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Structure of a Membrane Tethering Complex Incorporating Multiple SNAREs.

ABSTRACT: Most membrane fusion reactions in eukaryotic cells are mediated by membrane tethering complexes (MTCs) and SNARE proteins. MTCs are much larger than SNAREs and are thought to mediate the initial attachment of two membranes. Complementary SNAREs then form membrane-bridging complexes whose assembly draws the membranes together for fusion. Here, we present a cryo-EM structure of the simplest known MTC, the 255-kDa Dsl1 complex, bound to the two SNAREs that anchor it to the endoplasmic reticulum. N-terminal domains of the SNAREs form an integral part of the structure, stabilizing a Dsl1 complex configuration with remarkable and unexpected similarities to the 850-kDa exocyst MTC. The structure of the SNARE-anchored Dsl1 complex and its comparison with exocyst reveal what are likely to be common principles underlying MTC function. Our structure also implies that tethers and SNAREs can work together as a single integrated machine.

SUBMITTER: DAmico KA

PROVIDER: S-EPMC9915479 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature

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Structure of a Membrane Tethering Complex Incorporating Multiple SNAREs.

DAmico Kevin A KA Stanton Abigail E AE Shirkey Jaden D JD Travis Sophie M SM Jeffrey Philip D PD Hughson Frederick M FM

bioRxiv : the preprint server for biology 20230130

Most membrane fusion reactions in eukaryotic cells are mediated by membrane tethering complexes (MTCs) and SNARE proteins. MTCs are much larger than SNAREs and are thought to mediate the initial attachment of two membranes. Complementary SNAREs then form membrane-bridging complexes whose assembly draws the membranes together for fusion. Here, we present a cryo-EM structure of the simplest known MTC, the 255-kDa Dsl1 complex, bound to the two SNAREs that anchor it to the endoplasmic reticulum. N- ...[more]

PMID: 36778436

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