Effect of two consensus sequences preceding the translation initiator codon on gene expression in plant protoplasts

Guérineau, François; Lucy, Andrew P.; Mullineaux, Phil

doi:10.1007/bf00020027

Cited by 119 publications

(70 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…An SWP cDNA clone (AV52360) in pBluescript II SKϩ was obtained from the Kazusa DNA Research Institute (1) and verified by DNA sequence analysis before being cloned as a SalI-PciI fragment into SmaI-NcoI of the yeast vector pAS64F2 to give a LexA translational fusion (pAS-AtMED14). pJG contains the HindIII-SalI Gal4 DNA binding domain (G4BD) fragment from pGBT9 (Clontech) in HindIII-SalI sites of pJIT60 (14). pJG-LUG contains full-length LUG cDNA cloned as a translational fusion in pJG downstream of the G4BD.…”

Section: Methodsmentioning

confidence: 99%

The Transcription Corepressor LEUNIG Interacts with the Histone Deacetylase HDA19 and Mediator Components MED14 (SWP) and CDK8 (HEN3) To Repress Transcription

González

Bowen

Carroll

et al. 2007

Molecular and Cellular Biology

131

101

View full text Add to dashboard Cite

Transcription corepressors are general regulators controlling the expression of genes involved in multiple signaling pathways and developmental programs. Repression is mediated through mechanisms including the stabilization of a repressive chromatin structure over control regions and regulation of Mediator function inhibiting RNA polymerase II activity. Using whole-genome arrays we show that the Arabidopsis thaliana corepressor LEUNIG, a member of the GroTLE transcription corepressor family, regulates the expression of multiple targets in vivo. LEUNIG has a role in the regulation of genes involved in a number of different physiological processes including disease resistance, DNA damage response, and cell signaling. We demonstrate that repression of in vivo LEUNIG targets is achieved through histone deacetylase (HDAC)-dependent and -independent mechanisms. HDAC-dependent mechanisms involve direct interaction with HDA19, a class 1 HDAC, whereas an HDAC-independent repression activity involves interactions with the putative Arabidopsis Mediator components AtMED14/SWP and AtCDK8/HEN3. We suggest that changes in chromatin structure coupled with regulation of Mediator function are likely to be utilized by LEUNIG in the repression of gene transcription.The Arabidopsis thaliana gene LEUNIG (LUG) encodes a member of the conserved transcription corepressor family that includes Tup1 in yeast (Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Candida albicans), Groucho (Gro) in Drosophila melanogaster, and Transducin-Like Enhancer of split (TLE) in mammals. These corepressors do not possess DNA binding motifs but repress a diverse number of target genes through targeted recruitment by site-specific DNA binding transcription factors. In Arabidopsis, LUG represses target gene transcription by interacting with DNA binding transcription factors through an adaptor protein, SEUSS (SEU), in a fashion analogous to the interaction between the yeast corepressor components Tup1 and Ssn6 (27,28). Once recruited, corepressors mediate repression through mechanisms that include stabilization of a repressive chromatin structure over control regions, inhibition of recruitment of the transcription machinery, and direct inhibition of the RNA polymerase II (Pol II) holoenzyme regulated through the associated Mediator complex. The LUG-SEU corepressor fails to repress transcription in the presence of a histone deacetylase (HDAC) inhibitor, suggesting that one mechanism of LUG repression is through the recruitment of HDAC activities (27). This observation is consistent with Arabidopsis plants that harbor mutations in HDAC-encoding genes displaying pleotropic phenotypes similar to those reported for lug mutants (31). In lug mutant flowers the class C floral homeotic MADS box gene AGAMOUS (AG) is expressed in all four floral whorls, resulting in the ectopic formation of carpels and stamens in the outer two whorls (19), suggesting that LUG is a repressor of AG. In addition, plants harboring mutations in LUG exhibit further pleotropic defects,...

show abstract

Section: Methodsmentioning

confidence: 99%

The Transcription Corepressor LEUNIG Interacts with the Histone Deacetylase HDA19 and Mediator Components MED14 (SWP) and CDK8 (HEN3) To Repress Transcription

González

Bowen

Carroll

et al. 2007

Molecular and Cellular Biology

131

101

View full text Add to dashboard Cite

show abstract

“…Arabidopsis adult plants were dipped into a solution containing Agrobacterium, 5% sucrose, and 50 L/L of the surfactant Silwet (Witco, Geneva, Switzerland). The 70S-TT2 expression cassette was obtained by ligation of the TT2 cDNA between the double enhanced Cauliflower mosaic virus (CaMV) 35S promoter and the CaMV polyadenylation signals of plasmid pLBR19 (Guerineau et al, 1992). Details of the 70S-TT8 transgene can be found elsewhere (Nesi et al, 2000).…”

Section: Construction and Analyses Of Transgenic Plantsmentioning

confidence: 99%

The Arabidopsis TT2 Gene Encodes an R2R3 MYB Domain Protein That Acts as a Key Determinant for Proanthocyanidin Accumulation in Developing Seed

Nési¹

2001

The Plant Cell Online

297

389

View full text Add to dashboard Cite

In Arabidopsis, proanthocyanidins specifically accumulate in the endothelium during early seed development. At least three TRANSPARENT TESTA ( TT ) genes, TT2 , TT8 , and TTG1 , are necessary for the normal expression of several flavonoid structural genes in immature seed, such as DIHYDROFLAVONOL-4-REDUCTASE and BANYULS ( BAN ). TT8 and TTG1 were characterized recently and found to code for a basic helix-loop-helix domain transcription factor and a WDrepeat-containing protein, respectively. Here the molecular cloning of the TT2 gene was achieved by T-DNA tagging. TT2 encoded an R2R3 MYB domain protein with high similarity to the rice OsMYB3 protein and the maize COLORLESS1 factor. A TT2-green fluorescent protein fusion protein was located mostly in the nucleus, in agreement with the regulatory function of the native TT2 protein. TT2 expression was restricted to the seed during early embryogenesis, consistent with BAN expression and the proanthocyanidin deposition profile. Finally, in gain-of-function experiments, TT2 was able to induce ectopic expression of BAN in young seedlings and roots in the presence of a functional TT8 protein. Therefore, our results strongly suggest that stringent spatial and temporal BAN expression, and thus proanthocyanidin accumulation, are determined at least partially by TT2. INTRODUCTIONFlavonoids are secondary metabolites that are unique to higher plants. They are well known for the red, purple, and brown pigmentation they give to flowers, fruit, and seed. Flavonoids fulfill numerous physiological functions during plant life and also serve as beneficial micronutrients in human and animal diets (reviewed by Koes et al., 1994;Shirley, 1996;Mol et al., 1998;Harborne and Williams, 2000). Arabidopsis contains three major classes of flavonoids: the anthocyanins (red to purple pigments), the flavonols (colorless to pale yellow pigments), and the proanthocyanidins (colorless pigments that turn to brown), which also are known as condensed tannins (Figure 1). Anthocyanins and flavonols are synthesized in vegetative parts, whereas flavonols and proanthocyanidins accumulate in seed (Chapple et al., 1994).As shown in Figure 1, the different flavonoid subpathways share common initial biosynthetic steps, including synthesis of naringenin chalcone by chalcone synthase (CHS), conversion of naringenin chalcone to naringenin by chalcone isomerase (CHI), and subsequent hydroxylations of naringenin by flavanone 3-hydroxylase (F3H) and flavonoid 3 Ј -hydroxylase (F3 Ј H). Genetic and molecular study of flavonoid biosynthesis in Arabidopsis has revealed that the CHS, CHI, F3H, and F3 Ј H enzymes are encoded by the TRANSPAR-ENT TESTA4 ( TT4 ), TT5 , TT6 , and TT7 genes, respectively (Shirley et al., , 1995Wisman et al., 1998;Schoenbohm et al., 2000). Then, an NADPH-dependent dihydroflavonol reductase (DFR), encoded by the TT3 gene in Arabidopsis , leads to the production of flavan-3,4-diols (leucoanthocyanidins), which are the last common intermediates in anthocyanin and proanthocyanidin biosynthesis. Leu...

show abstract

“…Using primers complementary to the region upstream from the translation start site (deb122ATG, 5Ј-ATGGAT-GAATCAAGTATTATTCCGG-3Ј) and downstream from the stop codon (deb122Stop, 5Ј-CTATAGATTAGTATCATGTATTATG-3Ј), we amplified the TT8 full-coding region (TT8-CR) from a green siliques cDNA library (Giraudat et al, 1992) by PCR. The 1557-bp PCR fragment was directly blunt-end ligated (SmaI) between the doubleenhanced cauliflower mosaic virus (CaMV) 35S promoter and the CaMV polyadenylation signal of the pLBR19 vector (Guerineau et al, 1992). A clone carrying the TT8-CR fragment in sense orientation was isolated and sequenced to ensure that no mutation was introduced by the DNA polymerase.…”

mentioning

confidence: 99%

The TT8 Gene Encodes a Basic Helix-Loop-Helix Domain Protein Required for Expression of DFR and BAN Genes in Arabidopsis Siliques

Nési¹,

Debeaujon²,

Jond³

et al. 2000

Plant Cell

664

438

View full text Add to dashboard Cite

The TRANSPARENT TESTA8 ( TT8 ) locus is involved in the regulation of flavonoid biosynthesis in Arabidopsis. The tt8-3 allele was isolated from a T-DNA-mutagenized Arabidopsis collection and found to be tagged by an integrative molecule, thus permitting the cloning and sequencing of the TT8 gene. TT8 identity was confirmed by complementation of tt8-3 and sequence analysis of an additional allele. The TT8 gene encodes a protein that displays a basic helix-loophelix at its C terminus and represents an Arabidopsis ortholog of the maize R transcription factors. The TT8 transcript is present in developing siliques and in young seedlings. The TT8 protein is required for normal expression of two flavonoid late biosynthetic genes, namely, DIHYDROFLAVONOL 4-REDUCTASE ( DFR ) and BANYULS ( BAN ), in Arabidopsis siliques. Interestingly, TRANSPARENT TESTA GLABRA1 ( TTG1 ) and TT2 genes also control the expression of DFR and BAN genes. Our results suggest that the TT8, TTG1, and TT2 proteins may interact to control flavonoid metabolism in the Arabidopsis seed coat. INTRODUCTIONFlavonoids are derived from phenylalanine and malonyl-CoA and constitute one of the largest groups of secondary metabolites in plants. They are based on a 15-carbon skeleton, which can be modified to yield different subclasses, including flavonols, anthocyanins, and proanthocyanidins ( Figure 1). In plants, flavonoid derivatives are responsible for the pigmentation pattern of vegetative parts and seeds and are involved in a wide range of biological functions. For example, they protect against UV radiation, serve as signal molecules in plant-microbe interactions, and participate in plant defense responses (reviewed in Dooner et al., 1991;Koes et al., 1994;Dixon and Paiva, 1995;Shirley, 1996). Recent studies have also stressed the involvement of flavonoids in seed coat-imposed dormancy as well as in seed storability (Winkel-Shirley, 1998;Debeaujon et al., 2000). Moreover, flavonoids are receiving increasing interest as health-promoting components of animal and human diets (Lairon and Amiot, 1999). These diverse roles can be correlated, at least in part, with the well-documented antioxidant properties of phenylpropanoid derivatives, especially flavonoids (RiceEvans et al., 1997), and with their inhibitory effect on enzymatic activities (Castelluccio et al., 1995).Investigating the structure and regulation of the flavonoid biosynthetic pathway in plants may thus help us to better understand and monitor flavonoid metabolism with regard to properties of the end products (Weisshaar and Jenkins, 1998). Flavonoid biosynthesis has been studied extensively by several methods, from protein purification to screening libraries with heterologous probes (reviewed in Holton and Cornish, 1995). The ubiquitous and nonessential nature of pigments for plant viability has made it possible to identify many flavonoid mutants, which has facilitated the genetic and molecular dissection of the pathway. To date, most of the enzymes involved in flavonoid biosynthesis have been c...

show abstract

Effect of two consensus sequences preceding the translation initiator codon on gene expression in plant protoplasts

Cited by 119 publications

References 18 publications

The Transcription Corepressor LEUNIG Interacts with the Histone Deacetylase HDA19 and Mediator Components MED14 (SWP) and CDK8 (HEN3) To Repress Transcription

The Transcription Corepressor LEUNIG Interacts with the Histone Deacetylase HDA19 and Mediator Components MED14 (SWP) and CDK8 (HEN3) To Repress Transcription

The Arabidopsis TT2 Gene Encodes an R2R3 MYB Domain Protein That Acts as a Key Determinant for Proanthocyanidin Accumulation in Developing Seed

The TT8 Gene Encodes a Basic Helix-Loop-Helix Domain Protein Required for Expression of DFR and BAN Genes in Arabidopsis Siliques

Contact Info

Product

Resources

About