ION CHANNELS FROM SYNAPTIC VESICLE MEMBRANE

突触小泡膜的离子通道

基本信息

批准号：
2445520
负责人：
DIXON J WOODBURY
金额：
$ 9.98万
依托单位：
WAYNE STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1993
资助国家：
美国
起止时间：
1993-07-01 至 1999-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2445520
关键词：
Torpedo adenosine triphosphate alternatives to animals in research calcium channel calcium flux cell membrane inositol phosphates lipid bilayer membrane membrane channels membrane fusion membrane proteins membrane reconstitution /synthesis membrane structure synapses synaptic vesicles voltage gated channel

项目摘要

Neurotransmitter release is a key step in synaptic transmission. However, the molecular events that trigger fusion of synaptic vesicles and neurotransmitter release are unknown. One attractive hypothesis is that Ca2+-activated channels in the vesicle membrane control fusion of vesicles. If true, such a channel would provide a simple molecular link between Ca2+ entry and vesicle fusion. Previous experiments have lead to the identification of several kinds of ion channels that are credited to the synaptic vesicle membrane. The objective of this project is to study these ion channels to determine: 1) which, if any, are from the synaptic vesicle membrane; 2) the biophysical properties of these channels; and 3) regulators of the channels (such as voltage and Ca2+). These goals are directed toward elucidation of the mechanism(s) of fusion of synaptic vesicles to the nerve terminal membrane and the possible role of vesicular ion channels in this process. Plan: Planar bilayer experiments will be used to identify and characterize ion channels from synaptic vesicles purified from the electric organ of the electric fish, Torpedo californica. Vesicle membrane will be induced to fuse with bilayers by using a new technique that both enhances fusion of all vesicles and makes it possible to estimate the prevalence of any observed channels. That is, it will be possible to determine if a particular channel is representative of the population of synaptic vesicles or if it is from a minor contaminant. Preliminary Results: Synaptic vesicles from Torpedo californica have been isolated and treated so that they fuse with planar bilayers. Two kinds of ion channels have been detected from these vesicles having estimated single channel conductances of 180 pS and 14 pS.

神经递质释放是突触传输的关键步骤。但是，触发突触囊泡融合的分子事件神经递质释放尚不清楚。一个有吸引力的假设是在囊泡膜控制融合中的Ca2+激活的通道囊泡。如果是的，那么这样的通道将提供简单的分子链接在Ca2+进入和囊泡融合之间。以前的实验有铅识别所记入的几种离子频道到突触囊泡膜。该项目的目的是研究这些离子通道以确定：1），如果有的话突触囊泡膜； 2）这些的生物物理特性频道； 3）通道的调节器（例如电压和Ca2+）。这些目标是针对阐明机制的突触囊泡融合到神经末端膜和囊泡离子通道在此过程中的可能作用。计划：平面双层实验将用于识别和表征从纯化的突触囊泡中的离子通道加利福尼亚鱼雷鱼的电动器官。囊泡膜将通过使用新技术诱导与双层融合两者都增强了所有囊泡的融合，并使估计任何观察到的通道的患病率。也就是说，它将是可能确定特定信道是否代表突触囊泡的种群或是否来自较小的污染物。初步结果：来自Torpedo Californica的突触囊泡具有被隔离和处理，使其与平面双层融合。二从具有估计的单通道电导率为180 ps和14 ps。