A Chemical Controller of SNARE-Driven Membrane Fusion That Primes Vesicles for Ca2+-Triggered Millisecond Exocytosis

• DOI: 10.1021/jacs.5b13449
• Publication Date: 2016-03-18T02:12:26Z
• Authors: Paul Heo; Yoosoo Yang; Kyu Young Han; Byoungjae Kong; Jong-Hyeok Shin; Younghoon Jung; Cherlhyun Jeong; Jaeil Shin; Yeon-Kyun Shin; Taekjip Ha; Dae-Hyuk Kweon
• Keywords: Millisecond

Membrane fusion is mediated by the SNARE complex which formed through a zippering process. Here, we developed chemical controller for progress of membrane fusion. A hemifusion state was arrested polyphenol myricetin binds to complex. The arrest rescued an enzyme laccase that removes from metastable and long-lived with decay constant 39 min. This applied delineate how Ca(2+) stimulates fusion-pore formation in millisecond time scale. We found, using single-vesicle assay, such myricetin-primed vesicles synaptotagmin 1 respond synchronously physiological concentrations Ca(2+). When 10 μM added hemifused vesicles, majority rapidly advanced pores 16.2 ms. Thus, results demonstrate minimal exocytotic machinery composed SNAREs capable driving scale when proper vesicle priming established. SNARE-driven should serve as versatile tool investigating differential roles various synaptic proteins discrete steps.