Transient increase of ATP as a response to temperature up-shift in Escherichia coli

Soini Jaakko, Falschlehner Christina, Mayer Christina, Böhm Daniela, Weinel Stefan, Panula Johanna, Vasala Antti, Neubauer, Neubauer Peter

Description

Summary Background Escherichia coli induces the heat shock response to a temperature up-shift which is connected to the synthesis of a characteristic set of proteins, including ATP dependent chaperones and proteases. Therefore the balance of the nucleotide pool is important for the adaptation and continuous function of the cell. Whereas it has been observed in eukaryotic cells, that the ATP level immediately decreased after the temperature shift, no data are available for E. coli about the adenosine nucleotide levels during the narrow time range of minutes after a temperature up-shift. Results The current study shows that a temperature up-shift is followed by a very fast significant transient increase of the cellular ATP concentration within the first minutes. This increase is connected to a longer lasting elevation of the cellular respiration and glucose uptake. Also the mRNA level of typical heat shock genes increases within only one minute after the heat-shock. Conclusion The presented data prove the very fast response of E. coli to a heat-shock and that the initial response includes the increase of the ATP pool which is important to fulfil the need of the cell for new syntheses, as well as for the function of chaperones and proteases.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2005
• Nombre de lectures: 19
• Langue: English

Extrait

Microbial Cell Factories

BioMedCentral

Open Access Research Transient increase of ATP as a response to temperature upshift in Escherichia coli 1 1 1 1 Jaakko Soini , Christina Falschlehner , Christina Mayer , Daniela Böhm , 2 1 1 1,2 Stefan Weinel , Johanna Panula , Antti Vasala and Peter Neubauer*

1 Address: Bioprocess Engineering Laboratory and Biocenter Oulu, Department of Process and Environmental Engineering, University of Oulu, 2 P.O.Box 4300, FI – 90014 Oulu, Finland and Institute for Biotechnology, Department of Biochemistry/Biotechnology, MartinLutherUniversity HalleWittenberg, KurtMothesStr. 3, D06120 Halle, Germany Email: Jaakko Soini  [e-mail]; Christina Falschlehner  [e-mail]; Christina Mayer  [e-mail]; Daniela Böhm  daniela.boehm@tubs.de; Stefan Weinel  [e-mail]; Johanna Panula  [e-mail]; Antti Vasala  [e-mail]; Peter Neubauer*  [e-mail] * Corresponding author

Published: 01 April 2005 Received: 04 February 2005 Accepted: 01 April 2005 Microbial Cell Factories2005,4:9 doi:10.1186/1475285949 This article is available from: http://www.microbialcellfactories.com/content/4/1/9 © 2005 Soini et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Summary Background:Escherichia coliinduces the heat shock response to a temperature upshift which is connected to the synthesis of a characteristic set of proteins, including ATP dependent chaperones and proteases. Therefore the balance of the nucleotide pool is important for the adaptation and continuous function of the cell. Whereas it has been observed in eukaryotic cells, that the ATP level immediately decreased after the temperature shift, no data are available forE. coliabout the adenosine nucleotide levels during the narrow time range of minutes after a temperature upshift.

Results:The current study shows that a temperature upshift is followed by a very fast significant transient increase of the cellular ATP concentration within the first minutes. This increase is connected to a longer lasting elevation of the cellular respiration and glucose uptake. Also the mRNA level of typical heat shock genes increases within only one minute after the heatshock.

Conclusion:The presented data prove the very fast response ofE. colito a heatshock and that the initial response includes the increase of the ATP pool which is important to fulfil the need of the cell for new syntheses, as well as for the function of chaperones and proteases.

Background Bacteria, as all kind of organisms, respond to a sudden increase of the temperature by a heat shock response which induces a specific set of proteins. This stress system belongs to the beststudied cellular responses. As the pro tein composition of a cell determines substantially the cel lular functions, the heat shock response is mainly understood in terms of protein synthesis and composition.

The heat shock response ofE. coliis mediated by the alter 32 native sigma factorσ(rpoHgene product) and leads to induction of more than 20 heat shock proteins [1,2]. In difference to other stress responses ofE. coliwhich in a regulatory cascade first lead to synthesis of the respective sigma factors which then, consecutively, direct the tran scription of their genes, the transcriptional induction of the heat shock proteins can start very fast after a heat shock. This first fast synthesis of heat shock proteins is transient, followed by an adaptation period with a lower

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