2n9i

Structural highlights

Disease

CYC_HUMAN Defects in CYCS are the cause of thrombocytopenia type 4 (THC4) [MIM:612004; also known as autosomal dominant thrombocytopenia type 4. Thrombocytopenia is the presence of relatively few platelets in blood. THC4 is a non-syndromic form of thrombocytopenia. Clinical manifestations of thrombocytopenia are absent or mild. THC4 may be caused by dysregulated platelet formation.^[1]

Function

CYC_HUMAN Electron carrier protein. The oxidized form of the cytochrome c heme group can accept an electron from the heme group of the cytochrome c1 subunit of cytochrome reductase. Cytochrome c then transfers this electron to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain. Plays a role in apoptosis. Suppression of the anti-apoptotic members or activation of the pro-apoptotic members of the Bcl-2 family leads to altered mitochondrial membrane permeability resulting in release of cytochrome c into the cytosol. Binding of cytochrome c to Apaf-1 triggers the activation of caspase-9, which then accelerates apoptosis by activating other caspases.

References

1. ↑ Morison IM, Cramer Borde EM, Cheesman EJ, Cheong PL, Holyoake AJ, Fichelson S, Weeks RJ, Lo A, Davies SM, Wilbanks SM, Fagerlund RD, Ludgate MW, da Silva Tatley FM, Coker MS, Bockett NA, Hughes G, Pippig DA, Smith MP, Capron C, Ledgerwood EC. A mutation of human cytochrome c enhances the intrinsic apoptotic pathway but causes only thrombocytopenia. Nat Genet. 2008 Apr;40(4):387-9. Epub 2008 Mar 16. PMID:18345000 doi:ng.103
2. ↑ Imai M, Saio T, Kumeta H, Uchida T, Inagaki F, Ishimori K. Investigation of the redox-dependent modulation of structure and dynamics in human cytochrome c. Biochem Biophys Res Commun. 2016 Jan 22;469(4):978-84. doi:, 10.1016/j.bbrc.2015.12.079. Epub 2015 Dec 22. PMID:26718409 doi:http://dx.doi.org/10.1016/j.bbrc.2015.12.079