Cytochrome b-c1 complex subunit 6, mitochondrial (UQCRH)

Cytochrome b-c1 complex subunit 6, mitochondrial (UQCRH) is a nuclear-encoded subunit of the mitochondrial respiratory chain Complex III (ubiquinol:cytochrome c oxidoreductase), located in the inner mitochondrial membrane. UQCRH, also known as the mitochondrial hinge protein, regulates the electron transfer between cytochrome c1 and cytochrome c, contributing to maintenance of mitochondrial membrane potential and efficient oxidative phosphorylation. Although not strictly essential for Complex III assembly or basic function, UQCRH modulates electron flow efficiency; its loss in renal cell carcinoma is associated with DNA hypermethylation, mitochondrial dysfunction, a metabolic shift to glycolysis (the Warburg effect), impaired apoptosis, and worse clinical outcomes. UQCRH deficiency also underlies rare forms of mitochondrial complex III deficiency[1][2][3][6].

Other names

Ubiquinol-cytochrome c reductase hinge proteinQCR6UQCR8Complex III subunit 6Complex III subunit VIIICytochrome c1 non-heme 11 kDa proteinMitochondrial hinge proteinUbiquinol-cytochrome c reductase complex 11 kDa proteinMC3DN11Cytochrome b-c1 complex subunit 6, mitochondrial

Decitabine acts as a DNA methyltransferase inhibitor, reversing the hypermethylation and restoring UQCRH expression in affected tumors[1].