title: Cytosine methylation of tRNA-Asp by DNMT2 has a role in translation of proteins containing poly-Asp sequences.
abstract: The Dnmt2 RNA methyltransferase catalyses the methylation of C38 in the anticodon loop of tRNA-Asp, but the molecular role of this methylation is unknown. Here, we report that mouse aspartyl-tRNA synthetase shows a four to fivefold preference for C38-methylated tRNA-Asp. Consistently, a 30% reduced charging level of tRNA-Asp was observed in Dnmt2 knockout (KO) murine embryonic fibroblast cells. Gene expression analysis with fluorescent reporter proteins fused to an N-terminal poly-Asp sequence showed that protein synthesis of poly-Asp-tagged reporter proteins was reduced in Dnmt2 KO cells as well. The same effect was observed with endogenous proteins containing poly-Asp sequences, indicating that Dnmt2-mediated C38 methylation of tRNA-Asp regulates the translation of proteins containing poly-Asp sequences. Gene ontology searches for proteins containing poly-Asp sequences in the human proteome showed that a significant number of these proteins have roles in transcriptional regulation and gene expression. Hence, the Dnmt2-mediated methylation of tRNA-Asp exhibits a post-transcriptional regulatory role by controlling the synthesis of a group of target proteins containing poly-Asp sequences.
authors.affiliation: Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany.
authors.forename: Raghuvaran
authors.initials: R
authors.lastname: Shanmugam
authors.affiliation: MoLife Program, School of Engineering and Science, Jacobs University Bremen , Bremen, Germany.
authors.forename: Jacob
authors.initials: J
authors.lastname: Fierer
authors.affiliation: Institute of Pharmacy and Biochemistry, Faculty of Chemistry, Pharmaceutical Sciences and Geoscience, Johannes Gutenberg-Universität Mainz , Mainz, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Kaiser
authors.affiliation: Institute of Pharmacy and Biochemistry, Faculty of Chemistry, Pharmaceutical Sciences and Geoscience, Johannes Gutenberg-Universität Mainz , Mainz, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Helm
authors.affiliation: Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany.
authors.forename: Tomasz P
authors.initials: TP
authors.lastname: Jurkowski
authors.affiliation: Institute of Biochemistry, Stuttgart University, Faculty of Chemistry , Stuttgart, Germany.
authors.forename: Albert
authors.identifier: 0000-0001-6113-9290
authors.initials: A
authors.lastname: Jeltsch
keywords: Asp-rich proteins; Dnmt2; aminoacylation; regulation of translation; tRNA methylation