Guo Z, Turner C, Castle D
Department of Cell Biology, University of Virgina Health Sciences Center, Charlottesville 22908, USA.
Cell. 1998 Aug 21;94(4):537-48. doi: 10.1016/s0092-8674(00)81594-9.
For regulated secretion, mast cells and several other cell types utilize compound exocytosis, a combination of granule-plasma membrane and granule-granule fusions. The molecular machinery that controls this massive export process has not been identified. We report that SNAP-23, a t-SNARE related to SNAP-25, relocates in response to stimulation from plasma membrane lamellipodia-like projections to granule membranes in permeabilized mast cells. While relocation is a prerequisite for secretion, it can occur without membrane fusion and will expedite a subsequent secretory response. After relocation, SNAP-23 is required for exocytosis, implying a crucial role in promoting membrane fusion. Thus, relocation of this SNARE regulates compound exocytosis and links granule-plasma membrane and granule-granule fusions.
对于受调控的分泌，肥大细胞和其他几种细胞类型利用复合胞吐作用，即颗粒-质膜融合与颗粒-颗粒融合的结合。控制这一大量物质输出过程的分子机制尚未明确。我们报告称，与SNAP-25相关的t-SNARE蛋白SNAP-23，在通透的肥大细胞中，会响应来自质膜片状伪足样突起的刺激而重新定位到颗粒膜上。虽然重新定位是分泌的一个先决条件，但它可以在没有膜融合的情况下发生，并且会加速随后的分泌反应。重新定位后，胞吐作用需要SNAP-23，这意味着它在促进膜融合中起关键作用。因此，这种SNARE蛋白的重新定位调节复合胞吐作用，并将颗粒-质膜融合与颗粒-颗粒融合联系起来。
