":false},{"year":2026,"finding":"UQCRC1 deficiency impairs mitophagy via PINK1-dependent mechanisms: UQCRC1 mutation or depletion in SH-SY5Y cells and Drosophila reduces PINK1 mRNA levels; overexpression of Pink1 rescues locomotion and mitophagy defects in uqcrc1-deficient flies; PINK1 activators (kinetin and MTK458) produce similar protective effects.","method":"UQCRC1 mutant/KD in SH-SY5Y cells and Drosophila, PINK1 mRNA quantification, Pink1 overexpression rescue, pharmacological PINK1 activation (kinetin, MTK458), mitophagy flux assays, locomotor behavioral assays","journal":"NPJ Parkinson's disease","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis across two model systems, multiple orthogonal methods (genetic rescue, pharmacological rescue, mitophagy assays), PINK1 identified as downstream effector","pmids":["41540037"],"is_preprint":false},{"year":2025,"finding":"UQCRC1 deficiency triggers lysosomal Ca2+ overload-mediated proteolytic dysfunction and activates neuronal apoptotic pathways; AAV-mediated UQCRC1 overexpression reverses these pathological changes via AMPK signaling, as pharmacological AMPK inhibition abolishes the therapeutic benefit.","method":"Conditional UQCRC1 knockdown in APP/PS1 AD model mice, transmission electron microscopy (lysosomal morphology), AAV-mediated UQCRC1 overexpression, AMPK pharmacological inhibition, behavioral cognitive testing","journal":"Molecular neurobiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — single lab, multiple orthogonal methods (TEM, AAV rescue, pharmacological epistasis), but AMPK positioning relies on inhibitor pharmacology without direct biochemical confirmation","pmids":["40588669"],"is_preprint":false},{"year":2025,"finding":"UQCRC1 downregulation impairs AMPK activation and disrupts autophagic flux, leading to cognitive deficits; pharmacological activation of AMPK or enhancement of lysosomal activity in UQCRC1-deficient mice restores mitochondrial redox homeostasis and ameliorates cognitive impairment.","method":"Mouse model with downregulated UQCRC1, behavioral paradigms, ATP measurement, ROS detection, AMPK signaling analysis, autophagic flux assessment, pharmacological AMPK activation and lysosomal enhancement","journal":"PeerJ","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — single lab, multiple methods (genetic model, pharmacological interventions, metabolic assays), but AMPK pathway positioning based on correlational and pharmacological data","pmids":["40832581"],"is_preprint":false},{"year":2025,"finding":"UQCRC1 downregulation in the dentate gyrus reduces cilia (identified via RNA sequencing), impairs hippocampal theta and gamma oscillations and wide-wave interneuron activity, and causes cognitive deficits; overexpression of Ttbk2 in the DG restores ciliary function and rescues cognitive impairments and neural oscillations.","method":"Uqcrc1+/- mice, RNA sequencing of hippocampus, in vivo electrophysiology, Ttbk2 overexpression in dentate gyrus, behavioral cognitive testing, synaptic protein quantification","journal":"Neuroscience bulletin","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — single lab, multiple orthogonal methods (transcriptomics, electrophysiology, genetic rescue), but novel pathway (UQCRC1→cilia→cognition) needs independent replication","pmids":["41182502"],"is_preprint":false},{"year":2025,"finding":"Loganin inhibits DNMT1 (confirmed by molecular docking, surface plasmon resonance KD = 13.5 μM, and in vitro DNMT1 enzymatic inhibition assay), reduces methylation of the UQCRC1 promoter, restores UQCRC1 expression and mitochondrial complex III activity after myocardial infarction, and halts cardiac remodeling.","method":"Mouse MI model, RNA sequencing, promoter methylation analysis, complex III activity assay, molecular docking, surface plasmon resonance, in vitro DNMT1 enzymatic assay, Loganin treatment","journal":"Phytomedicine","confidence":"Medium","confidence_rationale":"Tier 1–2 / Moderate — direct biochemical binding assay (SPR) and enzymatic inhibition of DNMT1, coupled to functional methylation-UQCRC1-complex III rescue; single lab","pmids":["40645070"],"is_preprint":false},{"year":2007,"finding":"Two promoter polymorphisms in UQCRC1 (g.13487C>T and g.13709G>C) affect promoter activity: the TTCC haplotype produces 43–49% higher promoter activity than the CCGG haplotype in three cell lines, and is associated with greater subcutaneous fat depth and skeletal muscle lipid accumulation in cattle.","method":"Promoter activity luciferase reporter assays in three cell lines, genotyping and statistical association in Wagyu x Limousin F2 cattle","journal":"Obesity (Silver Spring, Md.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct promoter activity measurement in multiple cell lines, but functional link between promoter polymorphisms and fat accumulation is associative rather than mechanistically dissected","pmids":["18198295"],"is_preprint":false},{"year":2024,"finding":"Formoterol, acting via β2-adrenergic receptor (β2AR), restores mitochondrial complex III-linked respiration, normalizes fusion/fission dynamics (upregulating Drp-1 while not altering Mfn2), restores ERK signaling, inhibits Akt overactivity, and improves mitochondrial transport in cells carrying the UQCRC1 p.Tyr314Ser mutation.","method":"Cell model with UQCRC1 p.Tyr314Ser variant, formoterol treatment with/without β2AR antagonist, mitochondrial respiration assay, mitochondrial DNA copy number, Drp-1/Mfn2/Parkin western blot, ERK/Akt signaling analysis, mitochondrial morphology imaging","journal":"Biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — single lab, multiple orthogonal methods (respiration, signaling, morphology), β2AR dependence confirmed by receptor antagonist","pmids":["38666843"],"is_preprint":false}],"current_model":"UQCRC1 is an evolutionarily conserved core subunit of mitochondrial respiratory chain complex III (ubiquinol-cytochrome c reductase) that is essential for embryo survival and complex III assembly/activity; it physically associates with cytochrome c to retain it in mitochondria, preventing cytochrome c release, caspase cascade activation, and neuronal apoptosis, while its loss or disease-associated mutations impair OXPHOS and ATP production, trigger ROS generation, disrupt mitophagy via a PINK1-dependent pathway, activate AMPK-lysosomal dysfunction, and cause age-dependent dopaminergic neurodegeneration; in cancer contexts, UQCRC1 overexpression elevates extracellular ATP release through pannexin 1, driving tumor cell proliferation via the ATP/P2Y2-RTK/AKT axis and impairing NK cell surveillance, and its expression is epigenetically regulated by DNA methylation through DNMT1 and TET2."},"narrative":{"mechanistic_narrative":"UQCRC1 is an evolutionarily conserved core subunit of mitochondrial respiratory chain complex III (ubiquinol-cytochrome c reductase) that is required for embryonic viability and for normal complex III assembly, enzymatic activity, ATP production, and neuronal survival [PMID:30666338, PMID:33141179]. Beyond its catalytic role in oxidative phosphorylation, UQCRC1 physically associates with cytochrome c and retains it in mitochondria; its deficiency increases cytoplasmic cytochrome c, activates the caspase cascade, and drives neuronal apoptosis, which is reversed by cytochrome c depletion or anti-apoptotic p35 expression [PMID:34551295]. Disease-associated missense variants (p.Tyr314Ser, p.Ile311Leu) act as loss-of-function alleles that impair complex III activity and cause age-dependent dopaminergic neurodegeneration, locomotor decline, and peripheral neuropathy across human cell, Drosophila, and mouse models [PMID:33141179, PMID:34551295]. UQCRC1 dysfunction perturbs downstream quality-control and signaling programs: it reduces PINK1 expression and impairs mitophagy, a defect rescuable by Pink1 overexpression or PINK1 activators [PMID:41540037], and it disrupts AMPK signaling and lysosomal proteolytic function, producing cognitive deficits that can be corrected by UQCRC1 restoration or AMPK/lysosomal activation [PMID:40588669, PMID:40832581]. In cancer, UQCRC1 overexpression elevates OXPHOS-derived ATP that is released through pannexin 1 to drive proliferation via the ATP/P2Y2-RTK/AKT axis [PMID:32089737] and to suppress NK-cell cytotoxicity through purinergic signaling [PMID:35769718]. UQCRC1 expression is controlled by promoter DNA methylation, with the methyltransferase DNMT1 and the demethylase TET2 governing its transcription [PMID:32101022, PMID:33332241, PMID:40645070].","teleology":[{"year":2007,"claim":"Established that UQCRC1 transcription is genetically tunable, linking promoter variation to its expression level and a metabolic phenotype.","evidence":"Luciferase promoter reporter assays of haplotypes in three cell lines plus association genotyping in cattle","pmids":["18198295"],"confidence":"Medium","gaps":["Link between promoter activity and fat accumulation is associative","No human relevance demonstrated","Trans-acting regulators not identified here"]},{"year":2016,"claim":"Showed UQCRC1 is required to maintain mitochondrial membrane potential and cell survival, beyond a purely housekeeping bioenergetic role.","evidence":"siRNA knockdown in mouse GC2 spermatocytes with MMP, apoptosis, and ATP readouts","pmids":["27525561"],"confidence":"Medium","gaps":["Single cell type","Mechanism connecting loss to apoptosis not defined"]},{"year":2019,"claim":"Defined UQCRC1 as essential for development and for complex III formation, activity, and bioenergetics in the brain, with functional consequences for cognition and ischemic tolerance.","evidence":"Knockout/heterozygous mouse model with complex III activity, ATP, MMP, ROS, behavioral, and ischemia assays","pmids":["30666338"],"confidence":"High","gaps":["Does not resolve cell-type-specific requirements","Mechanism linking partial loss to behavior not dissected"]},{"year":2019,"claim":"Proposed that oxidative modification of a UQCRC1 residue (Trp395) can structurally compromise complex III electron flow, offering a redox-damage mechanism.","evidence":"Proteomic identification of oxidized UQCRC1 from muscle biopsies plus molecular dynamics simulation of complex III","pmids":["31337785"],"confidence":"Low","gaps":["Computational prediction without enzymatic reconstitution or mutagenesis","Causality between oxidation and dysfunction not experimentally tested"]},{"year":2020,"claim":"Identified UQCRC1 missense variants as causes of dopaminergic neurodegeneration via complex III dysfunction, establishing a Mendelian-type disease mechanism.","evidence":"CRISPR knock-in SH-SY5Y cells, Drosophila and mouse knock-in models, complex III assays, EM, behavior, levodopa rescue","pmids":["33141179"],"confidence":"High","gaps":["Why dopaminergic neurons are selectively vulnerable is unexplained","Whether variants act solely through complex III loss vs. gain-of-toxicity unresolved"]},{"year":2021,"claim":"Established that UQCRC1 retains cytochrome c in mitochondria and that its loss triggers caspase-dependent neuronal apoptosis, defining the proximal death mechanism.","evidence":"Co-IP, cellular fractionation, caspase assays, and genetic epistasis (cyt-c depletion, p35) in Drosophila and human neuronal cells","pmids":["34551295"],"confidence":"High","gaps":["Structural basis of UQCRC1-cytochrome c retention not resolved","Whether retention is separable from catalytic function unclear"]},{"year":2021,"claim":"Demonstrated the disease variant is loss-of-function by showing wild-type but not p.Tyr314Ser UQCRC1 rescues knockout lethality and neurodegeneration.","evidence":"Drosophila neuron-specific RNAi and rescue with wild-type vs. mutant UQCRC1, dopaminergic neuron counts and locomotor assays","pmids":["34551295"],"confidence":"High","gaps":["Residual partial function of variant not quantified at the enzyme level"]},{"year":2020,"claim":"Revealed an oncogenic role in which UQCRC1-driven OXPHOS produces ATP exported via pannexin 1 to fuel proliferation through ATP/P2Y2-RTK/AKT signaling.","evidence":"Extracellular flux, RNA-Seq, knockdown/overexpression in pancreatic cancer lines, in vivo transplant, ATP-release blockade","pmids":["32089737"],"confidence":"High","gaps":["Why cancer cells favor UQCRC1 upregulation not established","Direct UQCRC1-pannexin 1 coupling mechanism unknown"]},{"year":2020,"claim":"Placed UQCRC1 downstream of TET2 in an FGF21/melatonin–TET2 axis controlling endothelial pyroptosis through promoter demethylation.","evidence":"siRNA of UQCRC1/TET2, FGF21 and melatonin treatment, promoter methylation and mitochondrial function assays in HUVECs","pmids":["32101022","33332241"],"confidence":"Medium","gaps":["No direct demonstration TET2 acts at the UQCRC1 promoter via mutagenesis","Pathway ordering inferred from intervention rather than direct binding"]},{"year":2021,"claim":"Showed UQCRC1 functions as a node in oxLDL-induced endothelial injury, suppressed by PCSK9 to promote ROS and mitochondrial dysfunction.","evidence":"PCSK9/UQCRC1 knockdown and PCSK9 overexpression with ROS and JC-1 MMP assays in HUVECs","pmids":["33576442"],"confidence":"Medium","gaps":["UQCRC1 placement downstream of PCSK9 is associative","Direct regulatory mechanism not defined"]},{"year":2022,"claim":"Extended the cancer role to immune evasion, linking UQCRC1-driven extracellular ATP/adenosine to NK-cell suppression via purinergic receptors and chemokine modulation.","evidence":"UQCRC1 knockdown/overexpression, NK cytotoxicity/chemotaxis assays, adoptive NK therapy mouse model, P2Y11R/A2AR blockade, CCL5 analysis","pmids":["35769718"],"confidence":"Medium","gaps":["Single lab","Relative contribution of ATP vs. adenosine not fully separated"]},{"year":2024,"claim":"Identified pharmacological correction of variant phenotypes via β2AR signaling, restoring complex III respiration and rebalancing fusion/fission and ERK/Akt.","evidence":"Formoterol with β2AR antagonist in p.Tyr314Ser cells, respiration, mtDNA copy number, morphology, and signaling readouts","pmids":["38666843"],"confidence":"Medium","gaps":["Cell-line only","How β2AR signaling restores complex III activity mechanistically unclear"]},{"year":2025,"claim":"Connected UQCRC1 deficiency to lysosomal Ca2+ overload, proteolytic dysfunction, and AMPK-dependent rescue, defining a downstream proteostasis/autophagy axis.","evidence":"Conditional knockdown in APP/PS1 and downregulated UQCRC1 mice, TEM, AAV rescue, AMPK pharmacological modulation, autophagic flux and cognitive assays","pmids":["40588669","40832581"],"confidence":"Medium","gaps":["AMPK positioning relies on pharmacology without direct biochemical confirmation","Mechanistic link between complex III loss and lysosomal Ca2+ overload unresolved"]},{"year":2025,"claim":"Uncovered a non-canonical UQCRC1→cilia→neural oscillation pathway underlying cognitive deficits, rescuable by Ttbk2.","evidence":"Uqcrc1+/- mice, hippocampal RNA-seq, in vivo electrophysiology, Ttbk2 overexpression, behavioral testing","pmids":["41182502"],"confidence":"Medium","gaps":["Novel pathway needs independent replication","How a mitochondrial subunit regulates ciliary gene expression is unknown"]},{"year":2025,"claim":"Demonstrated that DNMT1-mediated promoter methylation directly represses UQCRC1, and its pharmacological inhibition restores complex III activity in cardiac disease.","evidence":"Mouse MI model, promoter methylation and complex III assays, Loganin with SPR binding (KD=13.5 μM) and in vitro DNMT1 enzymatic inhibition","pmids":["40645070"],"confidence":"Medium","gaps":["Whether DNMT1 acts directly at the UQCRC1 promoter shown indirectly","Single lab"]},{"year":2026,"claim":"Established PINK1 as a downstream effector of UQCRC1 in mitophagy, providing a mechanistic and therapeutic link to mitochondrial quality control.","evidence":"UQCRC1 mutant/knockdown in SH-SY5Y and Drosophila, PINK1 mRNA quantification, Pink1 overexpression and PINK1-activator (kinetin, MTK458) rescue, mitophagy flux assays","pmids":["41540037"],"confidence":"High","gaps":["How UQCRC1 loss reduces PINK1 mRNA mechanistically not defined","Whether mitophagy defect is cause or consequence of neurodegeneration not fully separated"]},{"year":null,"claim":"How UQCRC1 mechanistically couples its complex III/cytochrome c retention role to downstream PINK1 transcription, AMPK/lysosomal control, and ciliary gene programs remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of UQCRC1-cytochrome c retention","Signaling route from complex III dysfunction to nuclear/transcriptional programs unknown","Selective dopaminergic vulnerability unexplained"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016491","term_label":"oxidoreductase activity","supporting_discovery_ids":[2,3,5]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[2,3]}],"localization":[{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[0,2,3]}],"pathway":[{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[1,2,3]},{"term_id":"R-HSA-5357801","term_label":"Programmed Cell Death","supporting_discovery_ids":[0,10]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[11,13]}],"complexes":["mitochondrial respiratory chain complex III (ubiquinol-cytochrome c reductase)"],"partners":["CYCS"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P31930","full_name":"Cytochrome b-c1 complex subunit 1, mitochondrial","aliases":["Complex III subunit 1","Core protein I","Ubiquinol-cytochrome-c reductase complex core protein 1"],"length_aa":480,"mass_kda":52.6,"function":"Component of the ubiquinol-cytochrome c oxidoreductase, a multisubunit transmembrane complex that is part of the mitochondrial electron transport chain which drives oxidative phosphorylation. The respiratory chain contains 3 multisubunit complexes succinate dehydrogenase (complex II, CII), ubiquinol-cytochrome c oxidoreductase (cytochrome b-c1 complex, complex III, CIII) and cytochrome c oxidase (complex IV, CIV), that cooperate to transfer electrons derived from NADH and succinate to molecular oxygen, creating an electrochemical gradient over the inner membrane that drives transmembrane transport and the ATP synthase. The cytochrome b-c1 complex catalyzes electron transfer from ubiquinol to cytochrome c, linking this redox reaction to translocation of protons across the mitochondrial inner membrane, with protons being carried across the membrane as hydrogens on the quinol. In the process called Q cycle, 2 protons are consumed from the matrix, 4 protons are released into the intermembrane space and 2 electrons are passed to cytochrome c (By similarity). The 2 core subunits UQCRC1/QCR1 and UQCRC2/QCR2 are homologous to the 2 mitochondrial-processing peptidase (MPP) subunits beta-MPP and alpha-MPP respectively, and they seem to have preserved their MPP processing properties (By similarity). May be involved in the in situ processing of UQCRFS1 into the mature Rieske protein and its mitochondrial targeting sequence (MTS)/subunit 9 when incorporated into complex III (Probable). Seems to play an important role in the maintenance of proper mitochondrial function in nigral dopaminergic neurons (PubMed:33141179)","subcellular_location":"Mitochondrion inner membrane","url":"https://www.uniprot.org/uniprotkb/P31930/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/UQCRC1","classification":"Not Classified","n_dependent_lines":637,"n_total_lines":1208,"dependency_fraction":0.527317880794702},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"ASS1","stoichiometry":0.2},{"gene":"PHGDH","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/UQCRC1","total_profiled":1310},"omim":[{"mim_id":"619279","title":"PARKINSONISM WITH POLYNEUROPATHY; PKNPY","url":"https://www.omim.org/entry/619279"},{"mim_id":"191329","title":"UBIQUINOL-CYTOCHROME c REDUCTASE CORE PROTEIN II; UQCRC2","url":"https://www.omim.org/entry/191329"},{"mim_id":"191328","title":"UBIQUINOL-CYTOCHROME c REDUCTASE CORE PROTEIN I; UQCRC1","url":"https://www.omim.org/entry/191328"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Mitochondria","reliability":"Supported"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"heart muscle","ntpm":604.8},{"tissue":"skeletal muscle","ntpm":718.0},{"tissue":"tongue","ntpm":825.7}],"url":"https://www.proteinatlas.org/search/UQCRC1"},"hgnc":{"alias_symbol":["D3S3191","QCR1","UQCR1"],"prev_symbol":[]},"alphafold":{"accession":"P31930","domains":[{"cath_id":"3.30.830.10","chopping":"48-250","consensus_level":"medium","plddt":95.862,"start":48,"end":250},{"cath_id":"3.30.830.10","chopping":"272-473","consensus_level":"high","plddt":96.3807,"start":272,"end":473}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P31930","model_url":"https://alphafold.ebi.ac.uk/files/AF-P31930-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P31930-F1-predicted_aligned_error_v6.png","plddt_mean":91.44},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=UQCRC1","jax_strain_url":"https://www.jax.org/strain/search?query=UQCRC1"},"sequence":{"accession":"P31930","fasta_url":"https://rest.uniprot.org/uniprotkb/P31930.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P31930/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P31930"}},"corpus_meta":[{"pmid":"33141179","id":"PMC_33141179","title":"Mitochondrial UQCRC1 mutations cause autosomal dominant parkinsonism with polyneuropathy.","date":"2020","source":"Brain : a journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/33141179","citation_count":58,"is_preprint":false},{"pmid":"32089737","id":"PMC_32089737","title":"Mitochondrial Protein UQCRC1 is Oncogenic and a Potential Therapeutic Target for Pancreatic Cancer.","date":"2020","source":"Theranostics","url":"https://pubmed.ncbi.nlm.nih.gov/32089737","citation_count":51,"is_preprint":false},{"pmid":"30666338","id":"PMC_30666338","title":"Critical role of UQCRC1 in embryo survival, brain ischemic tolerance and normal cognition in mice.","date":"2019","source":"Cellular and molecular life sciences : CMLS","url":"https://pubmed.ncbi.nlm.nih.gov/30666338","citation_count":45,"is_preprint":false},{"pmid":"33576442","id":"PMC_33576442","title":"PCSK9 mediates the oxidative low‑density lipoprotein‑induced pyroptosis of vascular endothelial cells via the UQCRC1/ROS pathway.","date":"2021","source":"International journal of molecular medicine","url":"https://pubmed.ncbi.nlm.nih.gov/33576442","citation_count":33,"is_preprint":false},{"pmid":"34551295","id":"PMC_34551295","title":"UQCRC1 engages cytochrome c for neuronal apoptotic cell death.","date":"2021","source":"Cell reports","url":"https://pubmed.ncbi.nlm.nih.gov/34551295","citation_count":32,"is_preprint":false},{"pmid":"32101022","id":"PMC_32101022","title":"Inhibition of the ox-LDL-Induced Pyroptosis by FGF21 of Human Umbilical Vein Endothelial Cells Through the TET2-UQCRC1-ROS Pathway.","date":"2020","source":"DNA and cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/32101022","citation_count":31,"is_preprint":false},{"pmid":"27525561","id":"PMC_27525561","title":"2,2',4,4'-Tetrabromodiphenyl ether injures cell viability and mitochondrial function of mouse spermatocytes by decreasing mitochondrial proteins Atp5b and Uqcrc1.","date":"2016","source":"Environmental toxicology and pharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/27525561","citation_count":28,"is_preprint":false},{"pmid":"27845902","id":"PMC_27845902","title":"Systematic expression analysis of the mitochondrial complex III subunits identifies UQCRC1 as biomarker in clear cell renal cell carcinoma.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/27845902","citation_count":26,"is_preprint":false},{"pmid":"18198295","id":"PMC_18198295","title":"Functional UQCRC1 polymorphisms affect promoter activity and body lipid accumulation.","date":"2007","source":"Obesity (Silver Spring, Md.)","url":"https://pubmed.ncbi.nlm.nih.gov/18198295","citation_count":26,"is_preprint":false},{"pmid":"31337785","id":"PMC_31337785","title":"Tryptophan Oxidation in the UQCRC1 Subunit of Mitochondrial Complex III (Ubiquinol-Cytochrome C Reductase) in a Mouse Model of Myodegeneration Causes Large Structural Changes in the Complex: A Molecular Dynamics Simulation Study.","date":"2019","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/31337785","citation_count":21,"is_preprint":false},{"pmid":"33332241","id":"PMC_33332241","title":"Melatonin inhibits vascular endothelial cell pyroptosis by improving mitochondrial function via up-regulation and demethylation of UQCRC1.","date":"2020","source":"Biochemistry and cell biology = Biochimie et biologie cellulaire","url":"https://pubmed.ncbi.nlm.nih.gov/33332241","citation_count":19,"is_preprint":false},{"pmid":"35769718","id":"PMC_35769718","title":"Increased Expression of Mitochondrial UQCRC1 in Pancreatic Cancer Impairs Antitumor Immunity of Natural Killer Cells via Elevating Extracellular ATP.","date":"2022","source":"Frontiers in oncology","url":"https://pubmed.ncbi.nlm.nih.gov/35769718","citation_count":12,"is_preprint":false},{"pmid":"36570444","id":"PMC_36570444","title":"UQCRC1 variants in early-onset and familial Parkinson's disease in a Taiwanese cohort.","date":"2022","source":"Frontiers in neurology","url":"https://pubmed.ncbi.nlm.nih.gov/36570444","citation_count":4,"is_preprint":false},{"pmid":"40340509","id":"PMC_40340509","title":"Emodin ameliorates dopaminergic neuron loss in the MPP+ induced parkinson's disease model: significant inhibition of ferroptosis by activating UQCRC1 protein.","date":"2025","source":"Natural product research","url":"https://pubmed.ncbi.nlm.nih.gov/40340509","citation_count":4,"is_preprint":false},{"pmid":"37984314","id":"PMC_37984314","title":"Rare variant analysis of UQCRC1 in Chinese patients with early-onset Parkinson's disease.","date":"2023","source":"Neurobiology of aging","url":"https://pubmed.ncbi.nlm.nih.gov/37984314","citation_count":3,"is_preprint":false},{"pmid":"32302684","id":"PMC_32302684","title":"CYC1, SDHA, UQCRC1, UQCRQ, and SDHB might be important biomarkers in kidney transplant rejection.","date":"2020","source":"Clinica chimica acta; international journal of clinical chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/32302684","citation_count":3,"is_preprint":false},{"pmid":"38666843","id":"PMC_38666843","title":"Formoterol Acting via β2-Adrenoreceptor Restores Mitochondrial Dysfunction Caused by Parkinson's Disease-Related UQCRC1 Mutation and Improves Mitochondrial Homeostasis Including Dynamic and Transport.","date":"2024","source":"Biology","url":"https://pubmed.ncbi.nlm.nih.gov/38666843","citation_count":3,"is_preprint":false},{"pmid":"40588669","id":"PMC_40588669","title":"UQCRC1 is a Key Pathogenic Determinant and Potential Therapeutic Target for Cognitive Impairment in Alzheimer's Disease.","date":"2025","source":"Molecular neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/40588669","citation_count":2,"is_preprint":false},{"pmid":"40346065","id":"PMC_40346065","title":"Protein-truncating variants in UQCRC1 are associated with Parkinson's disease: evidence from half-million people.","date":"2025","source":"NPJ Parkinson's disease","url":"https://pubmed.ncbi.nlm.nih.gov/40346065","citation_count":2,"is_preprint":false},{"pmid":"40801581","id":"PMC_40801581","title":"Intranasal Mitochondrial Transplantation Restores Mitochondrial Function and Modulates Glial-Neuronal Interactions in a Genetic Parkinson's Disease Model of UQCRC1 Mutation.","date":"2025","source":"Cells","url":"https://pubmed.ncbi.nlm.nih.gov/40801581","citation_count":2,"is_preprint":false},{"pmid":"40645070","id":"PMC_40645070","title":"Loganin epigenetically rescues mitochondrial complex III dysfunction via DNMT1-UQCRC1 demethylation to halt cardiac remodeling after myocardial infarction.","date":"2025","source":"Phytomedicine : international journal of phytotherapy and phytopharmacology","url":"https://pubmed.ncbi.nlm.nih.gov/40645070","citation_count":2,"is_preprint":false},{"pmid":"33070102","id":"PMC_33070102","title":"Generation of a human induced pluripotent stem cell (iPSC) line (IBMS-iPSC-057-05) from a patient with familial parkinsonism and polyneuropathy having a heterozygous p.Y314S mutation in UQCRC1 gene.","date":"2020","source":"Stem cell research","url":"https://pubmed.ncbi.nlm.nih.gov/33070102","citation_count":1,"is_preprint":false},{"pmid":"41540037","id":"PMC_41540037","title":"UQCRC1 deficiency impairs mitophagy via PINK1-dependent mechanisms in Parkinson's disease.","date":"2026","source":"NPJ Parkinson's disease","url":"https://pubmed.ncbi.nlm.nih.gov/41540037","citation_count":1,"is_preprint":false},{"pmid":"39752790","id":"PMC_39752790","title":"A rare variant in the UQCRC1 gene, p.(Gly405Val) in three Austrian Parkinson's patients.","date":"2024","source":"Parkinsonism & related disorders","url":"https://pubmed.ncbi.nlm.nih.gov/39752790","citation_count":1,"is_preprint":false},{"pmid":"40832581","id":"PMC_40832581","title":"UQCRC1 downregulation impairs cognitive function in mice via AMPK inactivation.","date":"2025","source":"PeerJ","url":"https://pubmed.ncbi.nlm.nih.gov/40832581","citation_count":0,"is_preprint":false},{"pmid":"41182502","id":"PMC_41182502","title":"Downregulation of UQCRC1 Expression Leads to Cognitive Decline by Disrupting the Cilia in the Dentate Gyrus.","date":"2025","source":"Neuroscience bulletin","url":"https://pubmed.ncbi.nlm.nih.gov/41182502","citation_count":0,"is_preprint":false},{"pmid":"41838561","id":"PMC_41838561","title":"Rhein-Emodin Combination Activates UQCRC1 to Attenuate MPP+-Induced Ferroptosis in Dopaminergic Neurons.","date":"2026","source":"Chemistry & biodiversity","url":"https://pubmed.ncbi.nlm.nih.gov/41838561","citation_count":0,"is_preprint":false},{"pmid":"41783485","id":"PMC_41783485","title":"Characterization of a UQCRC1 variant in a patient with progressive weakness, pain and sleep issues reveals a functional mitochondrial defect restored by mitochondrial transplantation.","date":"2026","source":"Molecular genetics and metabolism reports","url":"https://pubmed.ncbi.nlm.nih.gov/41783485","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":15532,"output_tokens":4957,"usd":0.060476,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":13327,"output_tokens":4858,"usd":0.094043,"stage2_stop_reason":"end_turn"},"total_usd":0.154519,"stage1_batch_id":"msgbatch_017qqVz33Ga63SCDwzb35XPb","stage2_batch_id":"msgbatch_01Scr2Ei9x4HJMiRGxwrmvLK","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2021,\n      \"finding\": \"UQCRC1 physically associates with cytochrome c (cyt-c), and UQCRC1 deficiency increases cytochrome c in the cytoplasmic fraction and activates the caspase cascade, leading to neuronal apoptosis; depleting cyt-c or expressing anti-apoptotic p35 ameliorates UQCRC1-deficiency-mediated neurodegeneration.\",\n      \"method\": \"Co-immunoprecipitation/association assay, cellular fractionation, genetic rescue experiments in Drosophila and human neuronal cell lines, caspase activity assays\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal association established, multiple orthogonal methods (co-IP, fractionation, genetic epistasis with cyt-c depletion and p35 rescue), validated in two model systems\",\n      \"pmids\": [\"34551295\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"UQCRC1 overexpression in pancreatic cancer cells increases mitochondrial oxidative phosphorylation (OXPHOS) and ATP production; the overproduced ATP is released extracellularly via the pannexin 1 channel and acts as an autocrine/paracrine agent to promote cell proliferation through the ATP/P2Y2-RTK/AKT signaling axis.\",\n      \"method\": \"Extracellular flux analysis, RNA-Seq, UQCRC1 knockdown/overexpression in PANC-1 and CFPAC-1 cells, in vivo mouse transplant models, ATP release blockage experiments\",\n      \"journal\": \"Theranostics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (extracellular flux, genetic KD/OE, in vivo models, pathway inhibition), single lab with strong mechanistic follow-up\",\n      \"pmids\": [\"32089737\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Homozygous knockout of UQCRC1 causes embryonic lethality in mice; heterozygous loss decreases complex III formation, complex III activity, and ATP content in the brain, worsens neurological outcome after ischemia, reduces mitochondrial membrane potential, increases free radicals, and impairs learning and memory.\",\n      \"method\": \"Knockout/heterozygous mouse model, biochemical complex III activity assays, ATP measurement, mitochondrial membrane potential assay, ROS detection, behavioral testing (Barnes maze, novel object recognition), brain ischemia models\",\n      \"journal\": \"Cellular and molecular life sciences : CMLS\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean KO/heterozygous mouse model with multiple orthogonal functional readouts (complex III activity, ATP, MMP, ROS, behavior, ischemia tolerance)\",\n      \"pmids\": [\"30666338\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Mutant UQCRC1 (p.Tyr314Ser, p.Ile311Leu) causes neurite degeneration and mitochondrial respiratory chain complex III dysfunction in SH-SY5Y dopaminergic cells; knock-in Drosophila and mouse models show age-dependent locomotor defects, dopaminergic neuronal loss, peripheral neuropathy, impaired complex III activity, and aberrant mitochondrial ultrastructures in nigral neurons.\",\n      \"method\": \"CRISPR/Cas9 knock-in in SH-SY5Y cells, Drosophila knock-in model, mouse knock-in model, respiratory chain complex III activity assay, electron microscopy, behavioral testing, levodopa rescue experiment\",\n      \"journal\": \"Brain : a journal of neurology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple model systems (human cell line, Drosophila, mouse), multiple orthogonal methods (enzymatic assay, EM, behavior, pharmacological rescue)\",\n      \"pmids\": [\"33141179\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Neuronal knockdown of uqcrc1 in Drosophila causes age-dependent dopaminergic neuron reduction and locomotor decline; lethality of uqcrc1-KO is rescued by neuronal UQCRC1 expression but not by the disease-causing variant (p.Tyr314Ser), establishing the variant as loss-of-function pathogenic.\",\n      \"method\": \"Drosophila neuron-specific RNAi knockdown, genetic rescue with wild-type vs. mutant UQCRC1, dopaminergic neuron counting, locomotor assays\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — clean genetic epistasis with rescue experiments using wild-type vs. disease variant, multiple phenotypic readouts\",\n      \"pmids\": [\"34551295\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Oxidation of Trp395 in UQCRC1 (identified in a cardiotoxin myodegeneration model) causes large structural changes in mitochondrial complex III; molecular dynamics simulation shows decreased plasticity of the complex due to cross-talk among matrix-facing and intermembrane space subunits, impairing electron flow from cytochrome c.\",\n      \"method\": \"Proteomic identification of oxidized proteins from muscle biopsies, molecular dynamics simulation of oxidized vs. non-oxidized complex III\",\n      \"journal\": \"Scientific reports\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — molecular dynamics simulation with proteomic correlation only; no in vitro enzymatic reconstitution or mutagenesis to validate structural predictions\",\n      \"pmids\": [\"31337785\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"PCSK9 mediates oxLDL-induced pyroptosis of vascular endothelial cells by inhibiting UQCRC1 expression, leading to mitochondrial membrane potential collapse, increased ROS generation, and mitochondrial dysfunction; PCSK9 silencing reverses UQCRC1 suppression and the associated mitochondrial damage.\",\n      \"method\": \"siRNA knockdown of PCSK9 and UQCRC1, lentiviral PCSK9 overexpression, ROS probe assay, JC-1 mitochondrial membrane potential staining, western blot, RT-qPCR in HUVECs\",\n      \"journal\": \"International journal of molecular medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, multiple methods (KD, OE, ROS, MMP), but pathway placement is associative with UQCRC1 acting downstream of PCSK9\",\n      \"pmids\": [\"33576442\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"FGF21 inhibits oxLDL-induced HUVEC pyroptosis through a TET2-UQCRC1-ROS pathway: FGF21 upregulates TET2, which upregulates UQCRC1 expression; UQCRC1 silencing aggravates pyroptosis and impairs mitochondrial function and increases ROS production.\",\n      \"method\": \"siRNA knockdown of UQCRC1 and TET2, FGF21 treatment, ROS measurement, mitochondrial function assays, western blot in HUVECs\",\n      \"journal\": \"DNA and cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, multiple methods (KD, functional assays), pathway ordering established by genetic intervention\",\n      \"pmids\": [\"32101022\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Melatonin prevents endothelial cell pyroptosis by upregulating TET2 to inhibit methylation of the UQCRC1 promoter, thereby increasing UQCRC1 expression, improving mitochondrial function, and reducing oxidative stress.\",\n      \"method\": \"Melatonin treatment of HUVECs, TET2 upregulation assay, UQCRC1 methylation analysis, mitochondrial function assays, NLRP3/caspase-1/IL-1β expression\",\n      \"journal\": \"Biochemistry and cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — single lab, multiple methods including methylation analysis and functional mitochondrial readouts, but no direct methylation writer/eraser mutagenesis\",\n      \"pmids\": [\"33332241\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"UQCRC1 overexpression in pancreatic cancer cells inhibits NK cell cytotoxicity and chemotaxis via elevated extracellular ATP and its metabolite adenosine acting through P2Y11R and A2AR receptors; mechanistically, the UQCRC1/eATP axis reduces CCL5 chemokine expression in cancer cells and shifts the balance of activating receptor DNAM-1 vs. inhibitory receptor CD96 on NK cells toward exhaustion.\",\n      \"method\": \"UQCRC1 knockdown/overexpression in PC cells, NK cell cytotoxicity assays, NK cell chemotaxis assays, adoptive NK cell therapy in subcutaneous mouse model, CIBERSORTx analysis, P2Y11R/A2AR receptor blocking experiments, CCL5 expression analysis\",\n      \"journal\": \"Frontiers in oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — single lab, multiple orthogonal methods (in vitro functional assays, in vivo mouse model, receptor blocking), mechanistic pathway defined\",\n      \"pmids\": [\"35769718\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Knockdown of Uqcrc1 in mouse spermatocytes (GC2 cells) decreases mitochondrial membrane potential and induces apoptosis, establishing that UQCRC1 is required for mitochondrial membrane potential maintenance and cell survival in spermatocytes.\",\n      \"method\": \"siRNA knockdown of Uqcrc1 in GC2 cells, flow cytometry for mitochondrial membrane potential and apoptosis, ATP measurement\",\n      \"journal\": \"Environmental toxicology and pharmacology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — clean loss-of-function with defined cellular phenotype, single lab, single cell type\",\n      \"pmids\": [\"27525561\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"UQCRC1 deficiency impairs mitophagy via PINK1-dependent mechanisms: UQCRC1 mutation or depletion in SH-SY5Y cells and Drosophila reduces PINK1 mRNA levels; overexpression of Pink1 rescues locomotion and mitophagy defects in uqcrc1-deficient flies; PINK1 activators (kinetin and MTK458) produce similar protective effects.\",\n      \"method\": \"UQCRC1 mutant/KD in SH-SY5Y cells and Drosophila, PINK1 mRNA quantification, Pink1 overexpression rescue, pharmacological PINK1 activation (kinetin, MTK458), mitophagy flux assays, locomotor behavioral assays\",\n      \"journal\": \"NPJ Parkinson's disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis across two model systems, multiple orthogonal methods (genetic rescue, pharmacological rescue, mitophagy assays), PINK1 identified as downstream effector\",\n      \"pmids\": [\"41540037\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"UQCRC1 deficiency triggers lysosomal Ca2+ overload-mediated proteolytic dysfunction and activates neuronal apoptotic pathways; AAV-mediated UQCRC1 overexpression reverses these pathological changes via AMPK signaling, as pharmacological AMPK inhibition abolishes the therapeutic benefit.\",\n      \"method\": \"Conditional UQCRC1 knockdown in APP/PS1 AD model mice, transmission electron microscopy (lysosomal morphology), AAV-mediated UQCRC1 overexpression, AMPK pharmacological inhibition, behavioral cognitive testing\",\n      \"journal\": \"Molecular neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — single lab, multiple orthogonal methods (TEM, AAV rescue, pharmacological epistasis), but AMPK positioning relies on inhibitor pharmacology without direct biochemical confirmation\",\n      \"pmids\": [\"40588669\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"UQCRC1 downregulation impairs AMPK activation and disrupts autophagic flux, leading to cognitive deficits; pharmacological activation of AMPK or enhancement of lysosomal activity in UQCRC1-deficient mice restores mitochondrial redox homeostasis and ameliorates cognitive impairment.\",\n      \"method\": \"Mouse model with downregulated UQCRC1, behavioral paradigms, ATP measurement, ROS detection, AMPK signaling analysis, autophagic flux assessment, pharmacological AMPK activation and lysosomal enhancement\",\n      \"journal\": \"PeerJ\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — single lab, multiple methods (genetic model, pharmacological interventions, metabolic assays), but AMPK pathway positioning based on correlational and pharmacological data\",\n      \"pmids\": [\"40832581\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"UQCRC1 downregulation in the dentate gyrus reduces cilia (identified via RNA sequencing), impairs hippocampal theta and gamma oscillations and wide-wave interneuron activity, and causes cognitive deficits; overexpression of Ttbk2 in the DG restores ciliary function and rescues cognitive impairments and neural oscillations.\",\n      \"method\": \"Uqcrc1+/- mice, RNA sequencing of hippocampus, in vivo electrophysiology, Ttbk2 overexpression in dentate gyrus, behavioral cognitive testing, synaptic protein quantification\",\n      \"journal\": \"Neuroscience bulletin\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — single lab, multiple orthogonal methods (transcriptomics, electrophysiology, genetic rescue), but novel pathway (UQCRC1→cilia→cognition) needs independent replication\",\n      \"pmids\": [\"41182502\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Loganin inhibits DNMT1 (confirmed by molecular docking, surface plasmon resonance KD = 13.5 μM, and in vitro DNMT1 enzymatic inhibition assay), reduces methylation of the UQCRC1 promoter, restores UQCRC1 expression and mitochondrial complex III activity after myocardial infarction, and halts cardiac remodeling.\",\n      \"method\": \"Mouse MI model, RNA sequencing, promoter methylation analysis, complex III activity assay, molecular docking, surface plasmon resonance, in vitro DNMT1 enzymatic assay, Loganin treatment\",\n      \"journal\": \"Phytomedicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1–2 / Moderate — direct biochemical binding assay (SPR) and enzymatic inhibition of DNMT1, coupled to functional methylation-UQCRC1-complex III rescue; single lab\",\n      \"pmids\": [\"40645070\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Two promoter polymorphisms in UQCRC1 (g.13487C>T and g.13709G>C) affect promoter activity: the TTCC haplotype produces 43–49% higher promoter activity than the CCGG haplotype in three cell lines, and is associated with greater subcutaneous fat depth and skeletal muscle lipid accumulation in cattle.\",\n      \"method\": \"Promoter activity luciferase reporter assays in three cell lines, genotyping and statistical association in Wagyu x Limousin F2 cattle\",\n      \"journal\": \"Obesity (Silver Spring, Md.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct promoter activity measurement in multiple cell lines, but functional link between promoter polymorphisms and fat accumulation is associative rather than mechanistically dissected\",\n      \"pmids\": [\"18198295\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Formoterol, acting via β2-adrenergic receptor (β2AR), restores mitochondrial complex III-linked respiration, normalizes fusion/fission dynamics (upregulating Drp-1 while not altering Mfn2), restores ERK signaling, inhibits Akt overactivity, and improves mitochondrial transport in cells carrying the UQCRC1 p.Tyr314Ser mutation.\",\n      \"method\": \"Cell model with UQCRC1 p.Tyr314Ser variant, formoterol treatment with/without β2AR antagonist, mitochondrial respiration assay, mitochondrial DNA copy number, Drp-1/Mfn2/Parkin western blot, ERK/Akt signaling analysis, mitochondrial morphology imaging\",\n      \"journal\": \"Biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — single lab, multiple orthogonal methods (respiration, signaling, morphology), β2AR dependence confirmed by receptor antagonist\",\n      \"pmids\": [\"38666843\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"UQCRC1 is an evolutionarily conserved core subunit of mitochondrial respiratory chain complex III (ubiquinol-cytochrome c reductase) that is essential for embryo survival and complex III assembly/activity; it physically associates with cytochrome c to retain it in mitochondria, preventing cytochrome c release, caspase cascade activation, and neuronal apoptosis, while its loss or disease-associated mutations impair OXPHOS and ATP production, trigger ROS generation, disrupt mitophagy via a PINK1-dependent pathway, activate AMPK-lysosomal dysfunction, and cause age-dependent dopaminergic neurodegeneration; in cancer contexts, UQCRC1 overexpression elevates extracellular ATP release through pannexin 1, driving tumor cell proliferation via the ATP/P2Y2-RTK/AKT axis and impairing NK cell surveillance, and its expression is epigenetically regulated by DNA methylation through DNMT1 and TET2.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"UQCRC1 is an evolutionarily conserved core subunit of mitochondrial respiratory chain complex III (ubiquinol-cytochrome c reductase) that is required for embryonic viability and for normal complex III assembly, enzymatic activity, ATP production, and neuronal survival [#2, #3]. Beyond its catalytic role in oxidative phosphorylation, UQCRC1 physically associates with cytochrome c and retains it in mitochondria; its deficiency increases cytoplasmic cytochrome c, activates the caspase cascade, and drives neuronal apoptosis, which is reversed by cytochrome c depletion or anti-apoptotic p35 expression [#0]. Disease-associated missense variants (p.Tyr314Ser, p.Ile311Leu) act as loss-of-function alleles that impair complex III activity and cause age-dependent dopaminergic neurodegeneration, locomotor decline, and peripheral neuropathy across human cell, Drosophila, and mouse models [#3, #4]. UQCRC1 dysfunction perturbs downstream quality-control and signaling programs: it reduces PINK1 expression and impairs mitophagy, a defect rescuable by Pink1 overexpression or PINK1 activators [#11], and it disrupts AMPK signaling and lysosomal proteolytic function, producing cognitive deficits that can be corrected by UQCRC1 restoration or AMPK/lysosomal activation [#12, #13]. In cancer, UQCRC1 overexpression elevates OXPHOS-derived ATP that is released through pannexin 1 to drive proliferation via the ATP/P2Y2-RTK/AKT axis [#1] and to suppress NK-cell cytotoxicity through purinergic signaling [#9]. UQCRC1 expression is controlled by promoter DNA methylation, with the methyltransferase DNMT1 and the demethylase TET2 governing its transcription [#7, #8, #15].\"\n  ,\n  \"teleology\": [\n    {\n      \"year\": 2007,\n      \"claim\": \"Established that UQCRC1 transcription is genetically tunable, linking promoter variation to its expression level and a metabolic phenotype.\",\n      \"evidence\": \"Luciferase promoter reporter assays of haplotypes in three cell lines plus association genotyping in cattle\",\n      \"pmids\": [\"18198295\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Link between promoter activity and fat accumulation is associative\", \"No human relevance demonstrated\", \"Trans-acting regulators not identified here\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Showed UQCRC1 is required to maintain mitochondrial membrane potential and cell survival, beyond a purely housekeeping bioenergetic role.\",\n      \"evidence\": \"siRNA knockdown in mouse GC2 spermatocytes with MMP, apoptosis, and ATP readouts\",\n      \"pmids\": [\"27525561\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single cell type\", \"Mechanism connecting loss to apoptosis not defined\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Defined UQCRC1 as essential for development and for complex III formation, activity, and bioenergetics in the brain, with functional consequences for cognition and ischemic tolerance.\",\n      \"evidence\": \"Knockout/heterozygous mouse model with complex III activity, ATP, MMP, ROS, behavioral, and ischemia assays\",\n      \"pmids\": [\"30666338\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Does not resolve cell-type-specific requirements\", \"Mechanism linking partial loss to behavior not dissected\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Proposed that oxidative modification of a UQCRC1 residue (Trp395) can structurally compromise complex III electron flow, offering a redox-damage mechanism.\",\n      \"evidence\": \"Proteomic identification of oxidized UQCRC1 from muscle biopsies plus molecular dynamics simulation of complex III\",\n      \"pmids\": [\"31337785\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Computational prediction without enzymatic reconstitution or mutagenesis\", \"Causality between oxidation and dysfunction not experimentally tested\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identified UQCRC1 missense variants as causes of dopaminergic neurodegeneration via complex III dysfunction, establishing a Mendelian-type disease mechanism.\",\n      \"evidence\": \"CRISPR knock-in SH-SY5Y cells, Drosophila and mouse knock-in models, complex III assays, EM, behavior, levodopa rescue\",\n      \"pmids\": [\"33141179\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Why dopaminergic neurons are selectively vulnerable is unexplained\", \"Whether variants act solely through complex III loss vs. gain-of-toxicity unresolved\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Established that UQCRC1 retains cytochrome c in mitochondria and that its loss triggers caspase-dependent neuronal apoptosis, defining the proximal death mechanism.\",\n      \"evidence\": \"Co-IP, cellular fractionation, caspase assays, and genetic epistasis (cyt-c depletion, p35) in Drosophila and human neuronal cells\",\n      \"pmids\": [\"34551295\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of UQCRC1-cytochrome c retention not resolved\", \"Whether retention is separable from catalytic function unclear\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Demonstrated the disease variant is loss-of-function by showing wild-type but not p.Tyr314Ser UQCRC1 rescues knockout lethality and neurodegeneration.\",\n      \"evidence\": \"Drosophila neuron-specific RNAi and rescue with wild-type vs. mutant UQCRC1, dopaminergic neuron counts and locomotor assays\",\n      \"pmids\": [\"34551295\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Residual partial function of variant not quantified at the enzyme level\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Revealed an oncogenic role in which UQCRC1-driven OXPHOS produces ATP exported via pannexin 1 to fuel proliferation through ATP/P2Y2-RTK/AKT signaling.\",\n      \"evidence\": \"Extracellular flux, RNA-Seq, knockdown/overexpression in pancreatic cancer lines, in vivo transplant, ATP-release blockade\",\n      \"pmids\": [\"32089737\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Why cancer cells favor UQCRC1 upregulation not established\", \"Direct UQCRC1-pannexin 1 coupling mechanism unknown\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Placed UQCRC1 downstream of TET2 in an FGF21/melatonin–TET2 axis controlling endothelial pyroptosis through promoter demethylation.\",\n      \"evidence\": \"siRNA of UQCRC1/TET2, FGF21 and melatonin treatment, promoter methylation and mitochondrial function assays in HUVECs\",\n      \"pmids\": [\"32101022\", \"33332241\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct demonstration TET2 acts at the UQCRC1 promoter via mutagenesis\", \"Pathway ordering inferred from intervention rather than direct binding\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Showed UQCRC1 functions as a node in oxLDL-induced endothelial injury, suppressed by PCSK9 to promote ROS and mitochondrial dysfunction.\",\n      \"evidence\": \"PCSK9/UQCRC1 knockdown and PCSK9 overexpression with ROS and JC-1 MMP assays in HUVECs\",\n      \"pmids\": [\"33576442\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"UQCRC1 placement downstream of PCSK9 is associative\", \"Direct regulatory mechanism not defined\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Extended the cancer role to immune evasion, linking UQCRC1-driven extracellular ATP/adenosine to NK-cell suppression via purinergic receptors and chemokine modulation.\",\n      \"evidence\": \"UQCRC1 knockdown/overexpression, NK cytotoxicity/chemotaxis assays, adoptive NK therapy mouse model, P2Y11R/A2AR blockade, CCL5 analysis\",\n      \"pmids\": [\"35769718\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Single lab\", \"Relative contribution of ATP vs. adenosine not fully separated\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified pharmacological correction of variant phenotypes via β2AR signaling, restoring complex III respiration and rebalancing fusion/fission and ERK/Akt.\",\n      \"evidence\": \"Formoterol with β2AR antagonist in p.Tyr314Ser cells, respiration, mtDNA copy number, morphology, and signaling readouts\",\n      \"pmids\": [\"38666843\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Cell-line only\", \"How β2AR signaling restores complex III activity mechanistically unclear\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Connected UQCRC1 deficiency to lysosomal Ca2+ overload, proteolytic dysfunction, and AMPK-dependent rescue, defining a downstream proteostasis/autophagy axis.\",\n      \"evidence\": \"Conditional knockdown in APP/PS1 and downregulated UQCRC1 mice, TEM, AAV rescue, AMPK pharmacological modulation, autophagic flux and cognitive assays\",\n      \"pmids\": [\"40588669\", \"40832581\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"AMPK positioning relies on pharmacology without direct biochemical confirmation\", \"Mechanistic link between complex III loss and lysosomal Ca2+ overload unresolved\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Uncovered a non-canonical UQCRC1→cilia→neural oscillation pathway underlying cognitive deficits, rescuable by Ttbk2.\",\n      \"evidence\": \"Uqcrc1+/- mice, hippocampal RNA-seq, in vivo electrophysiology, Ttbk2 overexpression, behavioral testing\",\n      \"pmids\": [\"41182502\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Novel pathway needs independent replication\", \"How a mitochondrial subunit regulates ciliary gene expression is unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Demonstrated that DNMT1-mediated promoter methylation directly represses UQCRC1, and its pharmacological inhibition restores complex III activity in cardiac disease.\",\n      \"evidence\": \"Mouse MI model, promoter methylation and complex III assays, Loganin with SPR binding (KD=13.5 μM) and in vitro DNMT1 enzymatic inhibition\",\n      \"pmids\": [\"40645070\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether DNMT1 acts directly at the UQCRC1 promoter shown indirectly\", \"Single lab\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Established PINK1 as a downstream effector of UQCRC1 in mitophagy, providing a mechanistic and therapeutic link to mitochondrial quality control.\",\n      \"evidence\": \"UQCRC1 mutant/knockdown in SH-SY5Y and Drosophila, PINK1 mRNA quantification, Pink1 overexpression and PINK1-activator (kinetin, MTK458) rescue, mitophagy flux assays\",\n      \"pmids\": [\"41540037\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How UQCRC1 loss reduces PINK1 mRNA mechanistically not defined\", \"Whether mitophagy defect is cause or consequence of neurodegeneration not fully separated\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How UQCRC1 mechanistically couples its complex III/cytochrome c retention role to downstream PINK1 transcription, AMPK/lysosomal control, and ciliary gene programs remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No structural model of UQCRC1-cytochrome c retention\", \"Signaling route from complex III dysfunction to nuclear/transcriptional programs unknown\", \"Selective dopaminergic vulnerability unexplained\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016491\", \"supporting_discovery_ids\": [2, 3, 5]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [2, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [0, 2, 3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [1, 2, 3]},\n      {\"term_id\": \"R-HSA-5357801\", \"supporting_discovery_ids\": [0, 10]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [11, 13]}\n    ],\n    \"complexes\": [\"mitochondrial respiratory chain complex III (ubiquinol-cytochrome c reductase)\"],\n    \"partners\": [\"CYCS\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}