Identification of a reticulocyte-specific binding domain of Plasmodium vivax reticulocyte-binding protein 1 that is homologous to the PfRh4 erythrocyte-binding domain.
Identification of a reticulocyte-specific binding domain of Plasmodium vivax reticulocyte-binding protein 1 that is homologous to the PfRh4 erythrocyte-binding domain.
复制标题
鉴定与PFRH4红细胞结合域同源的疟原虫网状细胞结合蛋白1的网状细胞特异性结合结构域。
DOI：
10.1038/srep26993
复制
发表时间：
2016-05-31
影响因子：
4.6
通讯作者：
Han ET
中科院分区：
文献类型：
--
作者：
Han JH;Lee SK;Wang B;Muh F;Nyunt MH;Na S;Ha KS;Hong SH;Park WS;Sattabongkot J;Tsuboi T;Han ET
间日疟原虫网织红细胞结合蛋白（RBP）家族是基于间日疟原虫基因组中粘附配体的注释而鉴定的。网织红细胞与PvRBPs（PvRBP1和PvRBP2）的特异性相互作用先前已有报道。恶性疟原虫网织红细胞结合蛋白同源物4（PfRh4，PvRBP1的同源物）被观察到通过红细胞表面上的补体受体1具有红细胞结合活性。然而，由于PvRBP1的大分子量（> 326 kDa）和与体外培养相关的困难，间日疟原虫的网织红细胞结合机制尚不清楚。在本研究中，从PfRh4的30 kDa片段中选择34 kDa的PvRBP1a（PlasmoDB ID：PVX_098585）和32 kDa的PvRBP1b（PVX_098582）用于网织红细胞特异性结合活性分析。发现PvRBP1a和PvRBP1b都定位于成熟成虫期寄生虫的微线体。观察到针对PvRBP1a-34和PvRBP1b-32的自然获得性免疫应答低于PvDBP-RII。PvRBP1a-34和PvRBP1b-32的网织红细胞特异性结合活性显著高于正常细胞结合活性，并且被糜蛋白酶处理显著降低。PvRBP1a和1b与网织红细胞结合，这表明这些配体可能在间日疟原虫裂殖子入侵中起重要作用。
The Plasmodium vivax reticulocyte-binding protein (RBP) family was identified based on the annotation of adhesive ligands in the P. vivax genome. Reticulocyte-specific interactions with the PvRBPs (PvRBP1 and PvRBP2) were previously reported. Plasmodium falciparum reticulocyte-binding protein homologue 4 (PfRh4, a homologue of PvRBP1) was observed to possess erythrocyte-binding activity via complement receptor 1 on the erythrocyte surface. However, the reticulocyte-binding mechanisms of P. vivax are unclear because of the large molecular mass of PvRBP1 (>326 kDa) and the difficulty associated with in vitro cultivation. In the present study, 34 kDa of PvRBP1a (PlasmoDB ID: PVX_098585) and 32 kDa of PvRBP1b (PVX_098582) were selected from a 30 kDa fragment of PfRh4 for reticulocyte-specific binding activity analysis. Both PvRBP1a and PvRBP1b were found to be localized at the microneme in the mature schizont-stage parasites. Naturally acquired immune responses against PvRBP1a-34 and PvRBP1b-32 were observed lower than PvDBP-RII. The reticulocyte-specific binding activities of PvRBP1a-34 and PvRBP1b-32 were significantly higher than normocyte binding activity and were significantly reduced by chymotrypsin treatment. PvRBP1a and 1b, bind to reticulocytes and that this suggests that these ligands may have an important role in P. vivax merozoite invasion.