Abstract
The heat shock response is crucial for organisms against heat-damaged proteins and maintaining homeostasis at a high temperature. Heterologous expression of eukaryotic molecular chaperones protects Escherichia coli from heat stress. Here we report that expression of the plant E3 ligase BnTR1 significantly increases the thermotolerance of E. coli. Different from eukaryotic chaperones, BnTR1 expression induces the accumulation of heat shock factor σ32 and heat shock proteins. The active site of BnTR1 in E. coli is the zinc fingers of the RING domain, which interacts with DnaK resulting in stabilizing σ32. Our findings indicate the expression of BnTR1 confers thermoprotective effects on E. coli cells, and it may provide useful clues to engineer thermophilic bacterial strains.
Highlights
The heat shock response (HSR) is a universal signalling pathway in all organisms that maintains protein-folding homeostasis through the regulation of heat shock proteins (HSPs)[1, 2]
Because the σ32 is the central player in regulating HSP transcription[8], we investigated the changes of the σ32 level in E. coli cells expressing BnTR1
We report heterologous expression BnTR1, a plant E3 ligase containing a RING domain, could effectively protect E. coli cells from heat stress
Summary
The heat shock response (HSR) is a universal signalling pathway in all organisms that maintains protein-folding homeostasis through the regulation of heat shock proteins (HSPs)[1, 2]. It is widely accepted that a negative feedback loop exists such that HSR chaperones and proteases titrate free σ32 by binding or degrading unfolded proteins, the up-regulated σ32 increases the transcription of HSPs which subsequently decrease the σ32 activity and stability, facilitating E. coli cell viability and proliferation under heat stress[8]. In addition to endogenous HSPs, the heterologous expression of eukaryotic molecular chaperones increases E. coli cell viability at high temperatures[21,22,23,24]. We report that heterologous expression of a RING (Really Interesting New Gene) domain E3 ligase from Brassica napus, named BnTR1, conferred pronounced thermoprotection on E. coli cells. Unlike molecular chaperones such as sHSPs, the RING domain of BnTR1 was the active site for its function in E. coli. Our findings reveal that heterologous expression of BnTR1 provides thermoprotective effects on E. coli cells, and it may yield useful insights into the development of engineered thermophilic bacteria
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.
