Eukaryotic membrane fusion requires trans-SNARE complexes bridging the gap between adjacent membranes. Fusion between a transport vesicle and its target membrane transforms the trans- into a cis-SNARE complex. The latter interacts with the hexameric AAA-ATPase N-ethylmaleimide-sensitive factor (NSF) and its co-factor alpha-soluble NSF attachment protein (αSNAP), forming a 20S complex. ATPase activity disassembles the SNAP receptor (SNARE) complex into Qa-SNARE, which folds back onto itself, and its partners. The fusion of identical membranes has a different sequence of events. The fusion partners each have cis-SNARE complexes to be broken up by NSF and αSNAP. The Qa-SNARE monomers are then stabilized by interaction with Sec1/Munc18-type regulators (SM proteins) to form trans-SNARE complexes, as shown for the yeast vacuole. Membrane fusion in Arabidopsis cytokinesis is formally akin to vacuolar fusion. Membrane vesicles fuse with one another to form the partitioning membrane known as the cell plate. Cis-SNARE complexes of cytokinesis-specific Qa-SNARE KNOLLE and its SNARE partners are assembled at the endoplasmic reticulum and delivered by traffic via the Golgi/trans-Golgi network to the cell division plane. The SM protein KEULE is required for the formation of trans-SNARE complexes between adjacent membrane vesicles. Here we identify NSF and its adaptor αSNAP2 as necessary for the disassembly of KNOLLE cis-SNARE complexes, which is a prerequisite for KNOLLE-KEULE interaction in cytokinesis. In addition, we show that NSF is required for other trafficking pathways and interacts with the respective Q-SNAREs. The SNARE complex disassembly machinery is conserved in plants and plays a unique essential role in cytokinesis.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/s41477-023-01427-8 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Membrane fusion reactions limited by defective SNARE zippering or stiff lipid fatty acyl composition have distinct requirements for Sec17, Sec18, and adenine nucleotide.
bioRxiv
November 2024
Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, 7200 Vail Building, Hanover, N.H. 03755.
Intracellular membrane fusion is catalyzed by SNAREs, Rab GTPases, SM proteins, tethers, Sec18/NSF and Sec17/SNAP. Membrane fusion has been reconstituted with purified vacuolar proteins and lipids to address 3 salient questions: whether ATP hydrolysis by Sec18 affects its promotion of fusion, whether fusion promotion by Sec17 and Sec18 is only seen with mutant SNAREs or can also be seen with wild-type SNAREs, and whether Sec17 and Sec18 only promote fusion when they work together or whether they can each work separately. Fusion is driven by two engines, completion of SNARE zippering (which does not need Sec17/Sec18) and Sec17/Sec18-mediated fusion (needing SNAREs but not the energy from their complete zippering).
View Article and Find Full Text PDFAfter their membrane assembly, Sec18 (NSF) and Sec17 (SNAP) promote membrane fusion.
Mol Biol Cell
December 2024
Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755.
The energy that drives membrane fusion can come from either complete SNARE zippering, from Sec17 and Sec18, or both. Sec17 and Sec18 initially form a complex which binds membranes. Sec17, Sec18, and the apolarity of a loop on the N-domain of Sec17 are required for their interdependent membrane association.
View Article and Find Full Text PDFArticle Synopsis
- - Membrane fusion, crucial for processes like synaptic transmission, relies on the assembly of SNARE complexes, driven by various proteins that facilitate their formation.
- - This study highlights the essential roles of NSF (a AAA+ protein) and SNAP in preparing syntaxin clusters before fusion, indicating their involvement in maintaining SNARE protein quality and organization.
- - By using cryo-EM, researchers detailed how NSF and SNAP interact with syntaxin, revealing that sequential ATP hydrolysis is vital for the disassembly of SNARE complexes, suggesting these clusters act as reservoirs for efficient fusion.
Roles of the Arabidopsis Gene in Postembryonic Development.
Int J Mol Sci
June 2024
Instituto de Bioingeniería, Universidad Miguel Hernández, Campus de Elche, 03202 Elche, Spain.
Cytokinesis in plant cells begins with the fusion of vesicles that transport cell wall materials to the center of the cell division plane, where the cell plate forms and expands radially until it fuses with the parental cell wall. Vesicle fusion is facilitated by -SNARE complexes, with assistance from Sec1/Munc18 (SM) proteins. The SNARE protein KNOLLE and the SM protein KEULE are required for membrane fusion at the cell plate.
View Article and Find Full Text PDFDifferential SNARE chaperoning by Munc13-1 and Munc18-1 dictates fusion pore fate at the release site.
Nat Commun
May 2024
Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400005, India.
The regulated release of chemical messengers is crucial for cell-to-cell communication; abnormalities in which impact coordinated human body function. During vesicular secretion, multiple SNARE complexes assemble at the release site, leading to fusion pore opening. How membrane fusion regulators act on heterogeneous SNARE populations to assemble fusion pores in a timely and synchronized manner, is unknown.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!