Inosine in DNA and RNA
Inosine in DNA and RNA
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DOI：
10.1016/j.gde.2014.07.008
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发表时间：
2014-06-01
影响因子：
4
通讯作者：
Bjoras, Magnar
中科院分区：
文献类型：
--
作者：
Alseth, Ingrun;Dalhus, Bjorn;Bjoras, Magnar
DNA 和 RNA 中核碱基的脱氨是自发水解、内源性或环境因素以及脱氨酶的结果。腺苷脱氨基为肌苷，其编码错误并且优先与胞嘧啶碱基配对。就 DNA 而言，这是一种诱变前事件，可通过专门参与识别和去除肌苷的 DNA 修复酶来抵消。然而，在 RNA 中，肌苷是一种重要的修饰，由专门的酶以高度调控的方式引入，以产生转录组多样性。缺陷编辑存在于各种人类疾病中，包括癌症、病毒感染以及神经和精神疾病。催化脱氨酶反应的酶已得到很好的表征，并且最近揭示了核酸内切酶 V 在 RNA 加工中的意想不到的功能。虽然细菌核酸内切酶 V 酶被归类为 DNA 修复酶，但哺乳动物酶似乎参与了 RNA 中肌苷的加工。这在 DNA 和 RNA 加工之间产生了一个有趣但尚未探索的联系。需要进一步的工作来了解正常生理和疾病进展下肌苷对 DNA 和 RNA 的影响。
Deamination of the nucleobases in DNA and RNA is a result of spontaneous hydrolysis, endogenous or environmental factors as well as deaminase enzymes. Adenosine is deaminated to inosine which is miscoding and preferentially base pairs with cytosine. In the case of DNA, this is a premutagenic event that is counteracted by DNA repair enzymes specifically engaged in recognition and removal of inosine. However, in RNA, inosine is an essential modification introduced by specialized enzymes in a highly regulated manner to generate transcriptome diversity. Defect editing is seen in various human disease including cancer, viral infections and neurological and psychiatric disorders. Enzymes catalyzing the deaminase reaction are well characterized and recently an unexpected function of Endonuclease V in RNA processing was revealed. Whereas bacterial Endonuclease V enzymes are classified as DNA repair enzymes, it appears that the mammalian enzymes are involved in processing of inosine in RNA. This yields an interesting yet unexplored, link between DNA and RNA processing. Further work is needed to gain understanding of the impact of inosine in DNA and RNA under normal physiology and disease progression.