Cell-surface glycoprotein synthesis during differentiation of chicken erythroblasts transformed by temperature-sensitive avian erythroblastosis virus.

Chicken erythroblasts transformed by a temperature-sensitive mutant of avian erythroblastosis virus (ts34 AEV) have a greatly increased haemoglobin content (Graf, T., N. Ade and H. Beug: Nature 275, 496-501 (1978)) if allowed to grow for 3-5 days at the non-permissive temperature (41 degrees C), instead of the permissive temperature (35 degrees C) of the virus. Cell-surface molecular changes during this differentiation were investigated by examining the glycoproteins synthesized by a ts34-transformed erythroblast cell line. These cells synthesized a greatly increased amount of a 94,000 molecular weight erythrocyte cell-surface glycoprotein beginning 2-6 h after a shift in growth temperature from 35 degrees to 41 degrees C, consistent with the proposal that such a shift releases these transformed cells from a differentiation block.