Fig. 12.1.

Schematic diagram depicting that PGC-1α coordinates the induction of NRF-1 and NRF-2 in regulating the transcription of all ten nuclear-encoded COX subunit genes, as well as the genes for Tfam, Tfb1m, and Tfb2m in the nucleus. Translation in the cytoplasm leads to the generation of the respective proteins, all of which enter into the mitochondria. Within the mitochondrion, the three mitochondrial-encoded COX genes are transcribed aided by the TFs and translated into polypeptides. Together, the nuclear- and mitochondrial-encoded COX subunits form the holoenzyme that is complex IV of the electron transport chain (ETC).