Myo‐inositol‐1‐phosphate synthase (Ino‐1) functions as a protection mechanism in Corynebacterium glutamicum under oxidative stress

Abstract

Reactive oxygen species ( ROS ) generated in aerobic metabolism and oxidative stress lead to macromolecules damage, such as to proteins, lipids, and DNA , which can be eliminated by the redox buffer mycothiol (AcCys‐GlcN‐Ins, MSH ). Myo ‐inositol‐phosphate synthase (Ino‐1) catalyzes the first committed step in the synthesis of MSH , thus playing a critical role in the growth of the organism. Although Ino‐1s have been systematically studied in eukaryotes, their physiological and biochemical functions remain largely unknown in bacteria. In this study, we report that Ino‐1 plays an important role in oxidative stress resistance in the gram‐positive Actinobacteria Corynebacterium glutamicum . Deletion of the ino‐1 gene resulted in a decrease in cell viability, an increase in ROS production, and the aggravation of protein carbonylation levels under various stress conditions. The physiological roles of Ino‐1 in the resistance to oxidative stresses were corroborated by the absence of MSH in the Δ ino‐1 mutant. In addition, we found that the homologous expression of Ino‐1 in C. glutamicum yielded a functionally active protein, while when expressed in Escherichia coli BL 21( DE 3), it lacked measurable activity. An examination of the molecular mass (Mr) suggested that Ino‐1 expressed in E. coli BL 21( DE 3) was not folded in a catalytically competent conformation. Together, the results unequivocally showed that Ino‐1 was important for the mediation of oxidative resistance by C. glutamicum .

Comparative genomics and metabolomics analysis of Riemerella anatipestifer strain CH-1 and CH-2

“…Ins-1P is primarily formed by Myo-inositol-phosphate synthase (MIPS) catalyzing glucose-6-phosphate (Glc-6P) 60 , which is an important precursor substance of phosphatidyl- myo -inositol and mycothiol 61 . Ins-1P is an essential metabolite for growth and virulence in some bacteria 62 , 63 .…”

Propionibacterium freudenreichii CIRM-BIA 129 Osmoadaptation Coupled to Acid-Adaptation Increases Its Viability During Freeze-Drying

“…About proteins involved in the transport and metabolism of carbohydrate, proteins corresponding to the utilization of alternative carbon sources are induced, including Myo-inositol catabolism IolB protein (emb|CDP49182.1|), as it happens during unfavorable conditions in Corynebacterium glutamicum (Chen et al, 2019). The pentose phosphate pathway, including the phosphoketolase pyrophosphate (emb|CDP48739.1|) and the ribose-5-phosphate isomerase 3 (emb|CDP49834.1|), is also enhanced.…”

“…Concerning lipid and transport metabolism, the induction of inositol-1-phosphate synthase (emb|CDP49767.1|) and of acyltransferase PslC (emb|CDP49388.1|) indicates enhanced biosynthesis of phospholipids, in accordance with the observed effect of salt on membrane fatty acids. These proteins are also involved in stress response in Serratia plymuthica and C. glutamicum (Nurlinawati et al, 2015; Chen et al, 2019).…”

Role of Inositols and Inositol Phosphates in Energy Metabolism

“…d-myo-inositol supplement both orally (400 mg/kg) and intraperitoneally (200 and 800 mg/kg) suppressed inflammation in rats with adjuvant disease [119]. Moreover, myo-inositol-1-phosphate synthase (Ino-1) deletion in bacteria (Actinobacteria Corynebacterium glutamicum) increased production of ROS and decreased cell viability suggested that Ino-1 might have an effect on oxidative stress resistance [120]. Because of its ability to downregulate inflammation and cytokine release, it has been recently speculated that myoIns might be beneficial for Sars-CoV-2 patients [121].…”