Project description:To identify biological function of HSFB transcriptional repressor, we subjected hsfb1 hsfb2b double mutant and wild-type Arabidopsis plant under heat condition (32 Celsius degree) and did microarray experiment. The microarray experiment under non-heated condition is described in GSE14702. We found expression of many heat-shock proteins (HSPs) is not fully enhanced in the double mutant when compared to wild-type plant. This data suggest that the inhibition of expression of HSPs in non-heated condition is important for fully heat-stress response in plant.
Project description:Transcription factors (TFs) orchestrate the gene expression programs that define each cell’s identity, and the canonical TF accomplishes this with two functional domains1–7. The DNA-binding domain interacts with specific genomic sequences, and the effector domain binds coactivators or co-repressors that contribute to transcriptional regulation. We report here that TFs also frequently contain an RNA-binding domain and that this also contributes to gene regulation. Nearly half of TFs in human cells show evidence of RNA-binding and their affinities for RNA are similar to those of well-studied RNA-binding proteins. The RNA-binding sites of TFs have sequence and functional features analogous to the arginine-rich motif of the HIV transcriptional activator Tat8,9. RNA-binding contributes to TF function by promoting the dynamic association of TFs with chromatin. We conclude that the canonical definition of transcription factors is incomplete, and that the ability of many TFs to bind DNA, RNA and protein is fundamental to gene regulation.
Project description:To identify biological function of HSFB transcriptional repressor, we subjected hsfb1 hsfb2b double mutant and wild-type Arabidopsis plant under heat condition (32 Celsius degree) and did microarray experiment. The microarray experiment under non-heated condition is described in GSE14702. We found expression of many heat-shock proteins (HSPs) is not fully enhanced in the double mutant when compared to wild-type plant. This data suggest that the inhibition of expression of HSPs in non-heated condition is important for fully heat-stress response in plant. hsfb1 hsfb2b double mutant vs. wild-type seedlings of Arabidopsis thaliana subjected under heat condition (32 Celsius degree). Biological replicates: 4 replicates.
Project description:GATA transcription factors are involved in multiple processes in plant growth and development. Two GATA factors, nitrate-inducible, carbon metabolism-involved (GNC) and CYTOKININ-RESPONSIVE GATA FACTOR 1 (CGA1, also named GNL) are important regulators in greening, flowering, senescence and hormone signaling. However, their direct target genes in regulating these biological processes are poorly characterized. Here, we report a genome-wide identification of the target genes of Arabidopsis GNC and CGA1.
Project description:rs04-03_myb - myb - Xylogenesis is a fundamental developmental process that is specific of vascular plants. It allows the formation of xylem, also called wood in trees, a complex tridimensional tissue composed of different cell types. This process occurs through the control of fundamental cell mechanisms like cell division and differentiation, secondary cell wall synthesis, lignin deposition and programmed cell death. Xylogenesis is controlled spatially and temporally by specific genetic programs that involve hundreds of genes. For instance, lignin biosynthetic genes, CAD and CCR, are specifically expressed during xylogenesis through MYB transcription factor binding sites, a process that seems to be common to all vascular plants. We have cloned two xylem specific MYB transcription factors, EgMYB1 et EgMYB2, in Eucalyptus. Interestingly, they are able to bind MYB consensus sequences of CAD and CCR promoters in vitro and to modulate CAD and CCR expression in vivo. When overexpressed in Arabidopsis or tobacco, they affect xylem structure by changing cell wall structure and quality. To follow expression changes of Arabidopsis genes in transgenic plants overexpressing Eg MYB1 and EgMYB2 should help us to find out which genes might be target of those transcription factors. This should help us to decipher the actual role of those two MYBs in xylogenesis, two new members of a large family of transcription factors in plants. - Xylogenesis is a fundamental developmental process that is specific of vascular plants. It allows the formation of xylem, also called wood in trees, a complex tridimensional tissue composed of different cell types. This process occurs through the control of fundamental cell mechanisms like cell division and differentiation, secondary cell wall synthesis, lignin deposition and programmed cell death. Xylogenesis is controlled spatially and temporally by specific genetic programs that involve hundreds of genes. For instance, lignin biosynthetic genes, CAD and CCR, are specifically expressed during xylogenesis through MYB transcription factor binding sites, a process that seems to be common to all vascular plants. We have cloned two xylem specific MYB transcription factors, EgMYB1 et EgMYB2, in Eucalyptus. Interestingly, they are able to bind MYB consensus sequences of CAD and CCR promoters in vitro and to modulate CAD and CCR expression in vivo. When overexpressed in Arabidopsis or tobacco, they affect xylem structure by changing cell wall structure and quality. To follow expression changes of Arabidopsis genes in transgenic plants overexpressing Eg MYB1 and EgMYB2 should help us to find out which genes might be target of those transcription factors. This should help us to decipher the actual role of those two MYBs in xylogenesis, two new members of a large family of transcription factors in plants. Keywords: gene knock in (transgenic)
Project description:The lipid-derived phytohormone jasmonoyl-isoleucine (JA-Ile) regulates plant immunity, growth and development in vascular plants by activating genome-wide transcriptional reprogramming. In Arabidopsis, this is largely orchestrated by the master regulator MYC2 and related transcription factors (TFs). However, the TFs activating this pathway in basal plant lineages are currently unknown. We report the functional conservation of MYC-related TFs between the eudicot Arabidopsis thaliana and the liverwort Marchantia polymorpha, a plant belonging to one of the most basal land-plants lineages. Phylogenetic analysis suggests that MYC function first appeared in charophycean algae, and therefore predates the evolutionary appearance of any other jasmonate pathway component. Marchantia possesses two functionally interchangeable MYC genes, one in females and one in males. Similar to AtMYC2, MpMYCs showed nuclear localization, interaction with JAZ-repressors, and regulation by light. Phenotypic and molecular characterization of loss- or gain-of-function mutants demonstrated that MpMYCs are necessary and sufficient for the activation of the pathway in Marchantia, but unlike their Arabidopsis orthologs, do not regulate fertility. Our results show that despite 450 million years of independent evolution, MYCs are functionally conserved between bryophytes and eudicots. Genetic conservation in one of the most basal lineages suggests that MYC function existed in the common ancestor of land plants and evolved from a pre-existing MYC function in charophycean algae.
Project description:In Schizosaccharomyces pombe, over 90% of transcription factor genes are nonessential. Moreover, the majority do not exhibit significant growth defects under optimal conditions when deleted, complicating their functional characterization and target gene identification. Here, we systematically overexpressed 99 transcription factor genes with the nmt1 promoter. Screening the overexpression array revealed that 64 transcription factor genes exhibited reduced fitness when ectopically expressed. Cell cycle defects were also often observed. We further investigated three uncharacterized transcription factor genes (toe1+-toe3+) which displayed cell elongation when overexpressed. Ectopic expression of toe1+ resulted in a G1 delay while toe2+ and toe3+ overexpression produced an accumulation of septated cells with abnormalities in septum formation and nuclear segregation, respectively. Transcriptome profiling and ChIP-chip analysis of the transcription factor overexpression strains indicated that Toe1 activates target genes of the pyrimidine-salvage pathway, while Toe3 regulates target genes involved in polyamine synthesis. We also found that ectopic expression of the putative target genes SPBC3H7.05c, and dad5+ and SPAC11D3.06 could recapitulate the cell cycle phenotypes of toe2+ and toe3+ overexpression, respectively. Furthermore, the phenotypes of toe1+and toe2+ overexpression could be suppressed by deletion of the putative target genes urg2+ and SPAC1399.04c, and SPBC3H7.05c, SPACUNK4.15 and rds1+, respectively. This study implicates new transcription factors and metabolism genes in cell cycle regulation and demonstrates the potential of systematic overexpression analysis to elucidate the function and target genes of transcription factors in S. pombe.