Davies E, Dumont J E, Vassart G
Biochem J. 1978 May 15;172(2):227-31. doi: 10.1042/bj1720227.
Treatment of ox and dog thyroid slices in vitro with either thyrotropin or dibutyryl cyclic AMP elicited a variety of changes in polyribosome distribution. The most marked and consistent responses were decreases in both free and membrane-bound monoribosomes with a concomitant increase in the specific peak of thyroglobulin-synthesizing polyribosomes. On some occasions there was a shift towards heavier aggregates in the free polyribosomes. The increase in the amount of thyroglobulin-synthesizing polyribosomes was not accompanied by a shift in its location on the gradients. These changes were apparent within 30 min of thyrotropin addition and within 60 min of the addition of dibutyryl cyclic AMP. It is suggested that the major initial effect on translation of both thyrotropin and dibutyryl cyclic AMP is to stimulate the recruitment of pre-existing free monoribosomes on to pre-existing unloaded or under-loaded thyroglobulin mRNA molecules.
用促甲状腺激素或二丁酰环磷酸腺苷(dibutyryl cyclic AMP)对牛和狗的甲状腺切片进行体外处理,会引发多核糖体分布的多种变化。最显著且一致的反应是游离单核糖体和膜结合单核糖体均减少,同时甲状腺球蛋白合成多核糖体的特定峰增加。在某些情况下,游离多核糖体中会出现向较重聚集体的转变。甲状腺球蛋白合成多核糖体数量的增加并未伴随着其在梯度上位置的改变。这些变化在添加促甲状腺激素后30分钟内以及添加二丁酰环磷酸腺苷后60分钟内就很明显。有人提出,促甲状腺激素和二丁酰环磷酸腺苷对翻译的主要初始作用是刺激将预先存在的游离单核糖体募集到预先存在的未负载或负载不足的甲状腺球蛋白mRNA分子上。