Structural mechanism analysis of orderly and efficient vesicle transport by high-resolution imaging and fluorescence tracking.

The orderly organelle interaction network is essential for the normal biological activity of cells. However, the mechanism of orderly organelle interaction remains elusive. In this report, we analyzed the membrane characteristics of the cell membrane, endocytic vesicles and the Golgi membrane through high-resolution imaging technique and further comprehensively investigated the vesicle transport process via EGFR endocytosis and recycling pathway using a real-time fluorescence tracing method. Our data suggested that orderly vesicle transport is due to protein protrusion from the outer surface of endocytic vesicles and that full membrane fusion between homotypic endocytic vesicles is a result of the rough outer surface. Finally, the kiss-and-run method, which is utilized by endocytic vesicles to communicate with the TGN, is attributed to a dense protein layer at the outer surface of the TGN. In summary, by combining static structural analysis with dynamic tracing, we elucidate the mechanism of orderly vesicle transport from the overall structural features of the membrane. This work provides insight into the structural mechanisms underly-ing vital biological processes involving organelle interactions at the molecular level.