Stress- induced modification of Escherichia coli tRNA generates 5-methylcytidine in the variable loop

• 成果类型: Article
• 署名作者: Valesyan, Satenik; Jora, Manasses; Addepalli, Balasubrahmanyam; Limbach, Patrick A.
• 署名单位: University System of Ohio; University of Cincinnati; AstraZeneca; Waters Corporation
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10867
• DOI: 10.1073/pnas.2317857121
• 发表日期: 2024-11-12
• 关键词: dual-specificity enzyme; ribosomal-rna; oxidative stress; hydrogen-peroxide; m(5)c967 methyltransferase; nucleoside modifications; crystal-structure; gene-expression; dna-damage; identification

摘要

There has been recent interest in trying to understand the connection between transfer RNA (tRNA) posttranscriptional modifications and changes in-cellular environmental conditions. Here, we report on the identification of the modified nucleoside 5-methylcytidine (m(5)C) in Escherichia coli tRNAs. This modification was determined to be present at position 49 of tRNA Tyr-QUA-II. Moreover, m(5)C levels in this tRNA are significantly elevated under high reactive oxygen specieis (ROS) conditions in E. coli cells. We identified the known ribosomal RNA methyltransferase rsmF as the enzyme responsible for m(5)C synthesis in tRNA and enzyme transcript levels are responsive to elevated levels of ROS in the cell. We further find that changes in m(5)C levels in this tRNA are not specific to Fenton-like reaction conditions elevating ROS, but heat shock can also induce increased modification of tRNA Tyr-QUA-II. Altogether, this work illustrates how cells adapt to changing environmental conditions through variations in tRNA modification profiles.