Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Transcription profiling of Dictyostelium discoideum wild type and dupA null after infection with Legionella pneumophila

ABSTRACT: The social amoeba Dictyostelium discoideum is vulnerable to infection by the pathogen that causes Legionnaire's Disease, Legionella pneumophila. Dictystelium cells lacking the dual-specificity phospahatase DupA are at least partially resistant to infection, and strikingly the expression profile of uninfected dupA null cells mirrors the profile of infected wild-type cells to a considerable extent. This suggests that DupA has a key role in regulating host defence systems.

ORGANISM(S): Dictyostelium discoideum

SUBMITTER: Gareth Bloomfield

PROVIDER: E-TABM-509 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

The amoebal MAP kinase response to Legionella pneumophila is regulated by DupA.

Li Zhiru Z Dugan Aisling S AS Bloomfield Gareth G Skelton Jason J Ivens Alasdair A Losick Vicki V Isberg Ralph R RR

Cell host & microbe 20090901 3

The amoeba Dictyostelium discoideum can support replication of Legionella pneumophila. Here we identify the dupA gene, encoding a putative tyrosine kinase/dual-specificity phosphatase, in a screen for D. discoideum mutants altered in allowing L. pneumophila intracellular replication. Inactivation of dupA resulted in depressed L. pneumophila growth and sustained hyperphosphorylation of the amoebal MAP kinase ERK1, consistent with loss of a phosphatase activity. Bacterial challenge of wild-type am ...[more]

PMID: 19748467

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Project description:Bacterial competence is a genetically programmed process that is triggered as a response to environmental stimuli. DNA uptake from the extracellular milieu by competence requires the expression of a complex machinery composed of a competence pseudopilus and a DNA translocase. In L. pneumophila, it has been reported that microaerophilic conditions and genetic alteration of the competence repressors ComR and ProQ result in competence. We have analyzed the gene expression profiles of the proQ and comR mutants using the L. pneumophila Philadelphia-1 microarray. Many competence genes were found to be induced in the comR and proQ mutants and represent a defined, regulon. The gene expression profiling of the proQ and comR mutants was part of a study aimed at understanding the function of the processive 3'-5' exoribonuclease RNase R (rnr gene) in L. pneumophila. We found that the gene expression profile of the rnr mutant shares similarities with the gene expression profiles of the comR and proQ mutants and that loss of the exoribonuclease activity of RNase R was sufficient to induce competence development. RNase R is a processive 3'-5' exoribonuclease with a high degree of conservation in prokaryotes. Although some bacteria possess additional hydrolytic 3Â´-5-exoribonucleases such as RNase II, RNase R was found to be the only one predicted in the Legionella pneumophila genome. This provided a unique opportunity to study the role of RNase R in the absence of an additional RNase with similar enzymatic activity. We investigated the role of RNase R in the biology of Legionella pneumophila under various conditions and performed gene expression profiling using microarrays. At optimal growth temperature, loss of RNase R had no major consequence on bacterial growth and had a moderate impact on normal gene regulation. However, at lower temperatures loss of RNase R has a significant impact on bacterial growth and resulted in the accumulation of structured RNA degradation products. Concurrently, gene regulation was affected and specifically resulted in increased expression of the competence regulon. Loss of the exoribonuclease activity of RNase R was sufficient to induce competence development, a genetically-programmed process normally triggered as a response to environmental stimuli. Temperature-dependent expression of competence genes in the rnr mutant was found to be independent of the previously identified competence regulators comR and ProQ. comR: Three test samples and three reference samples were analyzed. The test sample being the strain KS79, a comR mutant of L. pneumophila strain JR32 which is used as a reference. proQ: Three test samples and three reference samples were analyzed. The test sample being the strain LELA3825, a proQ mutant of L. pneumophila strain JR32 which is used as a reference. rnr: Six test samples and six reference samples grown at 30Â°C or 37Â°C were analyzed. The test sample being the strain LELA559, a rnr mutant of L. pneumophila strain JR32 which is used as a reference.

Dataset Information

Transcription profiling of Dictyostelium discoideum wild type and dupA null after infection with Legionella pneumophila

Publications

The amoebal MAP kinase response to Legionella pneumophila is regulated by DupA.

Similar Datasets

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