Abstract
Glutaredoxin (Grx) is an important oxidoreductase to maintain the redox homoeostasis of cells. In our previous study, cold-adapted Grx from Psychrobacter sp. ANT206 (PsGrx) has been characterized. Here, we constructed an in-frame deletion mutant of psgrx (Δpsgrx). Mutant Δpsgrx was more sensitive to low temperature, demonstrating that psgrx was conducive to the growth of ANT206. Mutant Δpsgrx also had more malondialdehyde (MDA) and protein carbonylation content, suggesting that PsGrx could play a part in the regulation of tolerance against low temperature. A yeast two-hybrid system was adopted to screen interacting proteins of 26 components. Furthermore, two target proteins, glutathione reductase (GR) and alkyl hydroperoxide reductase subunit C (AhpC), were regulated by PsGrx under low temperature, and the interactions were confirmed via bimolecular fluorescence complementation (BiFC) and co-immunoprecipitation (Co-IP). Moreover, PsGrx could enhance GR activity. trxR expression in Δpsgrx, Δahpc, and ANT206 were illustrated 3.7, 2.4, and 10-fold more than mutant Δpsgrx Δahpc, indicating that PsGrx might increase the expression of trxR by interacting with AhpC. In conclusion, PsGrx may participate in glutathione metabolism and ROS-scavenging by regulating GR and AhpC to protect the growth of ANT206. These findings preliminarily suggest the role of PsGrx in the regulation of oxidative stress, which could improve the low-temperature tolerance of ANT206.
Highlights
Glutaredoxin (Grx), which is widely distributed in the cells of bacteria, plants, and mammals, is a general glutathione–disulfide reductase of importance in redox regulation
According to the schematic diagram of the in-frame gene deletion mutant strain construction process of psgrx in ANT206 (Figure 1), the ∆psgrx gene sequence, and the results shown in Figure 2A, a segment of 90 bp was deleted in psgrx ORF, and an in-frame deletion mutation gene with a length of 174 bp was identified
This study further examined the differences in the growth values of ANT206 and the mutant ∆psgrx under low temperature (Figure 3A)
Summary
Glutaredoxin (Grx), which is widely distributed in the cells of bacteria, plants, and mammals, is a general glutathione–disulfide reductase of importance in redox regulation. Grxs can be broadly separated into two highly abundant major subfamilies, which are termed class I and II Grxs Those in class I present the oxidoreductase activity, which control a variety of protein thiol redox homeostasis; these typically include dithiol enzymes with two active-site cysteine residues [1]. A class II Grxs play a role in regulating iron (Fe) metabolism as well as the maturation of the iron–sulfur protein [2,3]. As an important thiol disulfide bond oxidoreductase in the cell, Grxs play a significant part in the regulation of the intracellular redox balance and the process of resisting oxidative stress damage, which has become a hot scientific topic [5]. The regulatory mechanism of bacterial-derived Grxs under oxidative stress is still unclear
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
