Electrostatic attraction at the core of membrane fusion

FEBS Letters

Montal, M.¹ 

[1] Department of Biology, University of California San Diego, La Jolla, CA 92093, USA

关键词: SNARE protein;    Electrostatic attraction;    Membrane fusion;   

DOI  :  10.1016/S0014-5793(99)90269-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

SNARE proteins appear to be involved in homotypic and heterotypic membrane fusion events [Söllner et al. (1993) Nature 362, 318–324]. The crystal structure of the synaptic SNARE complex exhibits a parallel four-helical bundle fold with two helices contributed by SNAP-25, a target SNARE (t-SNARE), and the other two by a different t-SNARE, syntaxin, and a donor vesicle SNARE (v-SNARE), synaptobrevin. The carboxy-terminal boundary of the complex, predicted to occur at the closest proximity between the apposed membranes, displays a high density of positively charged residues. This feature combined with the enrichment of negatively charged phospholipids in the cytosolic exposed leaflet of the membrane bilayer suggest that electrostatic attraction between oppositely charged interfaces may be sufficient to induce dynamic and discrete micellar discontinuities of the apposed membranes with the transient breakdown at the junction and subsequent reformation. Thus, the positively charged end of the SNARE complex in concert with Ca²⁺ may be sufficient to generate a transient ‘fusion pore'.

【 授权许可】

Unknown