Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA.
Many Gram-negative pathogens possess virulence-related type III secretion systems. Salmonella enterica uses two of these systems, encoded on the pathogenicity islands SPI-1 and SPI-2, respectively, to translocate more than 30 effector proteins into eukaryotic host cells. SteA is one of the few effec...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2011-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3203157?pdf=render |
| _version_ | 1819123071941869568 |
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| author | Elena Cardenal-Muñoz Francisco Ramos-Morales |
| author_facet | Elena Cardenal-Muñoz Francisco Ramos-Morales |
| author_sort | Elena Cardenal-Muñoz |
| collection | DOAJ |
| description | Many Gram-negative pathogens possess virulence-related type III secretion systems. Salmonella enterica uses two of these systems, encoded on the pathogenicity islands SPI-1 and SPI-2, respectively, to translocate more than 30 effector proteins into eukaryotic host cells. SteA is one of the few effectors that can be translocated by both systems. We investigated the conditions affecting the synthesis of this effector, its secretion to culture media and its translocation into host cells. Whereas steA was expressed under a wide range of conditions, some factors, including low and high osmolarity, and presence of butyrate, decreased expression. SteA was efficiently secreted to the culture media under both SPI-1 and SPI-2 inducing conditions. The kinetics of translocation into murine macrophages and human epithelial cells was studied using fusions with the 3xFLAG tag, and fusions with CyaA from Bordetella pertussis. Translocation into macrophages under non-invasive conditions was mainly dependent on the SPI-2-encoded type III secretion system but some participation of the SPI-1 system was also detected 6 hours post-infection. Interestingly, both type III secretion systems had a relevant role in the translocation of SteA into epithelial cells. Finally, a deletion approach allowed the identification of the N-terminal signal necessary for translocation of this effector. The amino acid residues 1-10 were sufficient to direct translocation into host cells through both type III secretion systems. Our results provide new examples of functional overlapping between the two type III secretion systems of Salmonella. |
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| id | doaj.art-f3f0ddc770654e1791a7b0b6a74ba28a |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-22T07:02:32Z |
| publishDate | 2011-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-f3f0ddc770654e1791a7b0b6a74ba28a2022-12-21T18:34:46ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-01610e2693010.1371/journal.pone.0026930Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA.Elena Cardenal-MuñozFrancisco Ramos-MoralesMany Gram-negative pathogens possess virulence-related type III secretion systems. Salmonella enterica uses two of these systems, encoded on the pathogenicity islands SPI-1 and SPI-2, respectively, to translocate more than 30 effector proteins into eukaryotic host cells. SteA is one of the few effectors that can be translocated by both systems. We investigated the conditions affecting the synthesis of this effector, its secretion to culture media and its translocation into host cells. Whereas steA was expressed under a wide range of conditions, some factors, including low and high osmolarity, and presence of butyrate, decreased expression. SteA was efficiently secreted to the culture media under both SPI-1 and SPI-2 inducing conditions. The kinetics of translocation into murine macrophages and human epithelial cells was studied using fusions with the 3xFLAG tag, and fusions with CyaA from Bordetella pertussis. Translocation into macrophages under non-invasive conditions was mainly dependent on the SPI-2-encoded type III secretion system but some participation of the SPI-1 system was also detected 6 hours post-infection. Interestingly, both type III secretion systems had a relevant role in the translocation of SteA into epithelial cells. Finally, a deletion approach allowed the identification of the N-terminal signal necessary for translocation of this effector. The amino acid residues 1-10 were sufficient to direct translocation into host cells through both type III secretion systems. Our results provide new examples of functional overlapping between the two type III secretion systems of Salmonella.http://europepmc.org/articles/PMC3203157?pdf=render |
| spellingShingle | Elena Cardenal-Muñoz Francisco Ramos-Morales Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA. PLoS ONE |
| title | Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA. |
| title_full | Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA. |
| title_fullStr | Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA. |
| title_full_unstemmed | Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA. |
| title_short | Analysis of the expression, secretion and translocation of the Salmonella enterica type III secretion system effector SteA. |
| title_sort | analysis of the expression secretion and translocation of the salmonella enterica type iii secretion system effector stea |
| url | http://europepmc.org/articles/PMC3203157?pdf=render |
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