Endogenous F(1)F(o)-ATPase inhibitor limiting ATP depletion when the mitochondrial membrane potential falls below a threshold and the F(1)F(o)-ATP synthase starts hydrolyzing ATP to pump protons out of the mitochondrial matrix. Homodimer at a pH value below 6.5, inactive homotetramer above. Belongs to the ATPase inhibitor family. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Mitochondrial; Inhibitor protein
Cellular Component: cell surface; mitochondrion; mitochondrial proton-transporting ATP synthase complex
Biological Process: generation of precursor metabolites and energy; negative regulation of hydrolase activity; negative regulation of endothelial cell proliferation; erythrocyte differentiation; angiogenesis; protein homooligomerization; negative regulation of nucleotide metabolic process; protein homotetramerization; heme biosynthetic process
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.