UQCRC1, or Ubiquinol-cytochrome-c reductase complex core protein 1, is a core subunit of the mitochondrial respiratory complex III. It is the largest nuclear encoded subunit of the complex. UQCRC1 plays a key role in mitochondria-to-nucleus retrograde response and is involved in the mitochondrial proton gradient formation. It has also shown to interact with Nogo, an inhibitor of neurite growth after spinal cord injury. UQCRC1 has been found at high expression levels in breast and ovarian tumors, positively correlating with Cox-2 expression. Transcription of UQCRC1 is repressed by the nuclear protein methyl-CpG-binding protein-2 (MeCP2).
