Next Article in Journal
Gut Microbiota as the Link between Elevated BCAA Serum Levels and Insulin Resistance
Previous Article in Journal
Deficiency of the Lysosomal Protein CLN5 Alters Lysosomal Function and Movement
Article

Feeling the Heat: The Campylobacter jejuni HrcA Transcriptional Repressor Is an Intrinsic Protein Thermosensor

Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, 40126 Bologna, Italy
*
Authors to whom correspondence should be addressed.
Academic Editor: Joanna Skorko-Glonek
Biomolecules 2021, 11(10), 1413; https://doi.org/10.3390/biom11101413
Received: 11 August 2021 / Revised: 14 September 2021 / Accepted: 22 September 2021 / Published: 27 September 2021
The heat-shock response, a universal protective mechanism consisting of a transcriptional reprogramming of the cellular transcriptome, results in the accumulation of proteins which counteract the deleterious effects of heat-stress on cellular polypeptides. To quickly respond to thermal stress and trigger the heat-shock response, bacteria rely on different mechanisms to detect temperature variations, which can involve nearly all classes of biological molecules. In Campylobacter jejuni the response to heat-shock is transcriptionally controlled by a regulatory circuit involving two repressors, HspR and HrcA. In the present work we show that the heat-shock repressor HrcA acts as an intrinsic protein thermometer. We report that a temperature upshift up to 42 °C negatively affects HrcA DNA-binding activity to a target promoter, a condition required for de-repression of regulated genes. Furthermore, we show that this impairment of HrcA binding at 42 °C is irreversible in vitro, as DNA-binding was still not restored by reversing the incubation temperature to 37 °C. On the other hand, we demonstrate that the DNA-binding activity of HspR, which controls, in combination with HrcA, the transcription of chaperones’ genes, is unaffected by heat-stress up to 45 °C, portraying this master repressor as a rather stable protein. Additionally, we show that HrcA binding activity is enhanced by the chaperonin GroE, upon direct protein–protein interaction. In conclusion, the results presented in this work establish HrcA as a novel example of intrinsic heat-sensing transcriptional regulator, whose DNA-binding activity is positively modulated by the GroE chaperonin. View Full-Text
Keywords: transcriptional regulation; DNA-protein interaction; heat-shock response; HrcA repressor; HspR repressor; GroE chaperonin; heat-shock proteins; signal perception; Campylobacter jejuni transcriptional regulation; DNA-protein interaction; heat-shock response; HrcA repressor; HspR repressor; GroE chaperonin; heat-shock proteins; signal perception; Campylobacter jejuni
Show Figures

Figure 1

MDPI and ACS Style

Versace, G.; Palombo, M.; Menon, A.; Scarlato, V.; Roncarati, D. Feeling the Heat: The Campylobacter jejuni HrcA Transcriptional Repressor Is an Intrinsic Protein Thermosensor. Biomolecules 2021, 11, 1413. https://doi.org/10.3390/biom11101413

AMA Style

Versace G, Palombo M, Menon A, Scarlato V, Roncarati D. Feeling the Heat: The Campylobacter jejuni HrcA Transcriptional Repressor Is an Intrinsic Protein Thermosensor. Biomolecules. 2021; 11(10):1413. https://doi.org/10.3390/biom11101413

Chicago/Turabian Style

Versace, Giovanni, Marta Palombo, Anna Menon, Vincenzo Scarlato, and Davide Roncarati. 2021. "Feeling the Heat: The Campylobacter jejuni HrcA Transcriptional Repressor Is an Intrinsic Protein Thermosensor" Biomolecules 11, no. 10: 1413. https://doi.org/10.3390/biom11101413

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop