Multiple factors are involved in regulation of extracellular membrane vesicle biogenesis in Streptococcus mutans
Autor: | Zezhang T. Wen, Ashton N. Jorgensen, Kassapa Ellepola, Xiaochang Huang, L. Jeannine Brady, Hui Wu, Lynne Chapman |
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Rok vydání: | 2020 |
Předmět: |
0301 basic medicine
Microbiology (medical) 030106 microbiology Immunology Mutant Dental Caries Microbiology Article Streptococcus mutans 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Bacterial Proteins Biosynthesis Extracellular Humans General Dentistry biology Chemistry Biofilm Biofilm matrix Gene Expression Regulation Bacterial 030206 dentistry biology.organism_classification Culture Media Cell biology Biofilms Functional genomics Biogenesis |
Zdroj: | Mol Oral Microbiol |
ISSN: | 2041-1014 2041-1006 |
Popis: | Streptococcus mutans, a major etiological agent of human dental caries, produces membrane vesicles (MVs) that contain protein and extracellular DNA. In this study, functional genomics, along with in vitro biofilm models, was used to identify factors that regulate MV biogenesis. Our results showed that when added to growth medium, MVs significantly enhanced biofilm formation by S. mutans, especially during growth in sucrose. This effect occurred in the presence and absence of added human saliva. Functional genomics revealed several genes, including sfp, which have a major effect on S. mutans MVs. In Bacillus sp. sfp encodes a 4'-phosphopantetheinyl transferase that contributes to surfactin biosynthesis and impacts vesiculogenesis. In S. mutans, sfp resides within the TnSmu2 Genomic Island that supports pigment production associated with oxidative stress tolerance. Compared to the UA159 parent, the Δsfp mutant, TW406, demonstrated a 1.74-fold (p .05) higher MV yield as measured by BCA protein assay. This mutant also displayed increased susceptibility to low pH and oxidative stressors, as demonstrated by acid killing and hydrogen peroxide challenge assays. Deficiency of bacA, a putative surfactin synthetase homolog within TnSmu2, and especially dac and pdeA that encode a di-adenylyl cyclase and a phosphodiesterase, respectively, also significantly increased MV yield (p .05). However, elimination of bacA2, a bacitracin synthetase homolog, resulted in a1.5-fold (p .05) reduction of MV yield. These results demonstrate that S. mutans MV properties are regulated by genes within and outside of the TnSmu2 island, and that as a major particulate component of the biofilm matrix, MVs significantly influence biofilm formation. |
Databáze: | OpenAIRE |
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