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Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore

SNARE-dependent membrane fusion is essential for neurotransmitter release at the synapse. Recently, α-synuclein has emerged as an important regulator for membrane fusion. Misfolded α-synuclein oligomers are potent fusion inhibitors. However, the function of normal α-synuclein has been elusive. Here,...

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Autores principales: Khounlo, Ryan, Hawk, Brenden J. D., Khu, Tung-Mei, Yoo, Gyeongji, Lee, Nam Ki, Pierson, Josh, Shin, Yeon-Kyun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8326570/
https://www.ncbi.nlm.nih.gov/pubmed/34350173
http://dx.doi.org/10.3389/fcell.2021.663431
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author Khounlo, Ryan
Hawk, Brenden J. D.
Khu, Tung-Mei
Yoo, Gyeongji
Lee, Nam Ki
Pierson, Josh
Shin, Yeon-Kyun
author_facet Khounlo, Ryan
Hawk, Brenden J. D.
Khu, Tung-Mei
Yoo, Gyeongji
Lee, Nam Ki
Pierson, Josh
Shin, Yeon-Kyun
author_sort Khounlo, Ryan
collection PubMed
description SNARE-dependent membrane fusion is essential for neurotransmitter release at the synapse. Recently, α-synuclein has emerged as an important regulator for membrane fusion. Misfolded α-synuclein oligomers are potent fusion inhibitors. However, the function of normal α-synuclein has been elusive. Here, we use the single vesicle-to-supported bilayer fusion assay to dissect the role of α-synuclein in membrane fusion. The assay employs 10 kD Rhodamine B-dextran as the content probe that can detect fusion pores larger than ∼6 nm. We find that the SNARE complex alone is inefficient at dilating fusion pores. However, α-synuclein dramatically increases the probability as well as the duration of large pores. When the SNARE-interacting C-terminal region of α-synuclein was truncated, the mutant behaves the same as the wild-type. However, the double proline mutants compromising membrane-binding show significantly reduced effects on fusion pore expansion. Thus, our results suggest that α-synuclein stimulates fusion pore expansion specifically through its membrane binding.
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spelling pubmed-83265702021-08-03 Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore Khounlo, Ryan Hawk, Brenden J. D. Khu, Tung-Mei Yoo, Gyeongji Lee, Nam Ki Pierson, Josh Shin, Yeon-Kyun Front Cell Dev Biol Cell and Developmental Biology SNARE-dependent membrane fusion is essential for neurotransmitter release at the synapse. Recently, α-synuclein has emerged as an important regulator for membrane fusion. Misfolded α-synuclein oligomers are potent fusion inhibitors. However, the function of normal α-synuclein has been elusive. Here, we use the single vesicle-to-supported bilayer fusion assay to dissect the role of α-synuclein in membrane fusion. The assay employs 10 kD Rhodamine B-dextran as the content probe that can detect fusion pores larger than ∼6 nm. We find that the SNARE complex alone is inefficient at dilating fusion pores. However, α-synuclein dramatically increases the probability as well as the duration of large pores. When the SNARE-interacting C-terminal region of α-synuclein was truncated, the mutant behaves the same as the wild-type. However, the double proline mutants compromising membrane-binding show significantly reduced effects on fusion pore expansion. Thus, our results suggest that α-synuclein stimulates fusion pore expansion specifically through its membrane binding. Frontiers Media S.A. 2021-07-19 /pmc/articles/PMC8326570/ /pubmed/34350173 http://dx.doi.org/10.3389/fcell.2021.663431 Text en Copyright © 2021 Khounlo, Hawk, Khu, Yoo, Lee, Pierson and Shin. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Cell and Developmental Biology
Khounlo, Ryan
Hawk, Brenden J. D.
Khu, Tung-Mei
Yoo, Gyeongji
Lee, Nam Ki
Pierson, Josh
Shin, Yeon-Kyun
Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore
title Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore
title_full Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore
title_fullStr Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore
title_full_unstemmed Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore
title_short Membrane Binding of α-Synuclein Stimulates Expansion of SNARE-Dependent Fusion Pore
title_sort membrane binding of α-synuclein stimulates expansion of snare-dependent fusion pore
topic Cell and Developmental Biology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8326570/
https://www.ncbi.nlm.nih.gov/pubmed/34350173
http://dx.doi.org/10.3389/fcell.2021.663431
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