Targeting vesicles to specific sites on the plasma membrane: the role of the sec6/8 complex.

The delivery of secretory vesicles to appropriate docking and fusion sites on the plasma membrane is crucial for many cellular functions, including formation of synapses, exocytosis of neurotransmitter, establishment and maintenance of cell polarity, cell growth and plasma membrane wound healing. Cell-biological, genetic and biochemical approaches have identified crucial proteins and protein interactions important for vesicle docking and fusion. However, a description of the molecular mechanisms underlying vesicle targeting to specific membrane-fusion sites remains elusive. This review discusses a set of proteins that might direct vesicles to specific domains of the plasma membrane.