Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon
Background The ferric uptake regulator (Fur) is a transcription factor and the main regulator of iron acquisition in prokaryotes. When bound to ferric iron, Fur recognizes its DNA binding site and generally executes its function by repressing transcription of its target genes. Due to its importance...
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PeerJ Inc.
2017-07-01
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| Online Access: | https://peerj.com/articles/3461.pdf |
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| author | Sunniva Katharina Thode Cecilie Bækkedal Jenny Johansson Söderberg Erik Hjerde Hilde Hansen Peik Haugen |
| author_facet | Sunniva Katharina Thode Cecilie Bækkedal Jenny Johansson Söderberg Erik Hjerde Hilde Hansen Peik Haugen |
| author_sort | Sunniva Katharina Thode |
| collection | DOAJ |
| description | Background The ferric uptake regulator (Fur) is a transcription factor and the main regulator of iron acquisition in prokaryotes. When bound to ferric iron, Fur recognizes its DNA binding site and generally executes its function by repressing transcription of its target genes. Due to its importance in virulence, the Fur regulon is well studied for several model bacteria. In our previous work, we used computational predictions and microarray to gain insights into Fur-regulation in Aliivibrio salmonicida, and have identified a number of genes and operons that appear to be under direct control of Fur. To provide a more accurate and deeper global understanding of the biological role of Fur we have now generated an A. salmonicida fur knock-out strain and used RNA-sequencing to compare gene expression between the wild-type and fur null mutant strains. Results An A. salmonicida fur null mutant strain was constructed. Biological assays demonstrate that deletion of fur results in loss of fitness, with reduced growth rates, and reduced abilities to withstand low-iron conditions, and oxidative stress. When comparing expression levels in the wild-type and the fur null mutant we retrieved 296 differentially expressed genes distributed among 18 of 21 functional classes of genes. A gene cluster encoding biosynthesis of the siderophore bisucaberin represented the highest up-regulated genes in the fur null mutant. Other highly up-regulated genes all encode proteins important for iron acquisition. Potential targets for the RyhB sRNA was predicted from the list of down-regulated genes, and significant complementarities were found between RyhB and mRNAs of the fur, sodB, cysN and VSAL_I0422 genes. Other sRNAs with potential functions in iron homeostasis were identified. Conclusion The present work provides by far the most comprehensive and deepest understanding of the Fur regulon in A. salmonicida to date. Our data also contribute to a better understanding of how Fur plays a key role in iron homeostasis in bacteria in general, and help to show how Fur orchestrates iron uptake when iron levels are extremely low. |
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| language | English |
| last_indexed | 2024-03-09T06:35:10Z |
| publishDate | 2017-07-01 |
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| spelling | doaj.art-6bcc82e79fbd44d7aa34b013a7e60aa62023-12-03T10:58:47ZengPeerJ Inc.PeerJ2167-83592017-07-015e346110.7717/peerj.3461Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulonSunniva Katharina Thode0Cecilie Bækkedal1Jenny Johansson Söderberg2Erik Hjerde3Hilde Hansen4Peik Haugen5Department of Chemistry and The Norwegian Structural Biology Centre, Faculty of Science and Technology, UiTThe Arctic University of Norway, Tromsø, NorwayDepartment of Chemistry and The Norwegian Structural Biology Centre, Faculty of Science and Technology, UiTThe Arctic University of Norway, Tromsø, NorwayDepartment of Chemistry and The Norwegian Structural Biology Centre, Faculty of Science and Technology, UiTThe Arctic University of Norway, Tromsø, NorwayDepartment of Chemistry and The Norwegian Structural Biology Centre, Faculty of Science and Technology, UiTThe Arctic University of Norway, Tromsø, NorwayDepartment of Chemistry and The Norwegian Structural Biology Centre, Faculty of Science and Technology, UiTThe Arctic University of Norway, Tromsø, NorwayDepartment of Chemistry and The Norwegian Structural Biology Centre, Faculty of Science and Technology, UiTThe Arctic University of Norway, Tromsø, NorwayBackground The ferric uptake regulator (Fur) is a transcription factor and the main regulator of iron acquisition in prokaryotes. When bound to ferric iron, Fur recognizes its DNA binding site and generally executes its function by repressing transcription of its target genes. Due to its importance in virulence, the Fur regulon is well studied for several model bacteria. In our previous work, we used computational predictions and microarray to gain insights into Fur-regulation in Aliivibrio salmonicida, and have identified a number of genes and operons that appear to be under direct control of Fur. To provide a more accurate and deeper global understanding of the biological role of Fur we have now generated an A. salmonicida fur knock-out strain and used RNA-sequencing to compare gene expression between the wild-type and fur null mutant strains. Results An A. salmonicida fur null mutant strain was constructed. Biological assays demonstrate that deletion of fur results in loss of fitness, with reduced growth rates, and reduced abilities to withstand low-iron conditions, and oxidative stress. When comparing expression levels in the wild-type and the fur null mutant we retrieved 296 differentially expressed genes distributed among 18 of 21 functional classes of genes. A gene cluster encoding biosynthesis of the siderophore bisucaberin represented the highest up-regulated genes in the fur null mutant. Other highly up-regulated genes all encode proteins important for iron acquisition. Potential targets for the RyhB sRNA was predicted from the list of down-regulated genes, and significant complementarities were found between RyhB and mRNAs of the fur, sodB, cysN and VSAL_I0422 genes. Other sRNAs with potential functions in iron homeostasis were identified. Conclusion The present work provides by far the most comprehensive and deepest understanding of the Fur regulon in A. salmonicida to date. Our data also contribute to a better understanding of how Fur plays a key role in iron homeostasis in bacteria in general, and help to show how Fur orchestrates iron uptake when iron levels are extremely low.https://peerj.com/articles/3461.pdfAliivibrio salmonicidaFurGene dosage effectSmall regulatory RNAssRNAsRyhB |
| spellingShingle | Sunniva Katharina Thode Cecilie Bækkedal Jenny Johansson Söderberg Erik Hjerde Hilde Hansen Peik Haugen Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon PeerJ Aliivibrio salmonicida Fur Gene dosage effect Small regulatory RNAs sRNAs RyhB |
| title | Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon |
| title_full | Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon |
| title_fullStr | Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon |
| title_full_unstemmed | Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon |
| title_short | Construction of a fur null mutant and RNA-sequencing provide deeper global understanding of the Aliivibrio salmonicida Fur regulon |
| title_sort | construction of a fur null mutant and rna sequencing provide deeper global understanding of the aliivibrio salmonicida fur regulon |
| topic | Aliivibrio salmonicida Fur Gene dosage effect Small regulatory RNAs sRNAs RyhB |
| url | https://peerj.com/articles/3461.pdf |
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