Kweon Dae-Hyuk, Kong Byoungjae, Shin Yeon-Kyun
Department of Genetic Engineering, College of Biotechnology and Bioengineering, Sungkyunkwan University Suwon, South Korea.
Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University Ames, IA, USA.
Front Mol Neurosci. 2017 Mar 16;10:65. doi: 10.3389/fnmol.2017.00065. eCollection 2017.
In the neuron, early neurotransmitters are released through the fusion pore prior to the complete vesicle fusion. It has been thought that the fusion pore is a gap junction-like structure made of transmembrane domains (TMDs) of soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) proteins. However, evidence has accumulated that lipid mixing occurs prior to the neurotransmitter release through the fusion pore lined predominantly with lipids. To explain these observations, the hemifusion, a membrane structure in which two bilayers are partially merged, has emerged as a key step preceding the formation of the fusion pore. Furthermore, the hemifusion appears to be the bona fide intermediate step not only for the synaptic vesicle cycle, but for a wide range of membrane remodeling processes, such as viral membrane fusion and endocytotic membrane fission.
在神经元中，早期神经递质在囊泡完全融合之前通过融合孔释放。一直以来人们认为融合孔是一种类似间隙连接的结构，由可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）蛋白的跨膜结构域（TMDs）构成。然而，越来越多的证据表明，脂质混合发生在神经递质通过主要由脂质构成的融合孔释放之前。为了解释这些观察结果，半融合这种两个双层膜部分融合的膜结构，已成为融合孔形成之前的关键步骤。此外，半融合似乎不仅是突触囊泡循环的真正中间步骤，也是广泛的膜重塑过程的中间步骤，如病毒膜融合和内吞性膜裂变。
