PUBLICATION
The arginine methyltransferase NDUFAF7 is essential for complex I assembly and early vertebrate embryogenesis
- Authors
- Zurita, O., Silva Neiva, L., Sasarman, F., Shoubridge, E.A.
- ID
- ZDB-PUB-140520-4
- Date
- 2014
- Source
- Human molecular genetics 23(19): 5159-70 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Amino Acid Motifs
- Animals
- CDPdiacylglycerol-Serine O-Phosphatidyltransferase/genetics
- Cell Line
- Electron Transport Complex I/metabolism*
- Embryonic Development/genetics*
- Fibroblasts
- Gene Knockdown Techniques
- Genes, Lethal
- Humans
- Mice
- Mice, Knockout
- Mitochondria/metabolism
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- NADH Dehydrogenase/chemistry
- NADH Dehydrogenase/genetics*
- NADH Dehydrogenase/metabolism
- Phenotype
- Protein Interaction Domains and Motifs
- Proteolysis
- RNA Interference
- Substrate Specificity
- Vertebrates
- Zebrafish
- PubMed
- 24838397 Full text @ Hum. Mol. Genet.
Citation
Zurita, O., Silva Neiva, L., Sasarman, F., Shoubridge, E.A. (2014) The arginine methyltransferase NDUFAF7 is essential for complex I assembly and early vertebrate embryogenesis. Human molecular genetics. 23(19):5159-70.
Abstract
Complex I of the mitochondrial respiratory chain is a large multi-subunit enzyme that assembles from nuclear and mtDNA-encoded components. Several complex I assembly factors have been identified, but their precise functions are not well understood. Here we have investigated the function of one of these, NDUFAF7, a soluble matrix protein comprised of a DUF185 domain that harbors a methyltransferase motif. Knock down of NDUFAF7 by siRNA in human fibroblasts produced a specific complex I assembly defect, as did morpholino-mediated knockdown of the zebrafish orthologue. Germ line disruption of the murine orthologue was an early embryonic lethal. The complex I assembly defect was characterized by rapid, AFG3L2-dependent, turnover of newly synthesized ND1, the subunit that seeds the assembly pathway, and by decreased steady-state levels of several other structural subunits including NDUFS2, NDUFS1, and NDUFA9. Expression of an NDUFAF7 mutant (G124 V), predicted to disrupt methyltransferase activity, impaired complex I assembly, suggesting an assembly factor or structural subunit as a substrate for methylation. To identify the NDUFAF7 substrate we used an anti-ND1 antibody to immunoprecipitate complex I and its associated assembly factors, followed by mass spectrometry to detect post-translational protein modifications. Analysis of an NDUFAF7 methyltransferase mutant showed a ten-fold reduction in an NDUFS2 peptide containing dimethylated Arg85, but a five-fold reduction in three other NDUFS2 peptides. These results show that NUFAF7 functions to methylate NDUFS2 after it assembles into a complex I, stabilizing an early intermediate in the assembly pathway, and that this function is essential for normal vertebrate development.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping