Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>species
<p>Abstract</p> <p>Background</p> <p>Small RNAs (sRNAs) are widespread among bacteria and have diverse regulatory roles. Most of these sRNAs have been discovered by a combination of computational and experimental methods. In <it>Pseudomonas aeruginosa</it>,...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2008-04-01
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| Series: | BMC Genomics |
| Online Access: | http://www.biomedcentral.com/1471-2164/9/167 |
| _version_ | 1818677562765737984 |
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| author | Kay Elisabeth Valverde Claudio Heeb Stephan González Nicolas Reimmann Cornelia Junier Thomas Haas Dieter |
| author_facet | Kay Elisabeth Valverde Claudio Heeb Stephan González Nicolas Reimmann Cornelia Junier Thomas Haas Dieter |
| author_sort | Kay Elisabeth |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Small RNAs (sRNAs) are widespread among bacteria and have diverse regulatory roles. Most of these sRNAs have been discovered by a combination of computational and experimental methods. In <it>Pseudomonas aeruginosa</it>, a ubiquitous Gram-negative bacterium and opportunistic human pathogen, the GacS/GacA two-component system positively controls the transcription of two sRNAs (RsmY, RsmZ), which are crucial for the expression of genes involved in virulence. In the biocontrol bacterium <it>Pseudomonas fluorescens </it>CHA0, three GacA-controlled sRNAs (RsmX, RsmY, RsmZ) regulate the response to oxidative stress and the expression of extracellular products including biocontrol factors. RsmX, RsmY and RsmZ contain multiple unpaired GGA motifs and control the expression of target mRNAs at the translational level, by sequestration of translational repressor proteins of the RsmA family.</p> <p>Results</p> <p>A combined computational and experimental approach enabled us to identify 14 intergenic regions encoding sRNAs in <it>P. aeruginosa</it>. Eight of these regions encode newly identified sRNAs. The intergenic region 1698 was found to specify a novel GacA-controlled sRNA termed RgsA. GacA regulation appeared to be indirect. In <it>P. fluorescens </it>CHA0, an RgsA homolog was also expressed under positive GacA control. This 120-nt sRNA contained a single GGA motif and, unlike RsmX, RsmY and RsmZ, was unable to derepress translation of the <it>hcnA </it>gene (involved in the biosynthesis of the biocontrol factor hydrogen cyanide), but contributed to the bacterium's resistance to hydrogen peroxide. In both <it>P. aeruginosa </it>and <it>P. fluorescens </it>the stress sigma factor RpoS was essential for RgsA expression.</p> <p>Conclusion</p> <p>The discovery of an additional sRNA expressed under GacA control in two <it>Pseudomonas </it>species highlights the complexity of this global regulatory system and suggests that the mode of action of GacA control may be more elaborate than previously suspected. Our results also confirm that several GGA motifs are required in an sRNA for sequestration of the RsmA protein.</p> |
| first_indexed | 2024-12-17T09:01:21Z |
| format | Article |
| id | doaj.art-b0e5313e1bf745a3bcff1f0b01c7fd37 |
| institution | Directory Open Access Journal |
| issn | 1471-2164 |
| language | English |
| last_indexed | 2024-12-17T09:01:21Z |
| publishDate | 2008-04-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Genomics |
| spelling | doaj.art-b0e5313e1bf745a3bcff1f0b01c7fd372022-12-21T21:55:43ZengBMCBMC Genomics1471-21642008-04-019116710.1186/1471-2164-9-167Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>speciesKay ElisabethValverde ClaudioHeeb StephanGonzález NicolasReimmann CorneliaJunier ThomasHaas Dieter<p>Abstract</p> <p>Background</p> <p>Small RNAs (sRNAs) are widespread among bacteria and have diverse regulatory roles. Most of these sRNAs have been discovered by a combination of computational and experimental methods. In <it>Pseudomonas aeruginosa</it>, a ubiquitous Gram-negative bacterium and opportunistic human pathogen, the GacS/GacA two-component system positively controls the transcription of two sRNAs (RsmY, RsmZ), which are crucial for the expression of genes involved in virulence. In the biocontrol bacterium <it>Pseudomonas fluorescens </it>CHA0, three GacA-controlled sRNAs (RsmX, RsmY, RsmZ) regulate the response to oxidative stress and the expression of extracellular products including biocontrol factors. RsmX, RsmY and RsmZ contain multiple unpaired GGA motifs and control the expression of target mRNAs at the translational level, by sequestration of translational repressor proteins of the RsmA family.</p> <p>Results</p> <p>A combined computational and experimental approach enabled us to identify 14 intergenic regions encoding sRNAs in <it>P. aeruginosa</it>. Eight of these regions encode newly identified sRNAs. The intergenic region 1698 was found to specify a novel GacA-controlled sRNA termed RgsA. GacA regulation appeared to be indirect. In <it>P. fluorescens </it>CHA0, an RgsA homolog was also expressed under positive GacA control. This 120-nt sRNA contained a single GGA motif and, unlike RsmX, RsmY and RsmZ, was unable to derepress translation of the <it>hcnA </it>gene (involved in the biosynthesis of the biocontrol factor hydrogen cyanide), but contributed to the bacterium's resistance to hydrogen peroxide. In both <it>P. aeruginosa </it>and <it>P. fluorescens </it>the stress sigma factor RpoS was essential for RgsA expression.</p> <p>Conclusion</p> <p>The discovery of an additional sRNA expressed under GacA control in two <it>Pseudomonas </it>species highlights the complexity of this global regulatory system and suggests that the mode of action of GacA control may be more elaborate than previously suspected. Our results also confirm that several GGA motifs are required in an sRNA for sequestration of the RsmA protein.</p>http://www.biomedcentral.com/1471-2164/9/167 |
| spellingShingle | Kay Elisabeth Valverde Claudio Heeb Stephan González Nicolas Reimmann Cornelia Junier Thomas Haas Dieter Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>species BMC Genomics |
| title | Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>species |
| title_full | Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>species |
| title_fullStr | Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>species |
| title_full_unstemmed | Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>species |
| title_short | Genome-wide search reveals a novel GacA-regulated small RNA in <it>Pseudomonas </it>species |
| title_sort | genome wide search reveals a novel gaca regulated small rna in it pseudomonas it species |
| url | http://www.biomedcentral.com/1471-2164/9/167 |
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