A Dominant Negative Mutant of PG13 Suppresses Transcription from a Cauliflower Mosaic Virus 35S Truncated Promoter in Transgenic Tobacco Plants

Rieping, Mechthild; Fritz, Markus; Prat, Salomé; Gatz, Christiane

doi:10.2307/3869887

Cited by 25 publications

(38 citation statements)

References 33 publications

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“…At the highest amount of effector DNA tested (80 g), the activity of Ϫ76-CAT was unresponsive to TGA1a (lanes 10 -12). In contrast, TGA1a enhanced basal and auxinresponsive expression of Ϫ90-CAT (lanes [13][14][15]. Although this factor had only a modest effect on Ϫ90-CAT basal activity (compare lanes 7 and 13), the response to auxin was augmented Ͼ600% by TGA1a (compare lanes 8 and 14), resulting in a higher overall fold induction (compare lanes 9 and 15).…”

Section: Tga1amentioning

confidence: 91%

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Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

Pascuzzi

Hamilton

Bodily

et al. 1998

Journal of Biological Chemistry

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The promoter element activation sequence-1 (as-1) confers tissue-specific and signal-responsive transcription in plants. Hormone and chemical stress cues are thought to activate as-1-dependent transcription through specific basic/leucine-zipper proteins, termed TGA factors, that bind this element. We report here that a highly conserved TGA factor of tobacco, TGA1a, can selectively activate transcription in response to micromolar concentrations of auxin hormones or their analogs. This induction is chemically specific, as a range of other compounds tested at similar concentrations had little or no effect. Auxin was found to augment the transactivation potential of TGA1a through carboxyl-terminal residues. The amino-terminal domain of TGA1a, by gain-of-function assays, was found to both constitutively activate transcription and maximize the response to auxin. Further evidence indicates that the trans-activation potential of this domain in TGA1a is repressed, under basal conditions, by carboxyl-terminal residues. Because TGA1a and endogenous TGA factors are stimulated by auxin only at concentrations that inhibited cell growth, this response is likely to involve chemical stress.The expression of nuclear genes in response to cellular and environmental cues is largely regulated by trans-acting factors and their cognate cis-elements. In plants, auxin hormones (e.g., indole-3-acetic acid) promote growth and affect a number of cellular processes. Auxins are believed to mediate at least some of their effect by enhancing the expression of specific genes through target cis-elements (1, 2). The prototype for one class of auxin-responsive element is activation sequence-1 (as-1), 1 which was first identified by Lam et al. (3) in the cauliflower mosaic virus (CaMV) 35 S promoter. Homologs of as-1 (e.g., ocs and nos), moreover, occur in the promoters of plant-transforming T-DNA genes of agrobacteria (4 -6). Apart from regulating these genes in plants, a broader role for as-1 elements has been suggested by their functional presence in plant glutathione S-transferase genes (7-9). For example, auxin-responsive expression of at least one member of the tobacco GST gene family, GNT35, is mediated by as-1 (8, 9). Unlike other auxin-responsive elements, as-1 requires physiologically high (i.e. micromolar) concentrations of auxins to activate transcription, suggesting that this response may involve chemical stress. This view is further supported by the observation that biologically inactive analogs of auxins are also strong inducers of as-1-dependent activity.Multiple TGA factors that bind selectively to as-1 and related motifs have been cloned from several plant species, and some or all of these factors are likely to mediate as-1-dependent transcription. Based on their amino acid homology, at least three subclasses of TGA factors occur in plants, with multiple members in each class. Heterodimerization between these factors may generate new combinations with potentially distinct functional properties (10). Posttranscriptional regulation ...

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Section: Tga1amentioning

confidence: 91%

“…To test this view, trans-dominant inhibitors of TGA1a and of its homologue PG13 have been developed and expressed in plants (10,15). These inhibitors are believed to act by forming inactive "heterodimers" with their endogenous counterparts, thus markedly reducing their availability and activity.…”

mentioning

confidence: 99%

Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

Pascuzzi

Hamilton

Bodily

et al. 1998

Journal of Biological Chemistry

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“…8). As a control, exclusion outside the nucleus can be seen for RanBP1a-GFP fusion protein as has been described previously (19) (Fig. 3b).…”

Section: Ank1 Does Not Act As a Co-factor Of Bzi-1-mediatedmentioning

confidence: 99%

“…Binary vectors encoding the HA-tagged BZI-1 derivatives have been constructed. pBIN-HA-BZI-1-⌬N, pBIN-HA-BZI-1-⌬N⌬D1, and pBIN-HA-BZI-1-⌬N⌬D2 were obtained by inserting the KpnI/SalI fragment from pET28a-HA-BZI-1-⌬N⌬D1, pUCA7Tx-HA-BZI-1-⌬N, or pUCA7Tx-HA-BZI-1-⌬N⌬D2 into the plant transformation vector pBINHygTx (19). Tobacco transformation was described in Ref.…”

Section: Methodsmentioning

confidence: 99%

The α-Helical D1 Domain of the Tobacco bZIP Transcription Factor BZI-1 Interacts with the Ankyrin-repeat Protein ANK1 and Is Important for BZI-1 Function, Both in Auxin Signaling and Pathogen Response

Kuhlmann

Horvay

Strathmann

et al. 2003

Journal of Biological Chemistry

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The tobacco (Nicotiana tabacum) bZIP transcription factor BZI-1 is involved in auxin-mediated growth responses and in establishing pathogen defenses. Transgenic plants expressing a dominant-negative BZI-1-⌬N derivative, which lacks the N-terminal activation domain, showed altered vegetative growth. In particular auxin-induced rooting and formation of tobacco mosaic virus-induced hypersensitive response lesions are affected. BZI-1-related proteins described in various plant species share the conserved domains D1, D2, BD, and D4. To define those BZI-1 domains involved in transcription factor function, BZI-1 deletion derivatives were expressed in transgenic plants. The domains D1 or BD are crucial for BZI-1-⌬N function in planta. The basic BD domain is mediating DNA binding of BZI-1. Yeast twohybrid and in vitro binding studies reveal the ankyrinrepeat protein ANK1, which specifically interacts with a part of the BZI-1 protein (amino acids 73-222) encoding the D1 domain. ANK1 does not bind DNA or act as a co-activator of BZI-1-mediated transcription. Moreover, green fluorescence protein localization studies propose that ANK1 is acting mainly inside the cytosol. Transcription analysis reveals that ANK1 is ubiquitously expressed, but after pathogen attack transcription is transiently down-regulated. Along these lines, ANK1 homologous proteins in Arabidopsis thaliana have been reported to function in pathogen defense. We therefore propose that the D1 domain serves as an interaction surface for ANK1, which appears to regulate BZI-1 function in auxin signaling as well as pathogen response.The tobacco bZIP protein BZI-1 displays all the characteristic features of a transcription factor. It binds DNA, in particular ACGT containing cis-elements (ACEs), 1 it is localized inside the nucleus, and its N-terminal domain acts as a trans-activation domain in plant cells (1). Like CPRF2, a highly homologous bZIP protein from parsley, BZI-1 has been isolated by virtue of its in vitro binding to chalcone synthase promoter cis-elements (1-4). However, using various transgenic approaches that modulate the amount or the activation potential of BZI-1, we were not able to show any influence on transcription of phenylpropanoid pathway genes, such as chalcone synthase or phenylalanine ammonia lyase in vivo (1).Functional analysis has been performed in transgenic plants expressing a dominant-negative BZI-1 derivative lacking the N-terminal activation domain (BZI-1-⌬N). These plants display reduced internodes, small curly leaves, enhanced lateral shoot formation, and flowers that are reduced in size. In particular auxin responses appeared to be reduced with respect to auxininduced rooting and regulation of a GH3 target gene. Moreover, BZI-1 transcription is up-regulated in response to pathogen attack and pathogen-induced phosphorylation of BZI-1-related proteins has been described (1, 3, 4).BZI-1-related transcription factors have been isolated from various plant species, e.g. CPRF2, (2), OHP1/2 (5), BLZ1 (6), or bZIP63 (7). Apart from the N...

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“…In order to achieve an optimal expression of transgenes with minimum undesirable effects, it is highly desirable to regulate the expression of transgenes in a controllable fashion. A number of chemical inducible gene regulation systems, or gene switches, have been developed based on a diverse collection of non-plant regulatory elements that respond to a variety of chemicals (Gatz et al 1992;Wilde et al 1992;Williams et al 1992;Mett et al 1993;Rieping et al 1994;Weinmann et al 1994;Aoyama and Chua 1997;Caddick et al 1998;Bohner et al 1999;Martinez et al 1999a, b;Bruce et al 2000;Padidam et al 2003). A chemical inducible gene regulation system that specifically regulates transgene expression in response to an exogenous inducer at a particular stage of plant development or in a specific organ is very valuable when using transgenes whose constitutive over expression is detrimental or lethal to the plant.…”

Section: Introductionmentioning

confidence: 99%

Development of a tightly regulated and highly inducible ecdysone receptor gene switch for plants through the use of retinoid X receptor chimeras

et al. 2006

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Chemical inducible gene regulation systems provide essential tools for the precise regulation of transgene expression in plants and animals. Recent development of a two-hybrid ecdysone receptor (EcR) gene regulation system has solved some of the drawbacks that were associated with the monopartate gene switch. To further improve the versatility of the two-hybrid EcR gene switch for wide spread use in plants, chimeras between Homo sapiens retinoid X receptor (HsRXR) and insect, Locusta migratoria RXR (LmRXR) were tested in tobacco protoplasts as partners with Choristoneura fumiferana EcR (CfEcR) in inducing expression of the luciferase reporter gene. The RXR chimera 9 (CH9) along with CfEcR, in a two-hybrid format gave the best results in terms of low-background expression levels in the absence of ligand and high-induced expression levels of the reporter gene in the presence of nanomolar concentrations of the methoxyfenozide ligand. The performance of CH9 was further tested in corn and soybean protoplasts and the data obtained was compared with the other EcR switches that contained the wild-type LmRXR or HsRXR as EcR partners. In both transient expression studies and stable transformation experiments, the fold induction values obtained with the CH9 switch were several times higher than the values obtained with the other EcR switches containing LmRXR or HsRXR. The new CfEcR two-hybrid gene switch that uses the RXR CH9 as a partner in inducing reporter gene expression provides an efficient, ligand-sensitive and tightly regulated gene switch for plants.

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A Dominant Negative Mutant of PG13 Suppresses Transcription from a Cauliflower Mosaic Virus 35S Truncated Promoter in Transgenic Tobacco Plants

Cited by 25 publications

References 33 publications

Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

Auxin-induced Stress Potentiates trans-activation by a Conserved Plant Basic/Leucine-zipper Factor

The α-Helical D1 Domain of the Tobacco bZIP Transcription Factor BZI-1 Interacts with the Ankyrin-repeat Protein ANK1 and Is Important for BZI-1 Function, Both in Auxin Signaling and Pathogen Response

Development of a tightly regulated and highly inducible ecdysone receptor gene switch for plants through the use of retinoid X receptor chimeras

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