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Is Transcriptional Regulation of Metabolic Pathways and Optimal Strategy for Fitness?

Troein, Carl LU ; Ahrén, Dag LU ; Krogh, Morten LU and Peterson, Carsten LU (2007) In PLoS ONE 2(9).
Abstract
Background

Transcriptional regulation of the genes in metabolic pathways is a highly successful strategy, which is virtually universal in microorganisms. The lac operon of E. coli is but one example of how enzyme and transporter production can be made conditional on the presence of a nutrient to catabolize.





Methodology

With a minimalist model of metabolism, cell growth and transcriptional regulation in a microorganism, we explore how the interaction between environmental conditions and gene regulation set the growth rate of cells in the phase of exponential growth. This in silico model, which is based on biochemical rate equations, does not describe a specific organism, but the magnitudes of... (More)
Background

Transcriptional regulation of the genes in metabolic pathways is a highly successful strategy, which is virtually universal in microorganisms. The lac operon of E. coli is but one example of how enzyme and transporter production can be made conditional on the presence of a nutrient to catabolize.





Methodology

With a minimalist model of metabolism, cell growth and transcriptional regulation in a microorganism, we explore how the interaction between environmental conditions and gene regulation set the growth rate of cells in the phase of exponential growth. This in silico model, which is based on biochemical rate equations, does not describe a specific organism, but the magnitudes of its parameters are chosen to match realistic values. Optimizing the parameters of the regulatory system allows us to quantify the fitness benefit of regulation. When a second nutrient and its metabolic pathway are introduced, the system must further decide whether and how to activate both pathways.





Conclusions

Even the crudest transcriptional network is shown to substantially increase the fitness of the organism, and this effect persists even when the range of nutrient levels is kept very narrow. We show that maximal growth is achieved when pathway activation is a more or less steeply graded function of the nutrient concentration. Furthermore, we predict that bistability of the system is a rare phenomenon in this context, but outline a situation where it may be selected for. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
PLoS ONE
volume
2
issue
9
publisher
Public Library of Science
external identifiers
  • WOS:000207455500038
  • Scopus:41049101166
DOI
10.1371/journal.pone.0000855
language
English
LU publication?
yes
id
1e8ecee8-bb76-4478-8a86-899acb04315b (old id 628697)
date added to LUP
2007-11-27 14:18:32
date last changed
2016-12-04 04:44:57
@misc{1e8ecee8-bb76-4478-8a86-899acb04315b,
  abstract     = {Background<br/><br>
Transcriptional regulation of the genes in metabolic pathways is a highly successful strategy, which is virtually universal in microorganisms. The lac operon of E. coli is but one example of how enzyme and transporter production can be made conditional on the presence of a nutrient to catabolize.<br/><br>
<br/><br>
<br/><br>
Methodology<br/><br>
With a minimalist model of metabolism, cell growth and transcriptional regulation in a microorganism, we explore how the interaction between environmental conditions and gene regulation set the growth rate of cells in the phase of exponential growth. This in silico model, which is based on biochemical rate equations, does not describe a specific organism, but the magnitudes of its parameters are chosen to match realistic values. Optimizing the parameters of the regulatory system allows us to quantify the fitness benefit of regulation. When a second nutrient and its metabolic pathway are introduced, the system must further decide whether and how to activate both pathways.<br/><br>
<br/><br>
<br/><br>
Conclusions<br/><br>
Even the crudest transcriptional network is shown to substantially increase the fitness of the organism, and this effect persists even when the range of nutrient levels is kept very narrow. We show that maximal growth is achieved when pathway activation is a more or less steeply graded function of the nutrient concentration. Furthermore, we predict that bistability of the system is a rare phenomenon in this context, but outline a situation where it may be selected for.},
  author       = {Troein, Carl and Ahrén, Dag and Krogh, Morten and Peterson, Carsten},
  language     = {eng},
  number       = {9},
  publisher    = {ARRAY(0xace8de8)},
  series       = {PLoS ONE},
  title        = {Is Transcriptional Regulation of Metabolic Pathways and Optimal Strategy for Fitness?},
  url          = {http://dx.doi.org/10.1371/journal.pone.0000855},
  volume       = {2},
  year         = {2007},
}