Constitutive calcium-independent release of Toxoplasma gondii dense granules occurs through the NSF/SNAP/SNARE/Rab machinery
Constitutive calcium-independent release of Toxoplasma gondii dense granules occurs through the NSF/SNAP/SNARE/Rab machinery
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DOI：
10.1074/jbc.274.4.2424
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发表时间：
1999-01-22
影响因子：
4.8
通讯作者：
Joiner, KA
中科院分区：
文献类型：
--
作者：
Chaturvedi, S;Qi, HL;Joiner, KA
致病性原生动物寄生虫释放致密基质颗粒的信号和分子机制尚不清楚。我们比较了内源性致密颗粒标记物GRA 3在弓形虫释放的稳定转染的外国记者，β-内酰胺酶，定位于寄生虫致密颗粒的分泌。这两种蛋白质组成性释放的钙独立的方式，如所示使用完整的和链球菌溶血素O-透性寄生虫。N-乙基马来酰亚胺和重组牛Rab-guanine解离抑制剂抑制透化寄生虫的β-内酰胺酶分泌，而重组仓鼠N-乙基马来酰亚胺敏感的融合蛋白和牛α-SNAP增强释放。鸟苷5 '-3-O-（硫代）三磷酸，而不是cAMP，增加分泌的存在，但不存在ATP。霸王弓形虫NSF/SNAP/SNARE/Rab机制使用可与其哺乳动物同源物功能性相互作用的寄生虫蛋白组分参与致密颗粒释放。
The signals and the molecular machinery mediating release of dense matrix granules from pathogenic protozoan parasites are unknown. We compared the secretion of the endogenous dense granule marker GRA3 in Toxoplasma gondii with the release of a stably transfected foreign reporter, beta-lactamase, that localizes to parasite dense granules. Both proteins were released constitutively in a calcium-independent fashion, as shown using both intact and streptolysin O-permeabilized parasites. N-Ethylmaleimide and recombinant bovine Rab-guanine dissociation inhibitor inhibited p-lactamase secretion in permeabilized parasites, whereas recombinant hamster N-ethylmaleimide-sensitive fusion protein and bovine alpha-SNAP augmented release. Guanosine 5'-3-O-(thio)triphosphate, but not cAMP, augmented secretion in the presence but not in the absence of ATP. The T. gondii NSF/SNAP/SNARE/Rab machinery participates in dense granule release using parasite protein components that can interact functionally with their mammalian homologues.