Proteomic identification of early salicylate- and flg22-responsive redox-sensitive proteins in Arabidopsis

Abstract

Accumulation of reactive oxygen species (ROS) is one of the early defense responses against pathogen infection in plants. The mechanism about the initial and direct regulation of the defense signaling pathway by ROS remains elusive. Perturbation of cellular redox homeostasis by ROS is believed to alter functions of redox-sensitive proteins through their oxidative modifications. Here we report an OxiTRAQ-based proteomic study in identifying proteins whose cysteines underwent oxidative modifications in Arabidopsis cells during the early response to salicylate or flg22, two defense pathway elicitors that are known to disturb cellular redox homeostasis. Among the salicylate- and/or flg22-responsive redox-sensitive proteins are those involved in transcriptional regulation, chromatin remodeling, RNA processing, post-translational modifications, and nucleocytoplasmic shuttling. The identification of the salicylate-/flg22-responsive redox-sensitive proteins provides a foundation from which further study can be conducted toward understanding biological significance of their oxidative modifications during the plant defense response.

Nitric Oxide Modulates Histone Acetylation at Stress Genes by Inhibition of Histone Deacetylases

“…Our data suggest that the HDA19 complex might be targeted directly by NO, resulting in the inhibition of its activity and subsequent hyperacetylation of HDA19 target genes. This hypothesis is supported by the observation that HDA19 underwent oxidative Cys modifications in response to salicylate treatment, as demonstrated in a proteomic approach aimed to identify early redox-regulated proteins in the defense response (Liu et al, 2015). Furthermore, approximately 12.5% of all NO-regulated H3K9/14ac sites discovered in our work are putative HDA19-binding sites (Zhou et al, 2013), reinforcing that HDA19 might be one of the HDAC isoforms targeted by NO.…”

Identification of nuclear target proteins for S-nitrosylation in pathogen-treated Arabidopsis thaliana cell cultures

“…Ribosomal and heat shock proteins are known to accumulate during defense response in many other organisms and for some heat shock protein redoxreactive cysteine residues are already described in animals [57][58][59]. Moreover, redox-sensitive ribosomal proteins were identified in early response to salicylate and flg22 in Arabidopsis [60]. These results suggest a regulatory function of NO in protein folding, stabilization, protein-protein interaction and protein turnover.…”

“…Cys262 and Cys274 of human HDAC2 are also conserved in many Arabidopsis HDACs, representing these proteins as promising candidates for further studies [76]. Moreover, a redox-sensitive cysteine residue has been identified recently in Arabidopsis HDA19 [60].…”

Identification of sulfenylated cysteines inArabidopsis thalianaproteins using a disulfide-linked peptide reporter

“…Importantly, this method can be implemented for any species that can be genetically modified. Arabidopsis S-sulfenylated sites (blue) (Huang et al, 2019), S-nitrosylated sites (pink) (Fares et al, 2011;Puyaubert et al, 2014;Hu et al, 2015) and reversibly oxidized cysteine sites (green) (Liu et al, 2014(Liu et al, , 2015.…”

“…For instance, the C598SEIWDR CL peptides 'C#SEIWDR-DLKPSNLLLNANC#DLK' (Figure 4C) matched the Cys181 of MITOGEN-ACTIVATED PROTEIN KINASE4 (MPK4) that had been experimentally verified (Huang et al, 2019). Also, other site-specific reversibly oxidized cysteine studies (Liu et al, 2014(Liu et al, , 2015 and Snitrosylation studies (Fares et al, 2011;Puyaubert et al, 2014;Hu et al, 2015) were compared . In total, 295 S-nitrosylation and 201 reversible previously reported cysteine oxidation sites overlapped with the YAP1C-CL sites ( Figure 4C).…”