Department of Genetics In Ecology

European Project: Systems Biology of Microorganisms
A Silicon cell model for the central carbohydrate metabolism of the archaeon Sulfolobus solfataricus under temperature variation

Duration: 01.11.2007 - 30.09.2010

FUNDING

PARTICIPANTS

Temperature changes are not only most difficult to deal with for organisms, it is also unclear how biological networks can withstand and respond to such changes. Even slight differences between the rates of individual reactions in metabolic pathways should cause rapid accumulation or depletion of intermediates with various deleterious effects. With a change in temperature, the rates of individual reactions in metabolic pathways must therefore change by precisely the same extent. Organisms could adapt by (i) having identical temperature coefficients of the enzymes, (ii) metabolic regulation, (iii) adjusting Vmax-s (e.g. through enzyme phosphorylation), (iv) adjusting translation or protein stability, (v) adjusting transcription or mRNA stability, (vi) rerouting the metabolic flow, (vii)formation of compatible solutes, (viii) export of overflow metabolites or (ix) going into dormancy. We hypothesize that several of theses mechanisms contribute to different extents and will try to quantify each of these adaptations in a systems biology approach. As the issue should be most acute for thermophiles, we will perform these studies with a thermophilic archaeon.
The archaeal model organism of choice for this systems biology approach is Sulfolobus solfataricus, a thermoacidophilic Crenarchaeon that grows at around 80°C and pH 3 [2]. S. solfataricus uses an unusual branched Entner-Doudoroff (ED) pathway for glucose catabolism [3]. Life at high temperature requires a very efficient adaptation to temperature changes, which is most difficult to deal with for organisms and it is unclear how biological networks can withstand and respond to such changes. In this sysmo project,10 partner laboratories will study the central carbohydrate metabolism (CCM), i.e. the branched ED pathway of S. solfataricus and its regulation under temperature variation by the integration of genomic, transcriptomic, proteomic, metabolomic, kinetic and biochemical information. The long term goal of the project is to build a sufficiently precise replica for this part of the living cell (“a Silicon Cell”) to enable computation of life, particular its robustness to changes in temperature, at the system level.

Selected publications

[1] Siebers & Schönheit (2005) Curr. Opin. Microbiol. 8, 695-705
[2] Zillig et al. (1980) Arch. Microbiol. 125, 259-269
[3] Ahmed et al. (2005) Biochem. J. 390,