scholarly journals Transcription factor action orchestrates the complex expression pattern ofCRABS CLAW, a gynoecium developmental regulator in Arabidopsis

2021 ◽  
Author(s):  
Thomas Gross ◽  
Annette Becker

AbstractThe flower of angiosperms is the most complex organ that plants generate and many transcription factors (TFs) are involved to regulate its morphogenesis in a coordinated way. In its center, the gynoecium develops consisting of specialized tissues such as secondary meristems, sites of postgenital fusion, ovules, pollen transmitting tract, all to assure successful sexual reproduction. Gynoecium development requires tight regulation of developmental regulators across time and tissues. However, while we know of several examples how simple on/off regulation of gene expression is achieved in plants, it remains unclear which regulatory processes generate complex expression patterns. Here, we use the gynoecium developmental regulatorCRABS CLAW (CRC)from Arabidopsis to study regulatory mechanisms contributing to its sophisticated expression pattern. Using a combination ofin silicopromoter analyses, global TF-DNA interaction screens, co-expression and mutant analysis we find that miRNA action, DNA methylation, and chromatin remodeling do not contribute substantially toCRCregulation. We show that a plethora of TFs bind to theCRCpromoter to fine-tune transcript abundance by activation of transcription, linkingCRCto specific developmental processes but not biotic or abiotic stress. Interestingly, the temporal-spatial aspects of regulation of expression may be under the control of redundantly acting genes and may require higher order complex formation at TF binding sites. We conclude that endogenous regulation of complex expression pattern of Arabidopsis genes requires orchestrated transcription factor action on several conserved promotor sites over almost 4 kb in length.Significance statementDifferent to genes that are simply switched on or off, depending on an environmental cue we find that genes directing development in plants often show complex expression pattern dependent on internal factors only. Here, we addressed the question how an complex expression pattern is achieved and use theCRABS CLAW (CRC)gene required for gynoecium development as an example. Combining wet lab experiments andin silicoanalysis we find that epigenetic regulation plays only a minor role and that a large number of transcription factors activates the transcription ofCRC. Single regulators may have a profound effect onCRCtranscript abundance but less so on the pattern of expression. Complex patterns most likely require the interplay of several transcription factors.

Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1663
Author(s):  
Thomas Gross ◽  
Annette Becker

Angiosperm flowers are the most complex organs that plants generate, and in their center, the gynoecium forms, assuring sexual reproduction. Gynoecium development requires tight regulation of developmental regulators across time and tissues. How simple on and off regulation of gene expression is achieved in plants was described previously, but molecular mechanisms generating complex expression patterns remain unclear. We use the gynoecium developmental regulator CRABS CLAW (CRC) to study factors contributing to its sophisticated expression pattern. We combine in silico promoter analyses, global TF-DNA interaction screens, and mutant analyses. We find that miRNA action, DNA methylation, and chromatin remodeling do not contribute substantially to CRC regulation. However, 119 TFs, including SEP3, ETT, CAL, FUL, NGA2, and JAG bind to the CRC promoter in yeast. These TFs finetune transcript abundance as homodimers by transcriptional activation. Interestingly, temporal–spatial aspects of expression regulation may be under the control of redundantly acting genes and require higher order complex formation at TF binding sites. Our work shows that endogenous regulation of complex expression pattern requires orchestrated transcription factor action on several conserved promotor sites covering almost 4 kb in length. Our results highlight the utility of comprehensive regulators screens directly linking transcriptional regulators with their targets.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Annekarin Meyer ◽  
Stefanie Herkt ◽  
Heike Kunze-Schumacher ◽  
Nicole Kohrs ◽  
Julia Ringleb ◽  
...  

AbstractA network of gene regulatory factors such as transcription factors and microRNAs establish and maintain gene expression patterns during hematopoiesis. In this network, transcription factors regulate each other and are involved in regulatory loops with microRNAs. The microRNA cluster miR-17-92 is located within the MIR17HG gene and encodes six mature microRNAs. It is important for hematopoietic differentiation and plays a central role in malignant disease. However, the transcription factors downstream of miR-17-92 are largely elusive and the transcriptional regulation of miR-17-92 is not fully understood. Here we show that miR-17-92 forms a regulatory loop with the transcription factor TAL1. The miR-17-92 cluster inhibits expression of TAL1 and indirectly leads to decreased stability of the TAL1 transcriptional complex. We found that TAL1 and its heterodimerization partner E47 regulate miR-17-92 transcriptionally. Furthermore, miR-17-92 negatively influences erythroid differentiation, a process that depends on gene activation by the TAL1 complex. Our data give example of how transcription factor activity is fine-tuned during normal hematopoiesis. We postulate that disturbance of the regulatory loop between TAL1 and the miR-17-92 cluster could be an important step in cancer development and progression.


mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
Matthew J. Reichlen ◽  
Venkata R. Vepachedu ◽  
Katsuhiko S. Murakami ◽  
James G. Ferry

ABSTRACT Results are presented supporting a regulatory role for the product of the MA3302 gene locus (designated MreA) previously annotated as a hypothetical protein in the methanogenic species Methanosarcina acetivorans of the domain Archaea. Sequence analysis of MreA revealed identity to the TrmB family of transcription factors, albeit the sequence is lacking the sensor domain analogous to TrmBL2, abundant in nonmethanogenic species of the domain Archaea. Transcription of mreA was highly upregulated during growth on acetate versus methylotrophic substrates, and an mreA deletion (ΔmreA) strain was impaired for growth with acetate in contrast to normal growth with methylotrophic substrates. Transcriptional profiling of acetate-grown cells identified 280 genes with altered expression in the ΔmreA strain versus the wild-type strain. Expression of genes unique to the acetate pathway decreased whereas expression of genes unique to methylotrophic metabolism increased in the ΔmreA strain relative to the wild type, results indicative of a dual role for MreA in either the direct or indirect activation of acetate-specific genes and repression of methylotrophic-specific genes. Gel shift experiments revealed specific binding of MreA to promoter regions of regulated genes. Homologs of MreA were identified in M. acetivorans and other Methanosarcina species for which expression patterns indicate roles in regulating methylotrophic pathways. IMPORTANCE Species in the domain Archaea utilize basal transcription machinery resembling that of the domain Eukarya, raising questions addressing the role of numerous putative transcription factors identified in sequenced archaeal genomes. Species in the genus Methanosarcina are ideally suited for investigating principles of archaeal transcription through analysis of the capacity to utilize a diversity of substrates for growth and methanogenesis. Methanosarcina species switch pathways in response to the most energetically favorable substrate, metabolizing methylotrophic substrates in preference to acetate marked by substantial regulation of gene expression. Although conversion of the methyl group of acetate accounts for most of the methane produced in Earth’s biosphere, no proteins involved in the regulation of genes in the acetate pathway have been reported. The results presented here establish that MreA participates in the global regulation of diverse methanogenic pathways in the genus Methanosarcina. Finally, the results contribute to a broader understanding of transcriptional regulation in the domain Archaea.


Blood ◽  
2009 ◽  
Vol 114 (11) ◽  
pp. 2299-2306 ◽  
Author(s):  
Orapan Sripichai ◽  
Christine M. Kiefer ◽  
Natarajan V. Bhanu ◽  
Toshihiko Tanno ◽  
Seung-Jae Noh ◽  
...  

Abstract Therapeutic regulation of globin genes is a primary goal of translational research aimed toward hemoglobinopathies. Signal transduction was used to identify chromatin modifications and transcription factor expression patterns that are associated with globin gene regulation. Histone modification and transcriptome profiling were performed using adult primary CD34+ cells cultured with cytokine combinations that produced low versus high levels of gamma-globin mRNA and fetal hemoglobin (HbF). Embryonic, fetal, and adult globin transcript and protein expression patterns were determined for comparison. Chromatin immunoprecipitation assays revealed RNA polymerase II occupancy and histone tail modifications consistent with transcriptional activation only in the high-HbF culture condition. Transcriptome profiling studies demonstrated reproducible changes in expression of nuclear transcription factors associated with high HbF. Among the 13 genes that demonstrated differential transcript levels, 8 demonstrated nuclear protein expression levels that were significantly changed by cytokine signal transduction. Five of the 8 genes are recognized regulators of erythropoiesis or globin genes (MAFF, ID2, HHEX, SOX6, and EGR1). Thus, cytokine-mediated signal transduction in adult erythroid cells causes significant changes in the pattern of globin gene and protein expression that are associated with distinct histone modifications as well as nuclear reprogramming of erythroid transcription factors.


Zygote ◽  
1998 ◽  
Vol 6 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Justine N. Parrott ◽  
Nicholas J. Gay

We describe the expression patterns and subcellular localisation of murine rel/NFκB transcription factors and their inhibitors during preimplantation development in the mouse. We find that the known rel and IκB proteins are ubiquitously expressed during early murine embryogenesis. The differential persistence of individual rel and IκB transcripts in the first cleavage stage embryo and analysis of the 3'UTR suggests that rel and IκB protein expression may be regulated at the level of mRNA stability and translation. At the stages of early mouse embryogenesis examined, there was no evidence for strong induction of rel dimer translocation into the nucleus. However, novel κB-binding proteins are found in the mouse blastocyst and may provide an alternative mechanism for regulation of gene expression via the κB motif in the early mouse embryo.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 372 ◽  
Author(s):  
Delasa Aghamirzaie ◽  
Karthik Raja Velmurugan ◽  
Shuchi Wu ◽  
Doaa Altarawy ◽  
Lenwood S. Heath ◽  
...  

Motivation: The increasing availability of chromatin immunoprecipitation sequencing (ChIP-Seq) data enables us to learn more about the action of transcription factors in the regulation of gene expression. Even though in vivo transcriptional regulation often involves the concerted action of more than one transcription factor, the format of each individual ChIP-Seq dataset usually represents the action of a single transcription factor. Therefore, a relational database in which available ChIP-Seq datasets are curated is essential. Results: We present Expresso (database and webserver) as a tool for the collection and integration of available Arabidopsis ChIP-Seq peak data, which in turn can be linked to a user’s gene expression data. Known target genes of transcription factors were identified by motif analysis of publicly available GEO ChIP-Seq data sets. Expresso currently provides three services: 1) Identification of target genes of a given transcription factor; 2) Identification of transcription factors that regulate a gene of interest; 3) Computation of correlation between the gene expression of transcription factors and their target genes. Availability: Expresso is freely available at http://bioinformatics.cs.vt.edu/expresso/


2020 ◽  
Author(s):  
Yinruizhi Li ◽  
Mengdi Wang ◽  
Ke Teng ◽  
Di Dong ◽  
Zhuocheng Liu ◽  
...  

Abstract Background:Lolium perenne L. is a kind of high quality forage grass, which can provide a good nutritional basis for herbivorous livestock. However, how to improve the nitrogen utilization rate of ryegrass and avoid the nitrate toxicity caused by excessive nitrogen has been troubling people for a long time. Up to now, the molecular response mechanism of ryegrass to nitrogen is not clear, especially under the condition of excessive nitrogen. Based on this, we tried to obtain a new insight into molecular response of ryegrass in nitrogen utilization and excessive nitrogen stress, providing the molecular theoretical basis for solving this problem.Results: In this study, the transcription of perennial ryegrass at different nitrogen levels was identified by high-throughput next-generation DNA sequencing. Phenotypic characterizations investigated that ryegrass in treatment N0.5 has a better growth state than the other three groups. The treatment N1 and N10 contained excessive nitrogen, which had a stress effect on plant growth. Analysis of differentially expressed genes indicated that 345, 105 genes are considered to involve in the regulation of nitrogen utilization and excessive nitrogen stress, respectively. GO enrichment analysis revealed that plant response to nitrogen mainly enrich in two categories, including “biological process” and “molecular function”. KEGG enrichment analysis suggested that “Photosynthesis-antenna proteins” may respond positively to nitrogen under appropriate nitrogen conditions, whereas “steroid biosynthesis”, “carotenoid biosynthesis” and “C5-branched dibasic acid metabolism” had been identified as top significant enrichment pathways response to excessive nitrogen. Transcription factors analysis showed that 21 TFs related to nitrogen utilization were classified into 10 transcription factor families, especially AP2-EREBP and MYB TF families. 4 TFs related to excessive nitrogen stress were identified, which belonged to 4 transcription factor families including LOB, NAC, AP2-EREBP and HB. The expression patterns of these selected genes above were also analyzed. Conclusions: These results made a contribution to comprehend the molecular mechanism of perennial ryegrass response to nitrogen. It provides new ideas for guiding the production practice and variety improvement of forage and even food crops from the perspective of molecular biology.


2018 ◽  
Author(s):  
Tuan Tu Tran ◽  
Alvaro L Pérez-Quintero ◽  
Issa Wonni ◽  
Sara C. D. Carpenter ◽  
Yanhua Yu ◽  
...  

AbstractMost Xanthomonas species translocate Transcription Activator-Like (TAL) effectors into plant cells where they function like plant transcription factors via a programmable DNA-binding domain. Characterized strains of rice pathogenic X. oryzae pv. oryzae harbor 9-16 different tal effector genes, but the function of only a few of them has been decoded. Using sequencing of entire genomes, we first performed comparative analyses of the complete repertoires of TAL effectors, herein referred to as TALomes, in three Xoo strains forming an African genetic lineage different from Asian Xoo. A phylogenetic analysis of the three TALomes combined with in silico predictions of TAL effector targets showed that African Xoo TALomes are highly conserved, genetically distant from Asian ones, and closely related to TAL effectors from the bacterial leaf streak pathogen Xanthomonas oryzae pv. oryzicola (Xoc). Nine clusters of TAL effectors could be identified among the three TALomes, including three showing higher levels of variation in their repeat variable diresidues (RVDs). Detailed analyses of these groups revealed recombination events as a possible source of variation among TAL effector genes. Next, to address contribution to virulence, nine TAL effector genes from the Malian Xoo strain MAI1 and four allelic variants from the Burkinabe Xoo strain BAI3, thus representing most of the TAL effector diversity in African Xoo strains, were expressed in the TAL effector-deficient X. oryzae strain X11-5A for gain-of-function assays. Inoculation of the susceptible rice variety Azucena lead to the discovery of three TAL effectors promoting virulence, including two TAL effectors previously reported to target the susceptibility (S) gene OsSWEET14 and a novel major virulence contributor, TalB. RNA profiling experiments in rice and in silico prediction of EBEs were carried out to identify candidate targets of TalB, revealing OsTFX1, a bZIP transcription factor previously identified as a bacterial blight S gene, and OsERF#123, which encodes a subgroup IXc AP2/ERF transcription factor. Use of designer TAL effectors demonstrated that induction of either gene resulted in greater susceptibility to strain X11-5A. The induction of OsERF#123 by BAI3Δ1, a talB knockout derivative of BAI3, carrying these designer TAL effectors increased virulence of BAI3Δ1 validating OsERF#123 as a new, bacterial blight S gene.Author SummaryThe ability of most Xanthomonas plant pathogenic bacteria to infect their hosts relies on the action of a specific family of proteins called TAL effectors, which are transcriptional activators injected into the plant by the bacteria. TAL effectors enter the plant cell nucleus and bind to the promoters of specific plant genes. Genes that when induced can benefit pathogen multiplication or disease development are called susceptibility (S) genes. Here, we perform a comparative analysis of the TAL effector repertoires of three strains of X. oryzae pv. oryzae, which causes bacterial leaf blight of rice, a major yield constraint in this staple crop. Using sequencing of entire genomes, we compared the large repertoires of TAL effectors in three African Xoo strains which form a genetic lineage distinct from Asian strains. We assessed the individual contribution to pathogen virulence of 13 TAL effector variants represented in the three strains, and identified one that makes a major contribution. By combining host transcriptome profiling and TAL effector binding sites prediction, we identified two targets of this TAL effector that function as S genes, one previously identified, and one, new S gene. We validated the new S gene by functional characterization using designer TAL effectors. Both S genes encode transcription factors and can therefore be considered as susceptibility hubs for pathogen manipulation of the host transcriptome. Our results provide new insights into the diversified strategies underlying the roles of TAL effectors in promoting plant disease.


2019 ◽  
Vol 70 (12) ◽  
pp. 3111-3123 ◽  
Author(s):  
Lili Xiang ◽  
Xiaofen Liu ◽  
Heng Li ◽  
Xueren Yin ◽  
Donald Grierson ◽  
...  

Abstract ‘Jimba’, a well-known white flowered chrysanthemum cultivar, occasionally and spontaneously produces red colored petals under natural cultivation, but there is little information about the molecular regulatory mechanism underlying this process. We analysed the expression patterns of 91 MYB transcription factors in ‘Jimba’ and ‘Turning red Jimba’ and identified an R3 MYB, CmMYB#7, whose expression was significantly decreased in ‘Turning red Jimba’ compared with ‘Jimba’, and confirmed it is a passive repressor of anthocyanin biosynthesis. CmMYB#7 competed with CmMYB6, which together with CmbHLH2 is an essential component of the anthocyanin activation complex, for interaction with CmbHLH2 through the bHLH binding site in the R3 MYB domain. This reduced binding of the CmMYB6–CmbHLH2 complex and inhibited its ability to activate CmDFR and CmUFGT promoters. Moreover, using transient expression assays we demonstrated that changes in the expression of CmMYB#7 accounted for alterations in anthocyanin content. Taken together, our findings illustrate that CmMYB#7 is a negative regulator of anthocyanin biosynthesis in chrysanthemum.


2019 ◽  
Vol 39 (3) ◽  
Author(s):  
Damian Kołat ◽  
Żaneta Kałuzińska ◽  
Andrzej K. Bednarek ◽  
Elżbieta Płuciennik

Abstract The Activator Protein 2 (AP-2) transcription factor (TF) family is vital for the regulation of gene expression during early development as well as carcinogenesis process. The review focusses on the AP-2α and AP-2γ proteins and their dualistic regulation of gene expression in the process of carcinogenesis. Both AP-2α and AP-2γ influence a wide range of physiological or pathological processes by regulating different pathways and interacting with diverse molecules, i.e. other proteins, long non-coding RNAs (lncRNA) or miRNAs. This review summarizes the newest information about the biology of two, AP-2α and AP-2γ, TFs in the carcinogenesis process. We emphasize that these two proteins could have either oncogenic or suppressive characteristics depending on the type of cancer tissue or their interaction with specific molecules. They have also been found to contribute to resistance and sensitivity to chemotherapy in oncological patients. A better understanding of molecular network of AP-2 factors and other molecules may clarify the atypical molecular mechanisms occurring during carcinogenesis, and may assist in the recognition of new diagnostic biomarkers.


Sign in / Sign up

Export Citation Format

Share Document