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

Abstract

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.

Memory Effect on the Survival of Deinococcus radiodurans after Exposure in Near Space

“…According to published literature, numerous antioxidant proteins, e.g., superoxide dismutase (SOD), OxyR, PerR, DdrI, and PprI, as well as various antioxidant metabolites against ROS and PC, help to enhance protection of the proteome of D. radiodurans ( 50 ). Moreover, some studies showed that many small RNAs also play essential roles in the transport of antioxidant proteins and regulation of manganese and DNA repair systems in D. radiodurans ( 73 , 74 ). Some proteins reduced the effect of oxidized RNA, which also helped protect cells from oxidative stress ( 75 ).…”

PNPase and RhlB Interact and Reduce the Cellular Availability of Oxidized RNA in Deinococcus radiodurans

“…In the past, extensive studies have been conducted to understand the mechanism of the resistance of D. radiodurans to oxidative stresses, most of which mainly focused on gene regulation, protein functions, and sRNA regulations ( 38 , 39 , 46 , 50 – 52 ). Our previous work has revealed that ionizing radiation can cause a significantly increased 8-oxoG-RNA concentration in D. radiodurans ( 39 ).…”

Regulation of neutrophil myeloperoxidase inhibitor SPIN by the small RNA Teg49 in Staphylococcus aureus

“…RNA extraction and preparation were done immediately as described above. Densitometry with ImageJ was used to measure density counts in lane measurements, and compare density using integrated lane density over a defined region of interest with ImageJ/Fiji Tools (Belasco & Brawerman, 2012; Chen et al, 2008; Villa et al, 2021).…”