Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coli

Abstract Transcription networks consist of hundreds of transcription factors with thousands of often overlapping target genes. While we can reliably measure gene expression changes, we still understand relatively little why expression changes the way it does. How does a coordinated response emerge i...

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Main Authors: Karl Kochanowski, Luca Gerosa, Simon F Brunner, Dimitris Christodoulou, Yaroslav V Nikolaev, Uwe Sauer
Format: Article
Language:English
Published: Springer Nature 2017-01-01
Series:Molecular Systems Biology
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Online Access:https://doi.org/10.15252/msb.20167402
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author Karl Kochanowski
Luca Gerosa
Simon F Brunner
Dimitris Christodoulou
Yaroslav V Nikolaev
Uwe Sauer
author_facet Karl Kochanowski
Luca Gerosa
Simon F Brunner
Dimitris Christodoulou
Yaroslav V Nikolaev
Uwe Sauer
author_sort Karl Kochanowski
collection DOAJ
description Abstract Transcription networks consist of hundreds of transcription factors with thousands of often overlapping target genes. While we can reliably measure gene expression changes, we still understand relatively little why expression changes the way it does. How does a coordinated response emerge in such complex networks and how many input signals are necessary to achieve it? Here, we unravel the regulatory program of gene expression in Escherichia coli central carbon metabolism with more than 30 known transcription factors. Using a library of fluorescent transcriptional reporters, we comprehensively quantify the activity of central metabolic promoters in 26 environmental conditions. The expression patterns were dominated by growth rate‐dependent global regulation for most central metabolic promoters in concert with highly condition‐specific activation for only few promoters. Using an approximate mathematical description of promoter activity, we dissect the contribution of global and specific transcriptional regulation. About 70% of the total variance in promoter activity across conditions was explained by global transcriptional regulation. Correlating the remaining specific transcriptional regulation of each promoter with the cell's metabolome response across the same conditions identified potential regulatory metabolites. Remarkably, cyclic AMP, fructose‐1,6‐bisphosphate, and fructose‐1‐phosphate alone explained most of the specific transcriptional regulation through their interaction with the two major transcription factors Crp and Cra. Thus, a surprisingly simple regulatory program that relies on global transcriptional regulation and input from few intracellular metabolites appears to be sufficient to coordinate E. coli central metabolism and explain about 90% of the experimentally observed transcription changes in 100 genes.
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spelling doaj-art-8836ea3be6c6490591a7408cefebd07e2025-08-20T03:06:10ZengSpringer NatureMolecular Systems Biology1744-42922017-01-0113111410.15252/msb.20167402Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coliKarl Kochanowski0Luca Gerosa1Simon F Brunner2Dimitris Christodoulou3Yaroslav V Nikolaev4Uwe Sauer5Institute of Molecular Systems Biology, ETH ZurichInstitute of Molecular Systems Biology, ETH ZurichInstitute of Molecular Systems Biology, ETH ZurichInstitute of Molecular Systems Biology, ETH ZurichInstitute of Molecular Biology & Biophysics, ETH ZurichInstitute of Molecular Systems Biology, ETH ZurichAbstract Transcription networks consist of hundreds of transcription factors with thousands of often overlapping target genes. While we can reliably measure gene expression changes, we still understand relatively little why expression changes the way it does. How does a coordinated response emerge in such complex networks and how many input signals are necessary to achieve it? Here, we unravel the regulatory program of gene expression in Escherichia coli central carbon metabolism with more than 30 known transcription factors. Using a library of fluorescent transcriptional reporters, we comprehensively quantify the activity of central metabolic promoters in 26 environmental conditions. The expression patterns were dominated by growth rate‐dependent global regulation for most central metabolic promoters in concert with highly condition‐specific activation for only few promoters. Using an approximate mathematical description of promoter activity, we dissect the contribution of global and specific transcriptional regulation. About 70% of the total variance in promoter activity across conditions was explained by global transcriptional regulation. Correlating the remaining specific transcriptional regulation of each promoter with the cell's metabolome response across the same conditions identified potential regulatory metabolites. Remarkably, cyclic AMP, fructose‐1,6‐bisphosphate, and fructose‐1‐phosphate alone explained most of the specific transcriptional regulation through their interaction with the two major transcription factors Crp and Cra. Thus, a surprisingly simple regulatory program that relies on global transcriptional regulation and input from few intracellular metabolites appears to be sufficient to coordinate E. coli central metabolism and explain about 90% of the experimentally observed transcription changes in 100 genes.https://doi.org/10.15252/msb.20167402metabolismmodelingnetwork inferencetranscription factorstranscriptional regulation
spellingShingle Karl Kochanowski
Luca Gerosa
Simon F Brunner
Dimitris Christodoulou
Yaroslav V Nikolaev
Uwe Sauer
Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coli
Molecular Systems Biology
metabolism
modeling
network inference
transcription factors
transcriptional regulation
title Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coli
title_full Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coli
title_fullStr Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coli
title_full_unstemmed Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coli
title_short Few regulatory metabolites coordinate expression of central metabolic genes in Escherichia coli
title_sort few regulatory metabolites coordinate expression of central metabolic genes in escherichia coli
topic metabolism
modeling
network inference
transcription factors
transcriptional regulation
url https://doi.org/10.15252/msb.20167402
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AT dimitrischristodoulou fewregulatorymetabolitescoordinateexpressionofcentralmetabolicgenesinescherichiacoli
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