| Cytochrome c1 | |
|---|---|
| Gene Symbol | CYC1 |
| Full Name | Cytochrome c1, Mitochondrial |
| Chromosomal Location | 8q24.3 |
| NCBI Gene ID | 1535 |
| OMIM | 123980 |
| Ensembl ID | ENSG00000179091 |
| UniProt ID | CYC1_HUMAN |
| Associated Diseases | [Parkinson's Disease](/diseases/parkinsons-disease) [Alzheimer's Disease](/diseases/alzheimers-disease) [Leigh Syndrome](/diseases/leigh-syndrome) |
CYC1 is a human gene whose product cYC1** encodes cytochrome c1, a mitochondrial protein that is a critical component of the mitochondrial electron transport chain complex III (cytochrome bc1 complex). Cytochrome c1 receives electrons from the Rieske iron-sulfur protein (UQCRB) and transfers them to cytochrome c, completing the electron transfer chain 1. Variants in CYC1 have been implicated in Parkinson's Disease, Alzheimer's Disease, Leigh Syndrome. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
CYC1 encodes cytochrome c1, a mitochondrial protein that is a critical component of the mitochondrial electron transport chain complex III (cytochrome bc1 complex). Cytochrome c1 receives electrons from the Rieske iron-sulfur protein (UQCRB) and transfers them to cytochrome c, completing the electron transfer chain 1.
The protein is anchored to the inner mitochondrial membrane via a hydrophobic transmembrane helix, with the heme group oriented toward the intermembrane space where it interacts with cytochrome c 2.
Cytochrome c1 dysfunction contributes to mitochondrial complex III impairment in PD. The resulting electron leakage increases ROS production, which is particularly damaging to dopaminergic neurons in the substantia nigra 4.
CYC1 expression is altered in AD brain, contributing to the well-documented mitochondrial dysfunction. Impaired complex III activity leads to energy deficits and increased oxidative stress in neurons 5.
Pathogenic variants in complex III subunits, including CYC1, can cause Leigh syndrome, characterized by bilateral symmetric brainstem and basal ganglia lesions 6.
CYC1 is expressed throughout the brain with highest expression in:
Expression is neuron-enriched and decreases with age in certain brain regions 8.