Decker S
Biochem Biophys Res Commun. 1983 Jun 15;113(2):678-86. doi: 10.1016/0006-291x(83)91780-1.
Rat cells transformed by Rous sarcoma virus and Fujinami sarcoma virus bound 5-10% of the amount of epidermal growth factor (EGF) bound by normal cells. Scatchard plot analysis indicated that the reduction in binding by transformed cells was due to a decreased number of receptors rather than to altered binding affinity. In experiments with temperature sensitive mutants of Rous sarcoma virus and Fujinami sarcoma virus significant loss of EGF binding occurred within one hour of shift from non-permissive to permissive temperature. Conditioned media from various normal and transformed cell lines were examined for the ability to inhibit EGF binding to normal cells or to cause "down regulation" of EGF receptors. No activity of either type was found. EGF-dependent phosphorylation in isolated membrane preparations was also examined. Membranes from normal cells displayed EGF-dependent phosphorylation of a Mr 180,000 protein presumed to be the EGF receptor. This activity was absent in membranes from transformed cells. The data suggest a close correlation between activation of avian sarcoma virus transforming gene products and modulation of the EGF growth regulatory system.
劳氏肉瘤病毒和藤浪肉瘤病毒转化的大鼠细胞结合的表皮生长因子（EGF）量是正常细胞结合量的5 - 10%。Scatchard图分析表明，转化细胞结合能力的降低是由于受体数量减少，而非结合亲和力改变。在用劳氏肉瘤病毒和藤浪肉瘤病毒的温度敏感突变体进行的实验中，从非允许温度转变为允许温度后一小时内，EGF结合能力显著丧失。检测了各种正常和转化细胞系的条件培养基抑制EGF与正常细胞结合或导致EGF受体“下调”的能力。未发现任何一种类型的活性。还检测了分离膜制剂中依赖EGF的磷酸化作用。正常细胞的膜显示出一种分子量为180,000的蛋白质的依赖EGF的磷酸化作用，推测该蛋白质为EGF受体。转化细胞的膜中不存在这种活性。数据表明禽肉瘤病毒转化基因产物的激活与EGF生长调节系统的调节之间存在密切相关性。
