偶氮苯修饰的发夹DNA对RNA转录的光调控

Photoregulating RNA transcription using azobenzene modified hairpin DNA

通过偶氮苯的光异构化作用影响生物大分子的结构和功能是近年的热门研究课题。我们前期发现偶氮苯光控制DNA聚合酶的活性而调控引物的延伸。本文围绕遗传信息传递的转录过程,研究偶氮苯对RNA聚合酶反应的光调控。将4,4′-二羟甲基偶氮苯修饰在RNA转录的非模板链的T7启动子端,并连接5、7、9、11 nt的4种长度保护链。探究它们的光异构化能力以及RNA转录的光调节情况,结果发现偶氮苯修饰非模板链的DNA模板与T7 RNA聚合酶反应在紫外光响应下转录效率明显增加,RNA转录产物对于设计的5 nt长度的T7NC,从光照前3.4%增加到光照后21.4%,大约有6.25倍的变化。同样,对于含有T7NC1、T7NC2和T7NC3的DNA模板,紫外光照后其指导的RNA转录产物也有所增加,增加的效率分别为4、3和1.25倍。因此,我们设计的非模板链上通过偶氮苯连接5个碱基的发夹结构与模板链组合指导的RNA转录具有最佳的光控效果。本研究的重要价值在于发现了偶氮苯光活性修饰参与生命活动的模板序列,研究结果可有效应用于核酸药物的开发与应用。

Effects of light isomerization of azobenzene on the structure and function of biological macromolecules is a hot topic of research in recent years.We focus on the transcriptional process of genetic information transmission and study the light regulation of azobenzene on RNA polymerase reaction.We modified 4,4′-dimethylol azobenzene at the T7 promoter end of the non-template strand of RNA transcription and ligated the 4 protection chains with length of 5,7,9,and 11 nt.Their photoisomerization ability and light regulation of RNA transcription were explored.It was found that the azobenzene-modified non-template strand DNA template reacted with T7 RNA polymerase to increase transcription efficiency under UV light response.RNA transcripts were designed.The 5 nt length T7NC increased from approximately 3.4%before illumination to 21.4%after illumination,with a 6.25-fold change.Similarly,for DNA templates containing T7NC1,T7NC2,and T7NC3,the RNA transcripts directed by UV light also increased,with the increase efficiencies of 4,3,and 1.25 fold,respectively.Therefore,the non-templates we designed have the best light control effect on RNA transcription guided by a combination of a 5 base hairpin structure and a template strand.This discovery of the photoactive modification of azobenzene in the template sequence involved in life activities can be used as a future scientific tool and to guide the application of nucleic acid drugs.