The Function of Synuclein

突触核蛋白的功能

• 批准号: 10569089
• 负责人: ROBERT H EDWARDS
• 金额: $ 50.35万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10569089
• 关键词: Actins; Behavior; Binding; Biological Assay; Catecholamines; Cell membrane; Chromaffin Cells; Chromaffin granule; Cytoplasmic Granules; Cytoskeleton; Data; Dense Core Vesicle; Disease; Dyes; Early Intervention; Electron Microscopy; Event; Exocytosis; Human Genetics; Idiopathic Parkinson Disease; Image; Impairment; In Vitro; Individual; Inherited; Knockout Mice; Membrane; Membrane Fusion; Methods; Monitor; Mutation; N-terminal; Nerve Degeneration; Nervous System; Neuromodulator; Neurons; Neurotransmitters; Parkinson Disease; Pathogenesis; Pathogenicity; Patients; Peptides; Phosphorylation; Phosphorylation Site; Process; Proteins; Regulation; Resolution; Role; Running; Secretory Vesicles; Signal Transduction; Structure; Synaptic Vesicles; System; Terminal Repeat Sequences; Testing; Time; Vesicle; Work; alpha synuclein; genetic manipulation; light microscopy; millisecond; pharmacologic; postsynaptic; presynaptic; programs; response; seal; synuclein; tool; vesicular release

Signaling in the nervous system depends on the regulated exocytosis of specialized secretory vesicles. Membrane fusion initiates the process of release, but behavior of the pore formed by fusion can control the rate, extent and identity of what is released. Indeed, the fusion pore can reseal before full vesicle collapse into the plasma membrane, potentially trapping unreleased cargo in a form of exocytosis known as `kiss-and-run', a regulatory mechanism well-established for large dense core vesicles (LDCVs), which release neuromodulators. However, the mechanisms that regulate behavior of the fusion pore have remained unclear and its role in the release of classical neurotransmitters from synaptic vesicles (SVs) has been controversial. The actin cytoskeleton and its associated proteins have been suggested to influence pore behavior but the role has remained unclear. The presynaptic protein α-synuclein has a central role in the pathogenesis of Parkinson's disease (PD). Human genetics shows that mutations in synuclein can cause the disease and the protein accumulates in all patients with the idiopathic disorder. Like other proteins important for neurodegeneration, however, its normal function has remained unknown. Using knockout mice and imaging by light and electron microscopy, we have found that endogenous synuclein normally regulates the fusion pore formed by both LDCVs and SVs, thus influencing the mode of release. The long-term objectives of this program are to understand how synuclein cooperates with other cellular factors to promote fusion pore dilation and how a disturbance in this activity contributes to disease. Since the available methods have limited analysis of the fusion pore and vesicle collapse, we have developed new methods to image the full scope of exocytosis by individual vesicles. Using these, we will study the role of synuclein in pore dilation and membrane collapse by both large dense core vesicles and synaptic vesicles. Specifically, we propose to 1) Characterize the role of synuclein in exocytosis by imaging at high resolution with several complementary methods, including false fluorescent neurotransmitters and Alexa dye entry. 2) Assess the interaction of synuclein with the actin cytoskeleton. Observations in multiple systems have implicated the actin cystoskeleton in exocytosis including pore dilation and we will determine whether synuclein acts through a common or independent mechanism. 3) Determine how the structure of α-synuclein contributes to its role in exocytosis. We will determine how the N- terminal repeats and C-terminus contribute to normal function. We will test the role of established phosphorylation sites since they may contribute to idiopathic disease by mimicking inherited mutations.

神经系统中的信号依赖于特殊分泌囊泡的胞外分泌调节。

项目成果

High-speed imaging reveals the bimodal nature of dense core vesicle exocytosis.

• DOI: 10.1073/pnas.2214897120
• 发表时间: 2023-01-03
• 期刊: Proceedings of the National Academy of Sciences of the United States of America
• 影响因子: 11.1
• 作者: Zhang P;Rumschitzki D;Edwards RH
• 通讯作者: Edwards RH