Zimmerberg J, Coorssen J R, Vogel S S, Blank P S
Laboratory of Cellular and Molecular Biophysics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-1855, USA.
J Physiol. 1999 Oct 1;520 Pt 1(Pt 1):15-21. doi: 10.1111/j.1469-7793.1999.00015.x.
This paper reviews recent work in our laboratory on the mechanism of calcium-triggered exocytosis. Upon echinoderm egg fertilization, cortical secretory vesicle exocytosis is massive and synchronous. By combining physiological and molecular analyses with a variety of purified membrane isolates containing secretory vesicles that fuse to the plasma membrane or each other, we have characterized the final steps of this calcium-triggered exocytosis. Our kinetic analysis led to a functional definition of the fusion complex whose activation by calcium follows Poisson statistics. The properties of this complex are compared with the properties of the heterotrimeric SNARE protein complex that is present in the cortical vesicle system. Our data do not support the hypothesis that this particular heterotrimeric complex is by itself the biological fusogen.
本文综述了我们实验室最近关于钙触发胞吐作用机制的研究工作。在棘皮动物卵子受精时，皮质分泌囊泡的胞吐作用是大量且同步的。通过将生理学和分子分析与各种含有能与质膜或彼此融合的分泌囊泡的纯化膜分离物相结合，我们已经确定了这种钙触发胞吐作用的最后步骤。我们的动力学分析得出了融合复合物的功能定义，其由钙激活遵循泊松统计。将该复合物的特性与存在于皮质囊泡系统中的异源三聚体SNARE蛋白复合物的特性进行了比较。我们的数据不支持这一假设，即这种特定的异源三聚体复合物本身就是生物融合素。
