Accumulation of endogenous peptides triggers a pathogen stress response in Arabidopsis thaliana.

  title={Accumulation of endogenous peptides triggers a pathogen stress response in Arabidopsis thaliana.},
  author={Beata Kmiec and Rui Mamede Branca and Oliver Berkowitz and Lu Li and Yan Wang and Monika W. Murcha and James Whelan and Janne Lehti{\"o} and Elzbieta Glaser and Pedro F Teixeira},
  journal={The Plant journal : for cell and molecular biology},
  volume={96 4},
The stepwise degradation of peptides to amino acids in plant mitochondria and chloroplasts is catalyzed by a network of oligopeptidases (presequence protease PreP, organellar oligopeptidase OOP) and aminopeptidases. In the present report, we show that the lack of oligopeptidase activity in Arabidopsis thaliana results in the accumulation of endogenous free peptides, mostly of chloroplastic origin (targeting peptides and degradation products). Using mRNA sequencing and deep coverage proteomics… 
Profiling thimet oligopeptidase-mediated proteolysis in Arabidopsis thaliana.
Label-free peptidomics via liquid chromatography-tandem mass spectrometry was used to differentially quantify 1111 peptides between the Arabidopsis Col-0 wild type and top1top2 knock-out mutant, revealing 350 peptides as significantly more abundant in the mutant, representing accumulation of these potential TOP substrates.
The role of chloroplast protein remodeling in stress responses and shaping of the plant peptidome.
The experimental evidence supports the concept that peptides derived from chloroplast proteins can function as regulators of plant responses to (a)biotic stresses.
The peptidases involved in plant mitochondrial protein import.
The multitude of plant mitochondrial peptidases that are known to be involved in protein import and processing of targeting signals are reviewed to detail how their activities can affect organellar protein homeostasis and overall plant growth.
The Role of Peptide Signals Hidden in the Structure of Functional Proteins in Plant Immune Responses
The roles of cryptic peptide sequences hidden in the structure of functional proteins in plant defense and plant-pathogen interactions are discussed.
Deciphering the Proteotoxic Stress Responses Triggered by the Perturbed Thylakoid Proteostasis in Arabidopsis
Interestingly, the thylakoid-enriched high-density fractions included stromal translation factors and RNA-binding proteins, along with aminoacyl-tRNA synthetase, reminiscent of the formation of stress granules, which may reflect intracellular adaptation to the proteotoxic influences from the organelle.
Peptidome: Chaos or Inevitability
This review presents a comprehensive overview of the mechanisms of generation and properties of peptidomes across different organisms and proposes three large peptide groups—functional protein “degradome”, small open reading frame (smORF)-encoded peptides ( smORFome) and specific precursor-derived peptides.
The mitochondrial AAA protease FTSH3 regulates Complex I abundance by promoting its disassembly.
Results show that disassembly or degradation of Complex I plays a role in determining its steady-state abundance and thus turnover may vary under different conditions.
A Mitochondrial LYR Protein Is Required for Complex I Assembly1[OPEN]
Yeast-two-hybrid interaction and complementation assays indicate that CIAF1 specifically interacts with the 23-kD TYKY-1 matrix domain subunit of Complex I and likely plays a role in Fe-S insertion into this subunit.
Open questions on the mitochondrial unfolded protein response
This viewpoint describes the current knowledge and understanding of protective pathways in mitochondrial homeostasis, and addresses open questions and perspectives in the field of mitochondrial stress responses.
Undegraded peptides in organelles convey toxic signals.
  • S. McCormick
  • Engineering
    The Plant journal : for cell and molecular biology
  • 2018


Deletion of an organellar peptidasome PreP affects early development in Arabidopsis thaliana
In mitochondria, deletion of AtPreP was not compensated by activation of any peptidolytic activity, whereas chloroplast membranes contained a minor peptide activity not related to At preP.
A single locus determines sensitivity to bacterial flagellin in Arabidopsis thaliana.
Peptides corresponding to the most conserved domain of eubacterial flagellin act as potent elicitors in cells of different plant species and dominance of the locus sensing flageLLin, termed FLS-1, suggests that it encodes an element which is important for the perception of the flagella signal.
Organellar oligopeptidase (OOP) provides a complementary pathway for targeting peptide degradation in mitochondria and chloroplasts
The results demonstrate the complementary role of OOP in targeting-peptide degradation in mitochondria and chloroplasts and the structural and biochemical data suggest that the protein undergoes conformational changes to allow peptide binding and proteolysis.
The N Terminus of Bacterial Elongation Factor Tu Elicits Innate Immunity in Arabidopsis Plants
It is shown that elongation factor Tu, the most abundant bacterial protein, acts as a PAMP in Arabidopsis thaliana and other Brassicaceae, and an N-acetylated peptide comprising the first 18 amino acids, termed elf18, is fully active as inducer of defense responses.
Characterization of a novel zinc metalloprotease involved in degrading targeting peptides in mitochondria and chloroplasts.
The data show that the Zn-MP is present and serves the same function in chloroplasts as in mitochondria--degradation of targeting peptides.
Catalysis, subcellular localization, expression and evolution of the targeting peptides degrading protease, AtPreP2.
Overexpressed, purified and characterized proteolytic and targeting properties of AtPreP2, a zinc metalloprotease involved in the degradation of mitochondrial and chloroplast targeting peptides and their mutants that may have diverged through subfunctionalization in Arabidopsis thaliana.
Chloroplasts play a central role in plant defence and are targeted by pathogen effectors
It is shown that the chloroplast is a key component of early immune responses, and MAMP perception triggers the rapid, large-scale suppression of nuclear encoded chloroplasts-targeted genes (NECGs) in Virulent Pseudomonas syringae effectors.
EXECUTER1- and EXECUTER2-dependent transfer of stress-related signals from the plastid to the nucleus of Arabidopsis thaliana
Activity of a plastid-derived signal suggests a new function of the chloroplast, namely that of a sensor of environmental changes that activates a broad range of stress responses.