Rapid and efficient fusion of phospholipid vesicles by the alpha-helical core of a SNARE complex in the absence of an N-terminal regulatory domain.
A protease-resistant core domain of the neuronal SNARE complex consists of an alpha-helical bundle similar to the proposed fusogenic core of viral fusion proteins [Skehel, J. J. & Wiley, D. C. (1998) Cell 95, 871-874]. We find that the isolated core of a SNARE complex efficiently fuses artificial bilayers and does so faster than full length SNAREs. Unexpectedly, a dramatic increase in speed results from removal of the N-terminal domain of the t-SNARE syntaxin, which does not affect the rate of assembly of v-t SNARES. In the absence of this negative regulatory domain, the half-time for fusion of an entire population of lipid vesicles by isolated SNARE cores ( approximately 10 min) is compatible with the kinetics of fusion in many cell types.
Parlati
F
F
Cellular Biochemistry Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Box 251 New York, NY 10021, USA.
Weber
T
T
McNew
J A
JA
Westermann
B
B
Söllner
T H
TH
Rothman
J E
JE
D008051:Lipid Bilayers; D008561:Membrane Fusion; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000737:chemistry; D010743:Phospholipids / Q000378:metabolism*; D050765:Qa-SNARE Proteins; D050600:SNARE Proteins; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins
D008051:Lipid Bilayers; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010743:Phospholipids; D050765:Qa-SNARE Proteins; D050600:SNARE Proteins; D050825:Synaptosomal-Associated Protein 25; D033921:Vesicular Transport Proteins