RT Journal Article SR Electronic T1 N4-acetylcytidine and 5-formylcytidine are present in Saccharomyces cerevisiae mRNAs JF bioRxiv FD Cold Spring Harbor Laboratory SP 327585 DO 10.1101/327585 A1 Mehmet Tardu A1 Qishan Lin A1 Kristin S. Koutmou YR 2018 UL http://biorxiv.org/content/early/2018/05/21/327585.abstract AB Chemical modifications of RNAs have long been appreciated as key modulators of non-coding RNA structure and function. There is an emerging realization that chemical modification of protein-coding mRNAs also plays critical roles in the cell. Nonetheless, of the over 100 known RNA modifications found in biology only a handful have been identified in mRNAs. Here we use an ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to identify and quantify modifications present in mRNAs of yeast cells. We detect the presence of four modified nucleosides in mRNAs at relatively high abundances: N7-methylguanosine, N6-methyladenosine, N4-acetylcytidine and 5-formylcytidine. Additionally, we investigate how the levels of mRNA modifications change in response to cellular stress. We find that the concentrations of nine mRNA modifications including N6-methyladenosine and N4-acetylcytidine change in response to heat stress, glucose starvation and/or oxidative stress. Our findings suggest that mRNA modification may provide a potential mechanism for cells to rapidly respond to environmental stressors.