UQCRQ

Ubiquinol-cytochrome c reductase, complex III subunit VII, 9.5kDa is a protein that in humans is encoded by the UQCRQ gene. This ubiqinone-binding protein is a subunit of mitochondrial Complex III in the electron transport chain.[5] A mutation in the UQCRQ gene has been shown to cause severe neurological disorders.[6] Infection by Trypanosoma cruzi can cause oxidative modification of this protein in cardiac muscle tissue.[7]

UQCRQ
Identifiers
Aliases	UQCRQ, MC3DN4, QCR8, QP-C, QPC, UQCR7, ubiquinol-cytochrome c reductase complex III subunit VII
External IDs	OMIM: 612080 MGI: 107807 HomoloGene: 40942 GeneCards: UQCRQ
Gene location (Human) Chr. Chromosome 5 (human)[1] Band 5q31.1 Start 132,866,630 bp[1] End 132,868,847 bp[1]
Gene location (Mouse) Chr. Chromosome 11 (mouse)[2] Band 11|11 B1.3 Start 53,427,922 bp[2] End 53,430,831 bp[2]
Gene ontology Molecular function • ubiquinol-cytochrome-c reductase activity Cellular component • mitochondrial inner membrane • electron transport • mitochondrion • membrane • mitochondrial respiratory chain complex III Biological process • pons development • pyramidal neuron development • hippocampus development • oxidation-reduction process • cerebellar Purkinje cell layer development • midbrain development • thalamus development • hypothalamus development • subthalamus development • mitochondrial electron transport, ubiquinol to cytochrome c Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	27089	22272
Ensembl	ENSG00000164405	ENSMUSG00000044894
UniProt	O14949	Q9CQ69
RefSeq (mRNA)	NM_014402	NM_025352 NM_001326614
RefSeq (protein)	NP_055217	NP_001313543 NP_079628
Location (UCSC)	Chr 5: 132.87 – 132.87 Mb	Chr 11: 53.43 – 53.43 Mb
PubMed search	[3]	[4]
Wikidata
View/Edit Human View/Edit Mouse

Structure

The UQCRQ gene is located on the q arm of chromosome 5 in position 31.1 and spans 2,217 base pairs.[8] The gene produces a 9.9 kDa protein composed of 82 amino acids.[9][10] This protein is transmembranous, with more mass on the matrix side of the membrane.[11]

Function

This gene encodes a ubiquinone-binding protein of low molecular mass. It is a small core-associated protein and a subunit of ubiquinol-cytochrome c reductase complex III, which is part of the mitochondrial respiratory chain.[5]

Clinical significance

Variants of UQCRQ have been associated with complex III deficiency. One set of twenty consanguineous cases of a Ser45Phe mutation in the UQCRQ gene, and a different homozygous 4-bp deletion at p. 338-341, have been linked to this disease. In an inbred Israeli Bedouin family, the mutations, inherited in an autosomal recessive pattern, displayed the phenotype of mitochondrial Complex III deficiency, nuclear type 4, accompanied by severe neurological symptoms.[6] Other symptoms of complex III deficiency linked to these mutations have included hypoglycemia, lactic acidosis, and hypotonia.[12]

In another study of cardiac muscle tissue in individuals infected by Trypanosoma cruzi, an oxidative modification of the UQCRQ subunit was present, along with oxidative modification of subunits UQCRC1 and UQCRC2 of the same core complex and UQCRH and CYC1 of the neighboring subcomplex.[7]

Interactions

The protein encoded by UQCRQ has protein-protein interactions with UQCRC1, OPTN, ERCC8, GRINL1A, Dctn1, K8.1, XRCC3, PML, RAB7A, HNRNPA1L2, CDC73, NLRP3, HAUS2, TMEM248, and GOLT1B.[13]

References

1. GRCh38: Ensembl release 89: ENSG00000164405 - Ensembl, May 2017
2. GRCm38: Ensembl release 89: ENSMUSG00000044894 - 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: Ubiquinol-cytochrome c reductase, complex III subunit VII, 9.5kDa". This article incorporates text from this source, which is in the public domain.
6. Barel O, Shorer Z, Flusser H, Ofir R, Narkis G, Finer G, Shalev H, Nasasra A, Saada A, Birk OS (May 2008). "Mitochondrial complex III deficiency associated with a homozygous mutation in UQCRQ". American Journal of Human Genetics. 82 (5): 1211–6. doi:10.1016/j.ajhg.2008.03.020. PMC 2427202. PMID 18439546.
7. Wen JJ, Garg N (December 2004). "Oxidative modification of mitochondrial respiratory complexes in response to the stress of Trypanosoma cruzi infection". Free Radical Biology & Medicine. 37 (12): 2072–81. doi:10.1016/j.freeradbiomed.2004.09.011. PMID 15544925.
8. "Entrez Gene: Ubiquinol-cytochrome c reductase, complex III subunit VII, 9.5kDa".
9. 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.
10. "UQCRQ - Cytochrome b-c1 complex subunit 8". Cardiac Organellar Protein Atlas Knowledgebase (COPaKB).
11. Usui S, Yu L, Yu CA (May 1990). "The small molecular mass ubiquinone-binding protein (QPc-9.5 kDa) in mitochondrial ubiquinol-cytochrome c reductase: isolation, ubiquinone-binding domain, and immunoinhibition". Biochemistry. 29 (19): 4618–26. doi:10.1021/bi00471a017. PMID 2164842.
12. Haut S, Brivet M, Touati G, Rustin P, Lebon S, Garcia-Cazorla A, Saudubray JM, Boutron A, Legrand A, Slama A (July 2003). "A deletion in the human QP-C gene causes a complex III deficiency resulting in hypoglycaemia and lactic acidosis". Human Genetics. 113 (2): 118–22. doi:10.1007/s00439-003-0946-0. PMID 12709789.
13. IntAct. "Interactions with UQCRQ". www.ebi.ac.uk. Retrieved 2018-08-02.

Further reading

• Schägger H, Brandt U, Gencic S, von Jagow G (1995). "Ubiquinol-cytochrome-c reductase from human and bovine mitochondria". Methods in Enzymology. 260: 82–96. doi:10.1016/0076-6879(95)60132-5. PMID 8592474.
• Sifroni KG, Damiani CR, Stoffel C, Cardoso MR, Ferreira GK, Jeremias IC, Rezin GT, Scaini G, Schuck PF, Dal-Pizzol F, Streck EL (September 2010). "Mitochondrial respiratory chain in the colonic mucosal of patients with ulcerative colitis". Molecular and Cellular Biochemistry. 342 (1–2): 111–5. doi:10.1007/s11010-010-0474-x. PMID 20440543.

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