Compensatory evolution of a precursor messenger RNA secondary structure in the Drosophila melanogaster Adh gene
Compensatory evolution of a precursor messenger RNA secondary structure in the Drosophila melanogaster Adh gene
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DOI：
10.1073/pnas.1932834100
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发表时间：
2003-09-30
影响因子：
11.1
通讯作者：
Stephan, W
中科院分区：
文献类型：
--
作者：
Chen, Y;Stephan, W
在不同种类的果蝇中，乙醇脱氢酶基因(ADH)的内含子1中已经发现了可能参与内含子加工的发夹结构进化维持的证据。在这项研究中，通过定点突变消除了果蝇茎的两边，系统地评估了果蝇的发夹结构。在果蝇Schneider L2细胞和生殖系转化的成蝇中，检测了这些突变和补偿双突变体对内含子剪接效率和ADH蛋白产生的影响。研究发现，破坏内含子分支点上游假定发夹结构的突变会导致剪接效率和ADH蛋白产量的显着下降。相反，恢复可能发夹结构的补偿双突变体在剪接效率和ADH水平上与WT没有区别。突变分析还发现，该内含子中更稳定的二级结构(茎更长)会降低剪接效率和ADH蛋白产量。讨论了RNA二级结构和内含子进化的意义。
Evidence for the evolutionary maintenance of a hairpin structure possibly involved in intron processing had been found in intron 1 of the alcohol dehydrogenase gene (Adh) in diverse Drosophila species. In this study, the putative hairpin structure was evaluated systematically in Drosophila melanogaster by elimination of either side of the stem using site-directed mutagenesis. The effects of these mutations and the compensatory double mutant on intron splicing efficiency and ADH protein production were assayed in Drosophila melanogaster Schneider L2 cells and germ-line transformed adult flies. Mutations that disrupt the putative hairpin structure right upstream of the intron branch point were found to cause a significant reduction in both splicing efficiency and ADH protein production. In contrast, the compensatory double mutant that restores the putative hairpin structure was indistinguishable from the WT in both splicing efficiency and ADH level. It was also observed by mutational analysis that a more stable secondary structure (with a longer stem) in this intron decreases both splicing efficiency and ADH protein production. Implications for RNA secondary structure and intron evolution are discussed.