Role of the Enterococcus faecalis GelE protease in determination of cellular chain length, supernatant pheromone levels, and degradation of fibrin and misfolded surface proteins.
Gelatinase (GelE), a secreted Zn-metalloprotease of Enterococcus faecalis, has been implicated as a virulence factor by both epidemiological data and animal model studies. Expression of gelE is induced at a high cell density by the fsr quorum-sensing system. In the present study, GelE was shown to be responsible for the instability of a number of Asc10 (aggregation substance) mutant proteins, implying that GelE functions to clear the bacterial cell surface of misfolded proteins. Disruption of GelE production led to increased cell chain length of E. faecalis, from a typical diplococcus morphology to chains of 5 to 10 cells. This function of GelE was also exhibited when the protein was expressed in Streptococcus pyogenes. GelE-expressing E. faecalis strains were more autolytic, suggesting that GelE affects chain length through activation of an autolysin. GelE was also essential for degradation of polymerized fibrin. GelE expression reduced the titer of cCF10, the peptide pheromone that induces conjugation of pCF10, and pCF10 had increased conjugation into non-GelE-expressing strains. These new functions attributed to GelE suggest that it acts to increase the dissemination of E. faecalis in high-density environments.
Waters
Christopher M
CM
Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Antiporta
Michelle H
MH
Murray
Barbara E
BE
Dunny
Gary M
GM
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D013293:Enterococcus faecalis / Q000201:enzymology* / Q000254:growth & development / Q000472:pathogenicity; D004789:Enzyme Activation; D005337:Fibrin / Q000378:metabolism*; D018093:Gelatinases / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D005798:Genes, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism; D009842:Oligopeptides / Q000032:analysis / Q000378:metabolism*; D010675:Pheromones / Q000032:analysis / Q000378:metabolism*; D013297:Streptococcus pyogenes / Q000235:genetics / Q000378:metabolism; D014169:Transformation, Bacterial; D014774:Virulence
D001426:Bacterial Proteins; D008565:Membrane Proteins; D009842:Oligopeptides; D010675:Pheromones; C057280:peptide pheromone cCF10; C071729:Asc10 protein, Enterococcus faecalis; D005337:Fibrin; D018093:Gelatinases; D009238:N-Acetylmuramoyl-L-alanine Amidase