TY - JOUR IS - 1 PB - OXFORD UNIV PRESS Y1 - 2020/01/10/ A1 - Yang, T A1 - Low, JJA A1 - Woon, ECY N2 - RNA:5-methylcytosine (m?C) methyltransferases are currently the focus of intense research following a series of high-profile reports documenting their physiological links to several diseases. However, no methods exist which permit the specific analysis of RNA:m?C methyltransferases in cells. Herein, we described how a combination of biophysical studies led us to identify distinct duplex-remodelling effects of m5C on RNA and DNA duplexes. Specifically, m?C induces a C3?-endo to C2?-endo sugar-pucker switch in CpG RNA duplex but triggers a B-to-Z transformation in CpG DNA duplex. Inspired by these different ?structural signatures?, we developed a m?C-sensitive probe which fluoresces spontaneously in response to m5C-induced sugar-pucker switch, hence useful for sensing RNA:m?C methyltransferase activity. Through the use of this probe, we achieved real-time imaging and flow cytometry analysis of NOP2/Sun RNA methyltransferase 2 (NSUN2) activity in HeLa cells. We further applied the probe to the cell-based screening of NSUN2 inhibitors. The developed strategy could also be adapted for the detection of DNA:m?C methyltransferases. This was demonstrated by the development of DNA m?C-probe which permits the screening of DNA methyltransferase 3A inhibitors. To our knowledge, this study represents not only the first examples of m?C-responsive probes, but also a new strategy for discriminating RNA and DNA m?C methyltransferase activity in cells. VL - 48 SN - 0305-1048 N1 - © The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/). ID - discovery10106330 AV - public JF - Nucleic Acids Research EP - 17 UR - https://doi.org/10.1093/nar/gkz1047 KW - methyltransferase activity in cells. TI - A general strategy exploiting m?C duplex-remodelling effect for selective detection of RNA and DNA m?C methyltransferase activity in cells ER -