cytochrome c

Also found in: Dictionary, Thesaurus, Wikipedia.
Related to cytochrome c: Cytochrome c oxidase

cy·to·chrome c

(sī'tō-krōm), [MIM*123970]
The mobile cytochrome that transports electrons from Complex III to Complex IV of the respiratory chain.
Farlex Partner Medical Dictionary © Farlex 2012


A gene on chromosome 7p15.3 that encodes cytochrome c, an electron carrier protein, which transfers electrons from the heme group of the cytochrome c1 subunit of cytochrome reductase to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain. CYCS plays a role in apoptosis by suppressing anti-apoptotic members or by activating pro-apoptotic members of the Bcl-2 family, leading to altered mitochondrial membrane permeability and the release of cytochrome c into the cytosol. Binding of cytochrome c to Apaf-1 activates caspase-9, which then accelerates apoptosis by activating other caspases.

Molecular pathology
Defects in CYCS cause thrombocytopaenia type 4.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
References in periodicals archive ?
The main objective of the study was to assess the genetic variations in mitochondrial cytochrome b gene, mitochondrial cytochrome c gene and mitochondrial d-loop region in Axis porcinus of Pakistan.
Caption: Figure 1 A (left) and B (right): Separation of two proteins, Cytochrome C (-) and Ribonuclease A (-), on CEX resin (A) and Nuvia cPrime Resin (B).
Through the contribution of four electrons transferred via cytochrome c and four protons channeled from the mitochondrial matrix, it is capable of reducing dioxygen to water.
Caption: With an alteration to the part of the enzyme shown in pink, this cytochrome c's ability to bond carbon and silicon improved.
Mitochondria cytochrome C oxidase activity kit was purchased from Genmed Scientifics Inc., USA.
Analysis of mitochondrial cytochrome c oxidase II gene obtained from blood samples revealed that 4 nonrelated patients with probable AD harbored the polymorphism A8027G (three of them were diagnosed with late onset Alzheimer's disease, with familial history of the disease and one of them with early onset Alzheimer's disease) (Tables 1 and 2).
Conversely, there was no difference in expression of cytosolic cytochrome c protein in any of the groups, and there was a significant decrease in active caspase-9 protein level in the medium- and high-dose groups (Figure 4A,B).
Cytochrome c oxidase, the terminal oxidase in the respiratory chain, reduces oxygen to water through electron and proton transfer.
Prevention of apoptosis by Bcl-2: release of cytochrome c from mitochondria blocked.
Figure 3 shows representative spectrophotometric profiles of absorbance of cytochrome P450 and cytochrome b5 at different wave lengths in different experimental groups, whereas Figure 4 shows the same representative profiles of cytochrome c reductase.