Background: Gene regulation networks are made of recurring regulatory patterns, called network motifs. One of the most common network motifs is negative auto-regulation, in which a transcription factor represses its own production. Negative auto-regulation has several potential functions: it can shorten the response time (time to reach halfway to steady-state), stabilize expression against noise, and linearize the gene's input-output response curve. This latter function of negative auto-regulation, which increases the range of input signals over which downstream genes respond, has been studied by theory and synthetic gene circuits. Here we ask whether negative auto-regulation preserves this function also in the context of a natural system, where it is embedded within many additional interactions. To address this, we studied the negative auto-regulation motif in the arabinose utilization system of Escherichia coli, in which negative auto-regulation is part of a complex regulatory network.
Results: We find that when negative auto-regulation is disrupted by placing the regulator araC under constitutive expression, the input dynamic range of the arabinose system is reduced by 10-fold. The apparent Hill coefficient of the induction curve changes from about n = 1 with negative auto-regulation, to about n = 2 when it is disrupted. We present a mathematical model that describes how negative auto-regulation can increase input dynamic-range, by coupling the transcription factor protein level to the input signal.
Conclusions: Here we demonstrate that the negative auto-regulation motif in the native arabinose system of Escherichia coli increases the range of arabinose signals over which the system can respond. In this way, negative auto-regulation may help to increase the input dynamic-range while maintaining the specificity of cooperative regulatory systems. This function may contribute to explaining the common occurrence of negative auto-regulation in biological systems.
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http://dx.doi.org/10.1186/1752-0509-5-111 | DOI Listing |
Genome Res
January 2025
Whitehead Institute, Cambridge, Massachusetts 02142, USA;
The Y-linked gene and its X-linked homolog survived the evolution of the human sex chromosomes from ordinary autosomes. encodes a multifunctional RNA helicase, with mutations causing developmental disorders and cancers. We find that, among X-linked genes with surviving Y homologs, is extraordinarily dosage sensitive.
View Article and Find Full Text PDFbioRxiv
July 2024
Whitehead Institute, Cambridge, MA 02142, USA.
Synth Syst Biotechnol
September 2024
School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China.
In industrial fermentation processes, microorganisms often encounter acid stress, which significantly impact their productivity. This study focused on the acid-resistant module composed of small RNA (sRNA) DsrA and the sRNA chaperone Hfq. Our previous study had shown that this module improved the cell growth of MG1655 at low pH, but failed to obtain this desired phenotype in industrial strains.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
December 2021
Bioimaging Laboratory, Bioengineering Department, University of Louisville, Louisville, KY 40292, USA.
Objectives: Both stress and hypertension (HTN) are considered major health problems that negatively impact the cerebral vasculature. In this article we summarize the possible relationship between stress and HTN.
Methods: We conducted a systematic review of the literature using a database search of MEDLINE, PubMed, Scopus, and Web of Science.
Plant Biol (Stuttg)
May 2021
Plant Genomics and Breeding Center, Eliseu Maciel School of Agronomy, Federal University of Pelotas, Pelotas-RS, Brazil.
Rice is vital for food security. Due to its tropical origin, rice suffers from cold temperatures that affect its entire life cycle. Key genes have been identified involved in cold tolerance.
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