期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：34
页码：20689-20695
DOI：10.1073/pnas.2011511117
出版社：The National Academy of Sciences of the United States of America
摘要：RNA abasic sites and the mechanisms involved in their regulation are mostly unknown; in contrast, DNA abasic sites are well-studied. We found surprisingly that, in yeast and human cells, RNA abasic sites are prevalent. When a base is lost from RNA, the remaining ribose is found as a closed-ring or an open-ring sugar with a reactive C1′ aldehyde group. Using primary amine-based reagents that react with the aldehyde group, we uncovered evidence for abasic sites in nascent RNA, messenger RNA, and ribosomal RNA from yeast and human cells. Mass spectroscopic analysis confirmed the presence of RNA abasic sites. The RNA abasic sites were found to be coupled to R-loops. We show that human methylpurine DNA glycosylase cleaves N-glycosidic bonds on RNA and that human apurinic/apyrimidinic endonuclease 1 incises RNA abasic sites in RNA–DNA hybrids. Our results reveal that, in yeast and human cells, there are RNA abasic sites, and we identify a glycosylase that generates these sites and an AP endonuclease that processes them.
关键词：RNA abasic site ; R-loop ; methylpurine DNA glycosylase ; apurinic/apyrimidinic endonuclease 1 ; RNA
