Critical Minireview: The Fate of tRNACys during Oxidative Stress in Bacillus subtilis

Abstract

Oxidative stress occurs when cells are exposed to elevated levels of reactive oxygen species that can damage biological molecules. One bacterial response to oxidative stress involves disulfide bond formation either between protein thiols or between protein thiols and low-molecular-weight (LMW) thiols. Bacillithiol was recently identified as a major low-molecular-weight thiol in Bacillus subtilis and related Firmicutes. Four genes (bshA, bshB1, bshB2, and bshC) are involved in bacillithiol biosynthesis. The bshA and bshB1 genes are part of a seven-gene operon (ypjD), which includes the essential gene cca, encoding CCA-tRNA nucleotidyltransferase. The inclusion of cca in the operon containing bacillithiol biosynthetic genes suggests that the integrity of the 3′ terminus of tRNAs may also be important in oxidative stress. The addition of the 3′ terminal CCA sequence by CCA-tRNA nucleotidyltransferase to give rise to a mature tRNA and functional molecules ready for aminoacylation plays an essential role during translation and expression of the genetic code. Any defects in these processes, such as the accumulation of shorter and defective tRNAs under oxidative stress, might exert a deleterious effect on cells. This review summarizes the physiological link between tRNACys regulation and oxidative stress in Bacillus.

Regulatory Factors for tRNA Modifications in Extreme- Thermophilic Bacterium Thermus thermophilus

“…As a result, our knowledge about the effects of tRNA modifications on codon-anticodon interactions, on maintenance of reading frame and on dynamics of tRNA on ribosome at high temperatures is limited. Furthermore, recent studies on mesophiles reported that tRNA modifications occur in response to environmental stresses or function as stress resistance factors ( Nawrot et al, 2011 ; Preston et al, 2013 ; Endres et al, 2015 ; Jaroensuk et al, 2016 ; Campos Guillen et al, 2017 ). As yet, however, there are no studies from this viewpoint for T. thermophilus .…”

Ginger and Testosterone

“…Ginger root is rich with several potent antioxidant compounds such as gingerols, zingerone, zingiberene, glucosides-6-gingerdiol, flavonoids, and volatile oils [17]. These antioxidants protect both the reproductive organs from oxidative stress, an imbalance between prooxidants (reactive oxygen species such as superoxide ion, hydroxyl radical, and hydrogen peroxide) and antioxidants to the favor of the former [41], and lipid peroxidation. Ginger roots were found to enhance the activity of certain antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in different male reproductive organs such as testis, prostate, and epididymis [32].…”

Analysis of tRNACys processing under salt stress in Bacillus subtilis spore outgrowth using RNA sequencing data

“…It remains to be seen how these enzymes are affected under salt stress conditions during spore outgrowth, but Nagler et al (2016) reported the interesting observation that the cca gene was downregulated during 90 minutes of outgrowth in the presence of NaCl. A relevant feature is that the cca gene is immersed in the operon containing bacillithiol (a REDOX regulator and an α-anomeric glycoside of L-cysteinyl-D-glucosamine with L-malic acid) biosynthetic genes under σ A -dependent promoter control, which suggests that cca expression and the integrity of the 3’ terminus of tRNAs may be important during salt stress ( Campos Guillen et al , 2017 ; Gaballa et al , 2010 ; Gaballa et al , 2013 ).…”