Production and uptake of bacterial extracellular vesicles*

Bacteria naturally produce extracellular vesicles. Vesicles are approximately 100 nm in diameter and are involved in many cellular processes including infection and the exchange of genetic material. Vesicle production and uptake involves large amounts of energy associated with deforming and merging cellular membranes. In eukaryotic systems, such as human cells, many specialized proteins have evolved to create and traffic vesicles, however bacterial vesicles are not known to involve any specialized molecular machinery. Our work has examined how bacteria are able to overcome these energetic barriers. For example, membrane deformation can be assisted by the presence of molecules that bind to and restructure membranes. We have shown several such molecules produced by bacteria, including several antibiotics, increase the rate of the both vesicle production and uptake. In another study, we examine how the detachment of the bacterial outer membrane from the bacterial cell wall is another key step in vesicle production. This talk will discuss how such aspects of membrane mechanics influence the exchange of vesicles within bacterial populations.