Membrane vesicle trafficking in eukaryotic animal cells involves movement of important biochemical signal molecules from synthesis-and-packaging locations in Golgi body to specific 'release' locations on the inside of the plasma membrane of the secretory cell, in the form of Golgi membrane-bound micro-sized vesicles, termed membrane vesicles (MVs). In this process, the 'packed' cellular products are released/secreted outside the cell across plasma membrane. However, vesicular membrane is retained and recycled by the secretory cells. This phenomenon has key role in synaptic neurotransmission, endocrine secretion, mucous secretion, granular-product secretion by neutrophils,etc. The scientists behind this discovery were awarded Nobel prize for the year 2013. In the prokaryotic gram-negative bacterial cells, membrane vesicle trafficking is mediated via bacterial outer membrane bounded nano-sized vesicles, called bacterial outer membrane vesicles, (OMVs)(Fig.1). In this case, however, the OMV membrane is secreted as well, along with OMV-contents to outside the secretion-active bacterium. This phenomenon has key role in host-pathogen interactions, endotoxic shock in patients, invasion and infection of animals/plants, inter-species bacterial competition, qourum sensing, exocytosis,etc.(see External Links).