Comparative large scale characterization of plant versus mammal proteins reveals similar and idiosyncratic N-α-acetylation features

Mol Cell Proteomics. 2012 Jun;11(6):M111.015131. doi: 10.1074/mcp.M111.015131. Epub 2012 Jan 5.

Abstract

N-terminal modifications play a major role in the fate of proteins in terms of activity, stability, or subcellular compartmentalization. Such modifications remain poorly described and badly characterized in proteomic studies, and only a few comparison studies among organisms have been made available so far. Recent advances in the field now allow the enrichment and selection of N-terminal peptides in the course of proteome-wide mass spectrometry analyses. These targeted approaches unravel as a result the extent and nature of the protein N-terminal modifications. Here, we aimed at studying such modifications in the model plant Arabidopsis thaliana to compare these results with those obtained from a human sample analyzed in parallel. We applied large scale analysis to compile robust conclusions on both data sets. Our data show strong convergence of the characterized modifications especially for protein N-terminal methionine excision, co-translational N-α-acetylation, or N-myristoylation between animal and plant kingdoms. Because of the convergence of both the substrates and the N-α-acetylation machinery, it was possible to identify the N-acetyltransferases involved in such modifications for a small number of model plants. Finally, a high proportion of nuclear-encoded chloroplast proteins feature post-translational N-α-acetylation of the mature protein after removal of the transit peptide. Unlike animals, plants feature in a dedicated pathway for post-translational acetylation of organelle-targeted proteins. The corresponding machinery is yet to be discovered.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Acetyltransferases / chemistry
  • Acetyltransferases / metabolism
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / metabolism*
  • Cell Line
  • Chromatography, Ion Exchange
  • Computer Simulation
  • Humans
  • Models, Biological
  • Peptide Fragments / chemistry
  • Phylogeny
  • Protein Processing, Post-Translational*
  • Protein Structure, Tertiary
  • Protein Transport
  • Proteome / chemistry
  • Proteome / metabolism*
  • Tandem Mass Spectrometry

Substances

  • Arabidopsis Proteins
  • Peptide Fragments
  • Proteome
  • Acetyltransferases