Abstract
In natural environments microorganisms encounter extreme changes in temperature, pH, osmolarities and nutrient availability. The stress response of many bacterial species has been described in detail, however, knowledge in Archaea is limited. Here, we describe the cellular response triggered by nutrient limitation in the thermoacidophilic crenarchaeon Sulfolobus acidocaldarius. We measured changes in gene transcription and protein abundance upon nutrient depletion up to 4 h after initiation of nutrient depletion. Transcript levels of 1118 of 2223 protein coding genes and abundance of approximately 500 proteins with functions in almost all cellular processes were affected by nutrient depletion. Our study reveals a significant rerouting of the metabolism with respect to degradation of internal as well as extracellular-bound organic carbon and degradation of proteins. Moreover, changes in membrane lipid composition were observed in order to access alternative sources of energy and to maintain pH homeostasis. At transcript level, the cellular response to nutrient depletion in S. acidocaldarius seems to be controlled by the general transcription factors TFB2 and TFEβ. In addition, ribosome biogenesis is reduced, while an increased protein degradation is accompanied with a loss of protein quality control. This study provides first insights into the early cellular response of Sulfolobus to organic carbon and organic nitrogen depletion.
Highlights
Microorganisms are constantly challenged by changes of temperatures, pH, osmolarities or nutrient limitation in their direct environment
Sulfolobus acidocaldarius was grown in nutrient rich Brock medium to an optical density at 600 nm (OD600) of 0.4 and subsequently transferred to medium lacking organic carbon and organic nitrogen sources (Brock et al, 1972; Lassak et al, 2012; Wagner et al, 2012)
Cells were pelleted by centrifugation and the pelleted culture was resuspended in the original volume of 75◦C pre-warmed basal Brock medium lacking organic nutrients
Summary
Microorganisms are constantly challenged by changes of temperatures, pH, osmolarities or nutrient limitation in their direct environment. Knowledge on the stress response in Archaea is limited and it is not yet understood how changes in the environment are sensed and processed within the cell. Phosphate starvation negatively affects growth and leads to adaptations in the cellular proteome of S. acidocaldarius and it was proposed that the protein content of the cell is exclusive to certain stress sources (Osorio and Jerez, 1996). Altered phosphorylation patterns in proteins were observed under phosphate starvation, proposing a regulatory role in the cellular adaptation to external conditions (Osorio and Jerez, 1996)
Sign-in/Register to view highlights & summary 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.
