Phosphorylation and ubiquitination of immune sensory complexes in innate immune signaling Project Summary Plants and animals rely on pattern-recognition receptors (PRRs) to detect infection by recognizing microbe-associated molecular patterns (MAMPs). FLS2, a structural and functional ortholog of mammalian Toll-like receptors (TLRs) in plants, recognizes bacterial flagellin and initiates immune signaling by dimerizing with a co-receptor BAK1. With the previous NIH support, we have identified a plasma membrane-tethered receptor-like cytoplasmic kinase (RLCK) BIK1 as a convergent immune regulator by association with multiple PRR complexes. MAMP perception induces rapid BIK1 phosphorylation by BAK1, and subsequent release from PRR complexes to transduce diverse immune signaling. It remains unknown how PRR-associated BIK1 is activated and then bifurcates intracellular PRR signaling. Our preliminary data indicate that MAMP perception triggers rapid mono-ubiquitination of BIK1 and related RLCKs. A RING-type E3 ubiquitin ligase BMU1, that is phosphorylated by BIK1, mediates MAMP-induced BIK1 ubiquitination. BIK1 interacts and phosphorylates a diacylglycerol kinase DGK5 that regulates MAMP-induced phosphatidic acid (PA) production. Three over-arching aims are proposed to test a central hypothesis that mono-ubiquitination of BIK1 by BMU1 triggers release of BIK1 from PRR complexes, and subsequent endosomal trafficking and relaying intracellular signaling events, including activation of DGK5 for PA production.
Three specific aims are 1. Ubiquitination of BIK1 by BIK1-phosphorylated BMU1 in plant immunity; 2. Ligand-induced BIK1 mono-ubiquitination in endosomal trafficking and plant immunity; 3. Dual phosphorylation of DGK5 by PRR-activated BIK1 and MAP kinase 4 in plant immunity. Recent advance on the molecular architecture of nonself recognition has revealed remarkable conservation in the mechanisms of microbial perception and innate immune signaling in multicellular eukaryotes. Phosphorylation and ubiquitination are two key mechanisms in regulating diverse cellular and organismal processes. Our project on pathogen- induced sequential and intertwined phosphorylation and ubiquitination orchestrating PRR complex activation and signal transduction in plant immunity will generate conceptual advance in understanding the biological functions of these two universal regulatory mechanisms at the whole organismal level. The proposed research will also contribute to the general understanding of innate immune signaling and immune sensory complex function.
Phosphorylation and ubiquitination are two key mechanisms in regulating diverse cellular and organismal processes. Our project on pathogen-induced sequential and intertwined phosphorylation and ubiquitination orchestrating PRR complex activation and signal transduction in plant immunity will generate conceptual advance in understanding the biological functions of these two universal regulatory mechanisms at the whole organismal level. Given the considerable similarities of innate immunity among multicellular eukaryotes, we anticipate that our research will have broad impacts on the study of innate immunity and signal transduction in general.
|Wan, Wei-Lin; Zhang, Lisha; Pruitt, Rory et al. (2018) Comparing Arabidopsis receptor kinase and receptor protein-mediated immune signaling reveals BIK1-dependent differences. New Phytol :|
|Jamieson, Pierce A; Shan, Libo; He, Ping (2018) Plant cell surface molecular cypher: Receptor-like proteins and their roles in immunity and development. Plant Sci 274:242-251|
|Shan, Libo; He, Ping (2018) Pipped at the Post: Pipecolic Acid Derivative Identified as SAR Regulator. Cell 173:286-287|
|Lal, Neeraj K; Nagalakshmi, Ugrappa; Hurlburt, Nicholas K et al. (2018) The Receptor-like Cytoplasmic Kinase BIK1 Localizes to the Nucleus and Regulates Defense Hormone Expression during Plant Innate Immunity. Cell Host Microbe 23:485-497.e5|
|Zhou, Jinggeng; Liu, Derui; Wang, Ping et al. (2018) Regulation of Arabidopsis brassinosteroid receptor BRI1 endocytosis and degradation by plant U-box PUB12/PUB13-mediated ubiquitination. Proc Natl Acad Sci U S A 115:E1906-E1915|
|Fan, Jiangbo; Bai, Pengfei; Ning, Yuese et al. (2018) The Monocot-Specific Receptor-like Kinase SDS2 Controls Cell Death and Immunity in Rice. Cell Host Microbe 23:498-510.e5|
|He, Yunxia; Zhou, Jinggeng; Shan, Libo et al. (2018) Plant cell surface receptor-mediated signaling - a common theme amid diversity. J Cell Sci 131:|
|Huang, Yanyan; Jamieson, Pierce; Shan, Libo (2018) The APEX Approaches: A Unified LRR-RK Network Revealed. Trends Plant Sci 23:372-374|
|Mang, Hyunggon; Feng, Baomin; Hu, Zhangjian et al. (2017) Differential Regulation of Two-Tiered Plant Immunity and Sexual Reproduction by ANXUR Receptor-Like Kinases. Plant Cell 29:3140-3156|
|Cox, Kevin L; Meng, Fanhong; Wilkins, Katherine E et al. (2017) TAL effector driven induction of a SWEET gene confers susceptibility to bacterial blight of cotton. Nat Commun 8:15588|
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