A proteomic approach identifies many novel palmitoylated proteins in Arabidopsis

• Published in: The New phytologist 2013-02, Vol.197 (3), p.805-814
• Main Authors: Hemsley, Piers A., Weimar, Thilo, Lilley, Kathryn S., Dupree, Paul, Grierson, Claire S.
• Format: Article
• Language: English
• Subjects: Acylation; Acyltransferases - metabolism; Arabidopsis; Arabidopsis - chemistry; Arabidopsis - metabolism; Arabidopsis Proteins - metabolism; Binding Sites; Biotin; Cell membranes; Datasets; Flagellin; FLS2; Gene expression regulation; Identification; Identification methods; Kinases; Leucine; Lipids; Localization; LRR‐RLK; membrane; Membrane proteins; Membranes; Palmitoylation; pathogenesis; Pathogens; Plant cells; Plants; Protein Processing, Post-Translational; Proteins; Proteomics; Proteomics - methods; Receptors; Signal Transduction; SNAP receptors; SNARE; SNARE proteins; SNARE Proteins - chemistry; SNARE Proteins - metabolism; Stability; S‐acylation; Vitamin B complex
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.12077

S-acylation (palmitoylation) is a poorly understood post-translational modification of proteins involving the addition of acyl lipids to cysteine residues. S-acylation promotes the association of proteins with membranes and influences protein stability, microdomain partitioning, membrane targeting and activation state. No consensus motif for S-acylation exists and it therefore requires empirical identification. Here, we describe a biotin switch isobaric tagging for relative and absolute quantification (iTRAQ)-based method to identify S-acylated proteins from Arabidopsis. We use these data to predict and confirm S-acylation of proteins not in our dataset. We identified c. 600 putative S-acylated proteins affecting diverse cellular processes. These included proteins involved in pathogen perception and response, mitogen-activated protein kinases (MAPKs), leucine-rich repeat receptor-like kinases (LRR-RLKs) and RLK superfamily members, integral membrane transporters, ATPases, soluble N-ethylmaleimide-sensitive factor-activating protein receptors (SNAREs) and heterotrimeric G-proteins. The prediction of S-acylation of related proteins was demonstrated by the identification and confirmation of S-acylation sites within the SNARE and LRR-RLK families. We showed that S-acylation of the LRR-RLK FLS2 is required for a full response to elicitation by the flagellin derived peptide flg22, but is not required for localization to the plasma membrane. Arabidopsis contains many more S-acylated proteins than previously thought. These data can be used to identify S-acylation sites in related proteins. We also demonstrated that S-acylation is required for full LRR-RLK function.