Ubiquinol-cytochrome c reductase binding protein, also known as UQCRB, Complex III subunit 7, QP-C, or Ubiquinol-cytochrome c reductase complex 14 kDa protein is a protein which in humans is encoded by the UQCRB gene. This gene encodes a subunit of the ubiquinol-cytochrome c oxidoreductase complex, which consists of one mitochondrial-encoded and 10 nuclear-encoded subunits. Mutations in this gene are associated with mitochondrial complex III deficiency. Alternatively spliced transcript variants have been found for this gene. Related pseudogenes have been identified on chromosomes 1, 5 and X.[5]
UQCRB is located on the q arm of chromosome 8 in position 22.1, has 18 exons, and spans 8,958 base pairs.[5] The UQCRB gene produces a 5.9 kDa protein composed of 161 amino acids.[6][7] The gene product of UQCRB is a subunit of the respiratory chain protein Ubiquinol Cytochrome c Reductase (UQCR, Complex III or Cytochrome bc1 complex; E.C. 1.10.2.2), which consists of the products of one mitochondrially encoded gene, MTCYTB (mitochondrial cytochrome b) and ten nuclear genes: UQCRC1, UQCRC2, Cytochrome c1, UQCRFS1 (Rieske protein), UQCRB, "14kDa protein", UQCRH (cyt c1 Hinge protein), Rieske Protein presequence, "cyt. c1 associated protein", and "Rieske-associated protein". After processing, the cleaved leader sequence of the iron-sulfur protein is retained as subunit 9, giving 11 subunits from 10 genes.[5]
^Chang J, Jung HJ, Jeong SH, Kim HK, Han J, Kwon HJ (December 2014). "A mutation in the mitochondrial protein UQCRB promotes angiogenesis through the generation of mitochondrial reactive oxygen species". Biochemical and Biophysical Research Communications. 455 (3–4): 290–7. doi:10.1016/j.bbrc.2014.11.005. PMID25446085.
^Jung HJ, Cho M, Kim Y, Han G, Kwon HJ (October 2014). "Development of a novel class of mitochondrial ubiquinol-cytochrome c reductase binding protein (UQCRB) modulators as promising antiangiogenic leads". Journal of Medicinal Chemistry. 57 (19): 7990–8. doi:10.1021/jm500863j. PMID25244355.
^* Jung HJ, Kim KH, Kim ND, Han G, Kwon HJ (February 2011). "Identification of a novel small molecule targeting UQCRB of mitochondrial complex III and its anti-angiogenic activity". Bioorganic & Medicinal Chemistry Letters. 21 (3): 1052–6. doi:10.1016/j.bmcl.2010.12.002. PMID21215626.
Chang J, Jung HJ, Park HJ, Cho SW, Lee SK, Kwon HJ (September 2015). "Cell-permeable mitochondrial ubiquinol-cytochrome c reductase binding protein induces angiogenesis in vitro and in vivo". Cancer Letters. 366 (1): 52–60. doi:10.1016/j.canlet.2015.06.013. PMID26118773.
Jung HJ, Kwon HJ (May 2013). "Exploring the role of mitochondrial UQCRB in angiogenesis using small molecules". Molecular BioSystems. 9 (5): 930–9. doi:10.1039/c3mb25426g. PMID23475074.
Jung HJ, Kim Y, Chang J, Kang SW, Kim JH, Kwon HJ (September 2013). "Mitochondrial UQCRB regulates VEGFR2 signaling in endothelial cells". Journal of Molecular Medicine. 91 (9): 1117–28. doi:10.1007/s00109-013-1049-6. PMID23708980. S2CID13973232.
Hosokawa Y, Suzuki H, Nishikimi M, Matsukage A, Yoshida MC, Ozawa T (1990). "Chromosomal assignment of the gene for the ubiquinone-binding protein of human mitochondrial cytochrome bc1 complex". Biochemistry International. 21 (1): 41–4. PMID2167087.
Suzuki H, Hosokawa Y, Toda H, Nishikimi M, Ozawa T (May 1989). "Isolation of a single nuclear gene encoding human ubiquinone-binding protein in complex III of mitochondrial respiratory chain". Biochemical and Biophysical Research Communications. 161 (1): 371–8. doi:10.1016/0006-291X(89)91607-0. PMID2543413.
Suzuki H, Hosokawa Y, Toda H, Nishikimi M, Ozawa T (October 1988). "Cloning and sequencing of a cDNA for human mitochondrial ubiquinone-binding protein of complex III". Biochemical and Biophysical Research Communications. 156 (2): 987–94. doi:10.1016/S0006-291X(88)80941-0. PMID3056408.
Malaney S, Heng HH, Tsui LC, Shi XM, Robinson BH (1996). "Localization of the human gene encoding the 13.3-kDa subunit of mitochondrial complex III (UQCRB) to 8q22 by in situ hybridization". Cytogenetics and Cell Genetics. 73 (4): 297–9. doi:10.1159/000134360. hdl:10722/42534. PMID8751380. S2CID46788171.
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. PMID12709789. S2CID24273072.