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Phosphatases modulate the bistable sporulation gene expression pattern in Bacillus subtilis
Author(s) -
Veening JanWillem,
Hamoen Leendert W.,
Kuipers Oscar P.
Publication year - 2005
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2005.04659.x
Subject(s) - biology , bacillus subtilis , phosphatase , mutant , bistability , microbiology and biotechnology , quorum sensing , phenotype , gene expression , gene , genetics , bacteria , phosphorylation , virulence , physics , quantum mechanics
Summary Spore formation in the Gram‐positive bacterium Bacillus subtilis is a last resort adaptive response to starvation. To initiate sporulation, the key regulator in this process, Spo0A, needs to be activated by the so‐called phosphorelay. Within a sporulating culture of B. subtilis , some cells initiate this developmental program, while other cells do not. Therefore, initiation of sporulation appears to be a regulatory process with a bistable outcome. Using a single cell analytical approach, we show that the autostimulatory loop of spo0A is responsible for generating a bistable response resulting in phenotypic variation within the sporulating culture. It is demonstrated that the main function of RapA, a phosphorelay phosphatase, is to maintain the bistable sporulation gene expression. As rapA expression is quorum regulated, it follows that quorum sensing influences sporulation bistability. Deletion of spo0E , a phosphatase directly acting on Spo0A∼P, resulted in abolishment of the bistable expression pattern. Artificial induction of a heterologous Rap phosphatase restored heterogeneity in a rapA or spo0E mutant. These results demonstrate that with external phosphatases, B. subtilis can use the phosphorelay as a tuner to modulate the bistable outcome of the sporulating culture. This shows that B. subtilis employs multiple pathways to maintain the bistable nature of a sporulating culture, stressing the physiological importance of this phenomenon.