Endocytosis, Actin Cytoskeleton, and Signaling

Glycerolipid transfer for the building of membranes in plant cells

“…Consistently, in plant, monensin, a secretory pathway inhibitor, was shown to cause accumulation of part of the plasma membrane lipids in the Golgi [1]. This pathway is actin dependent [45]. The addressing of proteins to the plasma membrane seems to be controlled by the size and number of their hydrophobic domains [58].…”

“…On electron micrographs, the ER and nucleus membranes appear as connected, although a lumen constriction is observed at the junction area [44]. With or without Golgi participation, the ER is involved in protein and lipid supply for the vacuolar and plasma membranes by vesicles moving along actin filaments [45].…”

“…Lipids from clathrin-coated vesicles are transferred from the Golgi to a prevacuolar compartment, with the intervention of the actin cytoskeleton and dynamin [45]. Transfer between the prevacuolar compartment and the lytic vacuole is not yet characterised.…”

“…It is now well established that brefeldin A, an exocytosis inhibitor, induces the internalisation of plasma membrane proteins, like the auxincarrier proteins AUX1 and PIN1, in a compartment called the endosome [45]. The distinction between the endosome and prevacuolar compartments is not clear [64] because the fate of internalised proteins divides in two parts: a part is recycled to the plasma membrane and the other destined for the lytic vacuole.…”

“…Plant endocytosis implies at least two pathways: one is catalysed by clathrin-coated vesicles that are transported by the actin cytoskeleton and moved by myosin VIII [45]; another one, like the PIN endocytosis, depends on presence of sterols and of rafts [65]. In plants, no receptor for addressing sequences to clathrin-coated vesicles has been identified despite pointed homologies with some yeast receptors in the Arabidopsis genome [64].…”