Calcium and ionophore A23187 induce the sickle cell membrane phosphorylation pattern in normal erythrocytes

Pre-treatment of normal erythrocytes with micromolar Ca2+ and ionophore A23187 induces abnormal phosphorylation of membrane polypeptides, as determined by labeling with exogenous 32Pi. The Ca2+ -induced effects, which include increased incorporation of 32P into acid-stable linkages and increased labeling in the Band 3 and 4.5-4.9 regions of SDS gels, are similar to those seen in untreated sickle erythrocytes. Part of the abnormal phosphorylation of sickle cells may be caused by their elevated intracellular Ca2+ levels.