PHOSPHORYLATION AND DEPHOSPHORYLATION OF MEMBRANE PROTEINS AS A POSSIBLE MECHANISM FOR STRUCTURAL REARRANGEMENT OF MEMBRANE COMPONENTS

A correlation was found between dephosphorylation of chicken erythrocyte membrane proteins, aggregation of intramembrane particles, increase in the lipid bilayer phase of the membrane and exposure of membrane phospholipids toward phospholipase A and trinitrobenzene sulfonic acid. Most of the covalently bound phosphate of the membrane proteins turns over and is associated with 5 major bands. It is suggested that phosphorylation and dephosphorylation of these proteins causes changes in their charge and conformation. Such changes might affect the interaction of these proteins with the neighboring lipids or lipoprotein complexes and results in the aggregation of intramembrane particles and relative increase in the exposed free lipid bilayer phase of the membrane.