A proteomic approach identifies many novel palmitoylated proteins in Arabidopsis

New Phytol. 2013 Feb;197(3):805-814. doi: 10.1111/nph.12077. Epub 2012 Dec 17.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acylation
  • Acyltransferases / metabolism
  • Arabidopsis / chemistry
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Binding Sites
  • Protein Processing, Post-Translational*
  • Proteomics / methods*
  • SNARE Proteins / chemistry
  • SNARE Proteins / metabolism
  • Signal Transduction

Substances

  • Arabidopsis Proteins
  • SNARE Proteins
  • Acyltransferases
  • TIP1 protein, Arabidopsis