MT-CYB

MT-CYB (Mitochondrially Encoded Cytochrome B) is a protein coding gene. Diseases associated with MT-CYB include Cardiomyopathy, Infantile Histiocytoid and Mitochondrial Encephalomyopathy. Among its related pathways are Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. and Metabolism. Gene Ontology annotations related to this gene include oxidoreductase activity and ubiquinol-cytochrome-c reductase activity.

Full Name

Mitochondrially Encoded Cytochrome B

Function

Component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex) that is part of the mitochondrial respiratory chain. The b-c1 complex mediates electron transfer from ubiquinol to cytochrome c. Contributes to the generation of a proton gradient across the mitochondrial membrane that is then used for ATP synthesis.

Biological Process

Cellular respiration Source: ComplexPortal
Mitochondrial electron transport, ubiquinol to cytochrome c Source: UniProtKB

Cellular Location

Mitochondrion inner membrane

Involvement in disease

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).
Cardiomyopathy, infantile histiocytoid (CMIH):
A heart disease 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. The clinical course is usually fulminant, sometimes simulating sudden infant death syndrome.
Leber hereditary optic neuropathy (LHON);
A maternally inherited form of Leber hereditary optic neuropathy, a mitochondrial disease resulting in bilateral painless loss of central vision due to selective degeneration of the retinal ganglion cells and their axons. The disorder shows incomplete penetrance and male predominance. Cardiac conduction defects and neurological defects have also been described in some LHON patients. LHON results from primary mitochondrial DNA mutations affecting the respiratory chain complexes.