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Lookup NU author(s): Jan Kampf,
Dr Robert Cleverley,
Professor Rick Lewis
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Biofilm formation by Bacillus subtilis requires the expression of genes encoding enzymes forextracellular polysaccharide synthesis and for an amyloid-like protein. The master regulator SinRrepresses all the corresponding genes, and repression of these key biofilm genes is lifted when SinRinteracts with its cognate antagonist proteins. The YmdB phosphodiesterase is a recently discoveredfactor that is involved in the control of SinR activity: cells lacking YmdB exhibit hyperactive SinR andare unable to relieve the repression of the biofilm genes. In this study, we have examined thedynamics of gene expression patterns in wild type and ymdB mutant cells by microfluidic analysiscoupled to time-lapse microscopy. Our results confirm the bistable expression pattern for motilityand biofilm genes in the wild type strain, and the loss of biofilm gene expression in the mutant.Moreover, we demonstrate dynamic behavior in subpopulations of the wild type strain that ischaracterized by switches in sets of the expressed genes. In order to gain further insights into therole of YmdB, we isolated a set of spontaneous suppressor mutants derived from ymdB mutants thathad regained the ability to form complex colonies and biofilms. Interestingly, all of the mutationsaffected SinR. In some mutants, large genomic regions encompassing sinR were deleted whereasothers had alleles encoding SinR variants. Functional and biochemical studies with these SinRvariants revealed how these proteins allowed biofilm gene expression in the ymdB mutant strains.
Author(s): Kampf J, Gerwig J, Kruse K, Cleverley R, Dormeyer M, Grünberger A, Kohlheyer D, Commichau FM, Lewis RJ, Stülke J
Publication type: Article
Publication status: Published
Online publication date: 04/09/2018
Acceptance date: 30/07/2018
Date deposited: 31/07/2018
ISSN (print): 2161-2129
ISSN (electronic): 2150-7511
Publisher: American Society for Microbiology
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