Cytochrome b-c1 complex subunit 2, mitochondrial (UQCRC2), also known as QCR2, UQCR2, or MC3DN5 is a protein that in humans is encoded by the UQCRC2gene.[5] The product of UQCRC2 is a subunit of the respiratory chain protein Ubiquinol Cytochrome c Reductase (UQCR, Complex III or Cytochrome bc1 complex), 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, "11kDa protein", UQCRH (cyt c1 Hinge protein), Rieske Protein presequence, "cyt. c1 associated protein", and "Rieske-associated protein."[6][7] Defects in UQCRC2 are associated with mitochondrial complex III deficiency, nuclear, type 5.[5]
The protein encoded by this gene is located in the mitochondrion, where it is part of the ubiquinol-cytochrome c reductase complex (also known as complex III). This complex constitutes a part of the mitochondrial respiratory chain.[5] The core protein UQCRC2 is required for the assembly and stabilization of the complex.[10][11]
UQCRC2 has 98 protein-protein interactions with 90 of them being co-complex interactions. CAC1A, QCR1, UQCRC1, CACNA1A, STOM, a8k1f4, HLA-B, ARF6, and Mapk3 have been found to interact with UQCRC2.[10][11][15]
^Duncan AM, Ozawa T, Suzuki H, Rozen R (November 1993). "Assignment of the gene for the core protein II (UQCRC2) subunit of the mitochondrial cytochrome bc1 complex to human chromosome 16p12". Genomics. 18 (2): 455–6. doi:10.1006/geno.1993.1500. PMID8288258.
^Gaignard P, Eyer D, Lebigot E, Oliveira C, Therond P, Boutron A, Slama A (July 2017). "UQCRC2 mutation in a patient with mitochondrial complex III deficiency causing recurrent liver failure, lactic acidosis and hypoglycemia". Journal of Human Genetics. 62 (7): 729–731. doi:10.1038/jhg.2017.22. PMID28275242. S2CID4343047.
Hosokawa Y, Suzuki H, Toda H, Nishikimi M, Ozawa T (1990). "The primary structure of the precursor to core protein II, a putative member of mitochondrial processing protease family, of rat mitochondrial cytochrome bc1 complex deduced from cDNA sequence analysis". Biochemistry International. 20 (4): 731–7. PMID2162168.
Hu WH, Hausmann ON, Yan MS, Walters WM, Wong PK, Bethea JR (April 2002). "Identification and characterization of a novel Nogo-interacting mitochondrial protein (NIMP)". Journal of Neurochemistry. 81 (1): 36–45. doi:10.1046/j.1471-4159.2002.00788.x. PMID12067236. S2CID38794348.
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. PMID15544925.