Divergence of active site motifs among different classes of <i>Populus</i> glutaredoxins results in substrate switches

Xu, Hui; Li, Zhen; Jiang, Pengfei; Zhao, Li; Qu, Chang; Peer, Yves Van de; Liu, Yan-Jing; Zeng, Qiandong

doi:10.1111/tpj.15660

Cited by 6 publications

(9 citation statements)

References 65 publications

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“…Next, we tested the substrate cumene hydroperoxide (CHP) (Supplementary Fig. 6), which was previously reported to be reduced by some of the members of the poplar class III GRX gene family 39 . The assay was carried out similar to the HEDS assay but with HEDS being replaced as substrate by CHP.…”

Section: Strep-mbp-roxy9 Has No Oxidoreductase Activity With Heds or ...mentioning

confidence: 99%

Molecular basis for the enzymatic inactivity of class III glutaredoxins on standard glutathionylated substrates

Gatz

Mrozek

Treffon

et al. 2023

Preprint

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Glutaredoxins (GRXs) are small proteins that interact with the atypical tripeptide glutathione (GSH), a redox active metabolite that forms a disulfide (GSSG) upon oxidation. GRXs encoding variants of a CPYC motif at a conserved active site act as GSH-dependent thiol-disulfide oxidoreductases (class I). GRXs with a CGFS site (class II) bind GSH in a way that is non-permissive for thiol-disulfide oxidoreductase reactions and favours transient iron-sulfur cluster binding. The biochemical functions of CCxC/S-type (class III) GRXs, which are found only in land plants, have remained largely unexplored. In this study, we characterized the in vitro properties of one of the Arabidopsis thaliana class III GRXs, namely ROXY9. In contrast to class I GRX AtGRXC2, ROXY9 was inactive as a reductase on the small substrate bis(2-hydroxyethyl)disulfide (HEDS) and as an oxidase on the redox-sensitive fluorescent protein roGFP2. Redox titrations with different GSH/GSSG ratios revealed formation of a disulfide bond (S2) between the first and the last cysteine of the CCLC motif at -220 to -230 mV. Glutathionylation (SG) at the first reactive cysteine was not observed. In contrast, AtGRXC2 and another class I GRX, HsGRX1, were oxidized to roughly equal amounts of GRX-SG and GRX-S2 over a wide range of GSH/GSSG ratios. The different reactivity of ROXY9 towards GSSG as compared to class I GRXs is most likely due to subtle differences in the GSH binding mode and explains why ROXY9 does not function as a GSH-dependent oxidoreductase on standard substrates. This feature might have evolved to avoid overlapping functions with class I GRXs in planta.

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Section: Strep-mbp-roxy9 Has No Oxidoreductase Activity With Heds or ...mentioning

confidence: 99%

Molecular basis for the enzymatic inactivity of class III glutaredoxins on standard glutathionylated substrates

Gatz

Mrozek

Treffon

et al. 2023

Preprint

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“…According to sequence alignments, land plants contain a group of glutaredoxin-like proteins, which are called CC-type glutaredoxin-like proteins because of their conserved CCM/LC or CCM/LS motif (Rouhier et al, 2008). The few biochemical studies that are available have unraveled either weak (Couturier et al, 2010) or no oxidoreductase activity in the standard HEDS assay (Xu et al, 2022). Since it is not known whether they exert functions related to known glutaredoxin-related functions, we call them glutaredoxin-like proteins.…”

Section: Introductionmentioning

confidence: 99%

“…The family of CC-type glutaredoxin-like proteins has expanded during land plant evolution and is represented by 21 members (called ROXYs) in Arabidopsis thaliana (Ziemann et al, 2009). They are located in the cytosol and the nucleus (Li et al, 2009; Ohkubo et al, 2017; Xu et al, 2022) and interact with TGACG-binding transcription factors (TGAs) (Ndamukong et al, 2007; Li et al, 2009; Yang et al, 2021). Epistasis analysis has proven the functional relevance of the interaction of CC-type glutaredoxin-like proteins and TGAs: Arabidopsis ROXY1 represses the negative activity of TGA transcription factor PERIANTHIA (PAN) on petal primordia initiation (Li et al, 2009) and the maize CC-type glutaredoxin MSCA1 and its two orthologues ZmGRX2 and ZmGRX5 regulate the activity of TGA factor FEA4 in order to control meristem size (Yang et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

Shoot-to-root mobile CEPD proteins regulate TGA transcription factors to allow nitrate root-to-shoot transport inArabidopsis thaliana

Pelizaeus,

Thurow,

Oskam

et al. 2023

Preprint

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In Arabidopsis thaliana, nitrogen (N) starvation leads to increased synthesis of CEPD (C-TERMINALLY ENCODED PEPTIDE DOWNSTREAM) proteins in the shoot. CEPDs travel to the roots, where they activate expression of genes required for high affinity nitrate transport. CEPDs belong to a plant-specific class of glutaredoxin-like proteins that interact with TGACG-binding transcription factors (TGAs). Here we identified the redundant clade-I TGAs TGA1 and TGA4 as the link between CEPDs and target promoters. In the absence of CEPDs, TGA1/4 have a strong negative effect on N starvation-induced gene expression leading to reduced translocation of N from the root to the shoot and to reduced shoot fresh weight. Basal levels of CEPDs were sufficient to completely release TGA1/4-mediated repression of nitrate acquisition. The antagonism between CEPDs and TGA1/4 was also detected in shoots, where CEPDs dampened the activating function of TGA1/4 on hyponasty and defense. CEPDs encode the conserved putative active site motif CxxC/S that was suggested to mediate redox regulation of target proteins. Complementation of the tga1 tga4 mutant with a TGA1 variant containing amino acid substitutions of all four potentially redox-active cysteines showed that CEPDs do not regulate TGA1/4 by modulating their redox state.

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“…The GRX gene family of Populus trichocarpa has been identified, and researchers have systematically explored its phylogeny, gene structure, conserved domains, chromosome distribution, expression patterns, and subcellular localization (Xu et al . 2022). However, no systematic studies on similarities and differences in GRX genes among sections of poplar, responses of GRX genes to various stresses, and adaptive evolution of GRX genes in Populus spp.…”

Section: Introductionmentioning

confidence: 99%

Identification and adaptive evolution analysis of glutaredoxin genes in Populus spp.

Wang,

Dong,

et al. 2023

Plant Biol J

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Glutaredoxin (GRX) is a class of small redox proteins widely involved in cellular redox homeostasis and the regulation of various cellular processes. The role of GRX gene in the differentiation of Populus spp. is rarely reported. We compared the similarities and differences of GRX genes among four sections of poplar using bioinformatics, corrected the annotations of some GRX genes, and focused on analysing their transcript profiling and adaptive evolution in Populus spp. A total of 219 GRX genes were identified in four sections of poplar, among which annotations for 13 genes were corrected. Differences in GRX genes were found between sect. Turanga, represented by P. euphratica, and other poplar sections. Most notably, P. euphratica had the smallest number of duplication events for GRX genes (n = 9) and no tandem duplications, whereas there were >25 duplication events for all other poplars. Furthermore, we detected 18 pairs of GRX genes under positive selection pressure in various sections of poplar, and identified two groups of GRX genes in the Salicaceae that potentially underwent positive selection. Expression profiling results showed that the PtrGRX34 and its orthologous genes were upregulated under stress treatments. In summary, the GRX gene family underwent expansion during poplar differentiation, and some genes underwent rapid evolution during this process, which may be beneficial for Populus spp. to adapt to environmental changes. This study may provide more insights into the molecular mechanisms of Populus spp. adaptation to environmental changes and the adaptive evolution of GRX genes.

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Divergence of active site motifs among different classes of Populus glutaredoxins results in substrate switches

Cited by 6 publications

References 65 publications

Molecular basis for the enzymatic inactivity of class III glutaredoxins on standard glutathionylated substrates

Molecular basis for the enzymatic inactivity of class III glutaredoxins on standard glutathionylated substrates

Shoot-to-root mobile CEPD proteins regulate TGA transcription factors to allow nitrate root-to-shoot transport inArabidopsis thaliana

Identification and adaptive evolution analysis of glutaredoxin genes in Populus spp.

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