Protein Structure and Function
Team name
Protein Structure and Function
Principal Investigator
Research Objectives
Currently we focus our research interests on two aspects: (1) The molecular mechanisms underlying plant and microbial phytochromes sensing red/far-red light and assembling their early signaling complexes; we aim to analyze the structure and function of the phytochromes in multiple crops. (2) How the cell surface anchored receptor-like kinases perceive the assorted endogenous and exogenous signals. We aim to identify the structure of RLK-based complexes, and clarify the mechanism of recognition.
Team members
l Cheng Chi, Ph.D in Vegetable Science, associate professor, laboratory management and membraneprotein purification
l Xuehui Li, MSin horticulture, research assistant, protein purification of CSN
l Wenfeng Wang, MSin Cell Biology,research assistant, protein purification of phytochrome A
l Didi Zhao, MS in Biochemistry and Molecular Biology, research assistant, protein purification of phytochrome B
Research Projects
l Structure and function of phytoagglutinin-type pattern recognition immune receptors (2023-2026), National Natural Science Foundation of China. Project objectives:Plants rely on the membrane-anchored pattern recognition receptors (PRRs), most of which are receptor-like kinases (RLKs) and receptor-like proteins (RLPs), for extracellular recognition of pathogen-associated molecular patterns (PAMPs) to set off pattern-triggered immunity (PTI). RLKs have a conserved tripartite domain structure with a varied extracellular domain, a single transmembrane domain and a conserved cytoplasmic kinase domain, whereas RLPs lack an obvious intracellular domain. Ceramide D (Pi-Cer D) molecules derived from the cell membrane of Phytophthora infestans can induce disease resistance both in potatoes and Arabidopsis thaliana. Recently, the PRR receptor in Arabidopsis that perceives and transduces this signal molecule has been identified as RDA2, a member of LecRLK family, which can recognize sphingolipid base, the digested product of Pi-Cer D, and then cause immune signal transduction and immune responses. Our research group has successfully expressed and purified extracellular domain of RDA2 protein. We also obtained its high-quality protein crystals, and determined the high-resolution crystal structure of its apo state in 2.2 Å. Now we focus on solving the crystal structures of other states of this immune receptor including the sphingolipid base-bound form and the holo-immune signaling complex, and these results will reveal the molecular mechanisms underlying specifical recognition of Phytophthora infestans by potato immune receptor RDA2.
l The "switch" mechanism and application design of plant hybridization and self-incompatibility(2022-2027), National Key Research and Development Program for Young Scientists.
l Structure determination and function of biomolecules (2022-2024), China Association for Science and Technology.
Research Achievements
l Structural insights into plant phytochrome A as a highly sensitized photoreceptor.
Our structural analysis provides a mechanistic explanation for why phyA is a highly sensitized photoreceptor. Phy proteins exist in an equilibrium between Pr and Pfr states. Thus, the conformational stability of phy proteins might play a role in shifting this equilibrium. Structural comparison revealed much more extensive HKRD-PSM contacts in AtphyB-Pr than in AtphyA-Pr, indicating its higher conformational stability. The lower stability of AtpyA-Pr is expected to be more favorable for Pr-to-Pfr photoconversion. This may contribute to the higher photosensitivity of AtphyA. In addition, the thermal reversion rate of AtphyA is ~18-fold lower than that of AtphyB,indicating a more stable conformation of AtphyA-Pfr compared to AtphyB-Pfr. Whether the differences in PSM conformation, PSM-PAS2 interaction and HKRD-PSM interaction in AtphyA-Pr contribute to its Pfr stability remains to be investigated. Clearly, structures of phy proteins in their Pfr conformers will provide further mechanistic insights into their spectral characteristics. It should be mentioned that in addition to conformational stability, abundance, subcellular localization and half-life of phy proteins are also important in this aspect.
Figure. Structural features of the Pr conformer of plant phytochrome A contribute to its high photosensitivity
Selected Publications
Yuxuan Zhang#, Xiaoli Lin#, Chengying Ma#, Jun Zhao#, Xiaojin Shang, Zhengdong Wang, Bin Xu, Ning Gao, Xing Wang Deng*, Jizong Wang*. 2023. Structural insights into plant phytochrome A as a highly sensitized photoreceptor. Cell Research 33:806-809. DOI: 10.1038/s41422-023-00858-4