| UniProt Protein Function: | CYTB: Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is a respiratory chain that generates an electrochemical potential coupled to ATP synthesis. Defects in MT-CYB are a rare cause of mitochondrial dysfunction underlying different myopathies. They include mitochondrial encephalomyopathy, hypertrophic cardiomyopathy (HCM), and sporadic mitochondrial myopathy (MM). In mitochondrial myopathy, exercise intolerance is the predominant symptom. Additional features include lactic acidosis, muscle weakness and/or myoglobinuria. Defects in MTCYB are also found in cases of exercise intolerance accompanied by deafness, mental retardation, retinitis pigmentosa, cataract, growth retardation, epilepsy (multisystem disorder). Defects in MT-CYB are the cause of cardiomyopathy infantile histiocytoid (CMIH). CMIH is characterized by the presence of pale granular foamy histiocyte-like cells within the myocardium. It usually affects children younger than 2 years of age, with a clear predominance of females over males. Infants present with dysrhythmia or cardiac arrest, and the clinical course is usually fulminant, sometimes simulating sudden infant death syndrome. Defects in MT-CYB contribute to Leber hereditary optic neuropathy (LHON). LHON is a maternally inherited disease resulting in acute or subacute loss of central vision, due to optic nerve dysfunction. Cardiac conduction defects and neurological defects have also been described in some patients. LHON results from primary mitochondrial DNA mutations affecting the respiratory chain complexes. Belongs to the cytochrome b family. |
| UniProt Protein Details: | Protein type:Membrane protein, multi-pass; Mitochondrial; Energy Metabolism - oxidative phosphorylation; Membrane protein, integral Chromosomal Location of Human Ortholog: - Disease: Leber Optic Atrophy; Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, And Stroke-like Episodes |
| UniProt Code: | P00156 |
| NCBI GenInfo Identifier: | 408360043 |
| NCBI Gene ID: | 4519 |
| NCBI Accession: | P00156.2 |
| UniProt Secondary Accession: | P00156,Q34786, Q8HBR6, Q8HNQ0, Q8HNQ1, Q8HNQ9, Q8HNR4 Q8HNR7, Q8W7V8, Q8WCV9, Q8WCY2, Q8WCY7, |
| Molecular Weight: | 42,718 Da |
| NCBI Full Name: | Cytochrome b |
| NCBI Synonym Full Names: | mitochondrially encoded cytochrome b |
| NCBI Official Symbol: | MT-CYB |
| NCBI Official Synonym Symbols: | MTCYB; CYTB |
| NCBI Protein Information: | cytochrome b |
| UniProt Protein Name: | Cytochrome b |
| UniProt Synonym Protein Names: | Complex III subunit 3; Complex III subunit III; Cytochrome b-c1 complex subunit 3; Ubiquinol-cytochrome-c reductase complex cytochrome b subunit |
| UniProt Gene Name: | MT-CYB |
| UniProt Entry Name: | CYB_HUMAN |
