Sulfenome mining in Arabidopsis thaliana

Abstract

Reactive oxygen species (ROS) have been shown to be potent signaling molecules. Today, oxidation of cysteine residues is a well-recognized posttranslational protein modification, but the signaling processes steered by such oxidations are poorly understood. To gain insight into the cysteine thiol-dependent ROS signaling in Arabidopsis thaliana, we identified the hydrogen peroxide (H 2 O 2 )-dependent sulfenome: that is, proteins with at least one cysteine thiol oxidized to a sulfenic acid. By means of a genetic construct consisting of a fusion between the C-terminal domain of the yeast (Saccharomyces cerevisiae) AP-1-like (YAP1) transcription factor and a tandem affinity purification tag, we detected ∼100 sulfenylated proteins in Arabidopsis cell suspensions exposed to H 2 O 2 stress. The in vivo YAP1-based trapping of sulfenylated proteins was validated by a targeted in vitro analysis of DEHYDROASCORBATE REDUCTASE2 (DHAR2). In DHAR2, the active site nucleophilic cysteine is regulated through a sulfenic acid-dependent switch, leading to S-glutathionylation, a protein modification that protects the protein against oxidative damage.oxidative stress | redox regulation | cysteine oxidation N umerous posttranslational modifications (PTMs) have been discovered within proteomes, creating a complex landscape of protein diversity and function (1). One of the recognized reversible redox-based PTMs is the oxidation of a cysteine thiol group to a sulfenic acid (Cys-SOH) (2) that acts as regulatory switch in several oxidative stress signal transduction pathways (3). Sulfenic acids, unless they are stabilized into the protein environment, can react rapidly with other protein thiols or with low-molecular weight thiols to form intramolecular and intermolecular disulfides. These mechanisms protect the sulfenic acids against overoxidation to sulfinic (SO 2 H) or sulfonic (SO 3 H) acid and allow sulfur oxygen signaling (2).In plants, the best-known redox regulation mechanisms are the light-dependent thiol-disulfide exchange switches in chloroplast proteins (4). Examples of other redox-regulated proteins are the transcription coactivator NONEXPRESSER OF PR GENES 1 (5), the vacuolar H + -ATPase (6), and several transcription factors (TFs), such as the AP2-type RAP2.4a (7), the G-group of basic leucine zipper TFs (8), and the TEOSINTEBRANCHED1/ CYLOIDEA/PROLIFERATING CELL FACTOR class I TFs (9). The redox relay mechanisms that bridge the signal perception to the final oxidative stress response are largely unknown. Some thiol peroxidases have an H 2 O 2 -dependent signaling function and can act as receptor and transducer (10). In yeast (Saccharomyces cerevisiae), the H 2 O 2 sensor oxidant receptor peroxidase1 (ORP1/glutathione peroxidase 3) controls, together with the transcription factor YAP1 (yeast AP-1-like), a redox regulon via a sulfenic acid thiol-disulfide relay mechanism (11). Upon reaction with H 2 O 2 , the peroxidatic cysteine of ORP1 is oxidized to a sulfenic acid that reacts with the YAP1 C-terminal cysteine-rich domain (...

Intracellular Redox Compartmentation and ROS-Related Communication in Regulation and Signaling

“…The search for ROS sensors goes on, with much work focusing on the sulfenome and other thiol-related pathways (Waszczak et al, 2014). These pathways will undoubtedly turn out to be influential.…”

Role of Reactive Oxygen Species during Cell Expansion in Leaves

“…Since VHAa1 activity is redox regulated (Tavakoli et al, 2001), it might represent an integration site for ROS within the trafficking network. Treatment of Arabidopsis with H 2 O 2 results in Cys oxidation of VHA subunits (Waszczak et al, 2014), which inactivates their H + -pumping activity (Tavakoli et al, 2001). Thus, oxidative stress might act as a brake on vesicle trafficking, which could hamper cell expansion.…”

Convergent signaling pathways—interaction between methionine oxidation and serine/threonine/tyrosine O-phosphorylation

“…The roles of Cys-oxidation in protein folding and structural stability are manifold (Wedemeyer et al 2000;Trivedi et al 2009), and more recently, there has been an increased appreciation of the potential for Cys oxidation/ reduction as a component of cellular signaling pathways (Balsera et al 2014;García-Santamarina et al 2014;Kim et al 2014a, b). Furthermore, many enzymes have an activesite Cys residue (e.g., Waszczak et al 2014). In contrast, there is no established catalytic role for Met, and the structural role of Met can often be replaced by any other hydrophobic residues (Ile, Leu, Phe, and Val; Levine et al 1996;Rao et al 2013).…”