COX14

Cytochrome c oxidase assembly factor COX14 is a protein that in humans is encoded by the COX14 gene. This gene encodes a small single-pass transmembrane protein that localizes to mitochondria. This protein may play a role in coordinating the early steps of cytochrome c oxidase (COX; also known as complex IV) subunit assembly and, in particular, the synthesis and assembly of the COX I subunit of the holoenzyme. Mutations in this gene have been associated with mitochondrial complex IV deficiency. Alternative splicing results in multiple transcript variants.^[5]

COX14
Identifiers
Aliases	COX14, C12orf62, COX14 cytochrome c oxidase assembly factor, cytochrome c oxidase assembly factor, PCAG1, cytochrome c oxidase assembly factor MC4DN10
External IDs	OMIM: 614478; MGI: 1913629; HomoloGene: 50025; GeneCards: COX14; OMA:COX14 - orthologs
Gene location (Human) Chr. Chromosome 12 (human)[1] Band 12q13.12 Start 50,112,082 bp[1] End 50,120,457 bp[1]
Gene location (Mouse) Chr. Chromosome 15 (mouse)[2] Band 15|15 F1 Start 99,623,528 bp[2] End 99,627,413 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in apex of heart right auricle left ventricle muscle of thigh right adrenal gland gastrocnemius muscle anterior pituitary left adrenal gland mucosa of transverse colon left adrenal cortex Top expressed in embryo blastocyst extraocular muscle digastric muscle myocardium of ventricle temporal muscle morula sternocleidomastoid muscle soleus muscle facial motor nucleus More reference expression data BioGPS n/a
Orthologs Species Human Mouse Entrez 84987 66379 Ensembl ENSG00000178449 ENSMUSG00000023020 UniProt Q96I36 Q8BH51 RefSeq (mRNA) NM_001257133 NM_001257134 NM_032901 NM_183256 RefSeq (protein) NP_001244062 NP_001244063 NP_116290 NP_899079 Location (UCSC) Chr 12: 50.11 – 50.12 Mb Chr 15: 99.62 – 99.63 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Structure

The COX14 gene is located on the q arm of chromosome 12 at position 13.12 and it spans 8,476 base pairs.^[5] The COX14 gene produces a 6.6 kDa protein composed of 57 amino acids.^[6][7] COX14 is a component of the enzyme MITRAC (mitochondrial translation regulation assembly intermediate of cytochrome c oxidase complex) complex, and the structure contains a central transmembrane domain.^[8]

Function

The COX14 gene encodes for a core protein component of the MITRAC (mitochondrial translation regulation assembly intermediate of cytochrome c oxidase complex) complex, which is required for the proper regulation of complex IV assembly. Complex IV of the mitochondrial respiratory chain is essential in catalyzing the oxidation of cytochrome c by molecular oxygen. COX14 has been shown to contribute to the early stages of complex IV assembly by coelution with COX1 and COX4 for nucleation of the assembly. The protein participates in the coupling synthesis of COX1 followed by an assembly of nascent subunits into the holoenzyme complex IV.^[9][10][8] The knockdown of the protein COX14 involving small interfering RNA in regular human fibroblast has been shown to result in a complex IV defect with reduced activity.^[8]

Clinical significance

Variants of COX14 have been associated with the mitochondrial Complex IV deficiency, a deficiency in an enzyme complex of the mitochondrial respiratory chain which catalyzes the oxidation of cytochrome c utilizing molecular oxygen.^[11][9][10] The deficiency is characterized by heterogeneous phenotypes ranging from isolated myopathy to severe multisystem disease affecting several tissues and organs. Other Clinical Manifestations include hypertrophic cardiomyopathy, hepatomegaly and liver dysfunction, hypotonia, muscle weakness, exercise intolerance, developmental delay, delayed motor development and mental retardation.^[12] A mutation in the homozygous missense mutation c.88G>A in the COX14 gene has resulted in the dysfunction of complex IV assembly and an unstable nascent enzyme complex.^[8]

Interactions

Like COA3, COX14 is a key component of the MITRAC (mitochondrial translation regulation assembly intermediate of cytochrome c oxidase complex) complex.^[13] In addition, it has interactions with proteins such as COX17, COX1, LMNA, COA3, SPPL2B, and others.^[14][9]

References

1. GRCh38: Ensembl release 89: ENSG00000178449 – Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000023020 – Ensembl, May 2017
3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
5. "Entrez Gene: Cytochrome c oxidase assembly factor COX14". Retrieved 2018-08-08.
6. 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 (Oct 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.
7. "Cytochrome c oxidase assembly protein COX14". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB). Archived from the original on 2018-08-09. Retrieved 2018-08-08.
8. Weraarpachai, W; Sasarman, F; Nishimura, T; Antonicka, H; Auré, K; Rötig, A; Lombès, A; Shoubridge, EA (13 January 2012). "Mutations in C12orf62, a factor that couples COX I synthesis with cytochrome c oxidase assembly, cause fatal neonatal lactic acidosis". American Journal of Human Genetics. 90 (1): 142–51. doi:10.1016/j.ajhg.2011.11.027. PMC 3257963. PMID 22243966.
9. "COX14 - Cytochrome c oxidase assembly protein COX14 - Homo sapiens (Human) - COX14 gene & protein". Retrieved 2018-08-07. This article incorporates text available under the CC BY 4.0 license.
10. "UniProt: the universal protein knowledgebase". Nucleic Acids Research. 45 (D1): D158–D169. January 2017. doi:10.1093/nar/gkw1099. PMC 5210571. PMID 27899622.
11. Ostergaard E, Weraarpachai W, Ravn K, Born AP, Jønson L, Duno M, Wibrand F, Shoubridge EA, Vissing J (March 2015). "Mutations in COA3 cause isolated complex IV deficiency associated with neuropathy, exercise intolerance, obesity, and short stature". Journal of Medical Genetics. 52 (3): 203–7. doi:10.1136/jmedgenet-2014-102914. PMID 25604084. S2CID 43018915.
12. "Mitochondrial complex IV deficiency". www.uniprot.org.
13. Mick DU, Dennerlein S, Wiese H, Reinhold R, Pacheu-Grau D, Lorenzi I, Sasarman F, Weraarpachai W, Shoubridge EA, Warscheid B, Rehling P (December 2012). "MITRAC links mitochondrial protein translocation to respiratory-chain assembly and translational regulation". Cell. 151 (7): 1528–41. doi:10.1016/j.cell.2012.11.053. hdl:11858/00-001M-0000-000E-DDDF-4. PMID 23260140.
14. Dennerlein S, Oeljeklaus S, Jans D, Hellwig C, Bareth B, Jakobs S, Deckers M, Warscheid B, Rehling P (September 2015). "MITRAC7 Acts as a COX1-Specific Chaperone and Reveals a Checkpoint during Cytochrome c Oxidase Assembly". Cell Reports. 12 (10): 1644–55. doi:10.1016/j.celrep.2015.08.009. hdl:11858/00-001M-0000-0028-466E-C. PMID 26321642.

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. Bibcode:2010PLoSO...512862H. doi:10.1371/journal.pone.0012862. PMC 2943476. PMID 20877624.
• Lai Y, Yu Z, Wang Y, Ye J (March 2013). "Identification of PCAG1 as a novel prostate cancer-associated gene". Mol Med Rep. 7 (3): 755–60. doi:10.3892/mmr.2012.1249. PMID 23292432.

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