MgATP使通透的肾上腺嗜铬细胞中的SNAP - 25和VAMP - 2发生解离。

Dissociation of SNAP-25 and VAMP-2 by MgATP in permeabilized adrenal chromaffin cells.

作者信息

Misonou H, Nishiki T, Sekiguchi M, Takahashi M, Kamata Y, Kozaki S, Ohara-Imaizumi M, Kumakura K

机构信息

Life Science Institute, Sophia University, Tokyo, Japan.

出版信息

Brain Res. 1996 Oct 21;737(1-2):351-5. doi: 10.1016/0006-8993(96)00954-7.

DOI:10.1016/0006-8993(96)00954-7

PMID:8930391

Abstract

In digitonin-permeabilized adrenal chromaffin cells, Ca(2+)-induced catecholamine release can be resolved into at least two sequential steps: a MgATP-dependent priming step and a MgATP-independent Ca(2+)-triggered step. Botulinum neurotoxins types A and E cleaved SNAP-25, and blocked MgATP-independent Ca(2+)-induced catecholamine release from the permeabilized chromaffin cells. When the permeabilized cells were primed by pretreatment with MgATP, the amount of SNAP-25 associated with VAMP-2 decreased, and the fraction of SNAP-25 proteolyzed by the neurotoxins increased. These results suggest that dissociation of SNAP-25 and VAMP-2 occurs during the MgATP-dependent priming step, and SNAP-25 plays some important roles in the subsequent MgATP-independent step.

摘要

在洋地黄皂苷通透处理的肾上腺嗜铬细胞中，钙离子诱导的儿茶酚胺释放至少可分为两个连续步骤：一个依赖MgATP的引发步骤和一个不依赖MgATP的钙离子触发步骤。A型和E型肉毒杆菌神经毒素可切割SNAP-25，并阻断通透处理的嗜铬细胞中不依赖MgATP的钙离子诱导的儿茶酚胺释放。当用MgATP预处理使通透处理的细胞引发时，与VAMP-2相关的SNAP-25量减少，而被神经毒素蛋白水解的SNAP-25比例增加。这些结果表明，SNAP-25和VAMP-2的解离发生在依赖MgATP的引发步骤中，并且SNAP-25在随后的不依赖MgATP的步骤中发挥一些重要作用。