CALCIUM GRADIENTS AND EXOCYTOSIS IN CHROMAFFIN CELLS

嗜铬细胞中的钙梯度和胞吐作用

• 批准号: 2444900
• 负责人: JONATHAN R MONCK
• 金额: $ 10.03万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2444900
• 关键词: calcium channel; calcium flux; catecholamines; chromaffin cells; confocal scanning microscopy; cytoskeleton; exocytosis; guanine nucleotide binding protein; membrane fusion; tissue /cell culture; vesicle /vacuole; voltage /patch clamp

DESCRIPTION (adapted from the investigator's application): Ca2+ entry through voltage sensitive Ca2+ channels is the trigger for exocytosis in excitable cells. Recent evidence suggests that spatially localized Ca2+ gradients are important for regulating exocytosis. The goal of this proposal is to combine the pulsed laser Ca2+ imaging and confocal spot detection of Ca2+ transients with state-of-the-art methods for measuring exocytosis from single cells (patch clamp and voltametric measurements) in order to investigate the regulation of exocytosis by Ca2+ gradients in adrenal chromaffin cells. The experiments are designed to address the following questions. (1) What are the physiological mechanisms that control the development and extent of Ca2+ gradients at exocytotic sites? (2) What is the relationship between the Ca2+ gradients and exocytosis during depolarizing stimuli? (3) How do trains of short depolarizations, which are highly effective stimuli for exocytosis, alter the Ca2+ gradients and recruit secretory vesicles? (4) What are the roles of Ca2+ channel localization and Ca2+ buffers in Ca2+ signal localization? (5) Do the exocytotic sites behave as functional 'active zones'? And (6) what are the roles of Ca2+ gradients and GTP-binding proteins in recruitment of secretory vesicles to the exocytotic sites?

描述（改编自研究者的申请）：Ca2+ 进入 通过电压敏感的 Ca2+ 通道触发胞吐作用 兴奋细胞。 最近的证据表明，空间局部化的 Ca2+ 梯度对于调节胞吐作用很重要。 此举的目标 建议将脉冲激光 Ca2+ 成像和共焦光斑结合起来 使用最先进的测量方法检测 Ca2+ 瞬变 单细胞的胞吐作用（膜片钳和伏安测量） 为了研究Ca2+梯度对胞吐作用的调节 肾上腺嗜铬细胞。 这些实验旨在解决 以下问题。 (1) 控制的生理机制有哪些？ 胞吐位点 Ca2+ 梯度的发展和范围？ (2) 什么 是 Ca2+ 梯度和胞吐作用之间的关系 去极化刺激？ (3) 短去极化列车如何进行 高效刺激胞吐作用，改变 Ca2+ 梯度和 募集分泌囊泡？ (4)Ca2+通道的作用是什么 Ca2+信号定位中的定位和Ca2+缓冲液？ (5) 执行以下操作 胞吐位点充当功能性“活性区”？ 以及 (6) 什么是 Ca2+ 梯度和 GTP 结合蛋白在分泌细胞招募中的作用 囊泡到胞吐位点？