Fig. 1.

Sequential steps of cytoskeletal transport, membrane tethering, membrane docking, and membrane fusion in membrane trafficking of eukaryotic cells. Schematic representation of the four essential steps in eukaryotic membrane trafficking, showing the key components for each step, such as Rab-family small GTPases in membrane tethering and SNARE-family proteins in membrane docking and membrane fusion. Membrane tethering is a reversible step of the first physical contact between two distinct subcellular compartments in membrane trafficking, followed by irreversible steps of membrane docking and membrane fusion