Structure of a membrane tethering complex incorporating multiple SNAREs.
Kevin A DAmico1, Abigail E Stanton1, Jaden D Shirkey1
1Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
Nature Structural & Molecular Biology
|January 10, 2024
Summary
The study reveals the structure of the Dsl1 complex tethering complex bound to SNARE proteins, uncovering common principles in membrane fusion. This structure suggests tethers and SNAREs function as an integrated machine.
Area of Science:
- Cell biology
- Structural biology
- Biochemistry
Background:
- Membrane fusion in eukaryotic cells relies on multisubunit tethering complexes (MTCs) and SNARE proteins.
- MTCs mediate initial membrane attachment, while SNAREs drive membrane merging.
Purpose of the Study:
- To determine the cryo-electron microscopy structure of the Dsl1 complex, the simplest known MTC.
- To investigate the interaction between the Dsl1 complex and its cognate SNAREs.
Main Methods:
- Cryo-electron microscopy (cryo-EM) was used to determine the structure.
- Structural comparison between the Dsl1 complex and the exocyst MTC.
Main Results:
- The structure of the 255-kDa Dsl1 complex bound to endoplasmic reticulum-anchoring SNAREs was determined.
- Unexpected structural similarities were found between the SNARE-bound Dsl1 complex and the larger exocyst MTC.
- SNARE N-terminal domains are integral to the Dsl1 complex structure, stabilizing its conformation.
Conclusions:
- The findings suggest common functional principles for MTCs, regardless of size.
- Tethering complexes and SNAREs may operate as a unified machine in membrane fusion.
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