Plant glutaredoxins: still mysterious reducing systems

Rouhier, Nicolas; Gelhaye, Éric; Jacquot, Jean‐Pierre

doi:10.1007/s00018-004-3410-y

Cited by 192 publications

(175 citation statements)

References 61 publications

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“…According to the amino acid sequences of active site motifs, three classes of GRXs are defined in plants, namely the CPYC, the CGFS, and the CCtype classes (Rouhier et al, 2004). The CPYC and CGFS classes are common to all prokaryotes and eukaryotes, while the CC-type class is specific for land plants (Lemaire, 2004;Rouhier et al, 2006;Xing et al, 2006).…”

mentioning

confidence: 99%

The ROXY1 C-Terminal L**LL Motif Is Essential for the Interaction with TGA Transcription Factors

Gutsche

Zachgo

2011

Plant Physiology

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Glutaredoxins (GRXs) are small, ubiquitous, glutathione-dependent oxidoreductases that participate in redox-regulated processes associated with stress responses. Recently, GRXs have been shown to exert crucial functions during flower developmental processes. GRXs modulate their target protein activities by the reduction of protein disulfide bonds or deglutathionylation reactions. The Arabidopsis (Arabidopsis thaliana) GRX ROXY1 participates in petal primordia initiation and further petal morphogenesis. ROXY1 belongs to a land plant-specific class of GRXs with a CC-type active site motif, deviating from the ubiquitously occurring CPYC and CGFS GRX classes. ROXY1 was previously shown to interact with floral TGA transcription factors in the nucleus, and this interaction is a prerequisite for ROXY1 to exert its activity required for Arabidopsis petal development. Deletion analysis further identified the importance of the ROXY1 C terminus for the ROXY1/ TGA protein interactions and for the ROXY1 function in petal development. Here, by dissecting the ROXY1 C terminus, an a-helical L**LL motif immediately adjacent to the ROXY1 C-terminal eight amino acids was identified that is essential for the interaction with TGA transcription factors and crucial for the ROXY1 function in planta. Similar to the a-helical L**LL motifs binding to transcriptional coactivators with liganded nuclear receptors in animals, a hydrophobic face formed by the conserved leucines in the L**LL motif of ROXY1 possibly mediates the interaction with TGA transcription factors. Thus, the a-helical L**LL sequence is a conserved protein-protein interaction motif in both animals and plants. Furthermore, two separate TGA domains were identified by deletion experiments as being essential for mediating TGA protein interactions with ROXYs.

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confidence: 99%

The ROXY1 C-Terminal L**LL Motif Is Essential for the Interaction with TGA Transcription Factors

Gutsche

Zachgo

2011

Plant Physiology

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“…GrxS12, -S14, and -S16 in poplar as well as GrxS14 in A. thaliana (previously referred to as AtGRXcp) have already been confirmed as being located in plastids by GFP fusion (20,27,44). From localization prediction programs, only three additional A. thaliana Grxs exhibit a potential plastidial targeting sequence, namely AtGrxC5 (class I), AtGrxC10, and AtGrxS13 (class III) (10,11). It is important to note that GrxC5 and GrxS12, which form a specific subgroup of class I Grxs, display about 70% identity when considering the mature form of the proteins.…”

Section: Atgrxc5 the Fourth Plastidial Grx Of A Thaliana-the Amentioning

confidence: 99%

“…However, with the identification of new Grx sequences with more variable active site sequences, this classification has become insufficient. In particular, photosynthetic organisms possess a larger variety of Grxs with about 30 genes compared with two to seven in other prokaryotes or eukaryotes (10). An in-depth phylogenetic analysis of Grxs in photosynthetic organisms indicates that they are grouped into four classes (11).…”

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confidence: 99%

Arabidopsis Chloroplastic Glutaredoxin C5 as a Model to Explore Molecular Determinants for Iron-Sulfur Cluster Binding into Glutaredoxins

Couturier

Ströher

Albetel

et al. 2011

Journal of Biological Chemistry

107

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Unlike thioredoxins, glutaredoxins are involved in ironsulfur cluster assembly and in reduction of specific disulfides (i.e. protein-glutathione adducts), and thus they are also important redox regulators of chloroplast metabolism. Using GFP fusion, AtGrxC5 isoform, present exclusively in Brassicaceae, was shown to be localized in chloroplasts. A comparison of the biochemical, structural, and spectroscopic properties of Arabidopsis GrxC5 (WCSYC active site) with poplar GrxS12 (WCSYS active site), a chloroplastic paralog, indicated that, contrary to the solely apomonomeric GrxS12 isoform, AtGrxC5 exists as two forms when expressed in Escherichia coli. The monomeric apoprotein possesses deglutathionylation activity mediating the recycling of plastidial methionine sulfoxide reductase B1 and peroxiredoxin IIE, whereas the dimeric holoprotein incorporates a [2Fe-2S] cluster. Site-directed mutagenesis experiments and resolution of the x-ray crystal structure of AtGrxC5 in its holoform revealed that, although not involved in its ligation, the presence of the second active site cysteine (Cys 32 ) is required for cluster formation. In addition, thiol titrations, fluorescence measurements, and mass spectrometry analyses showed that, despite the presence of a dithiol active site, AtGrxC5 does not form any inter-or intramolecular disulfide bond and that its activity exclusively relies on a monothiol mechanism.

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“…7, D and H), implying that alteration of At3g62950 expression may be responsible for floral defects in ga1-3. At least 31 glutaredoxin genes that possess a typical glutathione-reducible CXXC or CXXS active site have been identified in the Arabidopsis genome (Rouhier et al, 2004). ROXY1, a member of the glutaredoxin family, is required for petal development in Arabidopsis (Xing et al, 2005).…”

Section: Functional Characterization Of Novel Rga-regulated Genesmentioning

confidence: 99%

Global Identification of DELLA Target Genes during Arabidopsis Flower Development

Hou

Shen

et al. 2008

Plant Physiology

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Gibberellin (GA) plays important roles in regulating many aspects of plant development. GA derepresses its signaling pathway by promoting the degradation of DELLA proteins, a family of nuclear growth repressors. Although the floral organ identity is established in flowers of the GA-deficient mutant ga1-3, the growth of all floral organs is severely retarded. In particular, abortive anther development in ga1-3 results in male sterility. Genetic analysis has revealed that various combinations of null mutants of DELLA proteins could gradually rescue floral organ defects in ga1-3 and that RGA is the most important DELLA protein involved in floral organ development. To elucidate the early molecular events controlled by RGA during flower development, we performed whole-genome microarray analysis to identify genes in response to the steroid-inducible activation of RGA in ga1-3 rgl2 rga 35S:RGA-GR. Although DELLA proteins were suggested as transcriptional repressors, similar numbers of genes were down-regulated or up-regulated by RGA during floral organ development. More than one-third of RGA down-regulated genes were specifically or predominantly expressed in stamens. A significant number of RGA-regulated genes are involved in phytohormone signaling or stress response. Further expression analysis through activation of RGA by steroid induction combined with cycloheximide identified eight genes as immediate targets of RGA. In situ hybridization and transgenic studies further showed that the expression pattern and function of several selected genes were consistent with the predictions from microarray analysis. These results suggest that DELLA regulation of floral organ development is modulated by multiple phytohormones and stress signaling pathways.

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Plant glutaredoxins: still mysterious reducing systems

Cited by 192 publications

References 61 publications

The ROXY1 C-Terminal L**LL Motif Is Essential for the Interaction with TGA Transcription Factors

The ROXY1 C-Terminal L**LL Motif Is Essential for the Interaction with TGA Transcription Factors

Arabidopsis Chloroplastic Glutaredoxin C5 as a Model to Explore Molecular Determinants for Iron-Sulfur Cluster Binding into Glutaredoxins

Global Identification of DELLA Target Genes during Arabidopsis Flower Development

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