| Information Item | Value |
|---|---|
| Dataset Name | Affymetrix chips for pefloxacin induction |
| Dataset Number | 55 |
| Short Description | Affymetrix Expression Experiments showing effect of induction by pefloxacin. |
| Source URL | http://arep.med.harvard.edu/supercoiling/supplement.htm |
| Reference | Cheung, KJ, Badarinarayana,V, Selinger, D, Janse, D, and Church, GM (2002)A microarray-based antibiotic screen identifies a regulatory role for supercoiling in the osmotic stress response of Escherichia coli. Genome Research Feb;13(2):206-15. |
| Strains | NONE |
| Conditions | Contains replicates of two samples: 0 timepoint and 7 minutes post induction with pefloxacin, plus a single sample 1 minute post induction with pefloxacin. |
| Date Added to ExpressDB | Aug 10 2001 10:49:34:236AM |
| Number of Measures on ExpressDB | 60 (here to download dataset and view measure details) |
| Long Description | Changes in DNA supercoiling are induced by a wide range of environmental stresses in Escherichia coli, but the physiological significance of these responses remains unclear. We now demonstrate that an increase in negative supercoiling is necessary for transcriptional activation of a large subset of osmotic stress response genes. Using a microarray-based approach, we have characterized supercoiling-dependent gene transcription by expression profiling under conditions of high salt, in conjunction with microbial antibiotics novobiocin, pefloxacin, and chloramphenicol. Algorithmic clustering and statistical measures for gauging cellular function show that this subset is enriched for genes critical in osmoprotectant transport/synthesis and rpoS-driven stationary phase adaptation. Transcription factor binding site analysis also supports regulation by the global stress sigma factor rpoS. In addition, these studies implicate 60 uncharacterized genes in the osmotic stress regulon, and offer evidence for a broader role for supercoiling in the control of stress-induced transcription. Data Set loaded by Wayne |
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Copyright (c) 2006 by Wayne Rindone and the President and Fellows of Harvard University