腺苷-肌苷(A-to-I)RNA编辑重新编码基因组并赋予生物体适应环境的灵活性。据信RNA重新编码位点非常适合通过以时空方式增加蛋白质组多样性来促进适应性进化。认识到一些保守的重新编码位点的功能和重要性。然而,实验发现的功能位点仅占总位点的一小部分,并且仍然需要使用生物信息学方法扩展此类功能站点的库。在这项研究中,我们定义了一类新的RNA编辑位点,称为“保守编辑与非保守重新编码”,并系统地鉴定了果蝇编辑组中的此类位点,找出它们在物种间和物种内水平上的选择压力和适应信号。令人惊讶的是,具有非保守重编码的保守编辑位点未被抑制,甚至在果蝇中被略微高估。导致这种情况的DNA突变在进化过程中也受到青睐,这表明这些记录事件在不同物种中的功能可能会有所不同,专业,并保持。最后,结构预测表明,钾通道Shab中的这种重新编码可能会增加离子渗透性并补偿低温的影响。总之,保守编辑与非保守重新编码也可能是功能性的。我们的研究在考虑RNA编辑位点的适应性进化方面提供了新的方面,同时扩展了功能重新编码位点的候选者以供将来验证。
Adenosine-to-inosine (A-to-I) RNA editing recodes the genome and confers flexibility for the organisms to adapt to the environment. It is believed that RNA
recoding sites are well suited for facilitating adaptive evolution by increasing the proteomic diversity in a temporal-spatial manner. The function and essentiality of a few conserved
recoding sites are recognized. However, the experimentally discovered functional sites only make up a small corner of the total sites, and there is still the need to expand the repertoire of such functional sites with bioinformatic approaches. In this study, we define a new category of RNA editing sites termed \'conserved editing with non-conserved recoding\' and systematically identify such sites in Drosophila editomes, figuring out their selection pressure and signals of adaptation at inter-species and intra-species levels. Surprisingly, conserved editing sites with non-conserved
recoding are not suppressed and are even slightly overrepresented in Drosophila. DNA mutations leading to such cases are also favoured during evolution, suggesting that the function of those recoding events in different species might be diverged, specialized, and maintained. Finally, structural prediction suggests that such
recoding in potassium channel Shab might increase ion permeability and compensate the effect of low temperature. In conclusion, conserved editing with non-conserved
recoding might be functional as well. Our study provides novel aspects in considering the adaptive evolution of RNA editing sites and meanwhile expands the candidates of functional recoding sites for future validation.