scholarly journals The NAC-like transcription factor CsNAC7 positively regulates the caffeine biosynthesis-related gene yhNMT1 in Camellia sinensis

2022 ◽  
Vol 9 ◽  
Author(s):  
Wenhui Ma ◽  
Xin Kang ◽  
Ping Liu ◽  
Kexin She ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Tea Plant ◽  
Transcriptional Level ◽  
Related Gene ◽  
Caffeine Synthase ◽  
N Terminus ◽  
Caffeine Biosynthesis ◽  
Encoding Gene

Abstract Caffeine is an important functional substance and is abundant in tea plant, but little is known about how its biosynthesis is regulated by transcription factors. In this study, the NAC-like transcription factor-encoding gene CsNAC7, which is involved in caffeine synthesis, was isolated from a Yinghong 9 cDNA library using a yeast one-hybrid assay; this gene comprises 1371 bp nucleotides and is predicted to encode 456 amino acids. The expression of CsNAC7 at the transcriptional level in tea shoots shared a similar pattern with that of the caffeine synthase gene yhNMT1 in the spring and summer, and its expressed protein was localized in the nucleus. Assays of gene activity showed that CsNAC7 has self-activation activity in yeast, that the active region is at the N-terminus, and that the transient expression of CsNAC7 could significantly promote the expression of yhNMT1 in tobacco leaves. In addition, overexpression or silencing of CsNAC7 significantly increased or decreased the expression of yhNMT1 and the accumulation of caffeine in transgenic tea calli, respectively. Our data suggest that the isolated transcription factor CsNAC7 positively regulates the caffeine synthase gene yhNMT1 and promotes caffeine accumulation in tea plant.

scholarly journals The Regulatory Mechanism of Water Activities on Aflatoxins Biosynthesis and Conidia Development, and Transcription Factor AtfB Is Involved in This Regulation

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 431
Author(s):  
Longxue Ma ◽  
Xu Li ◽  
Xiaoyun Ma ◽  
Qiang Yu ◽  
Xiaohua Yu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Environmental Factors ◽  
Health Risks ◽  
Sexual Development ◽  
Regulatory Mechanism ◽  
Food Storage ◽  
Economic Losses ◽  
Transcriptional Level ◽  
Conidia Production

Peanuts are frequently infected by Aspergillus strains and then contaminated by aflatoxins (AF), which brings out economic losses and health risks. AF production is affected by diverse environmental factors, especially water activity (aw). In this study, A. flavus was inoculated into peanuts with different aw (0.90, 0.95, and 0.99). Both AFB1 yield and conidia production showed the highest level in aw 0.90 treatment. Transcriptional level analyses indicated that AF biosynthesis genes, especially the middle- and later-stage genes, were significantly up-regulated in aw 0.90 than aw 0.95 and 0.99. AtfB could be the pivotal regulator response to aw variations, and could further regulate downstream genes, especially AF biosynthesis genes. The expressions of conidia genes and relevant regulators were also more up-regulated at aw 0.90 than aw 0.95 and 0.99, suggesting that the relative lower aw could increase A. flavus conidia development. Furthermore, transcription factors involved in sexual development and nitrogen metabolism were also modulated by different aw. This research partly clarified the regulatory mechanism of aw on AF biosynthesis and A. flavus development and it would supply some advice for AF prevention in food storage.

scholarly journals The Prodomain of Ssy5 Protease Controls Receptor-Activated Proteolysis of Transcription Factor Stp1

2010 ◽  
Vol 30 (13) ◽  
pp. 3299-3309 ◽  
Author(s):  
Thorsten Pfirrmann ◽  
Stijn Heessen ◽  
Deike J. Omnus ◽  
Claes Andréasson ◽  
Per O. Ljungdahl
Keyword(s):  
Amino Acids ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Amino Acid ◽  
Signaling Pathway ◽  
Temperature Control ◽  
Regulatory Mechanism ◽  
Potent Inhibitor ◽  
Large N

ABSTRACT Extracellular amino acids induce the yeast SPS sensor to endoproteolytically cleave transcription factors Stp1 and Stp2 in a process termed receptor-activated proteolysis (RAP). Ssy5, the activating endoprotease, is synthesized with a large N-terminal prodomain and a C-terminal chymotrypsin-like catalytic (Cat) domain. During biogenesis, Ssy5 cleaves itself and the prodomain and Cat domain remain associated, forming an inactive primed protease. Here we show that the prodomain is a potent inhibitor of Cat domain activity and that its inactivation is a requisite for RAP. Accordingly, amino acid-induced signals trigger proteasome-dependent degradation of the prodomain. A mutation that stabilizes the prodomain prevents Stp1 processing, whereas destabilizing mutations lead to constitutive RAP-independent Stp1 processing. We fused a conditional degron to the prodomain to synthetically reprogram the amino acid-responsive SPS signaling pathway, placing it under temperature control. Our results define a regulatory mechanism that is novel for eukaryotic proteases functioning within cells.

scholarly journals A Regulatory Circuit Composed of a Transcription Factor, IscR, and a Regulatory RNA, RyhB, Controls Fe-S Cluster Delivery

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Pierre Mandin ◽  
Sylvia Chareyre ◽  
Frédéric Barras
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Mutational Analysis ◽  
Essential Gene ◽  
Iron Concentration ◽  
Transcriptional Level ◽  
Iron Starvation ◽  
Control Of Gene Expression ◽  
Regulatory Circuit ◽  
Iron Concentrations

ABSTRACT Fe-S clusters are cofactors conserved through all domains of life. Once assembled by dedicated ISC and/or SUF scaffolds, Fe-S clusters are conveyed to their apo-targets via A-type carrier proteins (ATCs). Escherichia coli possesses four such ATCs. ErpA is the only ATC essential under aerobiosis. Recent studies reported a possible regulation of the erpA mRNA by the small RNA (sRNA) RyhB, which controls the expression of many genes under iron starvation. Surprisingly, erpA has not been identified in recent transcriptomic analysis of the iron starvation response, thus bringing into question the actual physiological significance of the putative regulation of erpA by RyhB. Using an sRNA library, we show that among 26 sRNAs, only RyhB represses the expression of an erpA-lacZ translational fusion. We further demonstrate that this repression occurs during iron starvation. Using mutational analysis, we show that RyhB base pairs to the erpA mRNA, inducing its disappearance. In addition, IscR, the master regulator of Fe-S homeostasis, represses expression of erpA at the transcriptional level when iron is abundant, but depleting iron from the medium alleviates this repression. The conjunction of transcriptional derepression by IscR and posttranscriptional repression by RyhB under Fe-limiting conditions is best described as an incoherent regulatory circuit. This double regulation allows full expression of erpA at iron concentrations for which Fe-S biogenesis switches from the ISC to the SUF system. We further provide evidence that this regulatory circuit coordinates ATC usage to iron availability. IMPORTANCE Regulatory small RNAs (sRNAs) have emerged as major actors in the control of gene expression in the last few decades. Relatively little is known about how these regulators interact with classical transcription factors to coordinate genetic responses. We show here how an sRNA, RyhB, and a transcription factor, IscR, regulate expression of an essential gene, erpA , in the bacterium E. coli . ErpA is involved in the biogenesis of Fe-S clusters, an important class of cofactors involved in a plethora of cellular reactions. Interestingly, we show that RyhB and IscR repress expression of erpA under opposite conditions in regard to iron concentration, forming a regulatory circuit called an “incoherent network.” This incoherent network serves to maximize expression of erpA at iron concentrations where it is most needed. Altogether, our study paves the way for a better understanding of mixed regulatory networks composed of RNAs and transcription factors.

scholarly journals The N-Terminal Domain of IκBα Masks the Nuclear Localization Signal(s) of p50 and c-Rel Homodimers

1998 ◽  
Vol 18 (5) ◽  
pp. 2640-2649 ◽  
Author(s):  
Matthew Latimer ◽  
Mary K. Ernst ◽  
Linda L. Dunn ◽  
Marina Drutskaya ◽  
Nancy R. Rice
Keyword(s):  
Amino Acids ◽  
Transcription Factors ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Mutational Analysis ◽  
Inhibitor Protein ◽  
N Terminus ◽  
Localization Signal ◽  
Terminal Section ◽  
Rel Homology Domain

ABSTRACT Members of the Rel/NF-κB family of transcription factors are related to each other over a region of about 300 amino acids called the Rel Homology Domain (RHD), which governs DNA binding, dimerization, and binding to inhibitor. At the C-terminal end of the RHD, each protein has a nuclear localization signal (NLS). The crystal structures of the p50 and RelA family members show that the RHD consists of two regions: an N-terminal section which contains some of the DNA contacts and a C-terminal section which contains the remaining DNA contacts and controls dimerization. In unstimulated cells, the homo- or heterodimeric Rel/NF-κB proteins are cytoplasmic by virtue of binding to an inhibitor protein (IκB) which somehow masks the NLS of each member of the dimer. The IκB proteins consist of an ankyrin-repeat-containing domain that is required for binding to dimers and N- and C-terminal domains that are dispensable for binding to most dimers. In this study, we examined the interaction between IκBα and Rel family homodimers by mutational analysis. We show that (i) the dimerization regions of p50, RelA, and c-Rel are sufficient for binding to IκBα, (ii) the NLSs of RelA and c-Rel are not required for binding to IκBα but do stabilize the interaction, (iii) the NLS of p50 is required for binding to IκBα, (iv) only certain residues within the p50 NLS are required for binding, and (v) in a p50-IκBα complex or a c-Rel-IκBα complex, the N terminus of IκBα either directly or indirectly masks one or both of the dimer NLSs.

scholarly journals The External Amino Acid Signaling Pathway Promotes Activation of Stp1 and Uga35/Dal81 Transcription Factors for Induction of the AGP1 Gene in Saccharomyces cerevisiae

Genetics ◽  
2004 ◽  
Vol 166 (4) ◽  
pp. 1727-1739 ◽  
Author(s):  
Fadi Abdel-Sater ◽  
Ismaïl Iraqui ◽  
Antonio Urrestarazu ◽  
Bruno André
Keyword(s):  
Amino Acids ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Amino Acid ◽  
Signaling Pathway ◽  
Nitrogen Supply ◽  
Upstream Region ◽  
Gata Factor ◽  
Amino Acid Permease ◽  
Amino Acid Signaling

Abstract Yeast cells respond to the presence of amino acids in their environment by inducing transcription of several amino acid permease genes including AGP1, BAP2, and BAP3. The signaling pathway responsible for this induction involves Ssy1, a permease-like sensor of external amino acids, and culminates with proteolytic cleavage and translocation to the nucleus of the zinc-finger proteins Stp1 and Stp2, the lack of which abolishes induction of BAP2 and BAP3. Here we show that Stp1—but not Stp2—plays an important role in AGP1 induction, although significant induction of AGP1 by amino acids persists in stp1 and stp1 stp2 mutants. This residual induction depends on the Uga35/Dal81 transcription factor, indicating that the external amino acid signaling pathway activates not only Stp1 and Stp2, but also another Uga35/Dal81-dependent transcriptional circuit. Analysis of the AGP1 gene’s upstream region revealed that Stp1 and Uga35/Dal81 act synergistically through a 21-bp cis-acting sequence similar to the UASAA element previously found in the BAP2 and BAP3 upstream regions. Although cells growing under poor nitrogen-supply conditions display much higher induction of AGP1 expression than cells growing under good nitrogen-supply conditions, the UASAA itself is totally insensitive to nitrogen availability. Nitrogen-source control of AGP1 induction is mediated by the GATA factor Gln3, likely acting through adjacent 5′-GATA-3′ sequences, to amplify the positive effect of UASAA. Our data indicate that Stp1 may act in combination with distinct sets of transcription factors, according to the gene context, to promote induction of transcription in response to external amino acids. The data also suggest that Uga35/Dal81 is yet another transcription factor under the control of the external amino acid sensing pathway. Finally, the data show that the TOR pathway mediating global nitrogen control of transcription does not interfere with the external amino acid signaling pathway.

scholarly journals ACE4, a novel transcriptional activator involved in the regulation of cellulase genes on cellulose in Trichoderma reesei

2021 ◽  
Author(s):  
Yumeng Chen ◽  
Aibo Lin ◽  
Pei Liu ◽  
Xingjia Fan ◽  
Chuan Wu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Trichoderma Reesei ◽  
Transcriptional Activator ◽  
Cellulase Production ◽  
Comparative Genomic ◽  
Transcriptional Level ◽  
Cellulase Gene ◽  
Cellulase Expression

The filamentous fungus Trichoderma reesei is a model strain for cellulase production. Cellulase gene expression in T. reesei is controlled by multiple transcription factors. Here, we identified by comparative genomic screening a novel transcriptional activator ACE4 ( A ctivator of c ellulase e xpression 4) that positively regulates cellulase gene expression on cellulose in T. reesei . Disruption of the ace4 gene significantly decreased expression of four main cellulase genes, and the essential cellulase transcription factor encoding gene ace3 . Overexpression of ace4 increased cellulase production by approximately 22% compared to that in the parental strain. Further investigations using electrophoretic mobility shift assays, DNase I footprinting assays, and chromatin immunoprecipitation assays indicated that ACE4 directly binds to the promoter of cellulase genes by recognizing the two adjacent 5′-GGCC-3′ sequences. Additionally, ACE4 directly binds to the promoter of ace3 and, in turn, regulates the expression of ACE3 to facilitate cellulase production. Collectively, these results demonstrate an important role for ACE4 in regulating cellulase gene expression, which will contribute to understanding the mechanism underlying cellulase expression in T. reesei . IMPORTANCE T. reesei is commonly utilized in industry to produce cellulases, enzymes that degrade lignocellulosic biomass for the production of bioethanol and bio-based products. T. reesei is capable of rapidly initiating the biosynthesis of cellulases in the presence of cellulose, which has made it useful as a model fungus for studying gene expression in eukaryotes. Cellulase gene expression is controlled through multiple transcription factors at the transcriptional level. However, the molecular mechanisms by which transcription is controlled remain unclear. In the present study, we identified a novel transcription factor, ACE4, which regulates cellulase expression on cellulose by binding to the promoters of cellulase genes and the cellulase activator ace3 . Our study not only expands the general functional understanding of the novel transcription factor ACE4 but also provides evidence for the regulatory mechanism mediating gene expression in T. reesei .

scholarly journals Two separation-of-function isoforms of human TPP1 and a novel intragenic noncoding RNA dictate telomerase regulation in somatic and germ cells

2019 ◽  
Author(s):  
Sherilyn Grill ◽  
Kamlesh Bisht ◽  
Valerie M. Tesmer ◽  
Christopher J. Sifuentes ◽  
Jayakrishnan Nandakumar
Keyword(s):  
Amino Acids ◽  
Stem Cells ◽  
Dna Synthesis ◽  
Differential Expression ◽  
Germ Cells ◽  
Noncoding Rna ◽  
N Terminus ◽  
Encoding Gene ◽  
Telomerase Regulation ◽  
Telomeric Protein

SummaryTelomerase replicates chromosome ends in germ and somatic stem cells to facilitate continued proliferation. Telomerase action depends on the telomeric protein TPP1, which recruits telomerase to telomeres and facilitates processive DNA synthesis. Here we identify separation-of-function long (TPP1-L) and short (TPP1-S) isoforms of TPP1 differing only in 86 amino acids at their N-terminus. While both isoforms retain the ability to recruit telomerase, only TPP1-S facilitates telomere synthesis. We identify a novel intragenic noncoding RNA in the 3’-UTR of the TPP1-encoding gene that specifically shuts down telomerase activation-incompatible TPP1-L to establish TPP1-S as the predominant isoform in somatic cells. Strikingly, TPP1-L is the major isoform in testes, where it can function to restrain telomerase in mature germ cells. Our studies uncover how differential expression of two isoforms allows TPP1 to perform separate functions in different cells, and demonstrate how isoform choice can be determined by an intragenic noncoding RNA.

scholarly journals Plant AP2/ERF transcription factors

Genetika ◽  
2003 ◽  
Vol 35 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Abdelaty Saleh ◽  
Montserrat Pagés
Keyword(s):  
Amino Acids ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Environmental Stress ◽  
Plant Development ◽  
Abiotic Stresses ◽  
Current Knowledge ◽  
Transcription Factor Family ◽  
Biotic And Abiotic Stresses ◽  
Erf Transcription Factors

Transcription factors (TFs) play important roles in plant development and its response to the biotic and abiotic stresses. AP2/ERF transcription factors family is unique to plants and a conserved AP2/ERF domain of about 60 amino acids characterized these transcription factors. AP2/ERF genes have been shown to regulate developmental processes and the response of plants to various types of biotic and environmental stress. Here, we summarize the current knowledge of AP2/ERF plant transcription factor family.

scholarly journals Broad-Spectrum HDAC Inhibitors Promote Autophagy through FOXO Transcription Factors in Neuroblastoma

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1001
Author(s):  
Katharina Körholz ◽  
Johannes Ridinger ◽  
Damir Krunic ◽  
Sara Najafi ◽  
Xenia F. Gerloff ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Tumor Growth ◽  
Broad Spectrum ◽  
Nuclear Translocation ◽  
Hdac Inhibitors ◽  
Neuroblastoma Cells ◽  
Autophagic Flux ◽  
Transcriptional Level ◽  
Hdaci Treatment

Depending on context and tumor stage, deregulation of autophagy can either suppress tumorigenesis or promote chemoresistance and tumor survival. Histone deacetylases (HDACs) can modulate autophagy; however, the exact mechanisms are not fully understood. Here, we analyze the effects of the broad-spectrum HDAC inhibitors (HDACi) panobinostat and vorinostat on the transcriptional regulation of autophagy with respect to autophagy transcription factor activity (Transcription factor EB—TFEB, forkhead boxO—FOXO) and autophagic flux in neuroblastoma cells. In combination with the late-stage autophagic flux inhibitor bafilomycin A1, HDACis increase the number of autophagic vesicles, indicating an increase in autophagic flux. Both HDACi induce nuclear translocation of the transcription factors FOXO1 and FOXO3a, but not TFEB and promote the expression of pro-autophagic FOXO1/3a target genes. Moreover, FOXO1/3a knockdown experiments impaired HDACi treatment mediated expression of autophagy related genes. Combination of panobinostat with the lysosomal inhibitor chloroquine, which blocks autophagic flux, enhances neuroblastoma cell death in culture and hampers tumor growth in vivo in a neuroblastoma zebrafish xenograft model. In conclusion, our results indicate that pan-HDACi treatment induces autophagy in neuroblastoma at a transcriptional level. Combining HDACis with autophagy modulating drugs suppresses tumor growth of high-risk neuroblastoma cells. These experimental data provide novel insights for optimization of treatment strategies in neuroblastoma.

Genetic analysis of theSalmonellatranscription factor HilA

2008 ◽  
Vol 54 (10) ◽  
pp. 854-860 ◽  
Author(s):  
Rebecca A. Daly ◽  
C. Phoebe Lostroh
Keyword(s):  
Amino Acids ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Dna Binding ◽  
Genetic Analysis ◽  
Transcription Activation ◽  
Winged Helix ◽  
Activation Domains

HilA, a Salmonella transcription factor, activates the invF-1 and prgH promoters through binding to the HilA box, which contains 2 copies of a TTKHAT motif separated by a T centered at –45 relative to the start sites of transcription. The N-terminal 112 amino acids of HilA are similar to winged helix-turn-helix DNA binding/transcription activation domains (wHTH DBDs). The remaining 441 amino acids are not similar in sequence to any other well-characterized transcription factors. Here, we report that the wHTH DBD is essential for activation of both promoters, but amino acids 113–554 are only required for normal activation of invF-1. Some alanine substitutions in the putative α loop, which connects the recognition and positioning helices in wHTH DBDs, cause a loss-of-activation phenotype. A hilA allele encoding a protein with an alanine substituted for arginine at position 71 in the α loop has a loss-of-activation defect exclusively at the prgH promoter. The results suggest distinct roles for one or more domains formed by amino acids 113–554 and for arginine 71 in activation of the 2 promoters.

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