CinA is regulated via ComX to modulate genetic transformation and cell viability in Streptococcus mutans
| Autor: | Dennis G. Cvitkovitch, Dilani B. Senadheera, Richard W. Mair |
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| Rok vydání: | 2012 |
| Předmět: |
Operon
Mutant Gene Expression Mutagenesis (molecular biology technique) Biology Microbiology Article Streptococcus mutans Gene Knockout Techniques chemistry.chemical_compound Transformation Genetic Bacterial Proteins Genetics Viability assay Molecular Biology Recombination Genetic Microbial Viability Genetic Complementation Test Gene Expression Regulation Bacterial Methyl Methanesulfonate DNA Transformation Competence Molecular biology Methyl methanesulfonate Complementation Rec A Recombinases Cell killing Regulon chemistry Transcription Factors |
| Zdroj: | FEMS Microbiology Letters. 331:44-52 |
| ISSN: | 0378-1097 |
| Popis: | The Streptococcus mutans ComX-regulon encompasses > 200 mostly uncharacterized genes, including cinA. Here we report that cinA is regulated by ComX in the presence of the competence stimulating peptide (CSP), wherein loss of CinA (strain SmuCinA) results in reduced transformability with or without added CSP by 74- and 15-fold, respectively (P < 0.003). In CSP-supplemented cultures, a two-fold increase in cell viability was noted for SmuCinA relative to UA159 (P < 0.002), suggesting CinA's involvement in the CSP-modulated cell killing response. Relative to UA159, loss of CinA also rendered the mutant hypersensitive to killing by methyl methanesulfonate (MMS), which impairs homologous recombination. Despite our use of a non-polar mutagenesis strategy to knockout cinA, which is the first gene of the multicistronic operon harboring cinA, we noted a drastic reduction in recA expression. By using a CinA-complemented mutant, we were able to partially, but not completely restore all phenotypes to UA159 levels. Complementation results suggested that although cinA participates in modulating competence, viability and MMS tolerance, genes downstream of the cinA transcript may also regulate these phenotypes, a finding that warrants further examination. This is the first report that describes a role for S. mutans' CinA in contending with DNA damage, genetic transformation and cell survival. |
| Databáze: | OpenAIRE |
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