Instituto de Neurociencias, Centro Mixto CSIC-Universidad Miguel Hernández, Campus de San Juan, 03550 Alicante, Spain.
Cell Mol Neurobiol. 2010 Nov;30(8):1315-9. doi: 10.1007/s10571-010-9565-1. Epub 2010 Nov 3.
In chromaffin cells, SNARE proteins, forming the basic exocytotic machinery are present in membrane clusters of 500-600 nm in diameter. These microdomains containing both SNAP-25 and syntaxin-1 are dynamic and the expression of altered forms of SNAREs modifies not only their motion but also the mobility of the associated granules. It is also clear that SNARE microdomain location defines the place for individual vesicle fusion and that the alteration of cluster dynamics affects the fusion process itself. Interestingly, these SNARE patches colocalize with the borders of F-actin cages forming the cytoskeletal cortical network, and these borders also contain clusters of L- and P/Q type calcium channels. The organization of the secretory machinery in association with the borders of cytoskeletal cages seems to be an effective way to promote fast coupling between calcium entry and catecholamine release as demonstrated with the use of mathematical secretory models.
在嗜铬细胞中，形成基本胞吐机制的 SNARE 蛋白存在于直径为 500-600nm 的膜簇中。这些含有 SNAP-25 和突触融合蛋白-1 的微域是动态的，SNARE 改变形式的表达不仅改变了它们的运动，也改变了相关颗粒的流动性。同样清楚的是，SNARE 微域的位置决定了单个囊泡融合的位置，而簇动力学的改变会影响融合过程本身。有趣的是，这些 SNARE 斑块与形成细胞骨架皮质网络的 F-肌动蛋白笼的边缘共定位，这些边缘还包含 L-和 P/Q 型钙通道簇。将分泌机制与细胞骨架笼的边缘组织起来，似乎是促进钙内流和儿茶酚胺释放之间快速偶联的一种有效方法，这已通过使用数学分泌模型得到证实。
