Structural Mechanism Analysis of Orderly and Efficient Vesicle Transport by High-Resolution Imaging and Fluorescence Tracking

The
orderly organelle interaction network is essential for normal
biological activity of cells. However, the mechanism of orderly organelle
interaction remains elusive. In this report, we analyzed the structure
characteristics of the cell membrane, endocytic vesicles, and the
Golgi membrane through a high-resolution imaging technique and further
comprehensively investigated the vesicle-transport process via epidermal
growth factor receptor endocytosis and a recycling pathway using a
real-time fluorescence tracing method. Our data suggest 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 trans-Golgi network (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 underlying vital biological processes involving
organelle interactions at the molecular level.