A direct role for the Sec1/Munc18-family protein Vps33 as a template for SNARE assembly

Science. 2015 Sep 4;349(6252):1111-4. doi: 10.1126/science.aac7906.

Authors

Richard W Baker¹, Philip D Jeffrey¹, Michael Zick², Ben P Phillips¹, William T Wickner², Frederick M Hughson³

Affiliations

¹ Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
² Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.
³ Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA. hughson@princeton.edu.

Abstract

Fusion of intracellular transport vesicles requires soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and Sec1/Munc18-family (SM) proteins. Membrane-bridging SNARE complexes are critical for fusion, but their spontaneous assembly is inefficient and may require SM proteins in vivo. We report x-ray structures of Vps33, the SM subunit of the yeast homotypic fusion and vacuole protein-sorting (HOPS) complex, bound to two individual SNAREs. The two SNAREs, one from each membrane, are held in the correct orientation and register for subsequent complex assembly. Vps33 and potentially other SM proteins could thus act as templates for generating partially zipped SNARE assembly intermediates. HOPS was essential to mediate SNARE complex assembly at physiological SNARE concentrations. Thus, Vps33 appears to catalyze SNARE complex assembly through specific SNARE motif recognition.

Publication types

Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Crystallography, X-Ray
Membrane Proteins / chemistry
Membrane Proteins / metabolism
Munc18 Proteins / metabolism*
Protein Binding
Protein Structure, Secondary
Protein Structure, Tertiary
Qa-SNARE Proteins / metabolism*
R-SNARE Proteins / metabolism*
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins / chemistry
Saccharomyces cerevisiae Proteins / metabolism*
Saccharomyces cerevisiae Proteins / ultrastructure
Synaptosomal-Associated Protein 25 / chemistry
Synaptosomal-Associated Protein 25 / metabolism
Vesicular Transport Proteins / chemistry
Vesicular Transport Proteins / metabolism*
Vesicular Transport Proteins / ultrastructure

Substances

Membrane Proteins
Munc18 Proteins
Nyv1 protein, S cerevisiae
Qa-SNARE Proteins
R-SNARE Proteins
Saccharomyces cerevisiae Proteins
Synaptosomal-Associated Protein 25
VAM7 protein, S cerevisiae
VPS33 protein, S cerevisiae
Vesicular Transport Proteins

Associated data

PDB/5BUZ
PDB/5BV0
PDB/5BV1

Abstract

Publication types

MeSH terms

Substances

Associated data

Grants and funding