Characterization and function of membrane vesicles in Gram-positive bacteria.

In recent years, extracellular vesicles have gained more attention. However, studies on membrane vesicles in Gram-positive bacteria were carried out relatively late because of the thick bacterial wall and the low production of membrane vesicles. Thanks to the research in recent years, the cognition of the composition and function of the membrane vesicles of Gram-positive bacteria has made significant progress. Membrane vesicles are spherical in shape comprising bilayer membranous structures with a diameter of 20-400 nm. Components of membrane vesicles are diverse, including proteins, nucleic acids, lipids, and metabolites. It also has been reported that membrane vesicles are involved in various pathophysiological processes and serve as communication tools in pathophysiological activities between the bacteria and the host. This review provided the current understanding of components and functions of membrane vesicles in Gram-positive bacteria. The findings might facilitate further research in the emerging field of membrane vesicles in Gram-positive bacteria. KEY POINTS: • Membrane vesicles in Gram-positive bacteria contain proteins, nucleic acids, lipids, and metabolites, suggesting their biological significance. • Membrane vesicles in Gram-positive bacteria are thought to be involved in stress response, biofilm formation, immune regulation, and so on.