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 (By similarity). Interacts with CCMH (via N-terminus) (PubMed:16236729). Interacts with CCMFN2 (PubMed:18644794). Loosely associated with the inner membrane. A number of isoforms are produced. According to EST sequences. Binds 1 heme c group covalently per subunit. Belongs to the cytochrome c family. Life shuttle - Issue 76 of November 2006