RIBOSOME PAUSING AND STACKING DURING TRANSLATION OF A EUKARYOTIC MESSENGER-RNA
RIBOSOME PAUSING AND STACKING DURING TRANSLATION OF A EUKARYOTIC MESSENGER-RNA
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DOI：
10.1002/j.1460-2075.1988.tb03233.x
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发表时间：
1988-11-01
期刊：
影响因子：
11.4
通讯作者：
WALTER, P
中科院分区：
文献类型：
--
作者：
WOLIN, SL;WALTER, P
我们设计了一种灵敏的测定方法来确定mRNA上翻译核糖体的分布。用这种方法来监测核糖体转运牛催乳素mRNA，我们已经检测到四个主要位置的核糖体暂停在小麦胚芽和兔网织红细胞提取物。其中两个限速步骤代表启动和终止。在. apprx之后出现一个暂停。75个氨基酸已聚合;信号识别颗粒在该位置阻止前催乳素合成。另一个内部停顿发生在160个氨基酸处。在后两种情况下，核糖体终止于GGC甘氨酸密码子;然而，另外两个GGC密码子翻译时没有明显的停顿。令人惊讶的是，我们发现多达9个核糖体紧密地堆叠在每个暂停的核糖体后面，这样核糖体中心之间只有27-29个核苷酸。该试验应证明用于探测翻译调控机制。
We have devised a sensitive assay to determine the distribution of translating ribosomes on a mRNA. Using this assay to monitor ribosome transit on bovine preprolactin mRNA, we have detected four major positions of ribosome pausing in both wheat-germ and rabbit reticulocyte extracts. Two of these rate-limiting steps represent initiation and termination. One pause occurs after .apprx. 75 amino acids have been polymerized; signal recognition particle arrests preprolactin synthesis at this position. The other internal pause occurs at 160 amino acids. In these latter two cases ribosomes stop at a GGC glycine codon; however, two other GGC codons are translated without apparent pausing. Surprisingly, we find that up to nine ribosomes are tightly stacked behind each pausing ribosome, such that the ribosome centers are only 27-29 nucleotides apart. The assay should prove useful for probing mechanisms of translational regulation.