Disease relevance of UQCRB

• A deletion in the human QP-C gene causes a complex III deficiency resulting in hypoglycaemia and lactic acidosis [1].

High impact information on UQCRB

• However, in rat and mouse a synteny break resides approximately 70 kb upstream of Gdf6, such that Gdf6 and Uqcrb are on separate chromosomes [2].
• We report here a deletion in the nuclear gene UQCRB encoding the human ubiquinone-binding protein of complex III (QP-C subunit or subunit VII) in a consanguineous family with an isolated complex III defect [1].
• Low temperature (-196 degrees C) spectral studies performed on isolated mitochondria from cultured skin fibroblast of the proband showed a decreased cytochrome b content suggestive of a role for the QP-C subunit in the assembly or maintenance of complex III structure [1].
• The ubiquinone-binding protein (QP-C) is a nuclear-encoded component of ubiquinol-cytochrome c oxidoreductase in the mitochondrial respiratory chain and plays an important role in electron transfer as a ubiquinone-QP-C complex [3].
• This implies that the human QP-C is synthesized without a presequence which is required for import of most nuclear-encoded mitochondrial proteins into mitochondria [3].

Biological context of UQCRB

• We have localized the human gene encoding the 13.3-kDa subunit of mitochondrial complex III (UQCRB) to chromosome 8 using both radioactive in situ hybridization and fluorescence in situ hybridization [4].
• The 111-amino acid sequence deduced from the nucleotide sequence of the cDNA is 85% homologous to that of bovine QP-C and contains only a single additional amino-terminal methionine [3].
• We obtained a partial cDNA for rat liver QP-C by screening a lambda gt11 rat liver cDNA library using antiserum directed against bovine heart QP-C [3].

Anatomical context of UQCRB

• We recently isolated a nuclear gene for human QP-C and used, in the present study, its fragment as a probe for Southern blot analysis of EcoRI-digested DNAs prepared from 14 human-mouse somatic cell hybrids [5].

Analytical, diagnostic and therapeutic context of UQCRB

• Localization of the human gene encoding the 13.3-kDa subunit of mitochondrial complex III (UQCRB) to 8q22 by in situ hybridization [4].

References