TY - JOUR
T1 - Structure and function of fusion pores in exocytosis and ectoplasmic membrane fusion
AU - Lindau, Manfred
AU - Almers, Wolfhard
PY - 1995
Y1 - 1995
N2 - Several proteins involved in exocytosis have been identified recently, but it is still completely unclear which molecules perform the fusion event itself. Although in viral fusion the fusion proteins are known, even there the molecular mechanism remains controversial. Investigation of single fusion events by electrophysiological techniques together with fluorimetric measurements have now provided some insight into the properties of the first aqueous connection, the fusion pore. This pore has an initial size similar to an ion channel and allows movement of lipids only after it has substantially expanded, indicating that it is initially not a purely lipidic structure, but incorporates lipids when it expands. Although neurotransmitter release may occur through narrow transient fusion pores, the fusion pore of synaptic vesicles probably expands very rapidly, making it unlikely that secretion is performed by rapid exo/endocytosis without full fusion under normal conditions. Recent recordings from small membrane patches have made it possible to resolve fusion events from vesicles as small as synaptic vesicles. Future experiments using excised patches may provide an approach to identify the molecular machinery of exocytotic membrane fusion.
AB - Several proteins involved in exocytosis have been identified recently, but it is still completely unclear which molecules perform the fusion event itself. Although in viral fusion the fusion proteins are known, even there the molecular mechanism remains controversial. Investigation of single fusion events by electrophysiological techniques together with fluorimetric measurements have now provided some insight into the properties of the first aqueous connection, the fusion pore. This pore has an initial size similar to an ion channel and allows movement of lipids only after it has substantially expanded, indicating that it is initially not a purely lipidic structure, but incorporates lipids when it expands. Although neurotransmitter release may occur through narrow transient fusion pores, the fusion pore of synaptic vesicles probably expands very rapidly, making it unlikely that secretion is performed by rapid exo/endocytosis without full fusion under normal conditions. Recent recordings from small membrane patches have made it possible to resolve fusion events from vesicles as small as synaptic vesicles. Future experiments using excised patches may provide an approach to identify the molecular machinery of exocytotic membrane fusion.
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U2 - 10.1016/0955-0674(95)80007-7
DO - 10.1016/0955-0674(95)80007-7
M3 - Article
C2 - 7495570
AN - SCOPUS:0029156059
SN - 0955-0674
VL - 7
SP - 509
EP - 517
JO - Current Opinion in Cell Biology
JF - Current Opinion in Cell Biology
IS - 4
ER -