ATPase inhibitory factor 1 （ATPIF1） attaches to the C-terminal region of a beta subunit of the F1-ATPase at low pH values and， through interference of the beta and gamma subunit interaction， ATPIF1 controls the activity of the F1 （the hydrophilic catalytic core）， F0 （the membrane embedded protein channel） ATPase. ATPIF1 overexpression in a number of human carcinomas additionally reinforces its participation in oncogenesis and offers insight into the transformed metabolism of cancer cells， including the reprogramming of energy metabolism in relation to glycolysis. Endogenous F1F（o）-ATPase inhibitor curbing ATP depletion when the mitochondrial membrane potential drops below a threshold and the F1F（o）-ATP synthase begins hydrolyzing ATP to pump protons out of the mitochondrial matrix.
