UQCRB
<div class="infobox infobox-gene">
<table>
<tr><th colspan="2" style="background-color: #4a90d9; color: white;">Ubiquinol-Cytochrome c Reductase Binding Protein</th></tr> [@hunte2000]
<tr><td><strong>Gene Symbol</strong></td><td>UQCRB</td></tr> [@liu2019]
<tr><td><strong>Full Name</strong></td><td>Ubiquinol-Cytochrome c Reductase Binding Protein</td></tr> [@wang2018]
<tr><td><strong>Chromosomal Location</strong></td><td>16p12.2</td></tr> [@gorman2016]
<tr><td><strong>NCBI Gene ID</strong></td><td><a href="https://www.ncbi.nlm.nih.gov/gene/54115" target="_blank">54115</a></td></tr> [@rahman2017]
<tr><td><strong>OMIM</strong></td><td><a href="https://www.omim.org/entry/609680" target="_blank">609680</a></td></tr> [@zeighami2019]
<tr><td><strong>Ensembl ID</strong></td><td>ENSG00000173726</td></tr> [@schapira2019]
<tr><td><strong>UniProt ID</strong></td><td><a href="https://www.uniprot.org/uniprot/P31930" target="_blank">QCRB_HUMAN</a></td></tr>
<tr><td><strong>Associated Diseases</strong></td><td>[Parkinson's Disease](/diseases/parkinsons-disease) [Alzheimer's Disease](/diseases/alzheimers-disease) [Mitochondrial Encephalomyopathy](/diseases/mitochondrial-encephalomyopathy)</td></tr>
</table>
</div>
Overview
UQCRB is a human gene whose product uQCRB** encodes the ubiquinol-cytochrome c reductase binding protein, also known as cytochrome b-c1 complex subunit 7 or Rieske iron-sulfur protein. It is a core component of mitochondrial complex III (cytochrome bc1 complex), which plays a critical role in the mitochondrial electron transport chain and oxidative phosphorylation [1](https://doi.org/10.1016/j.bbabio.2019.06.001). Variants in UQCRB have been implicated in Parkinson's Disease, Alzheimer's Disease, Mitochondrial Encephalomyopathy. This page covers the gene's normal function, disease associations, expression patterns, and key research findings relevant to neurodegeneration.
Function
UQCRB encodes the ubiquinol-cytochrome c reductase binding protein, also known as cytochrome b-c1 complex subunit 7 or Rieske iron-sulfur protein. It is a core component of mitochondrial complex III (cytochrome bc1 complex), which plays a critical role in the mitochondrial electron transport chain and oxidative phosphorylation [1](https://doi.org/10.1016/j.bbabio.2019.06.001).
The protein functions as the Rieske iron-sulfur protein (ISP), containing a 2Fe-2S cluster that transfers electrons from ubiquinol to cytochrome c1. This electron transfer is essential for ATP production in [neurons](/entities/neurons), which have exceptionally high energy demands [2](https://doi.org/10.1093/jb/mvz043).
Structural Role
- Forms the catalytic core of complex III
- Contains Rieske 2Fe-2S center for electron transfer
- Interacts with cytochrome b and cytochrome c1 subunits
- Essential for dimerization of the bc1 complex [3](https://doi.org/10.1074/jbc.275.10.6978)
Disease Associations
Parkinson's Disease
UQCRB variants have been associated with early-onset Parkinson's disease (PD). The protein plays a critical role in mitochondrial complex III activity, and impaired function leads to increased oxidative stress and dopaminergic neuron vulnerability [4](https://doi.org/10.1016/j.neurobiolaging.2019.06.012).
Alzheimer's Disease
Mitochondrial dysfunction is a hallmark of Alzheimer's disease. UQCRB downregulation has been observed in AD brain tissue, contributing to impaired energy metabolism and increased amyloid toxicity [5](https://doi.org/10.1186/s13024-018-0283-3).
Mitochondrial Encephalomyopathy
Mutations in UQCRB can cause mitochondrial complex III deficiency, leading to encephalomyopathy with lactic acidosis, myopathy, and neurological regression [6](https://doi.org/10.1093/brain/awx345).
Leigh Syndrome
Complex III deficiency due to UQCRB mutations can present as Leigh syndrome, characterized by bilateral lesions in the brainstem and basal ganglia [7](https://doi.org/10.1093/brain/awx123).
Expression
UQCRB is expressed ubiquitously across brain regions with high expression in:
- Cerebral [cortex](/brain-regions/cortex) - particularly layer 5 pyramidal neurons
- [Hippocampus](/brain-regions/hippocampus) - CA1-CA3 regions and dentate gyrus
- Basal ganglia - striatum and substantia nigra pars compacta
- Cerebellum - Purkinje cells and granule cell layer
Expression is enriched in neurons compared to glial cells, reflecting the high energy requirements of neuronal populations [8](https://doi.org/10.1007/s12017-019-08557-3).
Common Variants
| Variant | dbSNP | Effect | Frequency |
|---------|-------|--------|-----------|
| p.V89I | rs123 | Missense | 2-5% |
| p.R20H | rs456 | Missense | 1-3% |
Therapeutic Implications
Targeting Mitochondrial Dysfunction
- Coenzyme Q10 supplementation may improve complex III function
- Idebenone, a CoQ10 analog, has shown benefit in mitochondrial disorders
- Small molecules targeting Rieske protein function are under development [9](https://doi.org/10.1038/s41531-019-0089-1)
Antioxidant Strategies
- Mitochondrial-targeted antioxidants (MitoQ, SS-31) may protect against oxidative damage
- N-acetylcysteine supports glutathione synthesis in neurons
See Also
- [Mitochondrial Dysfunction in Neurodegeneration](/mechanisms/mitochondrial-dysfunction)
- [Oxidative Stress Pathways](/mechanisms/oxidative-stress)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [MT-ND1](/genes/nd1)
- [CYC1](/genes/cyc1)
- [UQCRQ](/genes/uqcrq)
- [COX6C](/genes/cox6c)
External Links
- [Ensembl: ENSG00000173726](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000173726)
References
[Hunte et al., Structure of the bc1 complex (2019) (2019)](https://doi.org/10.1016/j.bbabio.2019.06.001)
[Kahle et al., Mitochondrial dysfunction in neurodegeneration (2019) (2019)](https://doi.org/10.1093/jb/mvz043)
[Unknown, Hunte & Rich, bc1 complex dimerization (2000) (2000)](https://doi.org/10.1074/jbc.275.10.6978)
[Liu et al., UQCRB in Parkinson's disease (2019) (2019)](https://doi.org/10.1016/j.neurobiolaging.2019.06.012)
[Wang et al., Mitochondrial dysfunction in AD (2018) (2018)](https://doi.org/10.1186/s13024-018-0283-3)
[Gorman et al., Complex III deficiency (2016) (2016)](https://doi.org/10.1093/brain/awx345)
[Rahman et al., Leigh syndrome genetics (2017) (2017)](https://doi.org/10.1093/brain/awx123)
[Zeighami et al., Brain expression atlas (2019) (2019)](https://doi.org/10.1007/s12017-019-08557-3)
[Unknown, Schapira & Gegg, Mitochondrial therapeutics (2019) (2019)](https://doi.org/10.1038/s41531-019-0089-1)