![]()
|
|
||||||||
J. Biol. Chem., Vol. 280, Issue 16, 15595-15600, April 22, 2005
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||

From the Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
The SNARE complex acts centrally for intracellular membrane fusion, an essential process for vesicular transport in cells. Association between vesicle-associated (v-) SNARE and target membrane (t-) SNARE results in the coiled coil core that bridges two membranes. Here, the structure of the SNARE complex assembled by recombinant t-SNARE Sso1p/Sec9 and v-SNARE Snc2p, which are involved in post-Golgi trafficking in yeast, was investigated using EPR. In detergent solutions, SNAREs formed a fully assembled core. However, when t-SNAREs were reconstituted into the proteoliposome and mixed with the soluble SNARE motif of Snc2p, a partially zipped core in which the N-terminal region is structured, whereas the C-terminal region is frayed, was detected. The partially zipped and fully assembled complexes coexisted with little free energy difference between them. Thus, the core complex formation of yeast SNAREs might not serve as the energy source for the fusion, which is different from what has been known for neuronal SNAREs. On the other hand, the results from the proteoliposome fusion assay, employing cysteine- and nitroxide-scanning mutants of Sso1p, suggested that the formation of the complete core is required for membrane fusion. This implies that core SNARE assembly plays an essential role in setting up the proper geometry of the lipid-protein complex for the successful fusion.
Received for publication, January 20, 2005 , and in revised form, February 10, 2005.
* This work was supported by grants from the National Institutes of Health. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
To whom correspondence should be addressed. Tel.: 515-294-2530; Fax: 515-294-0453; E-mail: colishin{at}iastate.edu.
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:
![]() |
L. Wang, M. A. Bittner, D. Axelrod, and R. W. Holz The Structural and Functional Implications of Linked SNARE Motifs in SNAP25 Mol. Biol. Cell, September 1, 2008; 19(9): 3944 - 3955. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Togneri, Y.-S. Cheng, M. Munson, F. M. Hughson, and C. M. Carr Specific SNARE complex binding mode of the Sec1/Munc-18 protein, Sec1p PNAS, November 21, 2006; 103(47): 17730 - 17735. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. V. Chernomordik and K. Melikov Are There Too Many or Too Few SNAREs in Proteoliposomes? Biophys. J., April 15, 2006; 90(8): 2657 - 2658. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |