Proteins of the exocytotic core complex mediate platelet α-granule secretion -: Roles of vesicle-associated membrane protein, SNAP-23, and syntaxin 4
Proteins of the exocytotic core complex mediate platelet α-granule secretion -: Roles of vesicle-associated membrane protein, SNAP-23, and syntaxin 4
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DOI：
10.1074/jbc.274.4.2492
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发表时间：
1999-01-22
影响因子：
4.8
通讯作者：
Furie, BC
中科院分区：
文献类型：
--
作者：
Flaumenhaft, R;Croce, K;Furie, BC
为了了解血小板颗粒释放的分子基础，我们研究了囊泡相关膜蛋白、SNAP-23 和突触蛋白 4 在 α 颗粒分泌中的作用。在血小板裂解物中检测到囊泡相关膜蛋白 SNAP-23 和突触融合蛋白 4。这些蛋白质形成了 SDS 抗性复合物，在血小板激活后分解。为了确定这些蛋白质是否参与 α 颗粒分泌，我们开发了一种链球菌溶血素 O 通透性血小板分泌 α 颗粒模型。链球菌溶血素 O 通透性血小板释放 α 颗粒，通过 β 选择素的表面表达测量，响应 Ca2+ 高达 透化后120分钟。将链球菌溶血素 O 通透的血小板与针对囊泡相关膜蛋白的抗体一起孵育，可完全抑制 Ca2+ 诱导的 α 颗粒释放。破伤风毒素可裂解血小板囊泡相关膜蛋白并抑制链球菌溶血素 O 通透血小板中 Ca2+ 诱导的 α 颗粒分泌。在该系统中，突触融合蛋白 4 的抗体还可抑制 Ca2+ 诱导的 α 颗粒释放约 75%。这些结果表明，囊泡相关膜蛋白、SNAP-23 和突触蛋白 4 在血小板中形成异源三聚体复合物，该复合物随着激活而分解，并证明 α 颗粒释放依赖于囊泡 SNAP 受体-靶标 SNAP 受体 (vSNARE-tSNARE) 相互作用。
To understand the molecular basis of granule release from platelets, we examined the role of vesicle-associated membrane protein, SNAP-23, and syntaxin 4 in alpha-granule secretion. A vesicle-associated membrane protein, SNAP-23, and syntaxin 4 were detected in platelet lysate. These proteins form a SDS-resistant complex that disassembles upon platelet activation, To determine whether these proteins are involved in alpha-granule secretion, we developed a streptolysin O-permeabilized platelet model of alpha-granule secretion Streptolysin O-permeabilized platelets released alpha-granules, as measured by surface expression of beta-selectin, in response to Ca2+ up to 120 min after permeabilization. Incubation of streptolysin O-permeabilized platelets with an antibody directed against vesicle-associated membrane protein completely inhibited Ca2+-induced alpha-granule release. Tetanus toxin cleaved platelet vesicle-associated membrane protein and inhibited Ca2+-induced alpha-granule secretion from streptolysin O-perneabilized platelets. An antibody to syntaxin 4 also inhibited Ca2+-induced alpha-granule release by approximately 75% in this system. These results show that vesicle-associated membrane protein, SNAP-23, and syntaxin 4 form a heterotrimeric complex in platelets that disassembles with activation and demonstrate that alpha-granule release is dependent on vesicle SNAP receptor-target SNAP receptor (vSNARE-tSNARE) interactions.