Steric hindrance of SNARE transmembrane domain organization impairs the hemifusion‐to‐fusion transition

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Serval ID
serval:BIB_63B85777BBAC
Type
Article: article from journal or magazin.
Collection
Publications
Title
Steric hindrance of SNARE transmembrane domain organization impairs the hemifusion‐to‐fusion transition
Journal
EMBO Reports
Author(s)
D'Agostino Massimo, Risselada Herre Jelger, Mayer Andreas
ISSN
1469-3178
ISSN-L
1469-221X
Publication state
Published
Issued date
2016
Peer-reviewed
Oui
Volume
17
Number
11
Pages
1590-1608
Language
english
Abstract
SNAREs fuse membranes in several steps. Trans-SNARE complexes juxtapose membranes, induce hemifused stalk structures, and open the fusion pore. A recent penetration model of fusion proposed that SNAREs force the hydrophilic C-termini of their transmembrane domains through the hydrophobic core of the membrane(s). In contrast, the indentation model suggests that the C-termini open the pore by locally compressing and deforming the stalk. Here we test these models in the context of yeast vacuole fusion. Addition of small hydrophilic tags renders bilayer penetration by the C-termini energetically unlikely. It preserves fusion activity, however, arguing against the penetration model. Addition of large protein tags to the C-termini permits SNARE activation, trans-SNARE pairing, and hemifusion but abolishes pore opening. Fusion proceeds if the tags are detached from the membrane by a hydrophilic spacer or if only one side of the trans-SNARE complex carries a protein tag. Thus, both sides of a trans-SNARE complex can drive pore opening. Our results are consistent with an indentation model in which multiple SNARE C-termini cooperate in opening the fusion pore by locally deforming the inner leaflets.
Keywords
exocytosis, lysosome, membrane fusion, SNAREs, vacuole
Pubmed
Web of science
Open Access
Yes
Create date
01/12/2016 9:17
Last modification date
20/08/2019 15:20
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