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Mol Microbiol

Title:		Conservation of genes and processes controlled by the quorum response in bacteria: characterization of genes controlled by the quorum-sensing transcription factor ComA in Bacillus subtilis
Author(s):		Comella N; Grossman AD;
Address:		"Department of Biology, Building 68-530, Massachusetts Institute of Technology, Cambridge, MA 02139, USA"
Journal Title:		Mol Microbiol
Year:		2005
Volume:		57
Issue:		4
Page Number:		1159 - 1174
DOI:		10.1111/j.1365-2958.2005.04749.x
ISSN/ISBN:		0950-382X (Print) 0950-382X (Linking)
Abstract:		"Quorum or diffusion responses in bacteria are mediated by secreted signalling molecules that accumulate extracellularly as cultures grow to high density. The regulatory response to these signalling molecules can result in dramatic changes in gene expression. In Bacillus subtilis, a quorum response is mediated by a secreted 10-amino-acid modified peptide (ComX pheromone) that activates a receptor histidine kinase (ComP) that activates a response regulator transcription factor (ComA). We have used DNA microarrays to identify genes controlled by the ComX-ComP-ComA quorum-sensing pathway. We found that ComX, ComP and ComA affect the same set of genes, indicating that the kinase ComP is the only receptor for the signalling molecule ComX, and that ComA is the only transcription factor activated directly by ComP, under the conditions tested. Expression of over 20 genes appears to be controlled directly by this signalling pathway, and expression of over 150 additional genes, including those involved in competence development, appears to be controlled indirectly. The genes affected appear to have three general functions: (i) to co-ordinate physiological changes involved in developmental pathways, (ii) to produce extracellular products under conditions in which high concentrations of product are needed to be effective and (iii) to enhance survival, growth and colonization under conditions of crowding or limited diffusion. Many of the genes and processes controlled by the quorum response in B. subtilis are also regulated by quorum sensing in Gram-positive and Gram-negative bacteria. The quorum-sensing signalling molecules and regulatory proteins are quite different between Gram-positives and Gram-negatives and the convergent physiological regulation of similar genes and processes indicate the important and conserved nature of the quorum response"
Keywords:		"Arginine/biosynthesis Bacillus subtilis/*genetics Bacterial Proteins/genetics/*metabolism DNA-Binding Proteins/genetics/*metabolism Gene Expression Profiling *Gene Expression Regulation, Bacterial Genes, Bacterial/genetics Membrane Proteins/*metabolism Ol;"
Notes:		"MedlineComella, Natalia Grossman, Alan D eng Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. England 2005/08/11 Mol Microbiol. 2005 Aug; 57(4):1159-74. doi: 10.1111/j.1365-2958.2005.04749.x"