Brown A J, Purvis I J, Santiago T C, Bettany A J, Loughlin L, Moore J
Institute of Genetics, University of Glasgow, U.K.
Gene. 1988 Dec 10;72(1-2):151-60. doi: 10.1016/0378-1119(88)90137-0.
The analysis of 17 functional mRNAs and two recombinant mRNAs in the yeast Saccharomyces cerevisiae suggests that the length of an mRNA influences its half-life in this organism. The mRNAs are clearly divisible into two populations when their lengths and half-lives are compared. Differences in ribosome loading amongst the mRNAs cannot account for this division into relatively stable and unstable populations. Also, specific mRNAs seem to be destabilized to differing extents when their translation is disrupted by N-terminus-proximal stop codons. The analysis of a mutant mRNA, generated by the fusion of the yeast PYK1 and URA3 genes, suggests that a destabilizing element exists within the URA3 sequence. The presence of such elements within relatively unstable mRNAs might account for the division between the yeast mRNA populations. On the basis of these, and other previously published observations, a model is proposed for a general pathway of mRNA degradation in yeast. This model may be relevant to other eukaryotic systems. Also, only a minor extension to the model is required to explain how the stability of some eukaryotic mRNAs might be regulated.
对酿酒酵母中17种功能性mRNA和两种重组mRNA的分析表明，mRNA的长度会影响其在该生物体中的半衰期。当比较mRNA的长度和半衰期时，它们明显可分为两类。mRNA之间核糖体负载的差异并不能解释这种分为相对稳定和不稳定群体的现象。此外，当特定mRNA的翻译被N端近端终止密码子破坏时，它们似乎会在不同程度上变得不稳定。对通过酵母PYK1和URA3基因融合产生的突变mRNA的分析表明，URA3序列中存在一个不稳定元件。相对不稳定的mRNA中存在此类元件可能解释了酵母mRNA群体之间的差异。基于这些以及其他先前发表的观察结果，提出了一个酵母mRNA降解通用途径的模型。该模型可能与其他真核系统相关。此外，只需对该模型进行微小扩展，就能解释某些真核mRNA的稳定性是如何被调控的。
