Author/Editor		Vardjan, Nina; Jorgačevski, Jernej; Zorec, Robert
Title		Fusion pores, SNAREs, and exocytosis
Type		članek
Source		Neuroscientist
Vol. and No.		Letnik 19, št. 2
Publication year		2013
Volume		str. 160-74
Language		eng
Abstract		Exocytosis is a multistage process involving a merger between the vesicle and the plasma membranes, leading to the formation of a fusion pore, a channel, through which secretions are released from the vesicle to the cell exterior. A stimulus may influence the pore by either dilating it completely (full-fusion exocytosis) or mediating a reversible closure (transient exocytosis). In neurons, these transitions are short-lived and not accessible for experimentation. However, in some neuroendocrine cells, initial fusion pores may reopen several hundred times, indicating their stability. Moreover, these pores are too narrow to pass luminal molecules to the extracellular space, termed release-unproductive. However, on stimulation, their diameter dilates, initiating the release of cargo without de novo fusion pore formation. To explain the stability of the initial narrow fusion pores, anisotropic membrane constituents with non-axisymmetrical shape were proposed to accumulate in the fusion pore membrane. Although the nature of these is unclear, they may consist of lipids and proteins, including SNAREs, which may facilitate and regulate the pre- and post-fusional stages of exocytosis. In the future, a more detailed insight into the molecular control of fusion pore stabilization and regulation will generate a better understanding of fusion pore physiology in health and disease.
Descriptors		CELL MEMBRANE MEMBRANE FUSION EXOCYTOSIS SYNAPTIC VESICLES NEUROSECRETORY SYSTEMS GOLGI APPARATUS LIPID BILAYERS MEMBRANE PROTEINS PROTEIN BINDING PATCH-CLAMP TECHNIQUES MICROSCOPY, ELECTRON, SCANNING