气候变化领域集成服务门户(CCPortal): Nascent fusion pore opening monitored at single-SNAREpin resolution

CCPortal

DOI	10.1073/pnas.2024922118
	Nascent fusion pore opening monitored at single-SNAREpin resolution
	Heo P.; Coleman J.; Fleury J.-B.; Rothman J.E.; Pincet F.
发表日期	2021
ISSN	00278424
卷号	118 期号:5
英文摘要	Vesicle fusion with a target membrane is a key event in cellular trafficking and ensures cargo transport within the cell and between cells. The formation of a protein complex, called SNAREpin, provides the energy necessary for the fusion process. In a three-dimensional microfluidic chip, we monitored the fusion of small vesicles with a suspended asymmetric lipid bilayer. Adding ion channels into the vesicles, our setup allows the observation of a single fusion event by electrophysiology with 10-μs precision. Intriguingly, we identified that small transient fusion pores of discrete sizes reversibly opened with a characteristic lifetime of ∼350 ms. The distribution of their apparent diameters displayed two peaks, at 0.4 ± 0.1 nm and 0.8 ± 0.2 nm. Varying the number of SNAREpins, we demonstrated that the first peak corresponds to fusion pores induced by a single SNAREpin and the second peak is associated with pores involving two SNAREpins acting simultaneously. The pore size fluctuations provide a direct estimate of the energy landscape of the pore. By extrapolation, the energy landscape for three SNAREpins does not exhibit any thermally significant energy barrier, showing that pores larger than 1.5 nm are spontaneously produced by three or more SNAREpins acting simultaneously, and expand indefinitely. Our results quantitatively explain why one SNAREpin is sufficient to open a fusion pore and more than three SNAREpins are required for cargo release. Finally, they also explain why a machinery that synchronizes three SNAREpins, or more, is mandatory to ensure fast neurotransmitter release during synaptic transmission. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Membrane fusion; Metastable states; SNAREs; Suspended bilayer
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180807
作者单位	Laboratoire de Physique de l’Ecole Normale Supérieure, Ecole Normale Supérieure (ENS), Université Paris Sciences et Lettres (PSL), CNRS, Sorbonne Université, Université de Paris, Paris, F-75005, France; Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Paris, F-75014, France; Department of Cell Biology, School of Medicine, Yale University, New Haven, CT 06520, United States; Nanobiology Institute, Yale School of Medicine, West Haven, CT 06516, United States; Department of Experimental Physics, Saarland University, Saarbruecken, D-66123, Germany; Center for Biophysics, Saarland University, Saarbruecken, D-66123, Germany
推荐引用方式 GB/T 7714	Heo P.,Coleman J.,Fleury J.-B.,et al. Nascent fusion pore opening monitored at single-SNAREpin resolution[J],2021,118(5).
APA	Heo P.,Coleman J.,Fleury J.-B.,Rothman J.E.,&Pincet F..(2021).Nascent fusion pore opening monitored at single-SNAREpin resolution.Proceedings of the National Academy of Sciences of the United States of America,118(5).
MLA	Heo P.,et al."Nascent fusion pore opening monitored at single-SNAREpin resolution".Proceedings of the National Academy of Sciences of the United States of America 118.5(2021).