PREMATURE TRANSLATIONAL TERMINATION TRIGGERS MESSENGER-RNA DECAPPING
PREMATURE TRANSLATIONAL TERMINATION TRIGGERS MESSENGER-RNA DECAPPING
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DOI：
10.1038/370578a0
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发表时间：
1994-08-18
期刊：
影响因子：
64.8
通讯作者：
PARKER, R
中科院分区：
文献类型：
--
作者：
MUHLRAD, D;PARKER, R
真核细胞中信使RNA的降解是由核酸内切酶切割（1，2）或poly（A）尾的缩短（3-6）引发的，对于某些mRNA，这会激活依赖去腺苷化的脱帽反应（7）。真核生物中一种类型的快速mRNA降解是由翻译的过早终止引起的（8，9）。该转换过程阻止异常mRNA的翻译（10，11），可能影响核转录物的丰度和剪接模式（12，13），并可能参与人类遗传疾病的病因学（14）。在这里，我们表明，在酵母中的翻译提前终止触发脱帽，不依赖于去腺苷酸化，从而暴露的转录5 '到3'降解。5 '至3'核酸外切酶的失活揭示了mRNA周转的另外的3 '至5'途径。这些观察结果提供了两种新的mRNA衰变机制的体内证据。
THE degradation of messenger RNA in eukaryotic cells is initiated by endonucleolytic cleavage(1,2) or by shortening of the poly(A) tail(3-6), which for some mRNAs activates a deadenylation-dependent decapping reaction(7). One type of rapid mRNA degradation in eukaryotes is caused by premature termination of translation(8,9). This turnover process prevents the translation of aberrant mRNAs(10,11), may affect the abundance and splicing pattern of nuclear transcripts(12,13), and may be involved in the aetiology of human genetic disease(14). Here we show that premature translational termination in yeast triggers decapping, independent of deadenylation, thereby exposing the transcript to 5'-to-3' degradation. Inactivation of the 5'-to-3' exonuclease reveals an additional 3'-to-5' pathway of mRNA turnover. These observations provide in vivo evidence for two new mechanisms of mRNA decay.