The F0F1 ATP synthase regulates human neutrophil migration through cytoplasmic proton extrusion coupled with ATP generation

Abstract

Cytoplasmic alkalinization and extracellular adenosine triphosphate (ATP) signals are required for migration of chemokineactivated neutrophils, but the precise functions remain unclear. In this work, the effect of the plasma membrane-expressed F0F1-ATP synthase (FATPase) on human neutrophils was examined. We found F-ATPase to be involved in cytoplasm proton extrusion and extracellular ATP generation. Oligomycin A, an F-ATPase inhibitor that blocks proton transfer, inhibited cytoplasmic alkalinization, extracellular ATP generation, adhesion and chemotaxis in N-formyl-Met-Leu-Phe (fMLP)-stimulated neutrophils; however, adenosine diphosphate (ADP), a substrate and activator of F-ATPase, had the opposite effect. Further analysis revealed that cell surface F-ATPase can translocate to the leading edge of directional fMLP-stimulated neutrophils toward ADP hydrolyzed from pannexin 1 channel-released ATP, followed by F-ATPase-catalyzed ATP regeneration using ADP and protons transferred from the cytoplasm. Therefore, the membrane-expressed F-ATPase regulates human neutrophil migration via cytoplasm proton extrusion and extracellular ATP generation.