内吞作用是真核细胞获取细胞外物质的重要方式。大多数内吞作用依赖于网格蛋白。在网格蛋白中，End3、Pan1和Sla1是酵母特异的，在哺乳动物细胞中没有对应的组分。End3分别利用其C端和N端结合Pan1和招募Sla1，但分子机制未知。稻瘟菌是水稻稻瘟病的真菌病原菌。稻瘟菌中End3的同源蛋白MoEnd3对稻瘟菌的致病有重要作用。本研究以MoEnd3为研究对象，以结构生物学为主要手段，分析MoEnd3与MoSla1互作的机制。我们已制备MoEnd3的N端两个EH结构域（MoEnd3-EH）的重组蛋白并获得分辨率较高的晶体，已制备硒代MoEnd3-EH蛋白及其晶体来解析结构，将筛选MoSla1能结合MoEnd3-EH的肽段，再通过共结晶的方法分析二者的互作机制。本研究将阐明真菌特异的内吞作用相关蛋白End3发挥作用的分子机制，为设计干扰End3与Sla1互作的病原物特异性药物提供结构参考。

Endocytosis is indispensable for eukaryotic cells to acquire extracellular substances. Most endocytosis processes are mediated by clathrin. Of the identified clathrin proteins, End3, Pan1, and Sla1 are yeast specific, i.e. they have no direct homologs in mammals. End3 utilizes its C-terminal region to bind to Pan1 and its N-terminal two EH domains to recruit Sla1, while the interaction mechanism remains elusive. Magnaporthe oryzae is the fungal pathogen of rice blast. MoEnd3, the homolog of End3 of M. oryzae, is essential for the pathogenicity of M. oryzae. Here, we focus on MoEnd3 to evaluate the binding mechanism of MoEnd3 to MoSla1 with combined methods of structural biology, in vitro and in vivo assays. We have successfully expressed and purified the N-terminal two EH domains of MoEnd3 (MoEnd3-EH) and obtained crystals with high quality, and have prepared Se-Met MoEnd3-EH recombinant protein and crystals for structure determination. Next, we will screen peptides of MoSla1 that can bind to MoEnd3-EH, and analyze their interaction mechanism by co-crystallization and structure determination. This study will elucidate the working mechanism of the fungal-specific endocytosis-related protein End3, and can provide structural information for designing anti-fungal drugs that interfere with the interaction between End3 and Sla1.