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Series GSE9923 Query DataSets for GSE9923
Status Public on Jun 05, 2008
Title Indole cell signaling occurs primarily at low temperatures in Escherichia coli
Platform organisms Escherichia coli; Escherichia coli K-12
Sample organism Escherichia coli
Experiment type Expression profiling by array
Summary We have shown the quorum-sensing signals acylhomoserine lactones (AHLs), autoinducer-2 (AI-2), and indole influence the biofilm formation of Escherichia coli. Here, we investigate how the environment, i.e., temperature, affects indole and AI-2 signaling in E. coli. We show in biofilms that indole addition leads to more extensive differential gene expression at 30°C (186 genes) than at 37°C (59 genes), that indole reduces biofilm formation (without affecting growth) more significantly at 25°C and 30°C than at 37°C, and that the effect is associated with the quorum-sensing protein SdiA. The addition of indole at 30°C compared to 37°C most significantly repressed genes involved in uridine monophosphate (UMP) biosynthesis (carAB, pyrLBI, pyrC, pyrD pyrF, and upp) and uracil transport (uraA). These uracil-related genes are also repressed at 30°C by SdiA, which confirms SdiA is involved in indole signaling. Also, compared to 37°C, indole more significantly decreased flagella-related qseB, flhD, and fliA promoter activity, enhanced antibiotic resistance, and inhibited cell division at 30°C. In contrast to indole and SdiA, the addition of (S)-4,5-dihydroxy-2,3-pentanedione (the AI-2 precursor) leads to more extensive differential gene expression at 37°C (63 genes) than at 30°C (11 genes), and, rather than repressing UMP synthesis genes, AI-2 induces them at 37°C (but not at 30°C). Also, the addition of AI-2 induces the transcription of virulence genes in enterohemorrhagic E. coli O157:H7 at 37°C but not at 30°C. Hence, cell signals cause diverse responses at different temperatures, and indole- and AI-2-based signaling are intertwined.
 
Overall design We performed seven sets of microarray experiments in LB medium (Table 2): (i) biofilm cells of the BW25113 wild-type strain grown for 7 h at 30°C vs. 37°C to determine the effect of temperature on E. coli biofilm formation (initial absorbance of 0.05), (ii) biofilm cells of the tnaA mutant grown for 7 h with 1 mM indole vs. no indole at 30°C to determine the effect of temperature on indole signaling in E. coli (initial absorbance of 0.05), (iii) biofilm cells of the tnaA mutant grown for 7 h with 1 mM indole vs. no indole at 37°C to determine the effect of temperature on indole signaling in E. coli, (iv) suspension cells of the wild-type strain vs. the sdiA mutant at an absorbance of 4.0 at 600 nm at 30°C (since production of indole takes place primarily in the stationary phase) to discern the genes that SdiA controls (initial absorbance of 0.05), (v) biofilm cells of the sdiA mutant grown for 7 h with 1 mM indole vs. no indole at 30°C to determine gene expression in response to indole in the absence of SdiA, (vi) suspension cells of the luxS mutant with 100 micro M AI-2 vs. no AI-2 at 30°C for 3 h to determine the effect of temperature on AI-2 signaling in E. coli (initial absorbance of 0.5), and (vii) suspension cells of the luxS mutant with 100 micro M AI-2 vs. no AI-2 at 37°C for 3 h to determine the effect of temperature on AI-2 signaling in E. coli. Ten g of glass wool (Corning Glass Works, Corning, N.Y.) was used to form large amounts of biofilms (Ren et al., 2004a) in 250 mL LB in 1 L Erlenmeyer shake flasks. RNA was isolated from the suspension and biofilm cells as described previously (Ren et al., 2004b).
 
Contributor(s) Zhang X, Lee J, Wood TK
Citation(s) 18528414
Submission date Dec 19, 2007
Last update date Mar 08, 2019
Contact name Thomas K. Wood
E-mail(s) twood@engr.psu.edu
Phone 814-863-4811
Organization name Pennsylvania State University
Department Chemical Engineering & Biochemistry and Molecular Biology
Lab Dr. Wood's Lab
Street address Room 161 Fenske Laboratory, University Park
City State College
State/province PA
ZIP/Postal code 16802
Country USA
 
Platforms (2)
GPL199 [Ecoli_ASv2] Affymetrix E. coli Antisense Genome Array
GPL3154 [E_coli_2] Affymetrix E. coli Genome 2.0 Array
Samples (14)
GSM247664 BW25113 w/t LB 30C OD 4.0 free-living cells
GSM247665 BW25113 sdiA LB 30C OD 4.0 free-living cells
GSM247666 BW25113 luxS LB 30C free-living cells no AI2 for 3h
Relations
BioProject PRJNA103923

Download family Format
SOFT formatted family file(s) SOFTHelp
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Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE9923_RAW.tar 17.2 Mb (http)(custom) TAR (of CEL, CHP)
SRA Run SelectorHelp
Raw data provided as supplementary file
Processed data included within Sample table
Processed data provided as supplementary file

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