How do oomycete and fungal effectors enter host plant cells?

卵菌和真菌植物病原体引起许多非常重要的疾病。其中许多病原体可以将蛋白质传递到宿主细胞的细胞质中，使宿主丧失免疫力；这些蛋白质被称为效应器。这些蛋白质进入宿主细胞的机制尚不清楚。研究人员已经证明，卵菌和真菌效应蛋白可以在没有任何病原体编码机制的帮助下进入宿主细胞，而是依赖于n端被称为RXLR基序的短氨基酸序列。研究人员发现，RXLR基元可以结合一类称为磷酸肌苷的膜脂。在这个项目中，研究人员将测试效应器与磷酸肌苷的结合是否实际上负责将效应器转移到宿主细胞中。他们将确定哪些宿主磷酸肌苷被效应物利用，他们将描述结合机制。最后，他们将测试是否有可能阻止效应物进入，从而预防疾病。极广泛的最具破坏性的植物病原体，包括引起小麦锈病、稻瘟病、葡萄白粉病和马铃薯晚疫病的病原体，都依赖于效应剂。了解效应进入并确定如何阻止它将为治疗这类广泛的疾病提供一种全新的方法。治疗由真菌、卵菌和某些寄生虫引起的动物疾病也可以用这种方法治疗。该项目将培养两名研究生，并为多元文化本科生提供暑期研究机会。

Oomycete and fungal plant pathogens cause a number of very important diseases. Many of these pathogens can deliver proteins into the cytoplasm of their host cells to disable host immunity; these proteins are called effectors. The mechanism by which these proteins enter host cells is poorly understood. The investigators have shown that oomycete and fungal effector proteins can enter host cells without the aid of any pathogen-encoded machinery, but instead rely on short amino acid sequences in the N-termini called RXLR motifs. The investigators have discovered that the RXLR motifs can bind a class of membrane lipids called phosphoinositides. In this project, the investigators will test whether binding of the effectors to phosphoinositides is actually responsible for transferring the effectors into host cells. They will identify which host phosphoinositides are utilized by the effectors, and they will characterize the mechanism of binding. Finally they will test whether it is possible to block effector entry and so prevent disease. An extremely wide range of the most destructive plant pathogens, including those causing wheat rust, rice blast, grape powdery mildew and potato late blight depend on effectors. Understanding effector entry and determining how to block it would provide an entirely new approach to treating this broad class of diseases. Treatment of animal diseases caused by fungi, oomycetes and some parasites may also be treatable by this approach. This project will train two graduate students and provide summer research opportunities for multi-cultural undergraduate students.