UQCC5

UQCC5 (Ubiquinol-Cytochrome C Reductase Complex Assembly Factor 5), also known as C6orf176, is a mitochondrial matrix protein critical for late-stage assembly of respiratory chain Complex III (cytochrome bc1 complex). It mediates incorporation of key subunits like the Rieske iron-sulfur protein into the complex, ensuring proper electron transport chain (ETC) function and oxidative phosphorylation (OXPHOS) for ATP production.
Defects in UQCC5 cause autosomal recessive Complex III deficiency, leading to phenotypes such as encephalomyopathy, lactic acidosis, and developmental delay. Therapeutic efforts remain preclinical, focusing on restoring mitochondrial function via gene editing to correct mutations or small molecules enhancing Complex III assembly, with no approved drugs currently available.