Abstract
Phosphorylation of membrane proteins in human erythrocytes is mediated by intracellular ATP levels. Such phosphorylation modulates the interactions of the bilayer with the cytoskeleton and affects the membrane stability under high pressure. In erythrocytes with high intracellular ATP levels, the bilayer-cytoskeleton interaction was weakened. Compression of such erythrocytes induced the release of large vesicles due to the suppression of fragmentation and resulted in the enhanced hemolysis. On the other hand, in ATP-depleted erythrocytes the interaction between the bilayer and the cytoskeleton was strengthened. Upon compression of these erythrocytes, the release of small vesicles due to the facilitation of vesiculation resulted in suppression of hemolysis. Taken together, these results suggest that the responses, i.e., vesiculation, fragmentation, and hemolysis, of the erythrocytes to high pressure are largely modulated by the bilayer-cytoskeleton interaction, which is mediated by intracellular ATP levels.