High calcium concentrations shift the mode of exocytosis to the kiss-and-run mechanism
High calcium concentrations shift the mode of exocytosis to the kiss-and-run mechanism
复制标题
DOI：
10.1038/9012
复制
发表时间：
1999-05-01
影响因子：
21.3
通讯作者：
de Toledo, GA
中科院分区：
文献类型：
--
作者：
Alés, E;Tabares, L;de Toledo, GA
胞吐作用，分泌囊泡与质膜融合以允许囊泡的内容物释放到细胞外环境中，和胞吞作用，这些囊泡的内化以允许另一轮分泌，是偶联的。然而，它是不确定的胞吐和胞吞是否是紧密耦合的，这样的分泌囊泡融合只有短暂的质膜之前被内化（“吻和运行”的机制），或是否发生胞吞后，分泌囊泡完全纳入质膜一个独立的过程。在这里，我们调查的命运后，与质膜融合的单个分泌囊泡通过测量电容的变化和递质释放在大鼠嗜铬细胞使用细胞贴附贴片安培技术。我们发现，细胞外钙离子浓度升高，以钙浓度依赖的方式转移的首选模式的胞吐吻和运行机制。我们建议，在突触神经递质的分泌过程中，胞吐的模式是由钙调制，以达到最佳条件耦合胞吐和内吞根据突触活动。
Exocytosis, the fusion of secretory vesicles with the plasma membrane to allow release of the contents of the vesicles into the extracellular environment, and endocytosis, the internalization of these vesicles to allow another round of secretion, are coupled. It is, however, uncertain whether exocytosis and endocytosis are tightly coupled, such that secretory vesicles fuse only transiently with the plasma membrane before being internalized (the 'kiss-and-run' mechanism), or whether endocytosis occurs by an independent process following complete incorporation of the secretory vesicle into the plasma membrane. Here we investigate the fate of single secretory vesicles after fusion with the plasma membrane by measuring capacitance changes and transmitter release in rat chromaffin cells using the cell-attached patch-amperometry technique. We show that raised concentrations of extracellular calcium ions shift the preferred mode of exocytosis to the kiss-and-run mechanism in a calcium-concentration-dependent manner. We propose that, during secretion of neurotransmitters at synapses, the mode of exocytosis is modulated by calcium to attain optimal conditions for coupled exocytosis and endocytosis according to synaptic activity.