STRUCTURE OF THE EXOCYTOTIC FUSION PORE IN MAST CELLS

肥大细胞胞吐融合孔的结构

• 批准号: 2184179
• 负责人: Julio M Fernandez
• 金额: $ 23.03万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-02-01 至 1996-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2184179
• 关键词: anesthetics; biological signal transduction; calcium; cell membrane; cellular polarity; chemical structure function; conformation; electrical conductance; endocytosis; exocytosis; fatty acids; fluidity; fluorescence microscopy; fluorescent dye /probe; gene mutation; guanine nucleotide binding protein; guanine nucleotides; laboratory mouse; mast cell; membrane fusion; membrane lipids; membrane permeability; membrane potentials; membrane structure; pigments; pore forming protein; single cell analysis; temperature; time resolved data; vesicle /vacuole; voltage /patch clamp

The long-term goal of this proposal is to elucidate the molecular structure of the exocytotic fusion pore, the water-filled connection that forms between the lumen of a secretory granule and the extracellular space, upon exocytosis. Understanding the structure and regulation of the exocytotic fusion pore is one of the most outstanding questions on the mechanisms of exocytotic secretion. Towards this aim we will measure the time course of the conductance of single fusion pores. Pore conductance will be measured from the changes in the admittance of single patch-clamped mast cells caused by the formation of individual fusion pores as the cell undergoes exocytosis. We will study exocytotic fusion pores that form transiently and fusion pores that, after formation, expand irreversibly, completing exocytosis. We will also study the pores that form in the final stages of membrane retrieval events. We will classify and characterize the stages of development and the properties of the three types of pores. We will attempt to perturb each stage gain knowledge about the participating molecular structures. We will perturb pore structure by changing the physical properties of the mast cell membrane through changes in temperature, addition of anesthetics or fatty acid supplements; by chemical regulators like GTPgammaS and Ca++; and by genetic mutations like those of the pigment mutant Ruby. The result of these manipulations will be the basis for proposing models of the structure of the fusion pore as it evolves to complete the exocytotic event.

该提案的长期目标是阐明分子结构 胞吐融合孔，形成充满水的连接 分泌颗粒的内腔和细胞外空间之间， 胞吐作用。 了解胞吐的结构和调节 融合孔是有关机制中最突出的问题之一 胞吐分泌。 为了实现这一目标，我们将测量时间进程 单个熔合孔的电导率。 将测量孔隙电导率 来自单个膜片钳肥大细胞的接纳变化 由于细胞经历过程中形成单独的融合孔而引起 胞吐作用。 我们将研究瞬时形成的胞吐融合孔 和融合孔，形成后不可逆地扩大，完成 胞吐作用。 我们还将研究在最后阶段形成的毛孔 膜回收事件。 我们将对各个阶段进行分类和描述 三种孔隙的发育和性质。 我们将 尝试扰乱每个阶段获得有关参与的知识 分子结构。 我们将通过改变 通过改变肥大细胞膜的物理特性 温度、添加麻醉剂或脂肪酸补充剂；通过化学 GTPgammaS 和 Ca++ 等调节剂；以及像那些基因突变 色素突变体红宝石。 这些操作的结果将是 提出融合孔结构模型的基础 进化以完成胞吐事件。