Hemifusion in SNARE-mediated membrane fusion.
SNAREs are essential for intracellular membrane fusion. Using EPR, we determined the structure of the transmembrane domain (TMD) of the vesicle (v)-SNARE Snc2p involved in trafficking in yeast. Structural features of the TMD were used to design a v-SNARE mutant in which about half of the TMD was deleted. Liposomes containing this mutant induced outer leaflet mixing but not inner leaflet mixing when incubated with liposomes containing target membrane (t)-SNAREs. Hemifusion was also detected with wild-type SNAREs when low protein concentrations were reconstituted. Thus, these results show that SNARE-mediated fusion can transit through a hemifusion intermediate.
Xu
Yibin
Y
Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA.
Zhang
Fan
F
Su
Zengliu
Z
McNew
James A
JA
Shin
Yeon-Kyun
YK
D004578:Electron Spin Resonance Spectroscopy; D008055:Lipids / Q000494:pharmacology; D008561:Membrane Fusion; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D017434:Protein Structure, Tertiary; D050683:R-SNARE Proteins; D050600:SNARE Proteins; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013113:Spin Labels; D033921:Vesicular Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D008055:Lipids; D008565:Membrane Proteins; D050683:R-SNARE Proteins; D050600:SNARE Proteins; C083242:SNC2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D013113:Spin Labels; D033921:Vesicular Transport Proteins