Rapid structural change in synaptosomal-associated protein 25 (SNAP25) precedes the fusion of single vesicles with the plasma membrane in live chromaffin cells

Ying Zhao, Qinghua Fang, Adam Drew Herbst, Khajak N. Berberian, Wolfhard Almers, Manfred Lindau

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

The SNARE complex consists of the three proteins synaptobrevin-2, syntaxin, and synaptosomal-associated protein 25 (SNAP25) and is thought to execute a large conformational change as it drives membrane fusion and exocytosis. The relation between changes in the SNARE complex and fusion pore opening is, however, still unknown. We report here a direct measurement relating a change in the SNARE complex to vesicle fusion on the millisecond time scale. In individual chromaffin cells, we tracked conformational changes in SNAP25 by total internal reflection fluorescence resonance energy transfer (FRET) microscopy while exocytotic catecholamine release from single vesicles was simultaneously recorded using a microfabricated electrochemical detector array. A local rapid and transient FRET change occurred precisely where individual vesicles released catecholamine. To overcome the low time resolution of the imaging frames needed to collect sufficient signal intensity, a method named event correlation microscopy was developed, which revealed that the FRET change was abrupt and preceded the opening of an exocytotic fusion pore by ~90 ms. The FRET change correlated temporally with the opening of the fusion pore and not with its dilation.

Original languageEnglish (US)
Pages (from-to)14249-14254
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume110
Issue number35
DOIs
StatePublished - Aug 27 2013

Keywords

  • Electrochemical imaging
  • Image analysis
  • TIR-FRET imaging
  • Time superresolution microscopy
  • Transmitter release

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Rapid structural change in synaptosomal-associated protein 25 (SNAP25) precedes the fusion of single vesicles with the plasma membrane in live chromaffin cells'. Together they form a unique fingerprint.

  • Cite this