共 24 条
Fast Vesicle Fusion in Living Cells Requires at Least Three SNARE Complexes
被引:228
作者:
Mohrmann, Ralf
[1
,2
]
de Wit, Heidi
[3
,4
]
Verhage, Matthijs
[3
,4
]
Neher, Erwin
[1
]
Sorensen, Jakob B.
[1
,5
,6
]
机构:
[1] Max Planck Inst Biophys Chem, Dept Membrane Biophys, Gottingen, Germany
[2] Univ Saarland, Dept Physiol, D-6650 Homburg, Germany
[3] Vrije Univ Amsterdam, Dept Funct Genom, Ctr Neurogenom & Cognit Res, Amsterdam, Netherlands
[4] Vrije Univ Amsterdam Med Ctr, Amsterdam, Netherlands
[5] Univ Copenhagen, Fac Hlth Sci, Dept Neurosci & Pharmacol, Copenhagen, Denmark
[6] Univ Copenhagen, Lundbeck Fdn Ctr Biomembranes Nanomed, Copenhagen, Denmark
来源:
基金:
英国医学研究理事会;
关键词:
MEMBRANE-FUSION;
SECRETORY VESICLES;
EXOCYTOSIS;
RELEASE;
SYNAPSE;
DOMAIN;
D O I:
10.1126/science.1193134
中图分类号:
O [数理科学和化学];
P [天文学、地球科学];
Q [生物科学];
N [自然科学总论];
学科分类号:
07 ;
0710 ;
09 ;
摘要:
Exocytosis requires formation of SNARE [soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor] complexes between vesicle and target membranes. Recent assessments in reduced model systems have produced divergent estimates of the number of SNARE complexes needed for fusion. Here, we used a titration approach to answer this question in intact, cultured chromaffin cells. Simultaneous expression of wild-type SNAP-25 and a mutant unable to support exocytosis progressively altered fusion kinetics and fusion-pore opening, indicating that both proteins assemble into heteromeric fusion complexes. Expressing different wild-type: mutant ratios revealed a third-power relation for fast (synchronous) fusion and a near-linear relation for overall release. Thus, fast fusion typically observed in synapses and neurosecretory cells requires at least three functional SNARE complexes, whereas slower release might occur with fewer complexes. Heterogeneity in SNARE-complex number may explain heterogeneity in vesicular release probability.
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页码:502 / 505
页数:4
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