| Title: | Streptococcal peptides that signal Enterococcus faecalis cells carrying the pheromone-responsive conjugative plasmid pAM373 |
| Author(s): | Vickerman MM; Mansfield JM; |
| Address: | "Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, NY, USA" |
| ISSN/ISBN: | 2041-1014 (Electronic) 2041-1006 (Linking) |
| Abstract: | "Pheromone-mediated conjugative transfer of enterococcal plasmids can contribute to the dissemination of genes involved in antibiotic resistance, fitness, and virulence among co-residents of mixed microbial communities. We have previously shown that intergeneric signaling by the Streptococcus gordonii strain Challis heptapeptide s.g.cAM373 (SVFILAA) induces an aggregation substance-mediated mating response and facilitates plasmid transfer from Enterococcus faecalis cells carrying the pheromone-responsive plasmid pAM373 to both pheromone-producing and non-pheromone-producing oral streptococcal recipients. To further investigate the streptococcal pheromone-like peptides, s.g.cAM373-like sequences were identified in the signal sequences of streptococcal CamG lipoproteins and their abilities to induce a mating response in E. faecalis/pAM373 cells were examined. Synthetic heptamers with the consensus sequence (A/S)-(I/V)-F-I-L-(A/V/T)-(S/A) induced AS-mediated clumping. The conserved pheromone ABC transporter encoded by S. gordonii genome loci SGO_RS02660 and SGO_RS02665 was identified and confirmed to be required for s.g.cAM373 activity. Functional assays of culture supernatants from representative oral and blood isolates of S. gordonii showed that in addition to strains encoding s.g.cAM373, strain SK120, encoding the newly identified pheromone s.g.cAM373-V (SVFILVA), was able to induce enterococcal clumping, whereas strains SK6, SK8, SK9, and SK86 which encoded s.g.cAM373-T (SVFILTA) did not elicit a detectable mating response. Absence of pheromone activity in supernatants of heterologous hosts encoding its CamG precursor suggested that s.g.cAM373-T was not effectively processed and/or transported. Overall, these studies demonstrated the distribution of active pheromone peptides among strains of S. gordonii, and support a potential role for enterococcal-streptococcal communication in contributing to genetic plasticity in the oral metagenome" |
| Keywords: | "*Conjugation, Genetic *Enterococcus faecalis/physiology Metagenome Mouth/microbiology Peptides/*physiology *Pheromones/physiology Plasmids Streptococcus gordonii/*physiology Enterococcus faecalis conjugation oral streptococci pheromones plasmid signaling;" |
| Notes: | "MedlineVickerman, M Margaret Mansfield, Jillian M eng R21 DE022154/DE/NIDCR NIH HHS/ R21 DE023643/DE/NIDCR NIH HHS/ Research Support, N.I.H., Extramural Denmark 2019/10/15 Mol Oral Microbiol. 2019 Dec; 34(6):254-262. doi: 10.1111/omi.12271. Epub 2019 Oct 29" |
