Functional analysis of the quorum-sensing streptococcal invasion locus (sil).
Group A streptococcus (GAS) causes a wide variety of human diseases, and at the same time, GAS can also circulate without producing symptoms, similar to its close commensal relative, group G streptococcus (GGS). We previously identified, by transposon-tagged mutagenesis, the streptococcal invasion l...
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Format: | Article |
Language: | English |
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Public Library of Science (PLoS)
2009-11-01
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Series: | PLoS Pathogens |
Online Access: | http://europepmc.org/articles/PMC2766830?pdf=render |
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author | Ilia Belotserkovsky Moshe Baruch Asaf Peer Eran Dov Miriam Ravins Inbal Mishalian Merav Persky Yoav Smith Emanuel Hanski |
author_facet | Ilia Belotserkovsky Moshe Baruch Asaf Peer Eran Dov Miriam Ravins Inbal Mishalian Merav Persky Yoav Smith Emanuel Hanski |
author_sort | Ilia Belotserkovsky |
collection | DOAJ |
description | Group A streptococcus (GAS) causes a wide variety of human diseases, and at the same time, GAS can also circulate without producing symptoms, similar to its close commensal relative, group G streptococcus (GGS). We previously identified, by transposon-tagged mutagenesis, the streptococcal invasion locus (sil). sil is a quorum-sensing regulated locus which is activated by the autoinducer peptide SilCR through the two-component system SilA-SilB. Here we characterize the DNA promoter region necessary for SilA-mediated activation. This site is composed of two direct repeats of 10 bp, separated by a spacer of 11 bp. Fusion of this site to gfp allowed us to systematically introduce single-base substitutions in the repeats region and to assess the relative contribution of various positions to promoter strength. We then developed an algorithm giving different weights to these positions, and performed a chromosome-wide bioinformatics search which was validated by transcriptome analysis. We identified 13 genes, mostly bacteriocin related, that are directly under the control of SilA. Having developed the ability to quantify SilCR signaling via GFP accumulation prompted us to search for GAS and GGS strains that sense and produce SilCR. While the majority of GAS strains lost sil, all GGS strains examined still possess the locus and approximately 63% are able to respond to exogenously added SilCR. By triggering the autoinduction circle using a minute concentration of synthetic SilCR, we identified GAS and GGS strains that are capable of sensing and naturally producing SilCR, and showed that SilCR can be sensed across these streptococci species. These findings suggest that sil may be involved in colonization and establishment of commensal host-bacterial relationships. |
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issn | 1553-7366 1553-7374 |
language | English |
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publishDate | 2009-11-01 |
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spelling | doaj.art-ab8aa059ab9b4ad0aeb0f0c6cb3659c72022-12-22T03:42:50ZengPublic Library of Science (PLoS)PLoS Pathogens1553-73661553-73742009-11-01511e100065110.1371/journal.ppat.1000651Functional analysis of the quorum-sensing streptococcal invasion locus (sil).Ilia BelotserkovskyMoshe BaruchAsaf PeerEran DovMiriam RavinsInbal MishalianMerav PerskyYoav SmithEmanuel HanskiGroup A streptococcus (GAS) causes a wide variety of human diseases, and at the same time, GAS can also circulate without producing symptoms, similar to its close commensal relative, group G streptococcus (GGS). We previously identified, by transposon-tagged mutagenesis, the streptococcal invasion locus (sil). sil is a quorum-sensing regulated locus which is activated by the autoinducer peptide SilCR through the two-component system SilA-SilB. Here we characterize the DNA promoter region necessary for SilA-mediated activation. This site is composed of two direct repeats of 10 bp, separated by a spacer of 11 bp. Fusion of this site to gfp allowed us to systematically introduce single-base substitutions in the repeats region and to assess the relative contribution of various positions to promoter strength. We then developed an algorithm giving different weights to these positions, and performed a chromosome-wide bioinformatics search which was validated by transcriptome analysis. We identified 13 genes, mostly bacteriocin related, that are directly under the control of SilA. Having developed the ability to quantify SilCR signaling via GFP accumulation prompted us to search for GAS and GGS strains that sense and produce SilCR. While the majority of GAS strains lost sil, all GGS strains examined still possess the locus and approximately 63% are able to respond to exogenously added SilCR. By triggering the autoinduction circle using a minute concentration of synthetic SilCR, we identified GAS and GGS strains that are capable of sensing and naturally producing SilCR, and showed that SilCR can be sensed across these streptococci species. These findings suggest that sil may be involved in colonization and establishment of commensal host-bacterial relationships.http://europepmc.org/articles/PMC2766830?pdf=render |
spellingShingle | Ilia Belotserkovsky Moshe Baruch Asaf Peer Eran Dov Miriam Ravins Inbal Mishalian Merav Persky Yoav Smith Emanuel Hanski Functional analysis of the quorum-sensing streptococcal invasion locus (sil). PLoS Pathogens |
title | Functional analysis of the quorum-sensing streptococcal invasion locus (sil). |
title_full | Functional analysis of the quorum-sensing streptococcal invasion locus (sil). |
title_fullStr | Functional analysis of the quorum-sensing streptococcal invasion locus (sil). |
title_full_unstemmed | Functional analysis of the quorum-sensing streptococcal invasion locus (sil). |
title_short | Functional analysis of the quorum-sensing streptococcal invasion locus (sil). |
title_sort | functional analysis of the quorum sensing streptococcal invasion locus sil |
url | http://europepmc.org/articles/PMC2766830?pdf=render |
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