EN
In this review we discuss the evidence in support of the concept that a posttranslational modification in β-actin, in which a disulfide bridge is formed between cysteine284 and cysteine373, is the major cause of the formation of the irreversibly sickled cell (ISC). This ISC β-actin modification caused a decreased ability of the ISC membrane skeletal proteins to disassemble, as compared to the control and reversible sickled cell (RSC) membrane skeleton, because of altered actin filament formation. The slow disassembly of the ISC membrane skeleton proteins gives a reasonable explanation for the inability of the ISC to remodel its shape. An understanding of the molecular basis of the irreversibly sickled cells formation has helped initiate a rationale for development of drugs to block ISC formation in vivo.