scholarly journals Ectopic Overproduction of a Sporulation-Specific Transcription Factor Induces Assembly of Prespore-Like Membranous Compartments in Vegetative Cells of Fission Yeast

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 1195-1199 ◽  
Author(s):  
Yukiko Nakase ◽  
Aiko Hirata ◽  
Chikashi Shimoda ◽  
Taro Nakamura

Mei4 is a key sporulation-specific transcription factor in fission yeast. Ectopic expression of Mei4 in vegetative cells caused formation of nucleated membranous compartments, which shared common features with normal forespore membranes, thereby perturbing nuclear division. These results suggest why expression of development-specific transcription factors must be strictly controlled.

2021 ◽  
Vol 49 (17) ◽  
pp. 9809-9820
Author(s):  
Wakana Koda ◽  
Satoshi Senmatsu ◽  
Takuya Abe ◽  
Charles S Hoffman ◽  
Kouji Hirota

Abstract Transcriptional regulation, a pivotal biological process by which cells adapt to environmental fluctuations, is achieved by the binding of transcription factors to target sequences in a sequence-specific manner. However, how transcription factors recognize the correct target from amongst the numerous candidates in a genome has not been fully elucidated. We here show that, in the fission-yeast fbp1 gene, when transcription factors bind to target sequences in close proximity, their binding is reciprocally stabilized, thereby integrating distinct signal transduction pathways. The fbp1 gene is massively induced upon glucose starvation by the activation of two transcription factors, Atf1 and Rst2, mediated via distinct signal transduction pathways. Atf1 and Rst2 bind to the upstream-activating sequence 1 region, carrying two binding sites located 45 bp apart. Their binding is reciprocally stabilized due to the close proximity of the two target sites, which destabilizes the independent binding of Atf1 or Rst2. Tup11/12 (Tup-family co-repressors) suppress independent binding. These data demonstrate a previously unappreciated mechanism by which two transcription-factor binding sites, in close proximity, integrate two independent-signal pathways, thereby behaving as a hub for signal integration.


Development ◽  
1999 ◽  
Vol 126 (23) ◽  
pp. 5523-5531 ◽  
Author(s):  
I. Pata ◽  
M. Studer ◽  
J.H. van Doorninck ◽  
J. Briscoe ◽  
S. Kuuse ◽  
...  

In this paper, we show that the transcription factor GATA3 is dynamically expressed during hindbrain development. Function of GATA3 in ventral rhombomere (r) 4 is dependent on functional GATA2, which in turn is under the control of Hoxb1. In particular, the absence of Hoxb1 results in the loss of GATA2 expression in r4 and the absence of GATA2 results in the loss of GATA3 expression. The lack of GATA3 expression in r4 inhibits the projection of contralateral vestibuloacoustic efferent neurons and the migration of facial branchiomotor neurons similar to Hoxb1-deficient mice. Ubiquitous expression of Hoxb1 in the hindbrain induces ectopic expression of GATA2 and GATA3 in ventral r2 and r3. These findings demonstrate that GATA2 and GATA3 lie downstream of Hoxb1 and provide the first example of Hox pathway transcription factors within a defined population of vertebrate motor neurons.


2020 ◽  
Vol 37 (9) ◽  
pp. 2477-2486 ◽  
Author(s):  
Jingyi Li ◽  
MiOk Lee ◽  
Brian W Davis ◽  
Sangeet Lamichhaney ◽  
Ben J Dorshorst ◽  
...  

Abstract Feathered leg is a trait in domestic chickens that has undergone intense selection by fancy breeders. Previous studies have shown that two major loci controlling feathered leg are located on chromosomes 13 and 15. Here, we present genetic evidence for the identification of candidate causal mutations at these loci. This was accomplished by combining classical linkage mapping using an experimental cross segregating for feathered leg and high-resolution identical-by-descent mapping using whole-genome sequence data from 167 samples of chicken with or without feathered legs. The first predicted causal mutation is a single-base change located 25 kb upstream of the gene for the forelimb-specific transcription factor TBX5 on chromosome 15. The second is a 17.7-kb deletion located ∼200 kb upstream of the gene for the hindlimb-specific transcription factor PITX1 on chromosome 13. These mutations are predicted to activate TBX5 and repress PITX1 expression, respectively. The study reveals a remarkable convergence in the evolution of the feathered-leg phenotype in domestic chickens and domestic pigeons, as this phenotype is caused by noncoding mutations upstream of the same two genes. Furthermore, the PITX1 causal variants are large overlapping deletions, 17.7 kb in chicken and 44 kb in pigeons. The results of the present study are consistent with the previously proposed model for pigeon that feathered leg is caused by reduced PITX1 expression and ectopic expression of TBX5 in hindlimb buds resulting in a shift of limb identity from hindlimb to more forelimb-like identity.


Author(s):  
Sergey Abramov ◽  
Alexandr Boytsov ◽  
Dariia Bykova ◽  
Dmitry D. Penzar ◽  
Ivan Yevshin ◽  
...  

AbstractSequence variants in gene regulatory regions alter gene expression and contribute to phenotypes of individual cells and the whole organism, including disease susceptibility and progression. Single-nucleotide variants in enhancers or promoters may affect gene transcription by altering transcription factor binding sites. Differential transcription factor binding in heterozygous genomic loci provides a natural source of information on such regulatory variants. We present a novel approach to call the allele-specific transcription factor binding events at single-nucleotide variants in ChIP-Seq data, taking into account the joint contribution of aneuploidy and local copy number variation, that is estimated directly from variant calls. We have conducted a meta-analysis of more than 7 thousand ChIP-Seq experiments and assembled the database of allele-specific binding events listing more than half a million entries at nearly 270 thousand single-nucleotide polymorphisms for several hundred human transcription factors and cell types. These polymorphisms are enriched for associations with phenotypes of medical relevance and often overlap eQTLs, making candidates for causality by linking variants with molecular mechanisms. Specifically, there is a special class of switching sites, where different transcription factors preferably bind alternative alleles, thus revealing allele-specific rewiring of molecular circuitry.


2019 ◽  
Author(s):  
Roy Njoroge Kimotho ◽  
Elamin Hafiz Baillo ◽  
Zhengbin Zhang

Background: Maize (Zea mays L.) is a principal cereal crop cultivated worldwide for human food, animal feed, and more recently as a source of biofuel. However, as a direct consequence of water insufficiency and climate change, frequent occurrences of both biotic and abiotic stresses have been reported in different regions around the world, and recently, this has become a major threat in increasing global maize yields. Plants respond to abiotic stresses by utilizing the activity of transcription factors, which are families of genes coding for specific transcription factor proteins whose target genes form a regulon which is involved in the repression/ activation of genes associated with abiotic stress responses. Therefore, it is of uttermost importance to have a systematic study on each family of the transcription factors, the downstream target genes they regulate, and the specific transcription factor genes which are involved in multiple abiotic stress responses in maize and other main crops. Method: In this review, the main transcription factor families, the specific transcription factor genes and their regulons which are involved in abiotic stress regulation will be momentarily discussed. Great emphasis will be given on maize abiotic stress improvement throughout this review, although other examples from other plants like rice, Arabidopsis, wheat, and barley will be used. Results: We have described in detail the main transcription factor families in maize which take part in abiotic stress responses together with their regulons. Furthermore, we have also briefly described the utilization of high-efficiency technologies in the study and characterization of TFs involved in the abiotic stress regulatory networks in plants with an emphasis on increasing maize production. Examples of these technologies include next-generation sequencing, microarray analysis, machine learning and RNA-Seq technology. Conclusion: In conclusion, it is hoped that all the information provided in this review may in time contribute to the use of TF genes in the research, breeding, and development of new abiotic stress tolerant maize cultivars.


Author(s):  
Roy Njoroge Kimotho ◽  
Elamin Hafiz Baillo ◽  
Zhengbin Zhang

Background: Maize (Zea mays L.) is a principal cereal crop cultivated worldwide for human food, animal feed, and more recently as a source of biofuel. However, as a direct consequence of water insufficiency and climate change, frequent occurrences of both biotic and abiotic stresses have been reported in different regions around the world, and recently, this has become a major threat in increasing global maize yields. Plants respond to abiotic stresses by utilizing the activity of transcription factors, which are families of genes coding for specific transcription factor proteins whose target genes form a regulon which is involved in the repression/ activation of genes associated with abiotic stress responses. Therefore, it is of uttermost importance to have a systematic study on each family of the transcription factors, the downstream target genes they regulate, and the specific transcription factor genes which are involved in multiple abiotic stress responses in maize and other main crops. Method: In this review, the main transcription factor families, the specific transcription factor genes and their regulons which are involved in abiotic stress regulation will be momentarily discussed. Great emphasis will be given on maize abiotic stress improvement throughout this review, although other examples from other plants like rice, Arabidopsis, wheat, and barley will be used. Results: We have described in detail the main transcription factor families in maize which take part in abiotic stress responses together with their regulons. Furthermore, we have also briefly described the utilization of high-efficiency technologies in the study and characterization of TFs involved in the abiotic stress regulatory networks in plants with an emphasis on increasing maize production. Examples of these technologies include next-generation sequencing, microarray analysis, machine learning and RNA-Seq technology. Conclusion: In conclusion, it is hoped that all the information provided in this review may in time contribute to the use of TF genes in the research, breeding, and development of new abiotic stress tolerant maize cultivars.


Microbiology ◽  
2003 ◽  
Vol 149 (10) ◽  
pp. 3023-3034 ◽  
Author(s):  
Andrea Feucht ◽  
Louise Evans ◽  
Jeff Errington

Differentiation in the spore-forming bacterium Bacillus subtilis is governed by the sequential activation of five sporulation-specific transcription factors. The early mother-cell-specific transcription factor, σ E, directs the transcription of many genes that contribute to the formation of mature, dormant spores. In this study, DNA microarrays were used to identify genes belonging to the σ E regulon. In total, 171 genes were found to be under the control of σ E. Of these, 101 genes had not previously been described as being σ E dependent. Disruption of some of the previously unknown genes (ydcC, yhaL, yhbH, yjaV and yqfD) resulted in a defect in sporulation.


mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
Author(s):  
Beate Schwer ◽  
Ana M. Sanchez ◽  
Angad Garg ◽  
Debashree Chatterjee ◽  
Stewart Shuman

ABSTRACT Fission yeast phosphate homeostasis entails transcriptional induction of genes encoding phosphate-mobilizing proteins under conditions of phosphate starvation. Transcription factor Pho7, a member of the Zn 2 Cys 6 family of fungal transcription regulators, is the central player in the starvation response. The DNA binding sites in the promoters of phosphate-responsive genes have not been defined, nor have any structure-function relationships been established for the Pho7 protein. Here we narrow this knowledge gap by (i) delineating an autonomous DNA-binding domain (DBD) within Pho7 that includes the Zn 2 Cys 6 module, (ii) deploying recombinant Pho7 DBD in DNase I footprinting and electrophoretic mobility shift assays (EMSAs) to map the Pho7 recognition sites in the promoters of the phosphate-regulated pho1 and tgp1 genes to a 12-nucleotide sequence motif [5′-TCG(G/C)(A/T)xxTTxAA], (iii) independently identifying the same motif as a Pho7 recognition element via in silico analysis of available genome-wide ChIP-seq data, (iv) affirming that mutations in the two Pho7 recognition sites in the pho1 promoter efface pho1 expression in vivo , and (v) establishing that the zinc-binding cysteines and a pair of conserved arginines in the DBD are essential for Pho7 activity in vivo . IMPORTANCE Fungi respond to phosphate starvation by inducing the transcription of a set of phosphate acquisition genes that comprise a phosphate regulon. Pho7, a member of the Zn 2 Cys 6 family of fungal transcription regulators, is the central player in the phosphate starvation response in fission yeast. The present study identifies a 12-nucleotide Pho7 DNA binding motif [5′-TCG(G/C)(A/T)xxTTxAA] in the promoters of phosphate-regulated genes, pinpoints DNA and protein features important for Pho7 binding to DNA, and correlates them with Pho7-dependent gene expression in vivo . The results highlight distinctive properties of Pho7 vis-a-vis other fungal zinc binuclear cluster transcription factors as well as the divergent cast of transcription factors deployed for phosphate homeostasis in fission yeast versus budding yeast.


2018 ◽  
Vol 115 (8) ◽  
pp. E1829-E1838 ◽  
Author(s):  
Caia D. S. Duncan ◽  
María Rodríguez-López ◽  
Phil Ruis ◽  
Jürg Bähler ◽  
Juan Mata

Eukaryotes respond to amino acid starvation by enhancing the translation of mRNAs encoding b-ZIP family transcription factors (GCN4 in Saccharomyces cerevisiae and ATF4 in mammals), which launch transcriptional programs to counter this stress. This pathway involves phosphorylation of the eIF2 translation factor by Gcn2-protein kinases and is regulated by upstream ORFs (uORFs) in the GCN4/ATF4 5′ leaders. Here, we present evidence that the transcription factors that mediate this response are not evolutionarily conserved. Although cells of the fission yeast Schizosaccharomyces pombe respond transcriptionally to amino acid starvation, they lack clear Gcn4 and Atf4 orthologs. We used ribosome profiling to identify mediators of this response in S. pombe, looking for transcription factors that behave like GCN4. We discovered a transcription factor (Fil1) translationally induced by amino acid starvation in a 5′ leader and Gcn2-dependent manner. Like Gcn4, Fil1 is required for the transcriptional response to amino acid starvation, and Gcn4 and Fil1 regulate similar genes. Despite their similarities in regulation, function, and targets, Fil1 and Gcn4 belong to different transcription factor families (GATA and b-ZIP, respectively). Thus, the same functions are performed by nonorthologous proteins under similar regulation. These results highlight the plasticity of transcriptional networks, which maintain conserved principles with nonconserved regulators.


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