A chemical probe targets DNA 5-formylcytosine sites and inhibits TDG excision, polymerases bypass, and gene expression
作者:Liang Xu、Ying-Chu Chen、Satoshi Nakajima、Jenny Chong、Lanfeng Wang、Li Lan、Chao Zhang、Dong Wang
DOI:10.1039/c3sc51849c
日期:——
Dynamic regulation and faithful maintenance of proper DNA methylation patterns are essential for many cellular functions. 5-Formylcytosine (5fC), a newly discovered oxidized form of methylcytosine (mC), is involved in active DNA demethylation processes. The latest progress suggests exciting novel functional roles of this residue. Chemical tools are desired to further elucidate the functional roles of 5fC and to modulate dynamics of DNA demethylation and downstream biological processes. Here we designed and constructed a chemical probe, consisting of an aldehyde-targeting group and an intercalation group. This molecule can selectively react with 5fC and subsequently inhibit base excision by thymine DNA glycosylase (TDG) and cause significant pausing for both DNA and RNA polymerase elongation. Further investigation using a GFP reporter system in living cells revealed that the covalent modification in 5fC sites at 5′-UTR of the GFP gene greatly inhibited the GFP expression level. These results altogether confirmed our successful design and established a new approach for generating functional probes that target the formylcytosine sites and modulate 5fC-related biological processes.
动态调节和忠实维护适当的 DNA 甲基化模式对许多细胞功能至关重要。5-甲酰基胞嘧啶(5fC)是新发现的甲基胞嘧啶(mC)的氧化形式,它参与了活跃的 DNA 去甲基化过程。最新研究进展表明,该残基具有令人兴奋的新功能作用。我们需要化学工具来进一步阐明 5fC 的功能作用,并调节 DNA 去甲基化和下游生物过程的动态。在这里,我们设计并构建了一种化学探针,它由一个醛靶向基团和一个插层基团组成。这种分子能选择性地与 5fC 发生反应,随后抑制胸腺嘧啶 DNA 糖基化酶(TDG)的碱基切除,并导致 DNA 和 RNA 聚合酶的伸长明显暂停。利用活细胞中的 GFP 报告系统进行的进一步研究表明,GFP 基因 5′-UTR 上的 5fC 位点共价修饰极大地抑制了 GFP 的表达水平。这些结果完全证实了我们的设计是成功的,并为产生靶向甲酰胞嘧啶位点的功能探针和调节 5fC 相关生物过程建立了一种新方法。