{"gene":"ARMC12","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":2021,"finding":"ARMC12 is a mitochondrial peripheral membrane protein that functions as an adherence factor between mitochondria. In testicular germ cells, ARMC12 physically interacts with mitochondrial proteins MIC60, VDAC2, and VDAC3, as well as TBC1D21 and GK2, using VDAC2 and VDAC3 as scaffolds to link mitochondria together during mitochondrial sheath formation in spermiogenesis.","method":"FLAG-tagged knock-in mice, co-immunoprecipitation, Armc12-null mouse phenotypic analysis, TBC1D21-null mouse epistasis","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP with multiple binding partners, in vivo genetic models (null and knock-in mice), epistasis with TBC1D21 establishing hierarchy, replicated across orthogonal methods in one rigorous study","pmids":["33536340"],"is_preprint":false},{"year":2021,"finding":"TBC1D21 is required for the interaction between ARMC12 and VDAC proteins in vivo; in Tbc1d21-null mice, the ARMC12–VDAC interaction is disrupted, establishing TBC1D21 as an obligate mediator of this scaffold complex.","method":"Tbc1d21-null mice, co-immunoprecipitation from testicular germ cells","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic epistasis with co-IP validation in vivo, multiple orthogonal approaches in single rigorous study","pmids":["33536340"],"is_preprint":false},{"year":2021,"finding":"Absence of ARMC12 prevents mitochondrial elongation at the mitochondrial interlocking step during spermiogenesis, causing abnormal mitochondrial coiling along the flagellum, reduced sperm motility, and male sterility.","method":"Armc12-null mouse generation, sperm motility assay, electron microscopy of flagellar ultrastructure","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — defined loss-of-function phenotype with cellular and ultrastructural readout in knockout mice, multiple orthogonal methods","pmids":["33536340"],"is_preprint":false},{"year":2018,"finding":"ARMC12 physically interacts with retinoblastoma binding protein 4 (RBBP4) to facilitate the formation and activity of polycomb repressive complex 2 (PRC2), resulting in transcriptional repression of tumor suppressive genes in neuroblastoma cells.","method":"Co-immunoprecipitation, cell-penetrating inhibitory peptide blocking ARMC12–RBBP4 interaction, downstream gene expression assays","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus functional peptide inhibitor with downstream transcriptional readout, single lab","pmids":["30026490"],"is_preprint":false},{"year":2022,"finding":"Biallelic loss-of-function mutations in ARMC12 in humans cause asthenozoospermia with multiple midpiece defects including absent mitochondrial sheath, absent central pair, scattered or forked axoneme, and incomplete plasma membrane, confirming the conserved mitochondrial sheath assembly function of ARMC12 in humans.","method":"Whole-exome sequencing, Sanger sequencing, Armc12-knockout mice (CRISPR-Cas9), transmission electron microscopy, immunofluorescence","journal":"Journal of medical genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — human genetics validated by parallel CRISPR knockout mouse model with ultrastructural TEM, independently corroborating the null-mouse findings from PMID 33536340","pmids":["35534203"],"is_preprint":false},{"year":2026,"finding":"In a patient with MMAF carrying a homozygous ARMC12 c.686G>A variant, ARMC12 loss causes severe disorganization of mitochondrial sheath structures and loss of axonemal elements; mitochondrial outer membrane proteins COX IV and TOM20 shift from a continuous distribution along the mitochondrial sheath to a discontinuous punctate pattern without significant reduction in total protein levels.","method":"Whole exome sequencing, Sanger sequencing, immunofluorescence, Western blot, scanning electron microscopy, transmission electron microscopy","journal":"Translational andrology and urology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — single patient/family, multiple orthogonal morphological methods, consistent with prior literature but single case","pmids":["41971121"],"is_preprint":false},{"year":2026,"finding":"ARMC12 interacts with MYC within liquid condensates in neuroblastoma cells and upregulates nucleoporin-encoding targets (NUP62, NUP93, NUP98), promoting nuclear pore complex biogenesis to facilitate nuclear trafficking of oncogenic effectors and enhance invasion and metastasis.","method":"Co-immunoprecipitation, mass spectrometry, chromatin immunoprecipitation, dual-luciferase reporter assay, gene overexpression/silencing, RNA sequencing, nude mouse xenograft","journal":"Theranostics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus mass spectrometry plus ChIP plus reporter assay in single lab study; multiple orthogonal methods but not independently replicated","pmids":["41510169"],"is_preprint":false}],"current_model":"ARMC12 is a mitochondrial peripheral membrane protein that acts as a mitochondrial adherence factor by scaffolding onto VDAC2/VDAC3 and interacting with MIC60, TBC1D21, and GK2 to drive mitochondrial sheath assembly during spermiogenesis; loss of ARMC12 disrupts mitochondrial elongation and coiling along the sperm flagellum, causing asthenozoospermia in mice and humans. In neuroblastoma, ARMC12 co-operates with MYC within liquid condensates to upregulate nucleoporin expression and nuclear pore complex biogenesis, and also interacts with RBBP4 to promote PRC2-mediated transcriptional repression of tumor suppressor genes."},"narrative":{"mechanistic_narrative":"ARMC12 is a mitochondrial peripheral membrane protein that acts as an adherence factor driving mitochondrial sheath assembly during spermiogenesis [PMID:33536340]. In testicular germ cells it scaffolds mitochondria together by binding VDAC2 and VDAC3 and interacting with MIC60, TBC1D21, and GK2, with TBC1D21 acting as an obligate mediator of the ARMC12–VDAC interaction [PMID:33536340]. Loss of ARMC12 blocks mitochondrial elongation at the interlocking step, producing abnormal mitochondrial coiling along the flagellum, reduced sperm motility, and male sterility [PMID:33536340]; biallelic loss-of-function mutations in humans cause asthenozoospermia with absent mitochondrial sheath and associated midpiece and axonemal defects, establishing a conserved role [PMID:35534203]. Independent of this germline function, ARMC12 has been characterized in neuroblastoma, where it interacts with RBBP4 to promote PRC2-mediated transcriptional repression of tumor suppressor genes [PMID:30026490] and partners with MYC within liquid condensates to upregulate nucleoporin genes (NUP62, NUP93, NUP98) and nuclear pore complex biogenesis, enhancing invasion and metastasis [PMID:41510169].","teleology":[{"year":2018,"claim":"Established the first molecular function for ARMC12 in cancer, defining it as a chromatin regulator that physically partners with RBBP4 to enable PRC2-mediated silencing of tumor suppressors.","evidence":"Co-immunoprecipitation and cell-penetrating inhibitory peptide blocking ARMC12–RBBP4 interaction with downstream gene expression readout in neuroblastoma cells","pmids":["30026490"],"confidence":"Medium","gaps":["Single-lab study without reciprocal in vivo validation","Does not define how ARMC12 is recruited to PRC2 target loci","Relationship to ARMC12's mitochondrial role left unaddressed"]},{"year":2021,"claim":"Defined ARMC12 as a mitochondrial adherence factor and mapped its scaffold complex, resolving how mitochondria are physically linked during sheath formation.","evidence":"FLAG knock-in mice, reciprocal co-immunoprecipitation, Armc12-null phenotyping, and TBC1D21-null epistasis in testicular germ cells","pmids":["33536340"],"confidence":"High","gaps":["Structural basis of VDAC2/VDAC3 scaffolding not resolved","Biochemical activity of ARMC12 beyond protein scaffolding unknown"]},{"year":2021,"claim":"Ordered the assembly hierarchy by showing TBC1D21 is an obligate mediator of the ARMC12–VDAC interaction in vivo.","evidence":"Tbc1d21-null mice with co-immunoprecipitation from testicular germ cells","pmids":["33536340"],"confidence":"High","gaps":["Whether TBC1D21 acts catalytically or structurally in mediating the interaction is unresolved"]},{"year":2022,"claim":"Translated the mouse phenotype to human disease, confirming ARMC12 loss causes asthenozoospermia with mitochondrial sheath and midpiece defects.","evidence":"Whole-exome sequencing of patients plus parallel CRISPR-Cas9 Armc12-knockout mice with TEM and immunofluorescence","pmids":["35534203"],"confidence":"High","gaps":["Mechanism linking sheath loss to additional axonemal and membrane defects not dissected"]},{"year":2026,"claim":"Extended the disease phenotype to a single MMAF patient, showing ARMC12 loss redistributes mitochondrial outer-membrane proteins to a punctate pattern without reducing their levels.","evidence":"Whole-exome/Sanger sequencing with immunofluorescence, Western blot, SEM and TEM in a single patient carrying c.686G>A","pmids":["41971121"],"confidence":"Medium","gaps":["Single patient/family limits generalizability","Does not establish whether protein redistribution is cause or consequence of sheath disorganization"]},{"year":2026,"claim":"Uncovered a second oncogenic mechanism whereby ARMC12 cooperates with MYC in liquid condensates to drive nucleoporin expression and nuclear pore biogenesis supporting invasion and metastasis.","evidence":"Co-IP, mass spectrometry, ChIP, dual-luciferase reporter, overexpression/silencing, RNA-seq, and nude mouse xenograft in neuroblastoma","pmids":["41510169"],"confidence":"Medium","gaps":["Single-lab study not independently replicated","Biophysical basis of condensate formation and ARMC12's contribution to it undefined","Connection between the RBBP4/PRC2 and MYC/nucleoporin functions unresolved"]},{"year":null,"claim":"The intrinsic biochemical activity of ARMC12 and how a single protein partitions between mitochondrial sheath scaffolding and nuclear/chromatin oncogenic functions remain unknown.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No catalytic activity assigned","No structural model of ARMC12 or its complexes","Tissue-specific switch between germline and tumor functions uncharacterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,1]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[3,6]}],"localization":[{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[0,2,5]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[3,6]}],"pathway":[{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[2,4]},{"term_id":"R-HSA-4839726","term_label":"Chromatin organization","supporting_discovery_ids":[3]}],"complexes":["PRC2"],"partners":["VDAC2","VDAC3","MIC60","TBC1D21","GK2","RBBP4","MYC"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q5T9G4","full_name":"Armadillo repeat-containing protein 12","aliases":[],"length_aa":340,"mass_kda":38.6,"function":"Essential for male fertility and sperm mitochondrial sheath formation (By similarity). Required for proper mitochondrial elongation and coiling along the flagellum during the formation of the mitochondrial sheath (By similarity). Facilitates the growth and aggressiveness of neuroblastoma cells (PubMed:30026490). Increases the EZH2 activity and H3K27me3 levels in a RBBP4-dependent manner, and facilitates the enrichment of polycomb repressive complex 2 and H3K27me3 on gene promoters, resulting in transcriptional repression of tumor suppressors affecting the proliferation, invasion, and metastasis of tumor cells (PubMed:30026490)","subcellular_location":"Nucleus; Mitochondrion outer membrane","url":"https://www.uniprot.org/uniprotkb/Q5T9G4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ARMC12","classification":"Not Classified","n_dependent_lines":4,"n_total_lines":1208,"dependency_fraction":0.0033112582781456954},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/ARMC12","total_profiled":1310},"omim":[{"mim_id":"620744","title":"SPERMATOGENIC FAILURE 90; SPGF90","url":"https://www.omim.org/entry/620744"},{"mim_id":"620377","title":"ARMADILLO REPEAT-CONTAINING PROTEIN 12; ARMC12","url":"https://www.omim.org/entry/620377"},{"mim_id":"258150","title":"SPERMATOGENIC FAILURE 1; SPGF1","url":"https://www.omim.org/entry/258150"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Mitochondria","reliability":"Supported"}],"tissue_specificity":"Tissue enriched","tissue_distribution":"Detected in many","driving_tissues":[{"tissue":"testis","ntpm":58.4}],"url":"https://www.proteinatlas.org/search/ARMC12"},"hgnc":{"alias_symbol":["FLJ25390"],"prev_symbol":["C6orf81"]},"alphafold":{"accession":"Q5T9G4","domains":[{"cath_id":"1.20.58","chopping":"49-145","consensus_level":"medium","plddt":89.349,"start":49,"end":145},{"cath_id":"1.25.40","chopping":"201-319","consensus_level":"medium","plddt":95.8903,"start":201,"end":319}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5T9G4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q5T9G4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q5T9G4-F1-predicted_aligned_error_v6.png","plddt_mean":85.81},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ARMC12","jax_strain_url":"https://www.jax.org/strain/search?query=ARMC12"},"sequence":{"accession":"Q5T9G4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q5T9G4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q5T9G4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q5T9G4"}},"corpus_meta":[{"pmid":"33536340","id":"PMC_33536340","title":"ARMC12 regulates spatiotemporal mitochondrial dynamics during spermiogenesis and is required for male fertility.","date":"2021","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/33536340","citation_count":65,"is_preprint":false},{"pmid":"30026490","id":"PMC_30026490","title":"Armadillo repeat containing 12 promotes neuroblastoma progression through interaction with retinoblastoma binding protein 4.","date":"2018","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/30026490","citation_count":47,"is_preprint":false},{"pmid":"34912852","id":"PMC_34912852","title":"ARMC Subfamily: Structures, Functions, Evolutions, Interactions, and Diseases.","date":"2021","source":"Frontiers in molecular biosciences","url":"https://pubmed.ncbi.nlm.nih.gov/34912852","citation_count":25,"is_preprint":false},{"pmid":"35534203","id":"PMC_35534203","title":"Biallelic mutations in ARMC12 cause asthenozoospermia and multiple midpiece defects in humans and mice.","date":"2022","source":"Journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/35534203","citation_count":10,"is_preprint":false},{"pmid":"37274192","id":"PMC_37274192","title":"FKBP5 genetic variants are associated with respiratory- and sleep-related parameters in Chinese patients with obstructive sleep apnea.","date":"2023","source":"Frontiers in neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/37274192","citation_count":6,"is_preprint":false},{"pmid":"41971121","id":"PMC_41971121","title":"Homozygous ARMC12 variant causes multiple morphological abnormalities of the sperm flagella.","date":"2026","source":"Translational andrology and urology","url":"https://pubmed.ncbi.nlm.nih.gov/41971121","citation_count":0,"is_preprint":false},{"pmid":"41510169","id":"PMC_41510169","title":"Dual targeting of AMRC12 and Malassezia globosa disrupts MYC liquid condensates-driven nuclear pore complex biogenesis in neuroblastoma.","date":"2026","source":"Theranostics","url":"https://pubmed.ncbi.nlm.nih.gov/41510169","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":6161,"output_tokens":1832,"usd":0.022981,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8766,"output_tokens":2549,"usd":0.053777,"stage2_stop_reason":"end_turn"},"total_usd":0.076758,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2021,\n      \"finding\": \"ARMC12 is a mitochondrial peripheral membrane protein that functions as an adherence factor between mitochondria. In testicular germ cells, ARMC12 physically interacts with mitochondrial proteins MIC60, VDAC2, and VDAC3, as well as TBC1D21 and GK2, using VDAC2 and VDAC3 as scaffolds to link mitochondria together during mitochondrial sheath formation in spermiogenesis.\",\n      \"method\": \"FLAG-tagged knock-in mice, co-immunoprecipitation, Armc12-null mouse phenotypic analysis, TBC1D21-null mouse epistasis\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP with multiple binding partners, in vivo genetic models (null and knock-in mice), epistasis with TBC1D21 establishing hierarchy, replicated across orthogonal methods in one rigorous study\",\n      \"pmids\": [\"33536340\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"TBC1D21 is required for the interaction between ARMC12 and VDAC proteins in vivo; in Tbc1d21-null mice, the ARMC12–VDAC interaction is disrupted, establishing TBC1D21 as an obligate mediator of this scaffold complex.\",\n      \"method\": \"Tbc1d21-null mice, co-immunoprecipitation from testicular germ cells\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic epistasis with co-IP validation in vivo, multiple orthogonal approaches in single rigorous study\",\n      \"pmids\": [\"33536340\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Absence of ARMC12 prevents mitochondrial elongation at the mitochondrial interlocking step during spermiogenesis, causing abnormal mitochondrial coiling along the flagellum, reduced sperm motility, and male sterility.\",\n      \"method\": \"Armc12-null mouse generation, sperm motility assay, electron microscopy of flagellar ultrastructure\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — defined loss-of-function phenotype with cellular and ultrastructural readout in knockout mice, multiple orthogonal methods\",\n      \"pmids\": [\"33536340\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"ARMC12 physically interacts with retinoblastoma binding protein 4 (RBBP4) to facilitate the formation and activity of polycomb repressive complex 2 (PRC2), resulting in transcriptional repression of tumor suppressive genes in neuroblastoma cells.\",\n      \"method\": \"Co-immunoprecipitation, cell-penetrating inhibitory peptide blocking ARMC12–RBBP4 interaction, downstream gene expression assays\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus functional peptide inhibitor with downstream transcriptional readout, single lab\",\n      \"pmids\": [\"30026490\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Biallelic loss-of-function mutations in ARMC12 in humans cause asthenozoospermia with multiple midpiece defects including absent mitochondrial sheath, absent central pair, scattered or forked axoneme, and incomplete plasma membrane, confirming the conserved mitochondrial sheath assembly function of ARMC12 in humans.\",\n      \"method\": \"Whole-exome sequencing, Sanger sequencing, Armc12-knockout mice (CRISPR-Cas9), transmission electron microscopy, immunofluorescence\",\n      \"journal\": \"Journal of medical genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — human genetics validated by parallel CRISPR knockout mouse model with ultrastructural TEM, independently corroborating the null-mouse findings from PMID 33536340\",\n      \"pmids\": [\"35534203\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"In a patient with MMAF carrying a homozygous ARMC12 c.686G>A variant, ARMC12 loss causes severe disorganization of mitochondrial sheath structures and loss of axonemal elements; mitochondrial outer membrane proteins COX IV and TOM20 shift from a continuous distribution along the mitochondrial sheath to a discontinuous punctate pattern without significant reduction in total protein levels.\",\n      \"method\": \"Whole exome sequencing, Sanger sequencing, immunofluorescence, Western blot, scanning electron microscopy, transmission electron microscopy\",\n      \"journal\": \"Translational andrology and urology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — single patient/family, multiple orthogonal morphological methods, consistent with prior literature but single case\",\n      \"pmids\": [\"41971121\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"ARMC12 interacts with MYC within liquid condensates in neuroblastoma cells and upregulates nucleoporin-encoding targets (NUP62, NUP93, NUP98), promoting nuclear pore complex biogenesis to facilitate nuclear trafficking of oncogenic effectors and enhance invasion and metastasis.\",\n      \"method\": \"Co-immunoprecipitation, mass spectrometry, chromatin immunoprecipitation, dual-luciferase reporter assay, gene overexpression/silencing, RNA sequencing, nude mouse xenograft\",\n      \"journal\": \"Theranostics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus mass spectrometry plus ChIP plus reporter assay in single lab study; multiple orthogonal methods but not independently replicated\",\n      \"pmids\": [\"41510169\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ARMC12 is a mitochondrial peripheral membrane protein that acts as a mitochondrial adherence factor by scaffolding onto VDAC2/VDAC3 and interacting with MIC60, TBC1D21, and GK2 to drive mitochondrial sheath assembly during spermiogenesis; loss of ARMC12 disrupts mitochondrial elongation and coiling along the sperm flagellum, causing asthenozoospermia in mice and humans. In neuroblastoma, ARMC12 co-operates with MYC within liquid condensates to upregulate nucleoporin expression and nuclear pore complex biogenesis, and also interacts with RBBP4 to promote PRC2-mediated transcriptional repression of tumor suppressor genes.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ARMC12 is a mitochondrial peripheral membrane protein that acts as an adherence factor driving mitochondrial sheath assembly during spermiogenesis [#0]. In testicular germ cells it scaffolds mitochondria together by binding VDAC2 and VDAC3 and interacting with MIC60, TBC1D21, and GK2, with TBC1D21 acting as an obligate mediator of the ARMC12–VDAC interaction [#0, #1]. Loss of ARMC12 blocks mitochondrial elongation at the interlocking step, producing abnormal mitochondrial coiling along the flagellum, reduced sperm motility, and male sterility [#2]; biallelic loss-of-function mutations in humans cause asthenozoospermia with absent mitochondrial sheath and associated midpiece and axonemal defects, establishing a conserved role [#4]. Independent of this germline function, ARMC12 has been characterized in neuroblastoma, where it interacts with RBBP4 to promote PRC2-mediated transcriptional repression of tumor suppressor genes [#3] and partners with MYC within liquid condensates to upregulate nucleoporin genes (NUP62, NUP93, NUP98) and nuclear pore complex biogenesis, enhancing invasion and metastasis [#6].\",\n  \"teleology\": [\n    {\n      \"year\": 2018,\n      \"claim\": \"Established the first molecular function for ARMC12 in cancer, defining it as a chromatin regulator that physically partners with RBBP4 to enable PRC2-mediated silencing of tumor suppressors.\",\n      \"evidence\": \"Co-immunoprecipitation and cell-penetrating inhibitory peptide blocking ARMC12–RBBP4 interaction with downstream gene expression readout in neuroblastoma cells\",\n      \"pmids\": [\"30026490\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Single-lab study without reciprocal in vivo validation\",\n        \"Does not define how ARMC12 is recruited to PRC2 target loci\",\n        \"Relationship to ARMC12's mitochondrial role left unaddressed\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Defined ARMC12 as a mitochondrial adherence factor and mapped its scaffold complex, resolving how mitochondria are physically linked during sheath formation.\",\n      \"evidence\": \"FLAG knock-in mice, reciprocal co-immunoprecipitation, Armc12-null phenotyping, and TBC1D21-null epistasis in testicular germ cells\",\n      \"pmids\": [\"33536340\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Structural basis of VDAC2/VDAC3 scaffolding not resolved\",\n        \"Biochemical activity of ARMC12 beyond protein scaffolding unknown\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Ordered the assembly hierarchy by showing TBC1D21 is an obligate mediator of the ARMC12–VDAC interaction in vivo.\",\n      \"evidence\": \"Tbc1d21-null mice with co-immunoprecipitation from testicular germ cells\",\n      \"pmids\": [\"33536340\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Whether TBC1D21 acts catalytically or structurally in mediating the interaction is unresolved\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Translated the mouse phenotype to human disease, confirming ARMC12 loss causes asthenozoospermia with mitochondrial sheath and midpiece defects.\",\n      \"evidence\": \"Whole-exome sequencing of patients plus parallel CRISPR-Cas9 Armc12-knockout mice with TEM and immunofluorescence\",\n      \"pmids\": [\"35534203\"],\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Mechanism linking sheath loss to additional axonemal and membrane defects not dissected\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Extended the disease phenotype to a single MMAF patient, showing ARMC12 loss redistributes mitochondrial outer-membrane proteins to a punctate pattern without reducing their levels.\",\n      \"evidence\": \"Whole-exome/Sanger sequencing with immunofluorescence, Western blot, SEM and TEM in a single patient carrying c.686G>A\",\n      \"pmids\": [\"41971121\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Single patient/family limits generalizability\",\n        \"Does not establish whether protein redistribution is cause or consequence of sheath disorganization\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Uncovered a second oncogenic mechanism whereby ARMC12 cooperates with MYC in liquid condensates to drive nucleoporin expression and nuclear pore biogenesis supporting invasion and metastasis.\",\n      \"evidence\": \"Co-IP, mass spectrometry, ChIP, dual-luciferase reporter, overexpression/silencing, RNA-seq, and nude mouse xenograft in neuroblastoma\",\n      \"pmids\": [\"41510169\"],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"Single-lab study not independently replicated\",\n        \"Biophysical basis of condensate formation and ARMC12's contribution to it undefined\",\n        \"Connection between the RBBP4/PRC2 and MYC/nucleoporin functions unresolved\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The intrinsic biochemical activity of ARMC12 and how a single protein partitions between mitochondrial sheath scaffolding and nuclear/chromatin oncogenic functions remain unknown.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"\",\n      \"gaps\": [\n        \"No catalytic activity assigned\",\n        \"No structural model of ARMC12 or its complexes\",\n        \"Tissue-specific switch between germline and tumor functions uncharacterized\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [3, 6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [0, 2, 5]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [3, 6]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [2, 4]},\n      {\"term_id\": \"R-HSA-4839726\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [\"PRC2\"],\n    \"partners\": [\"VDAC2\", \"VDAC3\", \"MIC60\", \"TBC1D21\", \"GK2\", \"RBBP4\", \"MYC\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}