Moonlighting proteins have been defined as polypeptides exhibiting two mechanistically unrelated functions; notably, some of these multifunctional proteins have been demonstrated to be invovled in bacterial prthogenicity. Prominent examples are (I) Aeromonas hydrophila enolase, an intracellular glycolytic enzyme, shown to be also expressed at the cell-surface where it facilitates activation of plasminogen to plasmin and (II) the cytoplasmic glyceraldehyde-3-phosphate dehydrogenase, which has been identified in the extracellular sub-proteome of the foodborne opportunistic pathogen Cronobacter turicensis and was speculated to contribute to the strains virulence by adhering to host blood proteins. More recently, we tested different clinical and cheese-isolates of Enterococcus faecalis for their potential to express pathogenic traits and characterized the secretome of two representative strains by comparative two-dimensional gelelectrophoresis. E. faecalis is known as common nosocomial pathogens; however, it's also employed as cheese starter culture and has been discussed as probiotics due to its capacity to produce bacteriocins. Albeit all tested strains bore genes coding for virulence determinants such as gelatinase and serine protease, only the hospitalisolates were expressing these enzymes, thereby indicating an epigenetic control of pathogenicity genes. Interestingly, numerous moonlighting proteins were identified in the supernatant of the clinical strain but missing in the cheese-isolate's secretome, i.e. five glycolytic enzymes and the chaperone DnaK. It has been suggested that these proteins are able to bind plasminogen thereby rendering it more sensitive to host plasminogen activators and thus act as virulence factors. E. faecalis moonlighting proteins might serve as biomarkers to assess the risk potential of probiotic strains. Ongoing work therefore investigates, whether certain growth conditions might induce virulence factor production in the food-isolates.
Moonlighting proteins as biomarkers for probiotic safety.
LAMBERTI C;
2011
Abstract
Moonlighting proteins have been defined as polypeptides exhibiting two mechanistically unrelated functions; notably, some of these multifunctional proteins have been demonstrated to be invovled in bacterial prthogenicity. Prominent examples are (I) Aeromonas hydrophila enolase, an intracellular glycolytic enzyme, shown to be also expressed at the cell-surface where it facilitates activation of plasminogen to plasmin and (II) the cytoplasmic glyceraldehyde-3-phosphate dehydrogenase, which has been identified in the extracellular sub-proteome of the foodborne opportunistic pathogen Cronobacter turicensis and was speculated to contribute to the strains virulence by adhering to host blood proteins. More recently, we tested different clinical and cheese-isolates of Enterococcus faecalis for their potential to express pathogenic traits and characterized the secretome of two representative strains by comparative two-dimensional gelelectrophoresis. E. faecalis is known as common nosocomial pathogens; however, it's also employed as cheese starter culture and has been discussed as probiotics due to its capacity to produce bacteriocins. Albeit all tested strains bore genes coding for virulence determinants such as gelatinase and serine protease, only the hospitalisolates were expressing these enzymes, thereby indicating an epigenetic control of pathogenicity genes. Interestingly, numerous moonlighting proteins were identified in the supernatant of the clinical strain but missing in the cheese-isolate's secretome, i.e. five glycolytic enzymes and the chaperone DnaK. It has been suggested that these proteins are able to bind plasminogen thereby rendering it more sensitive to host plasminogen activators and thus act as virulence factors. E. faecalis moonlighting proteins might serve as biomarkers to assess the risk potential of probiotic strains. Ongoing work therefore investigates, whether certain growth conditions might induce virulence factor production in the food-isolates.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
