The Munc18-1 domain 3a hinge-loop controls syntaxin-1A nanodomain assembly and engagement with the SNARE complex during secretory vesicle priming

Kasula, Ravikiran, Chai, Ye Jin, Bademosi, Adekunle T., Harper, Callista B., Gormal, Rachel S., Morrow, Isabel C., Hosy, Eric, Collins, Brett M., Choquet, Daniel, Papadopulos, Andreas and Meunier, Frederic A. (2016) The Munc18-1 domain 3a hinge-loop controls syntaxin-1A nanodomain assembly and engagement with the SNARE complex during secretory vesicle priming. The Journal of Cell Biology, 214 7: 847-858. doi:10.1083/jcb.201508118


Author Kasula, Ravikiran
Chai, Ye Jin
Bademosi, Adekunle T.
Harper, Callista B.
Gormal, Rachel S.
Morrow, Isabel C.
Hosy, Eric
Collins, Brett M.
Choquet, Daniel
Papadopulos, Andreas
Meunier, Frederic A.
Title The Munc18-1 domain 3a hinge-loop controls syntaxin-1A nanodomain assembly and engagement with the SNARE complex during secretory vesicle priming
Journal name The Journal of Cell Biology   Check publisher's open access policy
ISSN 1540-8140
0021-9525
Publication date 2016-09-26
Year available 2016
Sub-type Article (original research)
DOI 10.1083/jcb.201508118
Open Access Status DOI
Volume 214
Issue 7
Start page 847
End page 858
Total pages 12
Place of publication New York, United States
Publisher Rockefeller University Press
Language eng
Abstract Munc 18-1 and syntaxin-1A control SNARE-dependent neuroexocytosis and are organized in nanodomains on the plasma membrane of neurons and neurosecretory cells. Deciphering the intra- and intermolecular steps via which they prepare secretory vesicles (SVs) for fusion is key to understanding neuronal and hormonal communication. Here, we demonstrate that expression of a priming-deficient mutant lacking 17 residues of the domain 3a hinge-loop (Munc 18-1(Delta 317-333)) in PC12 cells engineered to knockdown Munc 18-1/2 markedly prolonged SV docking. Single-molecule analysis revealed nonhomogeneous diffusion of Muncl 8-1 and syntaxin-1A in and out of partially overlapping nanodomains. Whereas Munc 18-1(WT) mobility increased in response to stimulation, syntaxin-1A became less mobile. These Munc 18-1 and syntaxin-1A diffusional switches were blocked by the expression of Munc 18-1(Delta 317-333), suggesting that a conformational change in the Munc 18-1 hinge-loop controls syntaxin-1A and subsequent SNARE complex assembly. Accordingly, syntaxin-1A confinement was prevented by expression of botulinum neurotoxin type E. The Munc 18-1 domain 3a hinge-loop therefore controls syntaxin-1A engagement into SNA RE complex formation during priming.
Formatted abstract
Munc18-1 and syntaxin-1A control SNARE-dependent neuroexocytosis and are organized in nanodomains on the plasma membrane of neurons and neurosecretory cells. Deciphering the intra- and intermolecular steps via which they prepare secretory vesicles (SVs) for fusion is key to understanding neuronal and hormonal communication. Here, we demonstrate that expression of a priming-deficient mutant lacking 17 residues of the domain 3a hinge-loop (Munc18-1Δ317-333) in PC12 cells engineered to knockdown Munc18-1/2 markedly prolonged SV docking. Single-molecule analysis revealed nonhomogeneous diffusion of Munc18-1 and syntaxin-1A in and out of partially overlapping nanodomains. Whereas Munc18-1WT mobility increased in response to stimulation, syntaxin-1A became less mobile. These Munc18-1 and syntaxin-1A diffusional switches were blocked by the expression of Munc18-1Δ317-333, suggesting that a conformational change in the Munc18-1 hinge-loop controls syntaxin-1A and subsequent SNARE complex assembly. Accordingly, syntaxin-1A confinement was prevented by expression of botulinum neurotoxin type E. The Munc18-1 domain 3a hinge-loop therefore controls syntaxin-1A engagement into SNARE complex formation during priming.
Keyword Cell Biology
Cell Biology
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID ANR ANR-10-INBS-04
GNT1044014
LE0882864
Institutional Status UQ

 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 1 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 1 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Fri, 30 Sep 2016, 23:21:40 EST by Susan Allen on behalf of Institute for Molecular Bioscience