COX6A2

Last updated • 1 min readFrom Wikipedia, The Free Encyclopedia
COX6A2
Identifiers
Aliases COX6A2 , COX6AH, COXVIAH, cytochrome c oxidase subunit 6A2, MC4DN18, COXVIa-M
External IDs OMIM: 602009 MGI: 104649 HomoloGene: 38020 GeneCards: COX6A2
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_005205

NM_009943

RefSeq (protein)

NP_005196

NP_034073

Location (UCSC) Chr 16: 31.43 – 31.43 Mb Chr 7: 127.8 – 127.81 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Cytochrome c oxidase subunit VIa polypeptide 2 is a protein that in humans is encoded by the COX6A2 gene. Cytochrome c oxidase 6A2 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. [5]

Contents

Structure

The COX6A2 gene, located on the p arm of chromosome 16 in position 11.12, contains 3 exons and is 698 base pairs in length. [5] The COX6A1 protein weighs 11 kDa and is composed of 97 amino acids. [6] [7] The protein is a subunit of Complex IV, a heteromeric complex consisting of 3 catalytic subunits encoded by mitochondrial genes and multiple structural subunits encoded by nuclear genes. This nuclear gene encodes polypeptide 2 (heart/muscle isoform) of subunit VIa, and polypeptide 2 is present only in striated muscles. Polypeptide 1 (liver isoform) of subunit VIa is encoded by a different gene, COX6A1, and is found in all non-muscle tissues. These two polypeptides share 66% amino acid sequence identity. [5]

Function

Cytochrome c oxidase (COX) is the terminal enzyme of the mitochondrial respiratory chain. It is a multi-subunit enzyme complex that couples the transfer of electrons from cytochrome c to molecular oxygen and contributes to a proton electrochemical gradient across the inner mitochondrial membrane to drive ATP synthesis via protonmotive force. The mitochondrially-encoded subunits perform the electron transfer of proton pumping activities. The functions of the nuclear-encoded subunits are unknown but they may play a role in the regulation and assembly of the complex. [5]

Summary reaction:

4 Fe2+-cytochrome c + 8 H+in + O2 → 4 Fe3+-cytochrome c + 2 H2O + 4 H+out [8]

Clinical significance

The Trans-activator of transcription protein (Tat) of human immunodeficiency virus (HIV) inhibits cytochrome c oxidase (COX) activity in permeabilized mitochondria isolated from both mouse and human liver, heart, and brain samples. Rapid loss of membrane potential (ΔΨm) occurs with submicromolar doses of Tat, and cytochrome c is released from the mitochondria. [9]

Related Research Articles

<span class="mw-page-title-main">Cytochrome c oxidase</span> Complex enzyme found in bacteria, archaea, and mitochondria of eukaryotes

The enzyme cytochrome c oxidase or Complex IV, is a large transmembrane protein complex found in bacteria, archaea, and mitochondria of eukaryotes.

<span class="mw-page-title-main">Cytochrome c oxidase subunit I</span> Enzyme of the respiratory chain encoded by the mitochondrial genome

Cytochrome c oxidase I (COX1) also known as mitochondrially encoded cytochrome c oxidase I (MT-CO1) is a protein that in humans is encoded by the MT-CO1 gene. In other eukaryotes, the gene is called COX1, CO1, or COI. Cytochrome c oxidase I is the main subunit of the cytochrome c oxidase complex. Mutations in MT-CO1 have been associated with Leber's hereditary optic neuropathy (LHON), acquired idiopathic sideroblastic anemia, Complex IV deficiency, colorectal cancer, sensorineural deafness, and recurrent myoglobinuria.

<span class="mw-page-title-main">Cytochrome c oxidase subunit 2</span> Enzyme of the respiratory chain encoded by the mitochondrial genome

Cytochrome c oxidase subunit 2, also known as cytochrome c oxidase polypeptide II, is a protein that in humans is encoded by the MT-CO2 gene. Cytochrome c oxidase subunit II, abbreviated COXII, COX2, COII, or MT-CO2, is the second subunit of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits of respiratory complex IV.

<span class="mw-page-title-main">Cytochrome c oxidase subunit III</span> Enzyme of the respiratory chain encoded by the mitochondrial genome

Cytochrome c oxidase subunit III (COX3) is an enzyme that in humans is encoded by the MT-CO3 gene. It is one of main transmembrane subunits of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits of respiratory complex IV. Variants of it have been associated with isolated myopathy, severe encephalomyopathy, Leber hereditary optic neuropathy, mitochondrial complex IV deficiency, and recurrent myoglobinuria.

<span class="mw-page-title-main">SCO2</span>

SCO2 cytochrome c oxidase assembly is a protein that in humans is encoded by the SCO2 gene. The encoded protein is one of the cytochrome c oxidase (COX)(Complex IV) assembly factors. Human COX is a multimeric protein complex that requires several assembly factors. Cytochrome c oxidase (COX) catalyzes the transfer of electrons from cytochrome c to molecular oxygen, which helps to maintain the proton gradient across the inner mitochondrial membrane that is necessary for aerobic ATP production. The encoded protein is a metallochaperone that is involved in the biogenesis of cytochrome c oxidase subunit II. Mutations in this gene are associated with fatal infantile encephalocardiomyopathy and myopia 6.

<span class="mw-page-title-main">SCO1</span> Protein-coding gene in the species Homo sapiens

Protein SCO1 homolog, mitochondrial, also known as SCO1, cytochrome c oxidase assembly protein, is a protein that in humans is encoded by the SCO1 gene. SCO1 localizes predominantly to blood vessels, whereas SCO2 is barely detectable, as well as to tissues with high levels of oxidative phosphorylation. The expression of SCO2 is also much higher than that of SCO1 in muscle tissue, while SCO1 is expressed at higher levels in liver tissue than SCO2. Mutations in both SCO1 and SCO2 are associated with distinct clinical phenotypes as well as tissue-specific cytochrome c oxidase deficiency.

<span class="mw-page-title-main">COX4I1</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase subunit 4 isoform 1, mitochondrial (COX4I1) is an enzyme that in humans is encoded by the COX4I1 gene. COX4I1 is a nuclear-encoded isoform of cytochrome c oxidase (COX) subunit 4. Cytochrome c oxidase is a multi-subunit enzyme complex that couples the transfer of electrons from cytochrome c to molecular oxygen and contributes to a proton electrochemical gradient across the inner mitochondrial membrane, acting as the terminal enzyme of the mitochondrial respiratory chain. Antibodies against COX4 can be used to identify the inner membrane of mitochondria in immunfluorescence studies. Mutations in COX4I1 have been associated with COX deficiency and Fanconi anemia.

<span class="mw-page-title-main">COX4I2</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase subunit 4 isoform 2, mitochondrial is an enzyme that in humans is encoded by the COX4I2 gene. COX4I2 is a nuclear-encoded isoform of cytochrome c oxidase (COX) subunit 4. Cytochrome c oxidase is a multi-subunit enzyme complex that couples the transfer of electrons from cytochrome c to molecular oxygen and contributes to a proton electrochemical gradient across the inner mitochondrial membrane, acting as the terminal enzyme of the mitochondrial respiratory chain. Mutations in COX4I2 have been associated with exocrine pancreatic insufficiency, dyserythropoietic anemia, and calvarial hyperostosis (EPIDACH).

<span class="mw-page-title-main">COX6B1</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase subunit 6B1 is an enzyme that in humans is encoded by the COX6B1 gene. Cytochrome c oxidase 6B1 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. Mutations of the COX6B1 gene are associated with severe infantile encephalomyopathy and mitochondrial complex IV deficiency (MT-C4D).

<span class="mw-page-title-main">COX7A2</span>

Cytochrome c oxidase polypeptide 7A2, mitochondrial is an enzyme that in humans is encoded by the COX7A2 gene.

<span class="mw-page-title-main">COX10</span> Mammalian protein found in Homo sapiens

Protoheme IX farnesyltransferase, mitochondrial is an enzyme that in humans is encoded by the COX10 gene. 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 duplication and with HNPP deletion.

<span class="mw-page-title-main">COX5B</span>

Cytochrome c oxidase subunit 5B, mitochondrial is an enzyme in humans that is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. In humans, cytochrome c oxidase subunit 5B is encoded by the COX5B gene.

<span class="mw-page-title-main">COX6A1</span>

Cytochrome c oxidase subunit 6A1, mitochondrial is a protein that in humans is encoded by the COX6A1 gene. Cytochrome c oxidase 6A1 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. A mutation of the COX6A1 gene is associated with a recessive axonal or mixed form of Charcot-Marie-Tooth disease.

<span class="mw-page-title-main">COX7A1</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase polypeptide 7A1, mitochondrial is an enzyme that in humans is encoded by the COX7A1 gene.

<span class="mw-page-title-main">COX7B</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase subunit 7B, mitochondrial (COX7B) is an enzyme that in humans is encoded by the COX7B gene. COX7B is a nuclear-encoded subunit of cytochrome c oxidase (COX). Cytochrome c oxidase is a multi-subunit enzyme complex that couples the transfer of electrons from cytochrome c to molecular oxygen and contributes to a proton electrochemical gradient across the inner mitochondrial membrane, acting as the terminal enzyme of the mitochondrial respiratory chain. Work with Oryzias latices has linked disruptions in COX7B with microphthalmia with linear skin lesions (MLS), microcephaly, and mitochondrial disease. Clinically, mutations in COX7B have been associated with linear skin defects with multiple congenital anomalies.

<span class="mw-page-title-main">COX7A2L</span>

Cytochrome c oxidase subunit 7A-related protein, mitochondrial is an enzyme that in humans is encoded by the COX7A2L gene.

<span class="mw-page-title-main">COX7C</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase subunit 7C, mitochondrial is an enzyme that in humans is encoded by the COX7C gene.

<span class="mw-page-title-main">COX5A</span>

Cytochrome c oxidase subunit 5a is a protein that in humans is encoded by the COX5A gene. Cytochrome c oxidase 5A is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain.

<span class="mw-page-title-main">COX6B2</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase subunit VIb polypeptide 2 is a protein that in humans is encoded by the COX6B2 gene. Cytochrome c oxidase 6B2 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain.

<span class="mw-page-title-main">COX8A</span>

Cytochrome c oxidase subunit 8A (COX8A) is a protein that in humans is encoded by the COX8A gene. Cytochrome c oxidase 8A is a subunit of the cytochrome c oxidase complex, also known as Complex IV. Mutations in the COX8A gene have been associated with complex IV deficiency with Leigh syndrome and epilepsy.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000156885 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000030785 - 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. 1 2 3 4 "Entrez Gene: Cytochrome c oxidase subunit VIa polypeptide 2".
  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 subunit 6A2, mitochondrial". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB). Archived from the original on 2018-07-19. Retrieved 2018-07-18.
  8. Voet D, Voet JG, Pratt CW (2013). "Chapter 18". Fundamentals of Biochemistry: Life at the Molecular Level (4th ed.). Hoboken, NJ: Wiley. pp. 581–620. ISBN   978-0-470-54784-7.
  9. Lecoeur H, Borgne-Sanchez A, Chaloin O, El-Khoury R, Brabant M, Langonné A, Porceddu M, Brière JJ, Buron N, Rebouillat D, Péchoux C, Deniaud A, Brenner C, Briand JP, Muller S, Rustin P, Jacotot E (2012). "HIV-1 Tat protein directly induces mitochondrial membrane permeabilization and inactivates cytochrome c oxidase". Cell Death & Disease. 3 (3): e282. doi:10.1038/cddis.2012.21. PMC   3317353 . PMID   22419111.

Further reading

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