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SNARE-mediated membrane fusion is a two-stage process driven by entropic forces.

ABSTRACT: SNARE proteins constitute the core of the exocytotic membrane fusion machinery. Fusion occurs when vesicle-associated and target membrane-associated SNAREs zipper into trans-SNARE complexes ('SNAREpins'), but the number required is controversial and the mechanism of cooperative fusion is poorly understood. We developed a highly coarse-grained molecular dynamics simulation to access the long fusion timescales, which revealed a two-stage process. First, zippering energy was dissipated and cooperative entropic forces assembled the SNAREpins into a ring; second, entropic forces expanded the ring, pressing membranes together and catalyzing fusion. We predict that any number of SNAREs fuses membranes, but fusion is faster with more SNAREs.

SUBMITTER: McDargh ZA

PROVIDER: S-EPMC6298751 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

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SNARE-mediated membrane fusion is a two-stage process driven by entropic forces.

McDargh Zachary A ZA Polley Anirban A O'Shaughnessy Ben B

FEBS letters 20181102 21

SNARE proteins constitute the core of the exocytotic membrane fusion machinery. Fusion occurs when vesicle-associated and target membrane-associated SNAREs zipper into trans-SNARE complexes ('SNAREpins'), but the number required is controversial and the mechanism of cooperative fusion is poorly understood. We developed a highly coarse-grained molecular dynamics simulation to access the long fusion timescales, which revealed a two-stage process. First, zippering energy was dissipated and cooperat ...[more]

PMID: 30346036

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