Affinage

NDUFAF3

NADH dehydrogenase [ubiquinone] 1 alpha subcomplex assembly factor 3 · UniProt Q9BU61

Round 2 corrected
Length
184 aa
Mass
20.4 kDa
Annotated
2026-04-29
43 papers in source corpus 5 papers cited in narrative 5 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

NDUFAF3 is a mitochondrial complex I assembly factor that forms a tight obligate partnership with NDUFAF4 to facilitate biogenesis of the Q-, N-, and PP-b modules of NADH:ubiquinone oxidoreductase, functioning in part by promoting integration of NDUFS3 into the Q-module and NDUFS5 into the PP-b module and by stabilizing the assembly factor TIMMDC1 within assembly intermediates (PMID:34386730). Loss-of-function mutations in NDUFAF3 cause fatal neonatal mitochondrial complex I deficiency with cavitating leukoencephalopathy, confirmed by complementation rescue in patient fibroblasts (PMID:19463981, PMID:29344937). The assembly function of NDUFAF3 is conserved from green algae to mammals, and forced overexpression of NDUFAF4 partially rescues Q-module biogenesis defects caused by NDUFAF3 loss, revealing an epistatic and partially redundant relationship between the two factors (PMID:28857403, PMID:34386730).

Mechanistic history

Synthesis pass · year-by-year structured walk · 4 steps
  1. 2009 High

    Identification of NDUFAF3 as a bona fide complex I assembly factor and disease gene resolved the cause of a previously unexplained fatal neonatal complex I deficiency and established its tight physical partnership with NDUFAF4.

    Evidence Homozygosity mapping, patient mutation analysis, GFP-baculovirus complementation in fibroblasts, co-immunoprecipitation, and BN-PAGE/LC-MS/MS co-migration profiling in human mitochondria

    PMID:19463981 PMID:19688755

    Open questions at the time
    • Which specific complex I assembly steps NDUFAF3 acts at was not resolved
    • The molecular mechanism by which NDUFAF3 and NDUFAF4 cooperate was unknown
    • No structural information on NDUFAF3 or its interaction interfaces
  2. 2017 Medium

    Demonstration that the NDUFAF3 ortholog in Chlamydomonas reinhardtii is essential for complex I activity and assembly established evolutionary conservation of its function across eukaryotic kingdoms.

    Evidence Insertional mutagenesis and complementation with complex I activity measurement in Chlamydomonas

    PMID:28857403

    Open questions at the time
    • Whether the algal ortholog also depends on an NDUFAF4-like partner was not tested
    • Module-level resolution of the assembly defect was not provided
  3. 2018 Medium

    Dissection of a new patient case with compound heterozygous NDUFAF3 variants revealed that NDUFAF3 is required for assembly of both the Q-module and the P-module of complex I, broadening its role beyond a single assembly step.

    Evidence 2D BN-PAGE/SDS-PAGE immunoblotting of module-specific subunits in patient skeletal muscle

    PMID:29344937

    Open questions at the time
    • Single patient case; independent replication in additional patients or model systems was lacking at that time
    • The distinction between direct assembly roles versus secondary destabilization was unresolved
  4. 2021 High

    Genetic epistasis analysis in Drosophila pinpointed the mechanistic basis: NDUFAF3 and NDUFAF4 jointly promote integration of NDUFS3 into the Q-module and NDUFS5 into the PP-b module, and stabilize TIMMDC1 in assembly intermediates, with NDUFAF4 overexpression partially rescuing NDUFAF3 loss.

    Evidence Drosophila loss-of-function and overexpression genetics with BN-PAGE, subunit-specific immunoblotting, and transgenic rescue

    PMID:34386730

    Open questions at the time
    • The direct biochemical contacts between NDUFAF3 and the subunits it integrates remain structurally undefined
    • Whether the NDUFAF4-mediated rescue operates through the same or a parallel pathway is unclear
    • Mammalian in vivo validation of the epistatic relationship has not been reported

Open questions

Synthesis pass · forward-looking unresolved questions
  • Key unresolved questions include the atomic-level structure of NDUFAF3 (alone and in complex with NDUFAF4 and assembly intermediates), the precise mechanism by which it facilitates subunit membrane insertion, and whether it has additional roles beyond complex I biogenesis.
  • No high-resolution structure of NDUFAF3 or its complexes
  • Mechanism linking NDUFAF3 to the ancestral SecF/SecD/YajC membrane-insertion function has not been experimentally tested
  • Potential roles outside complex I assembly have not been explored

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 2
Localization
GO:0005739 mitochondrion 5
Pathway
R-HSA-1852241 Organelle biogenesis and maintenance 3 R-HSA-1643685 Disease 2
Partners
NDUFAF4NDUFS2NDUFS3NDUFS5NDUFS7NDUFS8TIMMDC1

Evidence

Reading pass · 5 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2009 NDUFAF3 (C3ORF60) was identified as a genuine mitochondrial complex I assembly protein. Pathogenic mutations in NDUFAF3 cause fatal neonatal mitochondrial complex I deficiency, confirmed by NDUFAF3-GFP baculovirus complementation in patient fibroblasts. NDUFAF3 interacts directly with complex I subunits and tightly interacts with NDUFAF4 (C6ORF66), another complex I assembly factor. Gene conservation analysis links NDUFAF3 to the bacterial membrane-insertion gene cluster SecF/SecD/YajC, suggesting a role in membrane-arm assembly. Homozygosity mapping, gene sequencing, GFP-baculovirus complementation in patient fibroblasts, co-immunoprecipitation/interaction studies, gene conservation analysis American journal of human genetics High 19463981
2009 Blue native PAGE followed by label-free LC-MS/MS profiling of human mitochondrial fractions identified C3ORF60 (NDUFAF3) as a novel candidate involved in complex I biogenesis, based on its co-migration profile with complex I assembly/turnover intermediates alongside known subunits NDUFS2, NDUFS3, NDUFS7, and NDUFS8. 2D blue native PAGE combined with label-free semi-quantitative LC-MS/MS and protein correlation profiling Proteomics Medium 19688755
2018 Compound heterozygous variants in NDUFAF3 (c.342_343insGTG:p.117Valdup and c.505C>A:p.Pro169Thr) cause complex I deficiency with cavitating leukoencephalopathy. 2D BN-PAGE/SDS-PAGE analysis revealed reductions in Q-module subunits (NDUFS2, NDUFS3, NDUFA9) and P-module subunits (NDUFB10, NDUFB11), indicating that NDUFAF3 is required for assembly of both the Q-module and P-module of complex I. Whole exome sequencing, 2D blue native polyacrylamide gel electrophoresis (BN-PAGE)/SDS-PAGE with immunoblotting of module-specific subunits, respiratory enzyme activity assay in skeletal muscle Clinical genetics Medium 29344937
2021 In Drosophila, genetic disruption of either NDUFAF3 or NDUFAF4 impairs biogenesis of the Q-, N-, and PP-b modules of complex I. The mechanism involves compromised integration of NDUFS3 into the Q-module and NDUFS5 into the PP-b module, coupled with destabilization of the assembly factor TIMMDC1 in assembly intermediates. Importantly, forced overexpression of NDUFAF4 can rescue Q-module biogenesis defects caused by NDUFAF3 disruption, demonstrating partial functional redundancy and epistatic relationship between these two assembly factors. Drosophila genetics (loss-of-function and overexpression), BN-PAGE, immunoblotting for module-specific subunits, epistasis analysis by transgenic rescue iScience High 34386730
2017 In Chlamydomonas reinhardtii, insertional mutagenesis of the NDUFAF3 homolog abolished complex I activity and assembly. Complemented strains showed restored complex I activity and assembly, confirming a conserved role for NDUFAF3 as an assembly factor for mitochondrial complex I across eukaryotes. Insertional mutagenesis, chlorophyll fluorescence screening, whole genome sequencing, complementation assay, complex I activity measurement The Plant journal : for cell and molecular biology Medium 28857403

Source papers

Stage 0 corpus · 43 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2002 Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. Proceedings of the National Academy of Sciences of the United States of America 1479 12477932
2014 A proteome-scale map of the human interactome network. Cell 977 25416956
2020 A reference map of the human binary protein interactome. Nature 849 32296183
2008 Global analysis of host-pathogen interactions that regulate early-stage HIV-1 replication. Cell 787 18854154
2021 Dual proteome-scale networks reveal cell-specific remodeling of the human interactome. Cell 705 33961781
2012 A census of human soluble protein complexes. Cell 689 22939629
2011 Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium. Briefings in bioinformatics 656 21873635
2020 Comparative host-coronavirus protein interaction networks reveal pan-viral disease mechanisms. Science (New York, N.Y.) 564 33060197
2015 Widespread macromolecular interaction perturbations in human genetic disorders. Cell 454 25910212
2004 The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome research 438 15489334
1996 Normalization and subtraction: two approaches to facilitate gene discovery. Genome research 401 8889548
2021 A proximity-dependent biotinylation map of a human cell. Nature 339 34079125
2019 Mitochondrial ClpP-Mediated Proteolysis Induces Selective Cancer Cell Lethality. Cancer cell 298 31056398
2000 Systematic subcellular localization of novel proteins identified by large-scale cDNA sequencing. EMBO reports 281 11256614
2021 Quantitative high-confidence human mitochondrial proteome and its dynamics in cellular context. Cell metabolism 239 34800366
2016 Mitochondrial Protein Interaction Mapping Identifies Regulators of Respiratory Chain Function. Molecular cell 220 27499296
2016 An organelle-specific protein landscape identifies novel diseases and molecular mechanisms. Nature communications 211 27173435
2018 An AP-MS- and BioID-compatible MAC-tag enables comprehensive mapping of protein interactions and subcellular localizations. Nature communications 201 29568061
2010 A functional peptidyl-tRNA hydrolase, ICT1, has been recruited into the human mitochondrial ribosome. The EMBO journal 153 20186120
2020 A High-Density Human Mitochondrial Proximity Interaction Network. Cell metabolism 148 32877691
2009 Mutations in NDUFAF3 (C3ORF60), encoding an NDUFAF4 (C6ORF66)-interacting complex I assembly protein, cause fatal neonatal mitochondrial disease. American journal of human genetics 139 19463981
2019 Mapping the proximity interaction network of the Rho-family GTPases reveals signalling pathways and regulatory mechanisms. Nature cell biology 137 31871319
2004 A protein interaction framework for human mRNA degradation. Genome research 123 15231747
1989 Type III hyperlipoproteinemia associated with apolipoprotein E phenotype E3/3. Structure and genetics of an apolipoprotein E3 variant. The Journal of clinical investigation 93 2539388
2021 SARS-CoV-2 nucleocapsid protein binds host mRNAs and attenuates stress granules to impair host stress response. iScience 90 34901782
2021 SARS-CoV-2-host proteome interactions for antiviral drug discovery. Molecular systems biology 86 34709727
2017 A Single Adaptable Cochaperone-Scaffold Complex Delivers Nascent Iron-Sulfur Clusters to Mammalian Respiratory Chain Complexes I-III. Cell metabolism 78 28380382
2016 Substrate-Trapped Interactors of PHD3 and FIH Cluster in Distinct Signaling Pathways. Cell reports 77 26972000
2019 Parkinson's disease-associated LRRK2-G2019S mutant acts through regulation of SERCA activity to control ER stress in astrocytes. Acta neuropathologica communications 76 31046837
2009 LC-MS/MS as an alternative for SDS-PAGE in blue native analysis of protein complexes. Proteomics 73 19688755
2013 TIMMDC1/C3orf1 functions as a membrane-embedded mitochondrial complex I assembly factor through association with the MCIA complex. Molecular and cellular biology 72 24344204
1983 Atypical familial dysbetalipoproteinemia associated with apolipoprotein phenotype E3/3. The Journal of clinical investigation 72 6860421
2013 LGALS3BP regulates centriole biogenesis and centrosome hypertrophy in cancer cells. Nature communications 64 23443559
1995 Changing epidemiology of meningococcal invasive disease in the Czech republic caused by new clone Neisseria meningitidis C:2a:P1.2(P1.5), ET-15/37. Central European journal of public health 40 8903519
1996 Very low density lipoprotein receptor binds apolipoprotein E2/2 as well as apolipoprotein E3/3. FEBS letters 33 8647281
2018 NDUFAF3 variants that disrupt mitochondrial complex I assembly may associate with cavitating leukoencephalopathy. Clinical genetics 14 29344937
2021 Dissecting the concordant and disparate roles of NDUFAF3 and NDUFAF4 in mitochondrial complex I biogenesis. iScience 12 34386730
2017 In vivo chlorophyll fluorescence screening allows the isolation of a Chlamydomonas mutant defective for NDUFAF3, an assembly factor involved in mitochondrial complex I assembly. The Plant journal : for cell and molecular biology 8 28857403
2003 Lipoprotein glomerulopathy associated with psoriasis vulgaris: report of 2 cases with apolipoprotein E3/3. American journal of kidney diseases : the official journal of the National Kidney Foundation 7 12955707
2002 Remnant-like lipoprotein particles in type 2 diabetic patients with apolipoprotein E3/3 and apolipoprotein E2 genotypes. Metabolism: clinical and experimental 5 12145767
2003 2P1, a novel male mouse cDNA specifically expressed during meiosis. The International journal of developmental biology 4 12653254
1996 Remnant-like particles (RLP) from NIDDM patients with apolipoprotein E3/3 phenotype stimulate cholesteryl ester synthesis in human monocyte-derived macrophages. Artery 3 8893973
2021 Naturally induced humoral response against Plasmodium vivax reticulocyte binding protein 2P1. Malaria journal 0 34082763