苏云金芽胞杆菌(Bacillus thuringiensis，简称Bt)是最成功的杀虫微生物，其杀虫的主要活性成分为杀虫晶体蛋白(Cry)。目前Bt中已发现74大类780余个Cry蛋白，大部分具有3-Domain结构。经过20多年研究， 3-Domain结构类Cry蛋白作用机制已经明确，但非3-Domain结构类的作用机制并不清楚。Cry6Aa是一种重要的非3-Domain结构杀虫蛋白，对多种植物线虫具有高活性，具有与ɑ-穿孔素类似结构并可导致线虫细胞穿孔。但介导Cry6Aa细胞穿孔的受体和具体的穿孔方式都不清楚。本项目拟以秀丽小杆线虫为模型，鉴定介导Cry6Aa在细胞上穿孔的受体（已鉴定为膜脂类），并解析膜脂受体介导Cry6Aa穿孔的生化和细胞学机制。本项目将揭示一种全新的非3-Domian结构类Cry蛋白作用宿主机制，并可为新型杀线虫Bt农药创制和转基因抗线虫植物设计提供理论依据。

Bacillus thuringiensis is the most important insecticidal bacterial, it’s main active products is the insecticidal crystal protein (Abbreviated as Cry). At present, there are 74-class and more than 780 Cry proteins have been found in B. thuringiensis, most of which has a 3-Domain structure. After more than 20 years of research, we obtained the detailed action mechanism of the 3-Domain-Structure like Cry proteins. However, the action model of the non-3-Domain structure like Cry protein is still not clear. The Cry6Aa (one kind of important non-3-Domain structure like Cry protein) has high activity against several important plant parasite nematodes, which could induce the cell pore forming in nematode, and has similar structure to one kind of ɑ-pore forming toxin (PFTs) from E. coli. However, the membrane receptors and the detailed action mechanism of Cry6Aa-mediated cell pore forming are unclear. In this project, we will use a free living nematode Caenorhabditis elegans as model, to screen and identify the membrane receptors (we have confirmed it as membrane lipids) that mediate Cry6Aa target nematode as a ɑ-PFTs, then to reveal the detailed biochemical and cytological mechanisms of the specific membrane lipid receptor during Cry6Aa form the pore in nematode cell, as well as the specific signals pathways during this process. This project will reveal a novel action mechanism for non - 3 - Domain structure like Cry protein target its host, and will also provide a theoretical basis for the design of novel B. thuringiensis pesticide and transgenic plants based on nematicidal Cry proteins to control plant parasite-nematodes.