The formation of erythrocyte membrane proteins during erythropoietin-induced differentiation.

The effect of erythropoietin on the synthesis of the proteins characteristic of mature erythrocyte membranes was studied in cultures of bone marrow cells from adult, polycythemic rats. Stimulated synthesis of the major glycoprotein, glycophorin, was maximal at 30 h and fell to control level by 66 h. Stimulated synthesis of the major integral membrane protein, band 3, occurred at about 18 h was maximal at 66 h, and fell to control level by 114 h. In contrast, stimulated hemoglobin synthesis did not start until after 24 h, was maximal at 96 h, and was at control level at 114 h. Erythropoietin had, in addition, a transient effect on the synthesis of some membrane proteins found in marrow cells but not in mature red cells.