PbGCβ is essential for Plasmodium Ookinete motility to invade midgut cell and for successful completion of parasite life cycle in mosquitoes
PbGCβ is essential for Plasmodium Ookinete motility to invade midgut cell and for successful completion of parasite life cycle in mosquitoes
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DOI：
10.1093/jb/mvj205
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发表时间：
2006-11-01
影响因子：
2.7
通讯作者：
Matsuoka, Hiroyuki
中科院分区：
文献类型：
--
作者：
Hirai, Makoto;Arai, Meiji;Matsuoka, Hiroyuki
当疟原虫进入蚊子体内时，它们受精并分化为受精卵和动合子。能动的动卵细胞穿过中肠细胞到达基膜，在那里它们分化成卵囊。因此，中肠上皮是动合子完成其在蚊子中的生命周期的屏障。动合子发展滑行运动，成功地侵入中肠细胞，但背后的分子机制知之甚少。在此，我们在啮齿类疟原虫伯氏疟原虫中鉴定了一个具有鸟苷酸环化酶结构域和N-末端P-型ATP酶样结构域的分子，并将其命名为PbGC β。我们证明，PbGC β基因被破坏的转基因寄生虫形成了正常的动合子，但未能产生卵囊。共聚焦显微镜分析表明，破坏性的动卵细胞仍保留在微绒毛表面。破坏性动合子表现出严重的运动缺陷，导致寄生虫入侵中肠上皮失败。在体外培养时，分裂的动合子转化为卵囊和子孢子。这些结果表明，PbGC β是必要的动合子运动时，通过中肠细胞，但不是进一步发展的寄生虫。
When malaria parasites enter to mosquitoes, they fertilize and differentiate to zygotes and ookinetes. The motile ookinetes cross the midgut cells and arrive to the basement membranes where they differentiate into oocysts. The midgut epithelium is thus a barrier for ookinetes to complete their life cycle in the mosquitoes. The ookinetes develop gliding motility to invade midgut cells successfully, but the molecular mechanisms behind are poorly understood. Here, we identified a single molecule with guanylate cyclase domain and N-terminal P-type ATPase like domain in the rodent malaria parasite Plasmodium berghei and named it PbGC beta. We demonstrated that transgenic parasites in which the PbGC beta gene was disrupted formed normal ookinetes but failed to produce oocyst. Confocal microscopic analysis showed that the disruptant ookinetes remained on the surface of the microvilli. The disruptant ookinetes showed severe defect in motility, resulting in failure of parasite invasion of the midgut epithelium. When the disruptant ookinetes were cultured in vitro, they transformed into oocysts and sporozoites. These results demonstrate that PbGC beta is essential for ookinete motility when passing through the midgut cells, but not for further development of the parasites.