Small RNA-dependent expression of secondary metabolism is controlled by Krebs cycle function in Pseudomonas fluorescens. Export

@article{citeulike:6014756, abstract = {Pseudomonas fluorescens CHA0, an antagonist of phytopathogenic fungi in the rhizosphere of crop plants, elaborates and excretes several secondary metabolites with antibiotic properties. Their synthesis depends on three small RNAs (RsmX, RsmY, RsmZ) whose expression is positively controlled by the GacS-GacA two-component system at high cell population densities. To find regulatory links between primary and secondary metabolism in P. fluorescens and in the related species Pseudomonas aeruginosa, we searched for null mutations that affected central carbon metabolism as well as the expression of rsmY-gfp and rsmZ-gfp reporter constructs, however, without slowing down the growth rate in rich media. Mutation in the pycAB genes (for pyruvate carboxylase) led to down-regulation of rsmXYZ and secondary metabolism, whereas mutation in fumA (for a fumarase isoenzyme) resulted in up-regulation of the three small RNAs and secondary metabolism, in the absence of detectable nutrient limitation. These effects required the GacS sensor kinase, but not the accessory sensors RetS and LadS. An analysis of intracellular metabolites in P. fluorescens revealed a strong positive correlation between small RNA expression and the pools of 2-oxoglutarate, succinate and fumarate. We conclude that Krebs cycle intermediates (already known to control GacA-dependent virulence factors in P. aeruginosa) exert a critical trigger function in secondary metabolism via the expression of GacA-dependent small RNAs.}, author = {Takeuchi, Kasumi and Kiefer, Patrick and Reimmann, Cornelia and Keel, Christoph and Dubuis, Christophe and Rolli, Jo\"{e}lle and Vorholt, Julia A. and Haas, Dieter}, citeulike-article-id = {6014756}, citeulike-linkout-0 = {http://dx.doi.org/10.1074/jbc.M109.052571}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19840935}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19840935}, day = {19}, doi = {10.1074/jbc.M109.052571}, issn = {1083-351X}, journal = {The Journal of biological chemistry}, keywords = {cycle, expression, fluorescens, krebs, metabolism, pseudomonas, rna, secondary, small, srna}, month = {October}, posted-at = {2009-10-27 09:13:10}, priority = {2}, title = {Small RNA-dependent expression of secondary metabolism is controlled by Krebs cycle function in Pseudomonas fluorescens.}, url = {http://dx.doi.org/10.1074/jbc.M109.052571}, year = {2009} }

TY - JOUR ID - citeulike:6014756 L3 - citeulike-article-id:6014756 N2 - Pseudomonas fluorescens CHA0, an antagonist of phytopathogenic fungi in the rhizosphere of crop plants, elaborates and excretes several secondary metabolites with antibiotic properties. Their synthesis depends on three small RNAs (RsmX, RsmY, RsmZ) whose expression is positively controlled by the GacS-GacA two-component system at high cell population densities. To find regulatory links between primary and secondary metabolism in P. fluorescens and in the related species Pseudomonas aeruginosa, we searched for null mutations that affected central carbon metabolism as well as the expression of rsmY-gfp and rsmZ-gfp reporter constructs, however, without slowing down the growth rate in rich media. Mutation in the pycAB genes (for pyruvate carboxylase) led to down-regulation of rsmXYZ and secondary metabolism, whereas mutation in fumA (for a fumarase isoenzyme) resulted in up-regulation of the three small RNAs and secondary metabolism, in the absence of detectable nutrient limitation. These effects required the GacS sensor kinase, but not the accessory sensors RetS and LadS. An analysis of intracellular metabolites in P. fluorescens revealed a strong positive correlation between small RNA expression and the pools of 2-oxoglutarate, succinate and fumarate. We conclude that Krebs cycle intermediates (already known to control GacA-dependent virulence factors in P. aeruginosa) exert a critical trigger function in secondary metabolism via the expression of GacA-dependent small RNAs. JF - The Journal of biological chemistry SN - 1083-351X TI - Small RNA-dependent expression of secondary metabolism is controlled by Krebs cycle function in Pseudomonas fluorescens. KW - cycle KW - expression KW - fluorescens KW - krebs KW - metabolism KW - pseudomonas KW - rna KW - secondary KW - small KW - srna AU - Takeuchi, Kasumi AU - Kiefer, Patrick AU - Reimmann, Cornelia AU - Keel, Christoph AU - Dubuis, Christophe AU - Rolli, Joëlle AU - Vorholt, Julia AU - Haas, Dieter PY - 2009/10/19/ UR - http://dx.doi.org/10.1074/jbc.M109.052571 ER -