Plant E3 ligases SNIPER1 and SNIPER2 broadly regulate the homeostasis of sensor NLR immune receptors. (18th June 2020)

• Record Type: Journal Article
• Authors: Wu, Zhongshou; Tong, Meixuezi; Tian, Lei; Zhu, Chipan; Liu, Xueru; Zhang, Yuelin; Li, Xin
• Is Part Of: EMBO journal. Volume 39:Number 15(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-06-18
• Subjects: autoimmunity -- E3 ligase -- global turnover -- NLR immune receptors -- plant immunity; Molecular biology -- Periodicals; 572.805
• DOI: 10.15252/embj.2020104915
• Languages: English
• ISSNs: 0261-4189

Abstract

Abstract: In both plants and animals, nucleotide‐binding leucine‐rich repeat (NLR) immune receptors perceive pathogen‐derived molecules to trigger immunity. Global NLR homeostasis must be tightly controlled to ensure sufficient and timely immune output while avoiding aberrant activation, the mechanisms of which are largely unclear. In a previous reverse genetic screen, we identified two novel E3 ligases, SNIPER1 and its homolog SNIPER2, both of which broadly control the levels of NLR immune receptors in Arabidopsis . Protein levels of sensor NLRs (sNLRs) are inversely correlated with SNIPER1 amount and the interactions between SNIPER1 and sNLRs seem to be through the common nucleotide‐binding (NB) domains of sNLRs. In support, SNIPER1 can ubiquitinate the NB domains of multiple sNLRs in vitro . Our study thus reveals a novel process of global turnover of sNLRs by two master E3 ligases for immediate attenuation of immune output to effectively avoid autoimmunity. Such unique mechanism can be utilized in the future for engineering broad‐spectrum resistance in crops to fend off pathogens that damage our food supply. Synopsis: In plants, intracellular pathogen effector molecules are recognized by NOD‐like receptors (sensor NLRs) to activate effector‐triggered immunity. Here, two RING‐domain E3 ubiquitin ligases are shown to suppress sensor NLR‐induced immune response to avoid autoimmunity. SNIPER1 and SNIPER2 are redundant regulators of NLR‐mediated plant immunity. Overexpression of SNIPER1 or SNIPER2 suppresses autoimmunity phenotypes of snc1 mutant plants. SNIPER1 ubiquitinates multiple sensor NLRs and targets them for degradation. SNIPER1 associates with the NB domains of sensor NLRs. Abstract : Two Arabidopsis E3 ubiquitin ligases act redundantly to suppress immune response and prevent autoimmunity by targeting multiple pathogen effector‐sensing NOD‐like receptors for degradation.