蛋白质的正确折叠对其功能发挥至关重要，二硫键的形成对于蛋白质折叠非常关键。真核生物的内质网氧化还原酶ERO1和蛋白二硫键异构酶PDI协同催化底物蛋白的二硫键修饰，在动物中研究得非常广泛，在植物中却十分有限。本项目前期的研究发现，拟南芥中存在两个高度同源的ERO1(AtERO1和2)，可以氧化多个PDI，缺失突变体都对DTT敏感。然而AtERO1/2的氧化还原活性是如何调节的？在底物二硫键形成过程中，二硫键是如何沿着“AtERO1/2→PDI→底物”传递的？人们对这些问题的了解非常有限。我们筛选到一个与AtPDI5互作的受体激酶P5IR1，而许多受体激酶的亮氨酸富集区(LRR)可能存在多处二硫键修饰。因此，本项目将围绕以上学术问题，深入解析植物内质网中的二硫键传递机制，并对二硫键修饰参与调控植物生理活动的机理进行深入探讨。本项目的开展将为研究植物信号转导途径中的氧化还原调控机制提供新的思路。

The proper folding of the protein is critical for its function, the disulfide bond formation is one of the important types of protein folding. ER oxidoreductase1 (ERO1) and protein disulfide isomerase (PDI) synergistically catalyze the disulfide bond modification of the substrate protein in eukaryotes. The disulfide bond transfer pattern has been studied very extensive in animals, but little is known in plants. Our previous study found that, there are two homologues of ERO1 in Arabidopsis thaliana, AtERO1 and AtERO2, both of which can oxidize different PDIs, and the respective deletion mutants are sensitive to DTT. However, how the redox activity of AtERO1/2 is regulated? How the disulfide bond is delivered along the “AtERO1/2→PDI→substrate” during the formation of the disulfide bond? The understanding about these issues is still limited. We screened the substrates of AtPDIs and found a receptor kinase PDI5-interacting RLK1 (P5IR1) that interacts with PDI5, as predicted that many receptor kinases may have multiple disulfide bonds in the leucine-rich region (LRR). Therefore, this project will focus on the above academic issues to illuminate the transfer mechanism of the disulfide bond in plant endoplasmic reticulum, and explore the disulfide modification mechanism involved in regulating plant physiological activities. The implementation of this project will provide new ideas for studying the mechanism of redox regulation in plant signal transduction pathways.