Involvement of Lipid Rafts in the Invasion of Opportunistic Bacteria into Eukaryotic Cells.

Cell membrane rafts form signaling platforms on the cell surface, controlling numerous protein-protein and lipid-protein interactions. Bacteria invading eukaryotic cells trigger cell signaling to induce their own uptake by non-phagocytic cells. The aim of this work was to reveal the involvement of membrane rafts in the penetration of the bacteria and into eukaryotic cells.

Protealysin Targets the Bacterial Housekeeping Proteins FtsZ and RecA.

synthesizes the intracellular metalloprotease protealysin. This work was aimed at searching for bacterial substrates of protealysin among the proteins responsible for replication and cell division. We have shown that protealysin unlimitedly cleaves the SOS response protein RecA.

The Role of SprIR Quorum Sensing System in the Regulation of 94 Invasion.

The bacteria 94 have a LuxI/LuxR type QS system consisting of AHL synthase SprI and the regulatory receptor SprR. We have previously shown that inactivation of the AHL synthase gene resulted in an increase in the invasive activity of correlated with an increased bacterial adhesion. In the present work, the effects of inactivation of the receptor SprR are studied.

Invasion of Serratia proteamaculans is regulated by the sprI gene encoding AHL synthase.

Quorum Sensing (QS) system regulates gene expression in response to a change in the density of the bacterial population. Facultative pathogen Serratia proteamaculans 94 has a LuxI/LuxR type QS system consisting of regulatory protein SprR and AHL synthase SprI. Invasive activity of these bacteria appears at the stationary growth phase corresponding to a maximal density of the bacterial population in vitro.

Myopathy-Sensitive G-Actin Segment 227-235 Is Involved in Salt-Induced Stabilization of Contacts within the Actin Filament.

Formation of stable actin filaments, critically important for actin functions, is determined by the ionic strength of the solution. However, not much is known about the elements of the actin fold involved in ionic-strength-dependent filament stabilization. In this work, F-actin was destabilized by Cu binding to Cys374, and the effects of solvent conditions on the dynamic properties of F-actin were correlated with the involvement of Segment 227-235 in filament stabilization.