Fig. 4.

Post-translational regulation of IF1 activity. IF1 can be inhibited by pH-dependent oligomerization, phosphorylation mediated by a mitochondrial cAMP-dependent protein kinase A-like activity (PKA) or by sequestration by a mitochondrial membrane protein (IF1-BP). IF1 is also the substrate for acetylation, glycosylation and succinylation, although the physiological effects of these modifications remain to be fully characterized. The pool of active IF1 determines the population of inhibited H⁺-ATP synthase complexes, which might trigger retrograde signaling pathways