A small RNA regulates pprM, a modulator of pleiotropic proteins promoting DNA repair, in Deinococcus radiodurans under ionizing radiation

• Published in: Scientific reports Vol. 11; no. 1; pp. 12949 - 14
• Main Authors: Villa, Jordan K., Han, Runhua, Tsai, Chen-Hsun, Chen, Angela, Sweet, Philip, Franco, Gabriela, Vaezian, Respina, Tkavc, Rok, Daly, Michael J., Contreras, Lydia M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 21.06.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326/41; 631/337/1427/2566; 631/337/384/521; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Deinococcus - genetics; Deinococcus - growth & development; Deinococcus - radiation effects; Deinococcus radiodurans; Deoxyribonucleic acid; Desiccation; DNA; DNA repair; DNA Repair - radiation effects; Environmental stress; Gene expression; Gene Expression Regulation, Bacterial; Humanities and Social Sciences; Ionizing radiation; Models, Biological; multidisciplinary; Open Reading Frames; Post-radiation; Post-transcription; Radiation; Radiation, Ionizing; Radioresistance; RNA, Bacterial; Science; Science (multidisciplinary); Survival
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-91335-8

Networks of transcriptional and post-transcriptional regulators are critical for bacterial survival and adaptation to environmental stressors. While transcriptional regulators provide rapid activation and/or repression of a wide-network of genes, post-transcriptional regulators, such as small RNAs (sRNAs), are also important to fine-tune gene expression. However, the mechanisms of sRNAs remain poorly understood, especially in less-studied bacteria. Deinococcus radiodurans is a gram-positive bacterium resistant to extreme levels of ionizing radiation (IR). Although multiple unique regulatory systems (e.g., the Radiation and Desiccation Response (RDR)) have been identified in this organism, the role of post-transcriptional regulators has not been characterized within the IR response. In this study, we have characterized an sRNA, PprS (formerly Dsr2), as a post-transcriptional coordinator of IR recovery in D. radiodurans . PprS showed differential expression specifically under IR and knockdown of PprS resulted in reduced survival and growth under IR, suggesting its importance in regulating post-radiation recovery. We determined a number of potential RNA targets involved in several pathways including translation and DNA repair. Specifically, we confirmed that PprS binds within the coding region to stabilize the pprM (DR_0907) transcript, a RDR modulator. Overall, these results are the first to present an additional layer of sRNA-based control in DNA repair pathways associated with bacterial radioresistance.