The plasma membrane defines the spatial extent of a cell. The plasma membrane is not, however, an invariant entity as the membrane shape and area vary continuously. Specifically, the cellular events that underlie neurotransmitter release, as well as endocrine and exocrine secretion, depend on a continuous turnover of membrane components that involve the fusion (and subsequent retrieval) of intracellular vesicles and granules with the plasma membrane. Despite common elements (e.g., the fusion of two lipid bilayers into one), the molecular basis of secretion differs among cell types, and a given cell type may secrete different compounds using different mechanisms.
The generality and specificity of the secretory process was highlighted at The 51st Annual Meeting of the Society of General Physiologists, which took place in Woods Hole, MA, September 4–6, 1997. George J. Augustine (Duke University Medical Center) and Thomas F.J. Martin (University of Wisconsin) organized the symposium on Mechanisms...
