Molecular architecture of synaptic vesicles

• 成果类型: Article
• 署名作者: Kravcenko, Uljana; Ruwolt, Max; Kroll, Jana; Yushkevich, Artsemi; Zenkner, Martina; Ruta, Julia; Lotfy, Rowaa; Wanker, Erich E.; Rosenmund, Christian; Liu, Fan; Kudryashev, Mikhail
• 署名单位: Helmholtz Association; Max Delbruck Center for Molecular Medicine; Humboldt University of Berlin; Helmholtz Association; Max Delbruck Center for Molecular Medicine; Free University of Berlin; Free University of Berlin; Humboldt University of Berlin; Charite Universitatsmedizin Berlin; Humboldt University of Berlin; Helmholtz Association; Max Delbruck Center for Molecular Medicine; Free University of Berlin; Free University of Berlin; Humboldt University of Berlin; Charite Universitatsmedizin Berlin; Free University of Berlin; Humboldt University of Berlin; Charite Universitatsmedizin Berlin
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12030
• DOI: 10.1073/pnas.2407375121
• 发表日期: 2024-12-03
• 关键词: clathrin-coated vesicles; v-atpase; cryoelectron tomography; cryo-em; protein; synaptophysin; synaptobrevin; RESOLUTION; endocytosis; association

摘要

Synaptic vesicles (SVs) store and transport neurotransmitters to the presynaptic active zone for release by exocytosis. After release, SV proteins and excess membrane are recycled via endocytosis, and new SVs can be formed in a clathrin- dependent manner. This process maintains complex molecular composition of SVs through multiple recycling rounds. Previous studies explored the molecular composition of SVs through proteomic analysis and fluorescent microscopy, proposing a model for an average SV (1). However, the structural heterogeneity and molecular architecture of individual SVs are not well described. Here, we used cryoelectron tomography to visualize molecular details of SVs isolated from mouse brains and inside cultured neurons. We describe several classes of small proteins on the SV surface and long proteinaceous densities inside SVs. We identified V- ATPases, determined a structure using subtomogram averaging, and showed them forming a complex with the membrane- embedded protein synaptophysin (Syp). Our bioluminescence assay revealed pairwise interactions between vesicle- associated membrane protein 2 and Syp and V- ATPase Voe1 domains. Interestingly, V- ATPases were randomly distributed on the surface of SVs irrespective of vesicle size. A subpopulation of isolated vesicles and vesicles inside neurons contained a partially assembled clathrin coat with an icosahedral symmetry. We observed V- ATPases under clathrin cages in several isolated clathrin- coated vesicles (CCVs). Additionally, from isolated SV preparations and within hippocampal neurons we identified clathrin baskets without vesicles. We determined their and CCVs preferential location in proximity to the cell membrane. Our analysis advances the understanding of individual SVs' diversity and their molecular architecture.