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E-GEOD-33244 - Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa [LB]

Status
Released on 31 March 2012, last updated on 11 April 2012
Organism
Pseudomonas aeruginosa, Pseudomonas aeruginosa PAO1
Samples (8)
Array (1)
Protocols (7)
Description
The opportunistic human pathogen Pseudomonas aeruginosa can utilize several carbon and nitrogen compounds as energy sources, which allows the bacterium to grow on a variety of different environments. Nevertheless, the uptake and utilization of these compounds is organized in a hierarchical manner, which is guaranteed by a mechanism named catabolite repression. In P. aeruginosa catabolite repression is a post-transcriptional process with the translational repressor protein, Crc, as the main component. Crc recognizes CA-motifs (acronym for catabolite activity) present in the vicinity of the ribosome binfing site of corresponding target mRNAs and therefore compete with ribosome binding. Certain conditions, which are mainly related to changes in the carbon to nitrogen ratio, induce the two component system CbrAB, which activates the transcription of the sRNA CrcZ. The sRNA sequesters Crc and allows the translation of the target mRNAs. The main focus of this study was to identify novel direct targets of the CbrAB/Crc system with the use of a transcriptome analysis in combination with the search for CA-motifs. We were able to identify five novel targets (estA, acsA, dctP, bkdR and aroP2), which were involved in the uptake and utilization of less preferred carbon sources and amino acids. Direct interaction of Crc with these genes and the resulting regulation by CbrB and CrcZ were verified using mutational analysis and in vitro and in vivo experiments. Moreover, these targets were discussed in the light of growth and biofilm development in synthetic CF sputum medium which emphasised the importance of the CbrAB/Crc system as a regulator of chronic infection. Comparative transcriptome analysis with the PAO1 wild type strain and PAO6673 (delta crc), PAO66711 (delta cbrB), PAO6679 (delta crcZ) strains grown in LB medium.
Experiment type
transcription profiling by array 
Contacts
Sylvain Pradervand <Sylvain.Pradervand@unil.ch>, Haas Dieter, Haichar Feth El Zahare, Lapouge Karine, Sonnleitner Elisabeth, Valentini Martina, Wenner Nicolas
MIAME
PlatformsProtocolsVariablesProcessedRaw
Files
Investigation descriptionE-GEOD-33244.idf.txt
Sample and data relationshipE-GEOD-33244.sdrf.txt
Raw data (1)E-GEOD-33244.raw.1.zip
Processed data (1)E-GEOD-33244.processed.1.zip
Array designA-AFFY-30.adf.txt
R ExpressionSetE-GEOD-33244.eSet.r
Links