Savoie S, Rindress D, Posner B I, Bergeron J J
Mol Cell Endocrinol. 1986 May;45(2-3):241-6. doi: 10.1016/0303-7207(86)90153-x.
We have used the glycosylation inhibitor tunicamycin to assess the stability of the receptors for prolactin, insulin and epidermal growth factor (EGF) in rat liver cell membrane. Direct binding studies on liver plasmalemma fractions which were isolated from tunicamycin-treated rats revealed a rapid loss of prolactin receptors (t1/2 approximately 35 min) with a more prolonged half-life for insulin (10 h) and EGF receptors (8 h). The rates of receptor loss were similar to the respective half-lives of the receptors as documented by others using cultured cells. The respective ligands for each receptor were lost more rapidly from liver, i.e. prolactin, t1/2 approximately 10 min, insulin, t1/2 approximately 5 min and EGF, t1/2 approximately 17 min. Previous studies have shown ligand loss in vivo to be receptor mediated. Thus, receptors and their ligands do not turn over synchronously in vivo. These studies also point to a major role for N-linked oligosaccharide side chains in the functional insertion of prolactin, insulin and EGF receptors into the hepatocyte cell surface in vivo.
我们使用糖基化抑制剂衣霉素来评估大鼠肝细胞膜中催乳素、胰岛素和表皮生长因子（EGF）受体的稳定性。对从经衣霉素处理的大鼠分离出的肝质膜部分进行的直接结合研究显示，催乳素受体迅速丧失（半衰期约35分钟），而胰岛素受体（10小时）和EGF受体（8小时）的半衰期则更长。受体丧失的速率与其他人使用培养细胞记录的受体各自的半衰期相似。每种受体的相应配体从肝脏中丧失得更快，即催乳素，半衰期约10分钟；胰岛素，半衰期约5分钟；EGF，半衰期约17分钟。先前的研究表明体内配体丧失是由受体介导的。因此，受体及其配体在体内并非同步周转。这些研究还指出，N-连接寡糖侧链在体内将催乳素、胰岛素和EGF受体功能性插入肝细胞表面中起主要作用。
