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Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans
Integrative and conjugative elements (ICEs) are chromosomally encoded mobile genetic elements that can transfer DNA between bacterial strains. Recently, as part of efforts to determine hypothetical gene functions, we have discovered an important regulatory module encoded on an ICE known as TnSmu1 on...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Microbiology Society
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10233336/ https://www.ncbi.nlm.nih.gov/pubmed/36201342 http://dx.doi.org/10.1099/mic.0.001254 |
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author | King, Shawn Quick, Allison King, Kalee Walker, Alejandro R. Shields, Robert C. |
author_facet | King, Shawn Quick, Allison King, Kalee Walker, Alejandro R. Shields, Robert C. |
author_sort | King, Shawn |
collection | PubMed |
description | Integrative and conjugative elements (ICEs) are chromosomally encoded mobile genetic elements that can transfer DNA between bacterial strains. Recently, as part of efforts to determine hypothetical gene functions, we have discovered an important regulatory module encoded on an ICE known as TnSmu1 on the Streptococcus mutans chromosome. The regulatory module consists of a cI-like repressor with a helix-turn-helix DNA binding domain immR (Smu) (immunity repressor) and a metalloprotease immA (Smu) (anti-repressor). It is not possible to create an in-frame deletion mutant of immR (Smu) and repression of immR (Smu) with CRISPRi (CRISPR interference) causes substantial cell defects. We used a bypass of essentiality (BoE) screen to discover genes that allow deletion of the regulatory module. This revealed that conjugation genes, located within TnSmu1, can restore the viability of an immR (Smu) mutant. Deletion of immR (Smu) also leads to production of a circular intermediate form of TnSmu1, which is also inducible by the genotoxic agent mitomycin C. To gain further insights into potential regulation of TnSmu1 by ImmR(Smu) and broader effects on S. mutans UA159 physiology, we used CRISPRi and RNA-seq. Strongly induced genes included all the TnSmu1 mobile element, genes involved in amino acid metabolism, transport systems and a type I-C CRISPR-Cas system. Lastly, bioinformatic analysis shows that the TnSmu1 mobile element and its associated genes are well distributed across S. mutans isolates. Taken together, our results show that activation of TnSmu1 is controlled by the immRA (Smu) module, and that activation is deleterious to S. mutans , highlighting the complex interplay between mobile elements and their host. |
format | Online Article Text |
id | pubmed-10233336 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | Microbiology Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-102333362023-06-02 Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans King, Shawn Quick, Allison King, Kalee Walker, Alejandro R. Shields, Robert C. Microbiology (Reading) Regulation, Sensing and Signalling Integrative and conjugative elements (ICEs) are chromosomally encoded mobile genetic elements that can transfer DNA between bacterial strains. Recently, as part of efforts to determine hypothetical gene functions, we have discovered an important regulatory module encoded on an ICE known as TnSmu1 on the Streptococcus mutans chromosome. The regulatory module consists of a cI-like repressor with a helix-turn-helix DNA binding domain immR (Smu) (immunity repressor) and a metalloprotease immA (Smu) (anti-repressor). It is not possible to create an in-frame deletion mutant of immR (Smu) and repression of immR (Smu) with CRISPRi (CRISPR interference) causes substantial cell defects. We used a bypass of essentiality (BoE) screen to discover genes that allow deletion of the regulatory module. This revealed that conjugation genes, located within TnSmu1, can restore the viability of an immR (Smu) mutant. Deletion of immR (Smu) also leads to production of a circular intermediate form of TnSmu1, which is also inducible by the genotoxic agent mitomycin C. To gain further insights into potential regulation of TnSmu1 by ImmR(Smu) and broader effects on S. mutans UA159 physiology, we used CRISPRi and RNA-seq. Strongly induced genes included all the TnSmu1 mobile element, genes involved in amino acid metabolism, transport systems and a type I-C CRISPR-Cas system. Lastly, bioinformatic analysis shows that the TnSmu1 mobile element and its associated genes are well distributed across S. mutans isolates. Taken together, our results show that activation of TnSmu1 is controlled by the immRA (Smu) module, and that activation is deleterious to S. mutans , highlighting the complex interplay between mobile elements and their host. Microbiology Society 2022-10-06 /pmc/articles/PMC10233336/ /pubmed/36201342 http://dx.doi.org/10.1099/mic.0.001254 Text en © 2022 The Authors https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License. |
spellingShingle | Regulation, Sensing and Signalling King, Shawn Quick, Allison King, Kalee Walker, Alejandro R. Shields, Robert C. Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans |
title | Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans
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title_full | Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans
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title_fullStr | Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans
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title_full_unstemmed | Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans
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title_short | Activation of TnSmu1, an integrative and conjugative element, by an ImmR-like transcriptional regulator in Streptococcus mutans
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title_sort | activation of tnsmu1, an integrative and conjugative element, by an immr-like transcriptional regulator in streptococcus mutans |
topic | Regulation, Sensing and Signalling |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10233336/ https://www.ncbi.nlm.nih.gov/pubmed/36201342 http://dx.doi.org/10.1099/mic.0.001254 |
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