The conserved apicomplexan Aurora kinase TgArk3 is involved in endodyogeny, duplication rate and parasite virulence.
The conserved apicomplexan Aurora kinase TgArk3 is involved in endodyogeny, duplication rate and parasite virulence.
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DOI：
10.1111/cmi.12571
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发表时间：
2016-08
影响因子：
3.4
通讯作者：
Daher W
中科院分区：
文献类型：
--
作者：
Berry L;Chen CT;Reininger L;Carvalho TG;El Hajj H;Morlon-Guyot J;Bordat Y;Lebrun M;Gubbels MJ;Doerig C;Daher W
极光蛋白是真核丝氨酸/苏氨酸蛋白激酶，调节与染色质凝聚、中心体和纺锤体功能以及胞质分裂相关的关键事件。阐明极光激酶在顶端复合体寄生虫中的作用对于了解疟原虫分裂相或弓形虫内生过程中的细胞周期控制至关重要。在这里，我们报告了两个以前未描述的极光弓形虫相关蛋白(Ark2和Ark3)在速殖子中的定位，以及在恶性疟原虫红细胞阶段中未描述的Ark3同源物的定位。在弓形虫中，我们发现TgArk2和TgArk3集中在与寄生虫分裂有关的特定亚细胞结构：有丝分裂纺锤体和核内有丝分裂结构(TgArk2)，以及中心体和萌发子细胞的外核细胞骨架(TgArk3)。通过在活体寄生虫中用绿色荧光蛋白(GFP)标记内源PfArk3基因，我们发现PfArk3蛋白的表达在裂殖体分裂后期达到高峰，并定位于萌芽裂殖体的外围。TgArk2基因的破坏对速殖子的体外繁殖没有必要的功能，这是令人惊讶的，因为恶性疟原虫和伯氏疟原虫的同源基因对红细胞分裂是必不可少的。相反，TgArk3蛋白的敲除会导致寄生虫分裂的明显缺陷和主要的生长缺陷。TgArk3缺失的寄生虫表现出多种缺陷，如寄生虫生长速度减慢、出口和寄生虫复制延迟、玫瑰花环形成缺陷、寄生虫大小和入侵效率降低以及对小鼠的毒力不足。我们的研究为弓形虫和疟疾寄生虫的细胞周期控制提供了新的见解，并强调了极光激酶3作为潜在的药物靶点。
Aurora kinases are eukaryotic serine/threonine protein kinases that regulate key events associated with chromatin condensation, centrosome and spindle function, and cytokinesis. Elucidating the roles of Aurora kinases in apicomplexan parasites is crucial to understand the cell cycle control during Plasmodium schizogony or Toxoplasma endodyogeny. Here, we report on the localization of two previously uncharacterized Toxoplasma Aurora-related kinases (Ark2 and Ark3) in tachyzoites and of the uncharacterized Ark3 orthologue in Plasmodium falciparum erythrocytic stages. In T. gondii, we show that TgArk2 and TgArk3 concentrate at specific sub-cellular structures linked to parasite division: the mitotic spindle and intranuclear mitotic structures (TgArk2), and the outer core of the centrosome and the budding daughter cells cytoskeleton (TgArk3). By tagging the endogenous PfArk3 gene with the green fluorescent protein (GFP) in live parasites, we show that PfArk3 protein expression peaks late in schizogony and localizes at the periphery of budding schizonts. Disruption of the TgArk2 gene reveals no essential function for tachyzoite propagation in vitro, which is surprising giving that the P. falciparum and P. berghei orthologues are essential for erythrocyte schizogony. In contrast, knock-down of TgArk3 protein results in pronounced defects in parasite division and a major growth deficiency. TgArk3-depleted parasites display several defects, such as reduced parasite growth rate, delayed egress and parasite duplication, defect in rosette formation, reduced parasite size and invasion efficiency and lack of virulence in mice. Our study provides new insights into cell cycle control in Toxoplasma and malaria parasites, and highlights Aurora kinase 3 as potential drug target.