Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19731-6. Epub 2006 Dec 13.

Multiple intermediates in SNARE-induced membrane fusion.

Author information

1
Howard Hughes Medical Institute, Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.

Abstract

Membrane fusion in eukaryotic cells is thought to be mediated by a highly conserved family of proteins called SNAREs (soluble N-ethyl maleimide sensitive-factor attachment protein receptors). The vesicle-associated v-SNARE engages with its partner t-SNAREs on the target membrane to form a coiled coil that bridges two membranes and facilitates fusion. As demonstrated by recent findings on the hemifusion state, identifying intermediates of membrane fusion can help unveil the underlying fusion mechanism. Observation of SNARE-driven fusion at the single-liposome level has the potential to dissect and characterize fusion intermediates most directly. Here, we report on the real-time observation of lipid-mixing dynamics in a single fusion event between a pair of SNARE-reconstituted liposomes. The assay reveals multiple intermediate states characterized by discrete values of FRET between membrane-bound fluorophores. Hemifusion, flickering of fusion pores, and kinetic transitions between intermediates, which would be very difficult to detect in ensemble assays, are now identified. The ability to monitor the time course of fusion events between two proteoliposomes should be useful for addressing many important issues in SNARE-mediated membrane fusion.

Comment in

PMID:
17167056
PMCID:
PMC1698870
DOI:
10.1073/pnas.0606032103
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center