Table_2_Plasmodium yoelii Erythrocyte Binding Like Protein Interacts With Basigin, an Erythrocyte Surface Protein.xlsx

Erythrocyte recognition and invasion is critical for the intra-erythrocytic development of Plasmodium spp. parasites. The multistep invasion process involves specific interactions between parasite ligands and erythrocyte receptors. Erythrocyte-binding-like (EBL) proteins, type I integral transmembrane proteins released from the merozoite micronemes, are known to play an important role in the initiation and formation of tight junctions between the apical end of the merozoite and the erythrocyte surface. In Plasmodium yoelii EBL (PyEBL), a single amino acid substitution in the putative Duffy binding domain dramatically changes parasite growth rate and virulence. This suggests that PyEBL is important for modulating the virulence of P. yoelii parasites. Based on these observations, we sought to elucidate the receptor of PyEBL that mediates its role as an invasion ligand. Using the eukaryotic wheat germ cell-free system, we systematically developed and screened a library of mouse erythrocyte proteins against native PyEBL using AlphaScreen technology. We report that PyEBL specifically interacts with basigin, an erythrocyte surface protein. We further confirmed that the N-terminal cysteine-rich Duffy binding-like region (EBL region 2), is responsible for the interaction, and that the binding is not affected by the C351Y mutation, which was previously shown to modulate virulence of P. yoelii. The identification of basigin as the putative PyEBL receptor offers new insights into the role of this molecule and provides an important base for in-depth studies towards developing novel interventions against malaria.

红细胞识别与入侵过程对于疟原虫属（Plasmodium spp.）寄生虫的红细胞内发育阶段至关重要。该多步骤入侵过程涉及寄生虫配体与红细胞受体之间的特异性相互作用。红细胞结合样（Erythrocyte-binding-like, EBL）蛋白是一类由裂殖子微线体释放的I型整合跨膜蛋白，已知其在裂殖子顶端与红细胞表面之间紧密连接的启动与形成过程中发挥关键作用。在约氏疟原虫EBL（PyEBL）中，推定达菲结合结构域内的单个氨基酸替换可显著改变寄生虫的增殖速率与毒力表型。这表明PyEBL在调节约氏疟原虫毒力方面具有重要功能。基于上述研究发现，我们旨在阐明介导PyEBL作为入侵配体发挥功能的红细胞受体。我们借助真核小麦胚芽无细胞系统，通过AlphaScreen技术，系统性构建并筛选了针对天然PyEBL的小鼠红细胞蛋白文库。本研究证实，PyEBL可特异性结合红细胞表面蛋白basigin（CD147）。我们进一步验证，N端富含半胱氨酸的达菲结合样区域（即EBL区域2）负责该特异性相互作用，且该结合过程不受此前被证实可调节约氏疟原虫毒力的C351Y突变影响。将basigin鉴定为推定的PyEBL受体，为阐明该分子的功能提供了全新视角，并为开发新型疟疾干预策略的深入研究奠定了重要基础。