Temporary Expression of the TAF10 Gene and its Requirement for Normal Development of Arabidopsis thaliana (original) (raw)
Related papers
TBP-associated factors in Arabidopsis
Gene, 2004
Initiation of transcription mediated by RNA polymerase II requires a number of transcription factors among which TFIID is the major core promoter recognition factor. TFIID is composed of highly conserved factors which include the TATA-binding protein (TBP) and about 14 TBP-associated factors (TAFs). Since TAFs play important roles in transcription they have been extensively studied in organisms like yeast, Drosophila and human. Surprisingly, TAFs have been poorly characterized in plants. With the completion of the Arabidopsis genome sequence, it is possible to search for TAFs, since many of them have conserved amino acid sequences. Mining the genome of Arabidopsis for TAFs resulted in the identification of 18 putative Arabidopsis TAFs (AtTAFs). We have analyzed their protein structure and their genomic localisation. Expression profiling by RT-PCR showed that these TAFs are expressed in all parts of the plant which is in agreement with their general role in transcription. These analyses in combination with their evolutionary conservation with TAFs of other organisms are discussed.
Plant and Cell Physiology, 2005
TAF10 is one of the TATA box-binding protein-associated factors (TAFs), which constitute the TFIID complex. We isolated a plant TAF10 ortholog from a Flaveria trinervia cDNA library, and named it ftTAF10. The ftTAF10 polypeptide contains a histone-fold motif, which is highly conserved among the TAF10s of other organisms. A transiently expressed green fluorescent protein (GFP) fusion protein was translocated into the nuclei of onion epidermal cells, suggesting that the ftTAF10 functions in nuclei. The transcript level was higher in stems and roots than in leaves, and in situ hybridization of F. trinervia seedlings revealed that the ftTAF10 transcript is accumulated abundantly in vascular tissues of hypocotyls, in the central cylinder of roots, and slightly in bundle sheath cells of leaves. Overexpression of ftTAF10 in Arabidopsis under the cauliflower mosaic virus 35S promoter caused two kinds of abnormal morphology, limitation of the indeterminate inflorescence and production of deformed leaves. These results indicate the possibility that ftTAF10 is a plant 'selective TAF' involved in the expression of a subset of vascular abundant genes, and that its appropriate gene expression is necessary for normal development.
The Arabidopsis TFIID factor AtTAF6 controls pollen tube growth
Developmental Biology, 2005
Initiation of transcription mediated by RNA polymerase II requires a number of transcription factors among which TFIID is the major core promoter recognition factor. TFIID is composed of highly conserved factors which include the TATA-binding protein (TBP) and about 14 TBP-associated factors (TAFs). Recently, the complete Arabidopsis TAF family has been identified. To obtain functional information about Arabidopsis TAFs, we analyzed a T-DNA insertion mutant for AtTAF6. Segregation analysis showed that plants homozygous for the mutant allele were never found, indicating that inhibition of the AtTAF6 function is lethal. Genetic experiments also revealed that the male gametophyte was affected by the attaf6 mutation since significant reduced transmission of the mutant allele through the male gametophyte was observed. Detailed histological and morphological analysis showed that the T-DNA insertion in AtTAF6 specifically affects pollen tube growth, indicating that the transcriptional regulation of only a specific subset of genes is controlled by this basal transcription factor. D (M.M. Kater). Developmental Biology 285 (2005) 91 -100 www.elsevier.com/locate/ydbio
Arabidopsis thaliana TBP-associated factor 5 is essential for plant growth and development
Molecular Breeding, 2011
The TATA binding protein-associated factor 5 (TAF5) is a subunit of TFIID and SAGA complexes involved in RNA polymerase II transcription initiation and histone acetylation. Although members of the putative SAGA complex in Arabidopsis such as GCN5 and ADA2b have important roles in plant development and abiotic stress responses, the function of other components of the Arabidopsis putative SAGA complex, like TAF5, is unknown. We used reverse genetics to elucidate the biological role of TAF5 in Arabidopsis thaliana. The absence of homozygote taf5 mutants indicated that AtTAF5 is an essential gene for the plant viability. Genetic approaches also revealed that AtTAF5 plays a critical role in regulatory mechanisms involved in male gametogenesis and pollen tube growth. Moreover, Arabidopsis taf5 heterozygous mutants displayed terminal flower-like phenotype, suggesting that TAF5 could be involved in molecular mechanisms that regulate indeterminate inflorescence meristems. Therefore, this work suggests that Arabidopsis TAF5 is necessary and sufficient for a complete plant life cycle.
TAF13 interacts with PRC2 members and is essential for Arabidopsis seed development
Developmental Biology, 2013
TBP-Associated Factors (TAFs) are components of complexes like TFIID, TFTC, SAGA/STAGA and SMAT that are important for the activation of transcription, either by establishing the basic transcription machinery or by facilitating histone acetylation. However, in Drosophila embryos several TAFs were shown to be associated with the Polycomb Repressive Complex 1 (PRC1), even though the role of this interaction remains unclear. Here we show that in Arabidopsis TAF13 interacts with MEDEA and SWINGER, both members of a plant variant of Polycomb Repressive Complex 2 (PRC2). PRC2 variants play important roles during the plant life cycle, including seed development. The taf13 mutation causes seed defects, showing embryo arrest at the 8-16 cell stage and over-proliferation of the endosperm in the chalazal region, which is typical for Arabidopsis PRC2 mutants. Our data suggest that TAF13 functions together with PRC2 in transcriptional regulation during seed development.
The Plant Cell, 1995
The Arabidopsis thaliana Athb-7 is a homeobox gene of unknown function. 8 y analogy with homeobox genes of other organisms, its gene product, Athb-1, is most likely a transcription factor involved in developmental processes. We constructed a series of Athb-7-derived genes to examine the roles of Athb-1 in transcriptional regulation and plant development. Athb-1 was found to transactivate a promoter linked to a specific DNA binding site by transient expression assays. In transgenic tobacco plants, overexpression of Athb-1 or its chimeric derivatives with heterologous transactivating domains of the yeast transcription factor GAL4 or herpes simplex virus transcription factor VP16 conferred deetiolated phenotypes in the dark, including cotyledon expansion, true leaf development, and an inhibition of hypocotyl elongation. Expression of Athb-7 or the two chimeric derivatives also affected the development of palisade parenchyma under normal growth conditions, resulting in light green sectors in leaves and cotyledons, whereas other organs in the transgenic plants remained normal. Both developmental phenotypes were induced by glucocorticoid in transgenic plants expressing a chimeric transcription factor comprising the Athb-1 DNA binding domain, the VP16 transactivating domain, and the glucocorticoid receptor domain. Plants with Severe inducible phenotypes showed additional abnormality in cotyledon expansion. Our results suggest that Athb-1 is a transcription activator involved in leaf development. Soderman, E., Mattsson, J., Svenson, M., Borkird, C., and EngstrUm, P. (1994). Expression patterns of novel genes encoding homeodomain leucine-zipper proteins in Arabidopsis thaliana. Plant MOI. Biol. 26, 145-154. Triezenberg, S.J., Kingsbury, R.C., and McKnight, S.L. (1988). Functional dissection of VP16. the transactivator of herpes simplex virus immediate early gene expression. Genes Dev. 2, 718-729. Vollbrecht, E., Veit, B., Sinha, N., and Hake, S. (1991). The developmental gene KNOTTED-7 is a member of a maize homeobox gene family. Nature 350, 241-243. 563-564.
The Plant Journal, 2003
Previously, we identi®ed a novel rice gene, GROWTH-REGULATING FACTOR1 (OsGRF1), which encodes a putative transcription factor that appears to play a regulatory role in stem elongation. We now describe the GRF gene family of Arabidopsis thaliana (AtGRF), which comprises nine members. The deduced AtGRF proteins contain the same characteristic regionsÐthe QLQ (Gln, Leu, Gln) and WRC (Trp, Arg, Cys) domainsÐas do OsGRF1 and related proteins in rice, as well as features indicating a function in transcriptional regulation. Most of the AtGRF genes are strongly expressed in actively growing and developing tissues, such as shoot tips,¯ower buds, and roots, but weakly in mature stem and leaf tissues. Overexpression of AtGRF1 and AtGRF2 resulted in larger leaves and cotyledons, as well as in delayed bolting of the in¯orescence stem when compared to wild-type plants. In contrast, triple insertional null mutants of AtGRF1±AtGRF3 had smaller leaves and cotyledons, whereas single mutants displayed no changes in phenotype and double mutants displayed only minor ones. The alteration of leaf growth in overexpressors and triple mutants was based on an increase or decrease in cell size, respectively. These results indicate that AtGRF proteins play a role in the regulation of cell expansion in leaf and cotyledon tissues.
Transcript Elongation Factor TFIIS Is Involved in Arabidopsis Seed Dormancy
Journal of Molecular Biology, 2009
Transcript elongation factor TFIIS promotes efficient transcription by RNA polymerase II, since it assists in bypassing blocks during mRNA synthesis. While yeast cells lacking TFIIS are viable, inactivation of mouse TFIIS causes embryonic lethality. Here, we have identified a protein encoded in the Arabidopsis genome that displays a marked sequence similarity to TFIIS of other organisms, primarily within domains II and III in the C-terminal part of the protein. TFIIS is widely expressed in Arabidopsis, and a green fluorescent protein-TFIIS fusion protein localises specifically to the cell nucleus. When expressed in yeast cells lacking the endogenous TFIIS, Arabidopsis TFIIS partially complements the sensitivity of mutant cells to the nucleotide analog 6-azauridine, which is a typical characteristic of transcript elongation factors. We have characterised Arabidopsis lines harbouring T-DNA insertions in the coding sequence of TFIIS. Plants homozygous for T-DNA insertions are viable, and genomewide transcript profiling revealed that compared to control plants, a relatively small number of genes are differentially expressed in mutant plants. TFIIS −/− plants display essentially normal development, but they flower slightly earlier than control plants and show clearly reduced seed dormancy. Plants with RNAi-mediated knockdown of TFIIS expression also are affected in seed dormancy. Therefore, TFIIS plays a critical role in Arabidopsis seed development.
Uncovering Factors and Molecular Mechanisms in Transcriptional Regulation in Arabidopsis thaliana
2012
Cell fate specification in development requires transcription factors for proper regulation of gene expression. In Arabidopsis, transcription factors encoded by four classes of homeotic genes, A, B, C, and E, act in a combinatorial manner to control proper floral organ identity. The A-class gene APETALA2 (AP2) promotes sepal and petal identities in whorls 1 and 2 and restricts the expression of the C-class gene AGAMOUS (AG) from whorls 1 and 2. However, it is unknown how AP2 performs these functions. Unlike the other highly characterized floral homeotic proteins containing MADS domains, AP2 has two DNA binding domains referred to as the AP2 domains and its DNA recognition sequence is still unknown. Here, we show that AP2 binds a noncanonical AT-rich target sequence, and utilizing a GUS reporter system, we demonstrate that the presence of this sequence in the AG 2 nd intron is important for the restriction of AG expression in vivo. Furthermore, we show that AP2 binds the AG 2 nd intron and directly regulates AG expression through this sequence element. Computational analysis reveals that the binding site is highly conserved in the second intron of AG orthologs throughout Brassicaceae. By uncovering a biologically relevant AT-rich target sequence, this work shows that AP2 domains have wide-ranging target specificities and provides a 2 missing link in the mechanisms underlying flower development. It also sets the foundation for understanding the basis of the broad biological functions of AP2 in Arabidopsis as well as the divergent biological functions of AP2 orthologs in dicotyledonous plants.
Molecular and Cellular Biology, 2003
Although it is now well documented that metazoans have evolved general transcription factor (GTF) variants to regulate their complex patterns of gene expression, there is so far no information regarding the existence of specific GTFs in plants. Here we report the characterization of a ubiquitously expressed gene that encodes a bona fide novel transcription factor IIB (TFIIB)-related protein in Arabidopsis thaliana. We have shown that this protein is the founding member of a plant-specific TFIIB-related protein family named pBrp (for plantspecific TFIIB-related protein). Surprisingly, in contrast to common GTFs that are localized in the nucleus, the bulk of pBrp proteins are bound to the cytoplasmic face of the plastid envelope, suggesting an organelle-specific function for this novel class of TFIIB-related protein. We show that pBrp proteins harbor conditional proteolytic signals that can target these proteins for rapid turnover by the proteasome-mediated protein degradation pathway. Interestingly, under conditions of proteasome inhibition, pBrp proteins accumulate in the nucleus. Together, our results suggest a possible involvement of these proteins in an intracellular signaling pathway between plastids and the nucleus. Our data provide the first evidence for an organelle-related evolution of the eukaryotic general transcription machinery.