α-SNAP interferes with the zippering of the SNARE protein membrane fusion machinery.
Neuronal exocytosis is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. Before fusion, SNARE proteins form complexes bridging the membrane followed by assembly toward the C-terminal membrane anchors, thus initiating membrane fusion. After fusion, the SNARE complex is disassembled by the AAA-ATPase N-ethylmaleimide-sensitive factor that requires the cofactor α-SNAP to first bind to the assembled SNARE complex. Using chromaffin granules and liposomes we now show that α-SNAP on its own interferes with the zippering of membrane-anchored SNARE complexes midway through the zippering reaction, arresting SNAREs in a partially assembled trans-complex and preventing fusion. Intriguingly, the interference does not result in an inhibitory effect on synaptic vesicles, suggesting that membrane properties also influence the final outcome of α-SNAP interference with SNARE zippering. We suggest that binding of α-SNAP to the SNARE complex affects the ability of the SNARE complex to harness energy or transmit force to the membrane.
From the Department of Neurobiology.
Yongsoo
Y
Park
From the Department of Neurobiology, the AG Biomolecular Spectroscopy and Single-Molecule Detection, and.
Wensi
W
Vennekate
From the Department of Neurobiology.
Halenur
H
Yavuz
From the Department of Neurobiology.
Julia
J
Preobraschenski
From the Department of Neurobiology.
Javier M
JM
Hernandez
the Facility for Electron Microscopy, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen and.
Dietmar
D
Riedel
the AG Biomolecular Spectroscopy and Single-Molecule Detection, and the Department of Biophysical Chemistry, Institute for Physical and Theoretical Chemistry, Technical University of Braunschweig, 38106 Braunschweig, Germany.
Peter Jomo
PJ
Walla
From the Department of Neurobiology, rjahn@gwdg.de.
Reinhard
R
Jahn
D000818:Animals; D002417:Cattle; D004705:Endocytosis; D005454:Fluorescence Polarization; D031541:Fluorescence Resonance Energy Transfer; D008561:Membrane Fusion; D011510:Proteolipids; D050600:SNARE Proteins / Q000502:physiology*; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins / Q000502:physiology*
D011510:Proteolipids; D050600:SNARE Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; C020485:proteoliposomes
Chromaffin Cells; Fusion Protein; Neurobiology; Soluble NSF Attachment Protein Receptor (SNARE); Synapse; Vesicles