S-acylation of P2K1 mediates extracellular ATP-induced immune signaling in Arabidopsis

Dongqin Chen,Huiqi Mu,Gary Stacey,Fengsheng Hao,Nagib Ahsan,Jay J Thelen

doi:10.1038/s41467-021-22854-1

Abstract

S-acylation is a reversible protein post-translational modification mediated by protein S-acyltransferases (PATs). How S-acylation regulates plant innate immunity is our main concern. Here, we show that the plant immune receptor P2K1 (DORN1, LecRK-I.9; extracellular ATP receptor) directly interacts with and phosphorylates Arabidopsis PAT5 and PAT9 to stimulate their S-acyltransferase activity. This leads, in a time-dependent manner, to greater S-acylation of P2K1, which dampens the immune response. pat5 and pat9 mutants have an elevated extracellular ATP-induced immune response, limited bacterial invasion, increased phosphorylation and decreased degradation of P2K1 during immune signaling. Mutation of S-acylated cysteine residues in P2K1 results in a similar phenotype. Our study reveals that S-acylation effects the temporal dynamics of P2K1 receptor activity, through autophosphorylation and protein degradation, suggesting an important role for this modification in regulating the ability of plants in respond to external stimuli.

Highlights

S-acylation is a reversible protein post-translational modification mediated by protein Sacyltransferases (PATs)
To determine whether PAT5 and PAT9 are involved in immune signaling by the P2K1 receptor, we investigated the phenotypes of pat[5] or pat[9] mutants by examining the response to ATP
Our current study demonstrates that plant pattern-recognition receptors (PRRs) activation is mediated by specific PAT proteins on the plasma membrane (PM) through S-acylation

Summary

Introduction

S-acylation is a reversible protein post-translational modification mediated by protein Sacyltransferases (PATs). We show that the plant immune receptor P2K1 (DORN1, LecRK-I.9; extracellular ATP receptor) directly interacts with and phosphorylates Arabidopsis PAT5 and PAT9 to stimulate their S-acyltransferase activity. This leads, in a time-dependent manner, to greater S-acylation of P2K1, which dampens the immune response. The first layer of defense is termed pattern-triggered immunity (PTI), since it relies on PM, pattern-recognition receptors (PRRs), which recognize conserved, pathogen-associated molecular patterns (PAMPs). FLS2 (FLAGELLIN SENSITIVE 2), containing a leucine rich repeat (LRR) ectodomain, recognizes bacterial flagellin via direct binding to a conserved 22-aminoacid epitope, flg[224–6] Another well-studied plant LRR-RLK is the Arabidopsis EFR receptor, which recognizes EF-Tu via perception of the conserved N-acetylated epitope elf[187,8]. Most human DHHC-PATs are localized to endomembrane compartments such as Golgi, endosomes, endoplasmic reticulum, with only two proteins, DHHC20 and DHHC21, found at that the PM, which mediate epidermal growth factor receptor (EGFR) signaling in cancer and inflammatory responses[27,28]

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Results

Conclusion