How "Full" is "Full Fusion" during Exocytosis from Dense Core Vesicles? Effect of SDS on "Quantal" Release and Final Fusion Pore Size
How "Full" is "Full Fusion" during Exocytosis from Dense Core Vesicles? Effect of SDS on "Quantal" Release and Final Fusion Pore Size
复制标题
致密核心囊泡胞吐作用期间的“完全融合”有多“完全”？
DOI：
10.1149/2.1071609jes
复制
发表时间：
2016-01-01
影响因子：
3.9
通讯作者：
Amatore, Christian
中科院分区：
文献类型：
--
作者：
Hu, Ren;Ren, Bin;Amatore, Christian
在这项工作中，使用足够小浓度的十二烷基硫酸钠（SDS）来扰乱正常的释放机制，以试图在保持生理相容条件的同时揭示隐藏的信息，从而从PC 12中引发释放。安培法被用来监测和量化的释放通量和动力学在个人泡事件。这表明，与对照（在相同条件下用K+ 105 mM引发的释放）或SDS 250 μ M相比，用SDS 350 μ M刺激释放导致每次事件释放的儿茶酚胺阳离子的量加倍，并且释放通量大得多。这些定量测量证实了我们以前的理论模型和报告的基础上离体PC12囊泡，其中建立了释放是远远不是总在正常的胞吐条件下的非原位细胞计数实验。其次，这确定了在“完全融合”阶段结束时融合孔的最大尺寸受到与膜无关的一些装置的限制。事实上，本结果与SDS 350 μ M允许融合孔扩展到两倍大小（约100 μ M）的事实完全一致。与对照组和SDS 250 μ M（约28 nm半径）相比。14nm半径）。(C)作者（S）2016由ECS发布。All rights reserved.
In this work, release was elicited from PC12 using sufficiently small concentrations of sodium dodecyl sulfate (SDS) to perturb normal release mechanism in an attempt to reveal concealed information while keeping physiologically compatible conditions. Amperometry was used to monitor and quantify the released fluxes and kinetics in individual vesicular events. This showed that stimulating release with SDS 350 mu M leads to a doubling of the quantity of catecholamine cations released per event and much larger release fluxes as compared to controls (release elicited with K+ 105 mM under same conditions) or SDS 250 mu M. These quantitative measurements confirm our previous theoretical model and reports based on ex situ cytometric experiments on isolated PC12 vesicles, which established that release is far from being total under normal exocytotic conditions. Secondly, this establishes that the maximal size of fusion pores at the end of the "full fusion" phase is limited by some contraption unrelated to the membrane. Indeed, the present results are entirely consistent with the fact that SDS 350 mu M allows the fusion pore to expand to a double size (ca. 28 nm radius) compared to controls and SDS 250 mu M (ca. 14 nm radius). (C) The Author(s) 2016. Published by ECS. All rights reserved.