| Title |
ppGpp-Mediated Stationary Phase Induction of the Genes Encoded by Horizontally Acquired Pathogenicity Islands and cob/pdu Locus in Salmonella enterica serovar Typhimurium |
| Author |
Miryoung Song1,2, Hyun-Ju Kim1,2, Sangryeol Ryu3, Hyunjin Yoon3, Jiae Yun3, and Hyon E. Choy1,2* |
| Address |
1Research Center for Enteropathogenic Bacteria and Research Institute of Vibrio Infection, Chonnam National University Medical College, Gwangju 501-746, Republic of Korea, 2Department of Microbiology, Chonnam National University Medical College, Gwangju 501-746, Republic of Korea, 3Department of Food and Animal Technology, School of Agricultural Biotechnology, Center for Agricultural Biomaterials, Seoul National University, Seoul 151-742, Republic of Korea |
| Bibliography |
Journal of Microbiology, 48(1),89-95, 2010,
|
| DOI |
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| Key Words |
Salmonella, ppGpp, microarray analysis, stationary phase, pathogenic genes, dksA |
| Abstract |
Salmonella enterica is highly diverse in terms of genome structure, which is at least partly due to the horizontal transfer of genetic elements from various sources. In this study, we examined the expression profiles of such genes in Salmonella Pathogenicity Islands (SPIs) and the cob/pdu locus, horizontally acquired large DNA segments, during growth under standard growth conditions. Transcripts from exponentially growing and early stationary phase Salmonellae were compared using various methods including cDNA microarray analysis. Nearly all genes encoded by SPIs and the cob/pdu locus were induced at the onset of the stationary phase in a stringent molecule ppGpp-dependent but stationary phase σ, σ38-independent manner. Although, it has been suggested that ppGpp acts in concert with DksA, we found the stationary phase induction of those SPI genes was not DksA dependent. It is suggested that ppGpp stimulates the expression of these stress-inducible genes encoded by horizontally acquired DNA, by itself or in concert with DksA. |
