Influence of mutations in genes of global transcriptional regulators on production of autoinducer AI-2 in the Escherichia coli Quorum Sensing system

• Published in: Russian journal of genetics 2008-09, Vol.44 (9), p.1031-1036
• Main Authors: Belik, A. S., Zavil’gel’skii, G. B., Khmel, I. A.
• Format: Article
• Language: English
• Subjects: Animal Genetics and Genomics; Biomedical and Life Sciences; Biomedicine; Escherichia coli; Genetics of Microorganisms; Human Genetics; Microbial Genetics and Genomics
• ISSN: 1022-7954; 1608-3369
• DOI: 10.1134/S1022795408090044

The control of gene expression in response to an increase in the bacterial population density (Quorum Sensing) involves low-molecular-weight signal molecules (autoinducers, AI). AI-2 and synthase LuxS mediating its synthesis are widely distributed in Gram-negative and Gram-positive bacteria. In this work, the data were obtained on the role of global regulators of gene expression in AI-2 synthesis in Escherichia coli cells. The mutation inactivating gene rpoS (encodes sigma S subunit of RNA polymerase) was shown to drastically decrease an amount of active AI-2 in the culture medium. Mutations in gene rpoN that encodes sigma N subunit of RNA polymerase and also in gene lon , which encodes Lon proteinase, on the contrary, increase an amount of active AI-2 in supernatants of cultures. Mutant strains lacking histone-like proteins H-NS and StpA accumulate a slightly higher amount of AI-2 than the isogenic wild-type strain: however, an amount of AI-2 decreased in the culture medium of the double mutant devoid of both these proteins.