von Bohl Andreas, Kuehn Andrea, Simon Nina, Ngongang Vanesa Nkwouano, Spehr Marc, Baumeister Stefan, Przyborski Jude M, Fischer Rainer, Pradel Gabriele
Division of Cellular and Applied Infection Biology, Institute for Biology II, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
Institute of Molecular Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
Malar J. 2015 Nov 4;14:435. doi: 10.1186/s12936-015-0967-x.
During development in human erythrocytes, Plasmodium falciparum parasites display a remarkable number of adhesive proteins on their plasma membrane. In the invasive merozoites, these include members of the PfMSP1 and PfAMA1/RON complexes, which facilitate contact between merozoites and red blood cells. In gametocytes, sexual precursor cells mediating parasite transmission to the mosquito vector, plasma membrane-associated proteins primarily belong to the PfCCp and 6-cys families with roles in fertilization. This study describes a newly identified WD40-repeat protein unique to Plasmodium species that associates with adhesion protein complexes of both merozoites and gametocytes.
The WD40-repeat protein-like protein PfWLP1 was identified via co-immunoprecipitation assays followed by mass spectrometry and characterized using biochemical and immunohistochemistry methods. Reverse genetics were employed for functional analysis.
PfWLP1 is expressed both in schizonts and gametocytes. In mature schizonts, the protein localizes underneath the merozoite micronemes and interacts with PfAMA1, while in gametocytes PfWLP1 primarily accumulates underneath the plasma membrane and associates with PfCCp1 and Pfs230. Reverse genetics failed to disrupt the pfwlp1 gene, while haemagglutinin-tagging was feasible, suggesting a crucial function for PfWLP1 during blood stage replication.
This is the first report on a plasmodial WD40-repeat protein associating with cell adhesion proteins. Since WD40 domains are known to mediate protein-protein contact by serving as a rigid scaffold for protein interactions, the presented data suggest that PfWLP1 supports the stability of adhesion protein complexes of the plasmodial blood stages.
在人类红细胞内发育过程中，恶性疟原虫寄生虫在其质膜上展示出大量黏附蛋白。在侵入性裂殖子中，这些蛋白包括PfMSP1和PfAMA1/RON复合物的成员，它们促进裂殖子与红细胞之间的接触。在配子体中，介导寄生虫传播至蚊媒的有性前体细胞，质膜相关蛋白主要属于PfCCp和6-半胱氨酸家族，在受精过程中发挥作用。本研究描述了一种新鉴定的疟原虫属特有的WD40重复蛋白，它与裂殖子和配子体的黏附蛋白复合物相关。
通过免疫共沉淀测定，随后进行质谱分析，鉴定出WD40重复蛋白样蛋白PfWLP1，并使用生化和免疫组织化学方法对其进行表征。采用反向遗传学进行功能分析。
PfWLP1在裂殖体和配子体中均有表达。在成熟裂殖体中，该蛋白定位于裂殖子微线体下方，并与PfAMA1相互作用，而在配子体中，PfWLP1主要聚集在质膜下方，并与PfCCp1和Pfs230相关联。反向遗传学未能破坏pfwlp1基因，而血凝素标记是可行的，这表明PfWLP1在血液阶段复制过程中具有关键功能。
这是关于疟原虫WD40重复蛋白与细胞黏附蛋白相关的首次报道。由于已知WD40结构域通过作为蛋白质相互作用的刚性支架来介导蛋白质-蛋白质接触，因此所呈现的数据表明PfWLP1支持疟原虫血液阶段黏附蛋白复合物的稳定性。
