Publication Date:
2013-08-09
Description:
The cyclic AMP (cAMP)-dependent catabolite repression effect in Escherichia coli is among the most intensely studied regulatory processes in biology. However, the physiological function(s) of cAMP signalling and its molecular triggers remain elusive. Here we use a quantitative physiological approach to show that cAMP signalling tightly coordinates the expression of catabolic proteins with biosynthetic and ribosomal proteins, in accordance with the cellular metabolic needs during exponential growth. The expression of carbon catabolic genes increased linearly with decreasing growth rates upon limitation of carbon influx, but decreased linearly with decreasing growth rate upon limitation of nitrogen or sulphur influx. In contrast, the expression of biosynthetic genes showed the opposite linear growth-rate dependence as the catabolic genes. A coarse-grained mathematical model provides a quantitative framework for understanding and predicting gene expression responses to catabolic and anabolic limitations. A scheme of integral feedback control featuring the inhibition of cAMP signalling by metabolic precursors is proposed and validated. These results reveal a key physiological role of cAMP-dependent catabolite repression: to ensure that proteomic resources are spent on distinct metabolic sectors as needed in different nutrient environments. Our findings underscore the power of quantitative physiology in unravelling the underlying functions of complex molecular signalling networks.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4038431/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4038431/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉You, Conghui -- Okano, Hiroyuki -- Hui, Sheng -- Zhang, Zhongge -- Kim, Minsu -- Gunderson, Carl W -- Wang, Yi-Ping -- Lenz, Peter -- Yan, Dalai -- Hwa, Terence -- R01 GM095903/GM/NIGMS NIH HHS/ -- England -- Nature. 2013 Aug 15;500(7462):301-6. doi: 10.1038/nature12446. Epub 2013 Aug 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, University of California at San Diego, La Jolla, California 92093-0374, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23925119" target="_blank"〉PubMed〈/a〉
Keywords:
Cyclic AMP/*metabolism
;
Escherichia coli/*genetics/*metabolism
;
Escherichia coli Proteins/*genetics/*metabolism
;
*Gene Expression Regulation, Bacterial
;
Models, Biological
;
*Proteome
;
*Signal Transduction
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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