Alternative sigma factor σH activates competence gene expression in Lactobacillus sakei

BMC Microbiology

Research Article

Claudia Bevilacqua¹  Anne-Marie Crutz-Le Coq²  Solveig Schmid³ 

[1] UMR1313 Génétique Animale et Biologie Intégrative, plateforme ICE, Jouy-en-Josas, F-78350, INRA, France;UMR1319 Micalis, INRA, Jouy-en-Josas, F-78350, France;UMR1319 Micalis, INRA, Jouy-en-Josas, F-78350, France;UMR Micalis, AgroParisTech, Jouy-en-Josas, F-78350, INRA, France;Conceptus SAS, 50 avenue de Saint Cloud, F-78000, Versailles, France;

关键词: Lactobacillus;    Sigma Factor;    Competence Gene;    lacZ Reporter Gene;    Alternative Sigma Factor;   

DOI  :  10.1186/1471-2180-12-32

 received in 2011-06-08, accepted in 2012-03-12,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundAlternative sigma factors trigger various adaptive responses. Lactobacillus sakei, a non-sporulating meat-borne bacterium, carries an alternative sigma factor seemingly orthologous to σH of Bacillus subtilis, best known for its contribution to the initiation of a large starvation response ultimately leading to sporulation. As the role of σH-like factors has been little studied in non-sporulating bacteria, we investigated the function of σH in L. sakei.ResultsTranscription of sigH coding for σH was hardly affected by entry into stationary phase in our laboratory conditions. Twenty-five genes potentially regulated by σH in L. sakei 23 K were revealed by genome-wide transcriptomic profiling of sigH overexpression and/or quantitative PCR analysis. More than half of them are involved in the synthesis of a DNA uptake machinery linked to genetic competence, and in DNA metabolism; however, σH overproduction did not allow detectable genetic transformation. σH was found to be conserved in the L. sakei species.ConclusionOur results are indicative of the existence of a genetic competence state activated by σH in L. sakei, and sustain the hypothesis that σH-like factors in non sporulating Firmicutes share this common function with the well-known ComX of naturally transformable streptococci.

【 授权许可】

Unknown   
© Schmid et al; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.