Supplementary materials for "Morpho-functional characterisation of membrane carriers operating in post-Golgi transport routes"

This dataset comprises the contents of a CD-ROM which was attached to the thesis when it was submitted in 2005. It was uploaded to ORDO in 2024, for preservation purposes. For more information, please refer to "Morpho-functional characterisation of membrane carriers operating in post-Golgi transport routes" on ORO.

Thesis abstract

Transport of constitutive cargo proteins from the Golgi complex to the plasma membrane (PM) is known to be mediated by large tubular-saccular carriers moving along microtubules. However, the process by which these large structures emerge from the trans-Golgi network (TGN) remains unclear. The formation of Golgi-to-PM carriers (GPCs) has been investigated in the present study by using a suitable cluster of morphological techniques, providing an integrated view of GPC dynamics and three-dimensional structure. The results obtained indicate that exit from the TGN of a constitutive traffic marker, the VSVG protein, occurs by bulk flow and is a three-step process. First, the formation of a tubular-reticular TGN domain (GPC precursor) that includes PM-directed proteins and excludes other cargo and Golgi-resident proteins. Notably, this step does not require membrane fusion. Second, the docking of this preformed domain on microtubules and its kinesin-mediated extrusion. Finally, the detachment of the extruded domain by membrane fission. The formation of GPCs does not involve cargo concentration and is not associated with the presence of known coat proteins on GPC precursors. In summary, export from the Golgi occurs via the formation, protrusion and en bloc cleavage of specialized TGN tubular-saccular domains.