Protoheme IX farnesyltransferase, mitochondrial is an enzyme that in humans is encoded by the COX10 gene.[5][6] Cytochrome c oxidase (COX), the terminal component of the mitochondrial respiratory chain, catalyzes the electron transfer from reduced cytochrome c to oxygen. This component is a heteromeric complex consisting of 3 catalytic subunits encoded by mitochondrial genes and multiple structural subunits encoded by nuclear genes. The mitochondrially-encoded subunits function in electron transfer, and the nuclear-encoded subunits may function in the regulation and assembly of the complex. This nuclear gene, COX10, encodes heme A: farnesyltransferase, which is not a structural subunit but required for the expression of functional COX and functions in the maturation of the heme A prosthetic group of COX. A gene mutation, which results in the substitution of a lysine for an asparagine (N204K), is identified to be responsible for cytochrome c oxidase deficiency. In addition, this gene is disrupted in patients with CMT1A (Charcot-Marie-Tooth type 1A) duplication and with HNPP (hereditary neuropathy with liability to pressure palsies) deletion.[6]
Quick Facts Identifiers, Aliases ...
Close
The COX10 gene is located on the p arm of chromosome 17 in position 12 and spans 139,277 base pairs.[6] The gene produces a 48.9 kDa protein composed of 443 amino acids.[7][8] This gene has an unusually long 3' untranslated region measuring 1426 base pairs, compared to a 1329 base pair open reading frame.[9] The COX10 gene has 7 exons totaling 135 kilobases in length.[10] This protein is predicted to contain 7-9 transmembrane domains localized in the mitochondrial inner membrane.[6] There are hydrophilic loops between transmembrane domains II/III and VI/VII.[11] This protein is considered a constituent of the mitochondrial inner membrane.[12]
The protein encoded by COX10 is an assembly factor essential to COX synthesis, participating in the first step of the mitochondrial heme A biosynthetic pathway. It catalyzes the farnesylation of the vinyl group at position C2 of protoheme (heme B) and converts it to heme O.[10][11]
Mutations in the COX10 gene can result in numerous clinical phenotypes, from tubulopathy and leukodystrophy to Leigh syndrome to fatal infantile cardiomyopathy to a French Canadian form of Leigh Syndrome. A wide variety of symptoms encompassing the entire range of COX deficiency symptoms have been reported, including ataxia, hypotonia, ptosis, lactic acidosis, proximal tubulopathy, anemia, myopathy, hypertrophic cardiomyopathy, sensorineural hearing loss, and leukodystrophy.[11][9]
In addition, this gene is disrupted in patients with CMT1A (Charcot-Marie-Tooth type 1A) duplication and with HNPP (hereditary neuropathy with liability to pressure palsies) deletion.[6]
This protein interacts with FAM136A.[13]
Murakami T, Reiter LT, Lupski JR (May 1997). "Genomic structure and expression of the human heme A:farnesyltransferase (COX10) gene". Genomics. 42 (1): 161–4. doi:10.1006/geno.1997.4711. PMID 9177788. 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.
- Pitceathly RD, Taanman JW, Rahman S, Meunier B, Sadowski M, Cirak S, et al. (December 2013). "COX10 mutations resulting in complex multisystem mitochondrial disease that remains stable into adulthood". JAMA Neurology. 70 (12): 1556–61. doi:10.1001/jamaneurol.2013.3242. PMID 24100867.
- Glerum DM, Tzagoloff A (August 1994). "Isolation of a human cDNA for heme A:farnesyltransferase by functional complementation of a yeast cox10 mutant". Proceedings of the National Academy of Sciences of the United States of America. 91 (18): 8452–6. Bibcode:1994PNAS...91.8452G. doi:10.1073/pnas.91.18.8452. PMC 44624. PMID 8078902.
- Reiter LT, Murakami T, Koeuth T, Gibbs RA, Lupski JR (September 1997). "The human COX10 gene is disrupted during homologous recombination between the 24 kb proximal and distal CMT1A-REPs". Human Molecular Genetics. 6 (9): 1595–603. doi:10.1093/hmg/6.9.1595. PMID 9285799.
- Kennerson ML, Nassif NT, Dawkins JL, DeKroon RM, Yang JG, Nicholson GA (November 1997). "The Charcot-Marie-Tooth binary repeat contains a gene transcribed from the opposite strand of a partially duplicated region of the COX10 gene". Genomics. 46 (1): 61–9. doi:10.1006/geno.1997.5012. PMID 9403059.
- Kennerson ML, Nassif NT, Nicholson GA (October 1998). "Genomic structure and physical mapping of C17orf1: a gene associated with the proximal element of the CMT1A-REP binary repeat". Genomics. 53 (1): 110–2. doi:10.1006/geno.1998.5453. PMID 9787083.
- Valnot I, von Kleist-Retzow JC, Barrientos A, Gorbatyuk M, Taanman JW, Mehaye B, Rustin P, Tzagoloff A, Munnich A, Rötig A (May 2000). "A mutation in the human heme A:farnesyltransferase gene (COX10 ) causes cytochrome c oxidase deficiency". Human Molecular Genetics. 9 (8): 1245–9. doi:10.1093/hmg/9.8.1245. PMID 10767350.
- Bosetti F, Brizzi F, Barogi S, Mancuso M, Siciliano G, Tendi EA, Murri L, Rapoport SI, Solaini G (2002). "Cytochrome c oxidase and mitochondrial F1F0-ATPase (ATP synthase) activities in platelets and brain from patients with Alzheimer's disease". Neurobiology of Aging. 23 (3): 371–6. doi:10.1016/S0197-4580(01)00314-1. PMID 11959398. S2CID 5621542.
- Antonicka H, Leary SC, Guercin GH, Agar JN, Horvath R, Kennaway NG, Harding CO, Jaksch M, Shoubridge EA (October 2003). "Mutations in COX10 result in a defect in mitochondrial heme A biosynthesis and account for multiple, early-onset clinical phenotypes associated with isolated COX deficiency". Human Molecular Genetics. 12 (20): 2693–702. doi:10.1093/hmg/ddg284. PMID 12928484.
- Williams SL, Valnot I, Rustin P, Taanman JW (February 2004). "Cytochrome c oxidase subassemblies in fibroblast cultures from patients carrying mutations in COX10, SCO1, or SURF1". The Journal of Biological Chemistry. 279 (9): 7462–9. doi:10.1074/jbc.M309232200. PMID 14607829.
- Coenen MJ, van den Heuvel LP, Ugalde C, Ten Brinke M, Nijtmans LG, Trijbels FJ, Beblo S, Maier EM, Muntau AC, Smeitink JA (October 2004). "Cytochrome c oxidase biogenesis in a patient with a mutation in COX10 gene". Annals of Neurology. 56 (4): 560–4. doi:10.1002/ana.20229. PMID 15455402. S2CID 2348661.
- Veluthakal R, Kaur H, Goalstone M, Kowluru A (January 2007). "Dominant-negative alpha-subunit of farnesyl- and geranyltransferase inhibits glucose-stimulated, but not KCl-stimulated, insulin secretion in INS 832/13 cells". Diabetes. 56 (1): 204–10. doi:10.2337/db06-0668. PMID 17192483. S2CID 25460768.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.