RNA editing of the Drosophila para Na(+) channel transcript. Evolutionary conservation and developmental regulation.
RNA editing of the Drosophila para Na(+) channel transcript. Evolutionary conservation and developmental regulation.
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发表时间：
2000-07
期刊：
影响因子：
3.3
通讯作者：
C. Hanrahan;M. Palladino;B. Ganetzky;R. Reenan
中科院分区：
文献类型：
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作者：
C. Hanrahan;M. Palladino;B. Ganetzky;R. Reenan
通过dsRNA腺苷脱氨酶的作用对前mRNAs进行转录后编辑会导致特定的腺苷(A)残基修饰为肌苷(I)，这可以改变修饰后转录本的编码潜力。我们在这里描述了副转录本中的三个位置，它编码了果蝇中主要的电压激活的Na(+)通道多肽，RNA编辑发生在那里。这三个位置的RNA编辑的发生被发现是受发育调节的。其中两个地点的编辑也是在黑腹盘藻和维氏盘藻之间的物种之间保存的。在每种情况下，在编辑位点下游的内含子中都发现了一个高度保守的区域，并且该区域被证明与外显子编辑站点的区域是互补的。因此，在这些位点的编辑似乎涉及一种机制，即编辑后的外显子形成碱基配对的二级结构，远端保守的非编码序列位于相邻的下游内含子，类似于哺乳动物谷氨酸受体亚单位(GluR)的A-to-I RNA编辑机制。对于第三个位点，RNA编辑和预测的RNA二级结构在进化上都不是保守的。转基因果蝇表达该位点的最小编辑位点的转录本被证明忠实地进行了RNA编辑。这些结果表明，通过RNA编辑，果蝇的Na(+)通道多样性增加，其机制类似于编码哺乳动物GluR转录本的机制。
Post-transcriptional editing of pre-mRNAs through the action of dsRNA adenosine deaminases results in the modification of particular adenosine (A) residues to inosine (I), which can alter the coding potential of the modified transcripts. We describe here three sites in the para transcript, which encodes the major voltage-activated Na(+) channel polypeptide in Drosophila, where RNA editing occurs. The occurrence of RNA editing at the three sites was found to be developmentally regulated. Editing at two of these sites was also conserved across species between the D. melanogaster and D. virilis. In each case, a highly conserved region was found in the intron downstream of the editing site and this region was shown to be complementary to the region of the exonic editing site. Thus, editing at these sites would appear to involve a mechanism whereby the edited exon forms a base-paired secondary structure with the distant conserved noncoding sequences located in adjacent downstream introns, similar to the mechanism shown for A-to-I RNA editing of mammalian glutamate receptor subunits (GluRs). For the third site, neither RNA editing nor the predicted RNA secondary structures were evolutionarily conserved. Transcripts from transgenic Drosophila expressing a minimal editing site construct for this site were shown to faithfully undergo RNA editing. These results demonstrate that Na(+) channel diversity in Drosophila is increased by RNA editing via a mechanism analogous to that described for transcripts encoding mammalian GluRs.