Replacement of the yeast TRP4 3' untranslated region by a hammerhead ribozyme results in a stable and efficiently exported mRNA that lacks a poly(A) tail.
Replacement of the yeast TRP4 3' untranslated region by a hammerhead ribozyme results in a stable and efficiently exported mRNA that lacks a poly(A) tail.
复制标题
用锤头核酶替换酵母 TRP4 3 非翻译区会产生稳定且有效输出的 mRNA，该 mRNA 缺乏 Poly(A) 尾。
DOI：
10.1017/s1355838202021039
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Braus,GerhardH
中科院分区：
文献类型：
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作者：
Düvel,Katrin;Valerius,Oliver;Mangus,DavidA;Jacobson,Allan;Braus,GerhardH
mRNA聚(A)尾有不同的用途，包括促进核输出、稳定mRNA、有效翻译，以及最后的特异性降解。转录后多聚(a)尾的添加取决于mRNA 3 ‘非翻译区（3 ’ UTR）的序列基序和复杂的反式作用蛋白质机制。在这项研究中，我们用编码锤头核酶的序列取代了酵母TRP4基因的3 ' UTR，该序列在体内有效地自我切割。trp4核酶等位基因的表达导致非聚腺苷化mRNA的积累。表达trp4核酶mRNA的细胞由于Trp4p酶活性的降低而显示出生长速度的降低。酶活性的降低不是由于mRNA从细胞核输出效率低下或mRNA不稳定造成的。相反，对mRNA与多核糖体关联的分析表明，含有核酶的mRNA的翻译受损。这种翻译缺陷允许足够的Trp4p合成来支持trp4细胞的生长，但是，尽管如此，它的程度如此之大，以至于激活了氨基酸生物合成的一般控制网络。
The mRNA poly(A) tail serves different purposes, including the facilitation of nuclear export, mRNA stabilization, efficient translation, and, finally, specific degradation. The posttranscriptional addition of a poly(A) tail depends on sequence motifs in the 3′ untranslated region (3′ UTR) of the mRNA and a complex trans-acting protein machinery. In this study, we have replaced the 3′ UTR of the yeast TRP4 gene with sequences encoding a hammerhead ribozyme that efficiently cleaves itself in vivo. Expression of the TRP4-ribozyme allele resulted in the accumulation of a nonpolyadenylated mRNA. Cells expressing the TRP4-ribozyme mRNA showed a reduced growth rate due to a reduction in Trp4p enzyme activity. The reduction in enzyme activity was not caused by inefficient mRNA export from the nucleus or mRNA destabilization. Rather, analyses of mRNA association with polyribosomes indicate that translation of the ribozyme-containing mRNA is impaired. This translational defect allows sufficient synthesis of Trp4p to support growth of trp4 cells, but is, nevertheless, of such magnitude as to activate the general control network of amino acid biosynthesis.