Heat shock response in Sulfolobus acidocaldarius and first implications for cross-stress adaptation

Sulfolobus acidocaldarius, a thermoacidophilic crenarchaeon, frequently encounters temperature fluctuations, oxidative stress, and nutrient limitations in its environment. Here, we employed a highthroughput transcriptomic analysis to examine how the gene expression of S. acidocaldarius changes when exposed to high temperatures (92 degrees C). The data obtained was subsequently validated using quantitative reverse transcription-PCR (qRT-PCR) analysis. Our particular focus was on genes that are involved in the heat shock response, type-II Toxin-Antitoxin systems, and putative transcription factors. To investigate how S. acidocaldarius adapts to multiple stressors, we assessed the expression of these selected genes under oxidative and nutrient stresses using qRT-PCR analysis. The results demonstrated that the gene thb encoding the b subunit of the thermosome, as well as hsp14 and hsp20, play crucial roles in the majority of stress conditions. Furthermore, we observed overexpression of at least eight different TA pairs belonging to the type II TA systems under all stress conditions. Additionally, four common transcription factors: FadR, TFEb, CRISPR loci binding protein, and HTH family protein were consistently overexpressed across all stress conditions, indicating their significant role in managing stress. Overall, this work provides the first insight into molecular players involved in the cross-stress adaptation of S. acidocaldarius. (c) 2023 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Automated summary

This study used high-throughput transcriptomic analysis to investigate the gene expression changes of S. acidocaldarius under high temperatures and stress conditions. The results revealed key genes involved in stress adaptation and consistently overexpressed transcription factors across all stress conditions. This research provides the first insight into the molecular mechanisms of cross-stress adaptation in S. acidocaldarius.