Skip to main content
. 2021 Jan 23;11(2):82. doi: 10.3390/life11020082

Figure 2.

Figure 2

The phosphorylation of mammalian OXPHOS system components. The OXPHOS system consists of five protein complexes (NADH dehydrogenase, succinate dehydrogenase, cytochrome c reductase, cytochrome c oxidase and ATP synthase) embedded in the IMM. The protein kinase-regulated subunits are highlighted as follows: stimulation in green, repression in red and no effect in brown. Phosphorylation by PKA, PINK1, CDK1 and SRC increases the activity of complex I (NADH dehydrogenase). Succinate dehydrogenase (complex II) is regulated by the action of the FGR and SRC kinases. The activity of cytochrome c (Cytc) oxidase (complex III) is upregulated by phosphorylation by the SRC kinase. The activity of cytochrome c is impaired upon phosphorylation by AKT and AMPK. Complex IV (cytochrome c reductase) is negatively regulated by PKA (independently of cAMP levels) and positively by the cAMP-dependent action of PKA and PKC ε. Phosphorylation of ATP synthase (complex V) is upregulated by AKT and PKCα. Phosphorylation of the inhibition factor IF1 by PKA abolishes IF1 binding and its inhibition of ATP synthase activity. IMM, inner mitochondrial membrane.