Vitronectin Binds to a Specific Stretch within the Head Region of Yersinia Adhesin A and Thereby Modulates Yersinia enterocolitica Host Interaction.

Complement resistance is an important virulence trait of Yersinia enterocolitica (Ye). The predominant virulence factor expressed by Ye is Yersinia adhesin A (YadA), which enables bacterial attachment to host cells and extracellular matrix and additionally allows the acquisition of soluble serum factors. The serum glycoprotein vitronectin (Vn) acts as an inhibitory regulator of the terminal complement complex by inhibiting the lytic pore formation.

Excreted Cytoplasmic Proteins Contribute to Pathogenicity in Staphylococcus aureus.

Excretion of cytoplasmic proteins in pro- and eukaryotes, also referred to as "nonclassical protein export," is a well-known phenomenon. However, comparatively little is known about the role of the excreted proteins in relation to pathogenicity. Here, the impact of two excreted glycolytic enzymes, aldolase (FbaA) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), on pathogenicity was investigated in Staphylococcus aureus Both enzymes bound to certain host matrix proteins and enhanced adherence of the bacterial cells to host cells but caused a decrease in host cell invasion.

Excretion of cytoplasmic proteins in Staphylococcus is most likely not due to cell lysis.

The excretion of cytoplasmic proteins (ECP) is a long-known phenomenon in bacteria and eukaryotes. So far, it was not possible to associate either a signal peptide-dependent or a signal peptide-independent pathway to ECP. Nevertheless 25% of the proteins found in Staphylococcus aureus supernatants were cytoplasmic proteins.

Excretion of cytoplasmic proteins (ECP) in Staphylococcus aureus.

Excretion of cytoplasmic proteins (ECP) is a common physiological feature in bacteria and eukaryotes. However, how these proteins without a typical signal peptide are excreted in bacteria is poorly understood. We studied the excretion pattern of cytoplasmic proteins using two glycolytic model enzymes, aldolase and enolase, and show that their excretion takes place mainly during the exponential growth phase in Staphylococcus aureus very similar to that of Sbi, an IgG-binding protein, which is secreted via the Sec-pathway.