Elucidation of BiP-regulated Innate Immunity

水稻受体样激酶Xa21是天然免疫应答中的关键识别决定子，天然免疫应答是植物和动物之间广泛保守的病原体防御途径。很少有转导水稻先天免疫反应的蛋白质被鉴定。因此，从体内XA21复合体中分离出一种蛋白质，称为Bip(Lumina Binding Protein，又称葡萄糖调节蛋白78，GRP78)，就显得尤为重要。BIP是热休克蛋白(HSP)70分子伴侣家族中位于内质网(ER)的成员。在高表达BiP3的水稻植株中，Xa21介导的抗性受到损害，Xa21的稳定性显著降低。这些结果表明，BiP3调节Xa21蛋白的稳定性和加工，这一调节对抗性是至关重要的。该项目的长期目标是阐明先天免疫的机制，确定BiP在这些信号通路中的作用，并利用这些信息开发新的动植物疾病控制策略。该项目将使用生化、细胞生物学和遗传学方法来确定ER伴侣BIP如何影响XA21介导的信号转导。这些研究的结果将导致在理解病原体衍生分子的植物和动物传感器的生物发生和处理方面的重大进展。由于XA21与控制其他动植物天然免疫的传感器密切相关，因此预期的结果将对理解和控制谷物和人类疾病产生广泛影响。这一结果将与其他植物-微生物相互作用相关，并将广泛传播，以加强对先天免疫机制的科学和技术理解。博士后和研究生将接受细菌遗传学、生物化学和植物病理学方面的培训。教育外展包括一个为期一个月的科学和艺术项目，将在当地一所小学推出。

The rice receptor-like kinase, XA21, is a key recognition determinant in the innate immune response, a pathogen defense pathway widely conserved between plants and animals. Few proteins that transduce the rice innate immune response have been characterized. For this reason the isolation of a protein from an in vivo XA21 complex, called BiP (luminal binding protein, also called glucose regulated protein 78 (GRP78)), is particularly important. BiP is an endoplasmic reticulum (ER)-located member of the family of heat shock protein (HSP) 70 chaperones. In BiP3-overexpressing rice plants, XA21-mediated resistance is compromised and XA21 stability is significantly decreased. These results indicate that BiP3 regulates XA21 protein stability and processing and that this regulation is critical for resistance. The long-term goal of this project is to elucidate the mechanisms of innate immunity, determine the role of BiP in these signaling pathways, and use this information to develop new strategies for disease control in plants and animals. The project will use biochemical, cell biological and genetic approaches to determine how the ER chaperone BiP affects XA21-mediated signaling. Results from these studies will lead to major advances in understanding biogenesis and processing of plant and animal sensors of pathogen-derived molecules. Because XA21 is closely related to sensors controlling innate immunity in other plants and animals, the expected results will have a broad impact on understanding and controlling diseases of cereals and humans. The results will have relevance to other plant-microbe interactions and will be disseminated broadly to enhance scientific and technological understanding of the mechanisms of innate immunity. Postdoctoral and graduate students will receive training in bacterial genetics, biochemistry, and plant pathology. Educational outreach includes a month-long science and art program to be presented in a local elementary school.