The Plasmodium falciparum RhopH2 promoter and first 24 amino acids are sufficient to target proteins to the rhoptries
The Plasmodium falciparum RhopH2 promoter and first 24 amino acids are sufficient to target proteins to the rhoptries
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DOI：
10.1016/j.parint.2006.11.001
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发表时间：
2007-03-01
影响因子：
1.9
通讯作者：
Torii, Motomi
中科院分区：
文献类型：
--
作者：
Ghoneim, Ahmed;Kaneko, Osamu;Torii, Motomi
恶性疟原虫的棒状体分泌细胞器含有由蛋白质RhopH 1、RhopH 2和RhopH 3组成的RhopH复合物。RhopH 1由rhoph 1/clag多基因家族编码，而RhopH 2和RhopH 3由单拷贝基因编码。RhopH复合物的确切功能尚未确定，但已表明，组分蛋白质参与红细胞结合，并可能参与寄生虫空泡膜的形成。在这项研究中，我们已经分离出pfrhoph 2启动子加上信号肽编码序列，并产生转基因表达构建体，以评估在转基因恶性疟原虫株系中的运输和RhopH复合物的形成。有趣的是，我们发现RhopH 2的N-末端24个氨基酸，包括信号肽序列，足以将GFP靶向rhoph 2启动子下的棒状体。因为先前显示单独的表达时间不能将蛋白质靶向顶端细胞器，所以这种靶向可能通过依赖于分泌途径早期RhopH 2的N-末端24个氨基酸的独特机制介导。Clag3.1的N末端三分之一含有与刚地弓形虫RON 2不同的保守结构域，不能将RhopH复合物结合为GFP嵌合体，但缺乏C末端的c-Mye-Clag3.1嵌合体成功地将RhopH复合物结合，这表明可能需要中间区域的合作，但C末端不是必需的。(c)2006爱思唯尔爱尔兰有限公司保留所有权利。
The rhoptry secretory organelles of the malaria parasite, Plasmodium falciparum, contain a RhopH complex, which is composed of the proteins RhopH1, RhopH2, and RhopH3. RhopH1 is encoded by the rhophl/clag multi-gene family, whereas RhopH2 and RhopH3 are encoded by single-copy genes. The precise function of the RhopH complex has not been identified, but it has been shown that the component proteins are involved in erythrocyte binding and perhaps participate in the formation of the parasitophorous vacuolar membrane. In this study, we have isolated pfrhoph2 promoter plus the signal peptide encoding sequence and generated transgene expression constructs to evaluate a trafficking and the RhopH complex formation in transgenic R falciparum parasite lines. Interestingly, we found that the N-terminal 24 amino acids of RhopH2, including signal peptide sequence, were sufficient to target GFP to the rhoptries under the rhoph2 promoter. Because it was previously shown that the timing of the expression alone could not target proteins to the apical organelles, this targeting is likely mediated via a unique mechanism that is dependent on N-terminal 24 amino acids of RhopH2 early in the secretory pathway. The N-terminal one third of Clag3.1, which contains a distinct conserved domain with Toxoplasma gondii RON2, can not associate the RhopH complex as a GFP chimera, but a c-Mye-Clag3.1 chimera lacking the C-terminus successfully associates the RhopH complex indicating that cooperation of middle region is likely required but the C-terminus is not necessary. (c) 2006 Elsevier Ireland Ltd. All rights reserved.