Asymmetric phospholipid distribution drives in vitro reconstituted SNARE-dependent membrane fusion

Jérôme Vicogne, Daniel Vollenweider, Jeffery R. Smith, Ping Huang, Michael A. Frohman, Jeffrey E. Pessin

Research output: Contribution to journalArticle

91 Scopus citations

Abstract

Insulin-stimulated glucose uptake requires the fusion of GLUT4 transporter-containing vesicles with the plasma membrane, a process that depends on the SNARE (soluble N-ethylmaleimide-sensitive fusion factor attachment receptor) proteins VAMP2 (vesicle-associated membrane protein 2) and syntaxin 4 (Stx4)/SNAP23 (soluble N-ethylmaleimide-sensitive fusion factor attachment protein 23). Efficient SNARE-dependent fusion has been shown in many settings in vivo to require the generation of both phosphatidylinositol-4,5-bisphosphate (PIP2) and phosphatidic acid (PA). Addition of PA to Stx4/SNAP23 vesicles markedly enhanced the fusion rate, whereas its addition to VAMP2 vesicles was inhibitory. In contrast, addition of PIP2 to Stx4/SNAP23 vesicles inhibited the fusion reaction, and its addition to VAMP2 vesicles was stimulatory. The optimal distribution of phospholipids was found to trigger the progression from the hemifused state to full fusion. These findings reveal an unanticipated dependence of SNARE complex-mediated fusion on asymmetrically distributed acidic phospholipids and provide mechanistic insights into the roles of phospholipase D and PIP kinases in the late stages of regulated exocytosis.

Original languageEnglish (US)
Pages (from-to)14761-14766
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume103
Issue number40
DOIs
StatePublished - Oct 3 2006

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Keywords

  • SNAP23
  • Syntaxin 4
  • VAMP2

ASJC Scopus subject areas

  • General

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