NDUFAF7

Protein arginine methyltransferase NDUFAF7, mitochondrial, also known as NADH:ubiquinone oxidoreductase complex assembly factor 7 (NDUFAF7), MidA, C2orf56, or PRO1853, is a protein that in humans is encoded by the NDUFAF7 gene. NDUFAF7 is a methyltransferase mitochondrial assembly enzyme involved in the assembly and stabilization of NADH dehydrogenase (ubiquinone) also known as complex I, which is located in the mitochondrial inner membrane and is the largest of the five complexes of the electron transport chain.[4][5][6] Mutations in NDUFAF7 have been associated with pathologic myopia and complex I deficiency.[5][7]

NDUFAF7
Identifiers
Aliases	NDUFAF7, C2orf56, MidA, PRO1853, NADH:ubiquinone oxidoreductase complex assembly factor 7
External IDs	OMIM: 615898 MGI: 1920944 HomoloGene: 12508 GeneCards: NDUFAF7
Gene location (Mouse) Chr. Chromosome 17 (mouse)[1] Band 17|17 E3 Start 78,937,136 bp[1] End 78,948,052 bp[1]
Gene ontology Molecular function • enzyme binding • GO:0001948 protein binding • methyltransferase activity • transferase activity • protein-arginine omega-N symmetric methyltransferase activity Cellular component • mitochondrial matrix • mitochondrion • extracellular Biological process • mitochondrial respiratory chain complex I assembly • ATP metabolic process • methylation • peptidyl-arginine methylation, to symmetrical-dimethyl arginine Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	55471	73694
Ensembl	n/a	ENSMUSG00000024082
UniProt	Q7L592	Q9CWG8
RefSeq (mRNA)	NM_001083946 NM_018607 NM_144736	NM_028611 NM_144760
RefSeq (protein)	NP_001077415 NP_653337 NP_001336953 NP_001336954 NP_001336956	NP_082887
Location (UCSC)	n/a	Chr 17: 78.94 – 78.95 Mb
PubMed search	[2]	[3]
Wikidata
View/Edit Human View/Edit Mouse

Structure

NDUFAF7 is located on the p arm of chromosome 2 in position 22.2 and has 14 exons.[4] The NDUFAF7 gene produces a 49.2 kDa protein composed of 441 amino acids.[8][9] NDUFAF7 is believed to be a part of the S-adenosylmethionine-dependent methyltransferase family. This family has a characteristic seven-β-strand protein fold. NDUFAF7 is a type II arginine methyltransferase, meaning that its enzymatic activity produces a symmetrical ω-N^G,N^G′-dimethylarginine.[10] It has a methyltransferase domain and an N-terminal sequence that corresponds to the recognized mitochondrial-targeting peptide.[11] NDUFAF7's stoichometry is disputed with some findings indicating that it is a homodimer,[11] while others denote it to be monomeric.[12][5]

Function

The NDUFAF7 gene encodes an assembly factor protein that is localized in the mitochondria and which helps in the assembly and stabilization of complex I, a large multi-subunit enzyme in the mitochondrial respiratory chain.[4][11] NADH:ubiquinone oxidoreductase (complex I) is involved in several physiological activities in the cell, including metabolite transport and ATP synthesis. Complex I catalyzes the transfer of electrons from NADH to ubiquinone (coenzyme Q) in the first step of the mitochondrial respiratory chain, resulting in the translocation of protons across the inner mitochondrial membrane.[13] The encoded protein of NDUFAF7 is a methyltransferase that symmetrically dimethylates the ω-N^G,N^G′ atoms of Arg85 of subunit NDUFS2 of complex I in the early stages of its assembly. This interaction between NDUFAF7 and NDUFS2 is believed to be transient and it is suggested that this methylation stabilizes a 400 kDa subcomplex primarily associated with the peripheral arm of complex I. Without this methylation, the amount of intact complex I is significantly reduced, illustrating NDUFAF7's importance to the mitochondrial respiratory chain. A pseudogene related to this gene is located on chromosome 8. Alternative splicing results in multiple transcript variants.[4][10]

Clinical significance

Defects in NDUFAF7 may be a cause of susceptibility to pathologic myopia, a genetically heterogeneous disorder characterized by extreme, familial, early-onset vision loss and described as myopia accompanied by severe deformation of the eye besides excessive elongation of the eye. This defect, a heterozygous D266E missense mutation, also resulted in reduced complex I activity.[5][7] Due to is role in early assembly of complex I, it has been suggested that mutations affecting NDUFAF7 may be lethal.[10]

Interactions

NDUFAF7 interacts transiently with NDUFS2, dimethylating Arg85 on the subunit.[10] A correlation between the presence of MidA and NDUFS7 was also identified.[11] In addition to co-complexes, NDUFAF4 has protein-protein interactions with LRRK2, q5nfq6_fratt, and q5ngw2_fratt.[14]

References

1. GRCm38: Ensembl release 89: ENSMUSG00000024082 - Ensembl, May 2017
2. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
3. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Entrez Gene: NADH:ubiquinone oxidoreductase complex assembly factor 7". Retrieved 2018-07-26.
5. "NDUFAF7 - Protein arginine methyltransferase NDUFAF7, mitochondrial precursor - Homo sapiens (Human) - NDUFAF7 gene & protein". www.uniprot.org. Retrieved 2018-07-27.
6. Donald Voet; Judith G. Voet; Charlotte W. Pratt (2013). "18". Fundamentals of biochemistry : life at the molecular level (4th ed.). Hoboken, NJ: Wiley. pp. 581–620. ISBN 9780470547847.
7. Wang B, Liu Y, Chen S, Wu Y, Lin S, Duan Y, Zheng K, Zhang L, Gu X, Hong W, Shao H, Zeng X, Sun B, Duan S (August 2017). "A Novel Potentially Causative Variant of NDUFAF7 Revealed by Mutation Screening in a Chinese Family With Pathologic Myopia". Investigative Ophthalmology & Visual Science. 58 (10): 4182–4192. doi:10.1167/iovs.16-20941. PMID 28837730.
8. Zong NC, Li H, Li H, Lam MP, Jimenez RC, Kim CS, Deng N, Kim AK, Choi JH, Zelaya I, Liem D, Meyer D, Odeberg J, Fang C, Lu HJ, Xu T, Weiss J, Duan H, Uhlen M, Yates JR, Apweiler R, Ge J, Hermjakob H, Ping P (October 2013). "Integration of cardiac proteome biology and medicine by a specialized knowledgebase". Circulation Research. 113 (9): 1043–53. doi:10.1161/CIRCRESAHA.113.301151. PMC 4076475. PMID 23965338.
9. Yao, Daniel. "Cardiac Organellar Protein Atlas Knowledgebase (COPaKB) —— Protein Information". amino.heartproteome.org. Retrieved 2018-07-27.
10. Rhein VF, Carroll J, Ding S, Fearnley IM, Walker JE (November 2013). "NDUFAF7 methylates arginine 85 in the NDUFS2 subunit of human complex I". The Journal of Biological Chemistry. 288 (46): 33016–26. doi:10.1074/jbc.M113.518803. PMC 3829151. PMID 24089531.
11. Carilla-Latorre S, Gallardo ME, Annesley SJ, Calvo-Garrido J, Graña O, Accari SL, Smith PK, Valencia A, Garesse R, Fisher PR, Escalante R (May 2010). "MidA is a putative methyltransferase that is required for mitochondrial complex I function". Journal of Cell Science. 123 (Pt 10): 1674–83. doi:10.1242/jcs.066076. PMID 20406883.
12. Zurita Rendón O, Silva Neiva L, Sasarman F, Shoubridge EA (October 2014). "The arginine methyltransferase NDUFAF7 is essential for complex I assembly and early vertebrate embryogenesis". Human Molecular Genetics. 23 (19): 5159–70. doi:10.1093/hmg/ddu239. PMC 4159157. PMID 24838397.
13. Reference, Genetics Home. "NDUFAF1 gene". Genetics Home Reference. Retrieved 2018-07-27.
14. "9 binary interactions found for search term NDUFAF7". IntAct Molecular Interaction Database. EMBL-EBI. Retrieved 2018-08-25.

Further reading

• Hendrickson SL, Lautenberger JA, Chinn LW, Malasky M, Sezgin E, Kingsley LA, Goedert JJ, Kirk GD, Gomperts ED, Buchbinder SP, Troyer JL, O'Brien SJ (September 2010). "Genetic variants in nuclear-encoded mitochondrial genes influence AIDS progression". PLOS One. 5 (9): e12862. doi:10.1371/journal.pone.0012862. PMC 2943476. PMID 20877624.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.