scholarly journals Isolation and Functional Characterization of the Promoters of Miltiradiene Synthase Genes, TwTPS27a and TwTPS27b, and Interaction Analysis with the Transcription Factor TwTGA1 from Tripterygium wilfordii

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 418
Author(s):  
Yanbo Huo ◽  
Bin Zhang ◽  
Ling Chen ◽  
Jing Zhang ◽  
Xing Zhang ◽  
...  

Miltiradiene synthase (MS) genes, TwTPS27a and TwTPS27b, are the key diterpene synthase genes in the biosynthesis of triptolide, which is an important medicinally active diterpenoid in Tripterygium wilfordii. However, the mechanism underlying the regulation of key genes TwTPS27a/b in triptolide biosynthesis remains unclear. In this study, the promoters of TwTPS27a (1496 bp) and TwTPS27b (1862 bp) were isolated and analyzed. Some hormone-/stress-responsive elements and transcription factor (TF) binding sites were predicted in both promoters, which might be responsible for the regulation mechanism of TwTPS27a/b. The β-glucuronidase (GUS) activity analysis in promoter deletion assays under normal and methyl jasmonate (MeJA) conditions showed that the sequence of −921 to −391 bp is the potential core region of the TwTPS27b promoter. And the TGACG-motif, a MeJA-responsive element found in this core region, might be responsible for MeJA-mediated stress induction of GUS activity. Moreover, the TGACG-motif is also known as the TGA TF-binding site. Yeast one-hybrid and GUS transactivation assays confirmed the interaction between the TwTPS27a/b promoters and the TwTGA1 TF (a MeJA-inducible TGA TF upregulating triptolide biosynthesis in T. wilfordii), indicating that TwTPS27a/b are two target genes regulated by TwTGA1. In conclusion, our results provide important information for elucidating the regulatory mechanism of MS genes, TwTPS27a and TwTPS27b, as two target genes of TwTGA1, in jasmonic acid (JA)-inducible triptolide biosynthesis.

Epigenomics ◽  
2021 ◽  
Author(s):  
Huanhou Su ◽  
Jingzhou Xie ◽  
Lijing Wen ◽  
Shunyi Wang ◽  
Sishuo Chen ◽  
...  

Aim: Although studies on lncRNAs in renal fibrosis have focused on target genes and functions of lncRNAs, a comprehensive interaction analysis of lncRNAs is lacking. Materials & methods: Differentially expressed genes in renal fibrosis were screened, and the interaction between lncRNAs and miRNAs was searched. Results: We constructed a ceRNA network associated with renal fibrosis, by which we found the transcription factor Creb5, a target gene of lncRNA Gas5 that might regulate extracellular Fn1 deposition. Conclusion: Our study not only provides a theoretical basis for the ceRNA regulation mechanism of Gas5 but also provides experimental evidence supporting the use of Gas5 targeting in the treatment of renal fibrosis.


2021 ◽  
Vol 22 (15) ◽  
pp. 8193
Author(s):  
Daniel Pérez-Cremades ◽  
Ana B. Paes ◽  
Xavier Vidal-Gómez ◽  
Ana Mompeón ◽  
Carlos Hermenegildo ◽  
...  

Background/Aims: Estrogen has been reported to have beneficial effects on vascular biology through direct actions on endothelium. Together with transcription factors, miRNAs are the major drivers of gene expression and signaling networks. The objective of this study was to identify a comprehensive regulatory network (miRNA-transcription factor-downstream genes) that controls the transcriptomic changes observed in endothelial cells exposed to estradiol. Methods: miRNA/mRNA interactions were assembled using our previous microarray data of human umbilical vein endothelial cells (HUVEC) treated with 17β-estradiol (E2) (1 nmol/L, 24 h). miRNA–mRNA pairings and their associated canonical pathways were determined using Ingenuity Pathway Analysis software. Transcription factors were identified among the miRNA-regulated genes. Transcription factor downstream target genes were predicted by consensus transcription factor binding sites in the promoter region of E2-regulated genes by using JASPAR and TRANSFAC tools in Enrichr software. Results: miRNA–target pairings were filtered by using differentially expressed miRNAs and mRNAs characterized by a regulatory relationship according to miRNA target prediction databases. The analysis identified 588 miRNA–target interactions between 102 miRNAs and 588 targets. Specifically, 63 upregulated miRNAs interacted with 295 downregulated targets, while 39 downregulated miRNAs were paired with 293 upregulated mRNA targets. Functional characterization of miRNA/mRNA association analysis highlighted hypoxia signaling, integrin, ephrin receptor signaling and regulation of actin-based motility by Rho among the canonical pathways regulated by E2 in HUVEC. Transcription factors and downstream genes analysis revealed eight networks, including those mediated by JUN and REPIN1, which are associated with cadherin binding and cell adhesion molecule binding pathways. Conclusion: This study identifies regulatory networks obtained by integrative microarray analysis and provides additional insights into the way estradiol could regulate endothelial function in human endothelial cells.


Author(s):  
Qi Qiao ◽  
Cui-Mei Zhao ◽  
Chen-Xi Yang ◽  
Jia-Ning Gu ◽  
Yu-Han Guo ◽  
...  

AbstractObjectivesDilated cardiomyopathy (DCM) represents the most frequent form of cardiomyopathy, leading to heart failure, cardiac arrhythmias and death. Accumulating evidence convincingly demonstrates the crucial role of genetic defects in the pathogenesis of DCM, and over 100 culprit genes have been implicated with DCM. However, DCM is of substantial genetic heterogeneity, and the genetic determinants underpinning DCM remain largely elusive.MethodsWhole-exome sequencing and bioinformatical analyses were implemented in a consanguineous Chinese family with DCM. A total of 380 clinically annotated control individuals and 166 more DCM index cases then underwent Sanger sequencing analysis for the identified genetic variation. The functional characteristics of the variant were delineated by utilizing a dual-luciferase assay system.ResultsA heterozygous variation in the MEF2A gene (encoding myocyte enhancer factor 2A, a transcription factor pivotal for embryonic cardiogenesis and postnatal cardiac adaptation), NM_001365204.1: c.718G>T; p. (Gly240*), was identified, and verified by Sanger sequencing to segregate with autosome-dominant DCM in the family with complete penetrance. The nonsense variation was neither detected in 760 control chromosomes nor found in 166 more DCM probands. Functional analyses revealed that the variant lost transactivation on the validated target genes MYH6 and FHL2, both causally linked to DCM. Furthermore, the variation nullified the synergistic activation between MEF2A and GATA4, another key transcription factor involved in DCM.ConclusionsThe findings firstly indicate that MEF2A loss-of-function variation predisposes to DCM in humans, providing novel insight into the molecular mechanisms of DCM and suggesting potential implications for genetic testing and prognostic evaluation of DCM patients.


Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 85
Author(s):  
Haifeng Yan ◽  
Yuping Xiong ◽  
Jaime A. Teixeira da Silva ◽  
Jinhui Pang ◽  
Ting Zhang ◽  
...  

Bisabolene-type sesquiterpenoids, which have multiple bioactivities, including anticancer activity, are one of the main groups of compounds in the essential oil extracted from Santalum album L. and other Santalum species. Bisabolene synthetase (SaBS) is a key enzyme for the synthesis of bisabolene in S. album, but the regulation of the SaBS gene’s expression is poorly understood. In this study, a 1390-bp promoter sequence of the SaBS gene was isolated from the leaves of six-year-old S. album. A bioinformatics analysis showed that certain environment stresses and phytohormone-activated cis-acting elements were distributed in different regions of the SaBS promoter (PSaBS). Transgenic Arabidopsis carrying full-length PSaBS had significantly higher β-glucuronidase (GUS) activity than the untreated control after treatment with salicylic acid (SA), suggesting that PSaBS is a SA-inducible promoter. Histochemical GUS staining and GUS fluorometric assays of transgenic Arabidopsis showed that the GUS activity directed by PSaBS was mainly expressed in stem tissue, followed by leaves and flowers. Moreover, different regions of PSaBS showed significantly different GUS activity. A 171-bp fragment upstream of the transcriptional initiation codon (ATG) is the core promoter region of PSaBS. Our results provide insight into and a greater understanding of the transcriptional regulation mechanism of the SaBS gene, which could serve as an alternative inducible promoter for transgenic plant breeding.


2015 ◽  
Vol 26 (12) ◽  
pp. 2357-2374 ◽  
Author(s):  
Chen Bai ◽  
Masha Tesker ◽  
David Engelberg

Transcription factors are commonly activated by signal transduction cascades and induce expression of many genes. They therefore play critical roles in determining the cell's fate. The yeast Hog1 MAP kinase pathway is believed to control the transcription of hundreds of genes via several transcription factors. To identify the bona fide target genes of Hog1, we inducibly expressed the spontaneously active variant Hog1D170A+F318Lin cells lacking the Hog1 activator Pbs2. This system allowed monitoring the effects of Hog1 by itself. Expression of Hog1D170A+F318Lin pbs2∆ cells imposed induction of just 105 and suppression of only 26 transcripts by at least twofold. We looked for the Hog1-responsive element within the promoter of the most highly induced gene, STL1 (88-fold). A novel Hog1 responsive element (HoRE) was identified and shown to be the direct target of the transcription factor Hot1. Unexpectedly, we could not find this HoRE in any other yeast promoter. In addition, the only gene whose expression was abolished in hot1∆ cells was STL1. Thus Hot1 is essential for transcription of just one gene, STL1. Hot1 may represent a class of transcription factors that are essential for transcription of a very few genes or even just one.


2021 ◽  
Author(s):  
Patricia Mendoza-Garcia ◽  
Swaraj Basu ◽  
Sanjay Kumar Sukumar ◽  
Badrul Arefin ◽  
Georg Wolfstetter ◽  
...  

AbstractDevelopment of the midgut visceral muscle of Drosophila crucially depends on Anaplastic Lymphoma Kinase (Alk) receptor tyrosine kinase (RTK) signalling, which is needed to specify founder cells (FCs) in the circular visceral mesoderm (VM). While activation of the Alk receptor by its ligand Jelly Belly (Jeb) is well characterized, only a small number of target molecules have been identified. Here, we assayed RNA polymerase II (Pol II) occupancy in VM cells by using the targeted DamID (TaDa) approach. To identify Alk targets we employed comparative analysis of embryos overexpressing Jeb versus embryos with abrogated Alk activity, revealing differential expression of a number of genes, including the Snail/Scratch family transcription factor Kahuli (Kah). Upon further in vivo validation, we confirmed that Alk signalling regulates Kah mRNA expression in the VM. We show that Kah mutants display defects in the formation of midgut constrictions, similar to that of pointed (pnt) mutants. Analysis of publicly available ChIP data defined a Kah target-binding site similar to that of Snail. In addition, we compared genes that were differentially expressed in Kah mutants with publicly available Kah- and Pnt-ChIP datasets identifying a set of common target genes putatively regulated by Kah and Pnt in midgut constriction. Taken together, we (i) report a rich dataset of Alk responsive loci in the embryonic VM, (ii) provide the first functional characterization of the Kah transcription factor, identifying a role in embryonic midgut constriction, and (iii) suggest a model in which Kah and Pnt cooperate in embryonic midgut morphogenesis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fengqing Wang ◽  
Xinrong Li ◽  
Xin Zuo ◽  
Mingming Li ◽  
Chunyan Miao ◽  
...  

WRKYs play important roles in plant metabolism, but their regulation mechanism in Rehmannia glutinosa remains elusive. In this study, 37 putative WRKY transcription factors (TFs) with complete WRKY domain from R. glutinosa transcriptome sequence data were identified. Based on their conserved domains and zinc finger motif, the R. glutinosa WRKY TFs were divided into five groups. Structural feature analysis shows that the 37 RgWRKY proteins contain WRKYGQK/GKK domains and a C2H2/C2HC-type zinc finger structure. To identify the function of RgWRKY members involved in acteoside biosynthesis, transcriptional profiles of 37 RgWRKYs in hairy roots under salicylic acid (SA), methyl jasmonate (MeJA), and hydrogen peroxide (H2O2) treatments were systematically established using RNA-seq analysis. Based on the correlationship between the expression levels of RgWRKY genes and acteoside content, RgWRKY7, RgWRKY23, RgWRKY34, RgWRKY35, and RgWRKY37 were suggested to be involved in acteoside biosynthesis in R. glutinosa, and RgWRKY37 was selected for gene functional research. Overexpression of RgWRKY37 increased the content of acteoside and total phenylethanoid glycosides (PhGs) in hairy roots and enhanced the transcript abundance of seven enzyme genes involved in the acteoside biosynthesis pathway. These results strongly suggest the involvement of the WRKY transcription factor in the regulation of acteoside biosynthesis.


Author(s):  
Jogendra Singh Nim ◽  
Mohit Yadav ◽  
Lalit Kumar Gautam ◽  
Chaitali Ghosh ◽  
Shakti Sahi ◽  
...  

Background: Xenorhabdus nematophila maintains species-specific mutual interaction with nematodes of Steinernema genus. Type II Toxin Antitoxin (TA) systems, the mazEF TA system controls stress and programmed cell death in bacteria. Objective: This study elucidates the functional characterization of Xn-mazEF, a mazEF homolog in X. nematophila by computational and in vitro approaches. Methods: 3 D- structural models for Xn-MazE toxin and Xn-MazF antitoxin were generated, validated and characterized for protein - RNA interaction analysis. Further biological and cellular functions of Xn-MazF toxin were also predicted. Molecular dynamics simulations of 50ns for Xn-MazF toxin complexed with nucleic acid units (DU, RU, RC, and RU) were performed. The MazF toxin and complete MazEF operon were endogenously expressed and monitored for the killing of Escherichia coli host cells under arabinose induced tightly regulated system. Results: Upon induction, E. coli expressing toxin showed rapid killing within four hours and attained up to 65% growth inhibition, while the expression of the entire operon did not show significant killing. The observation suggests that the Xn-mazEF TA system control transcriptional regulation in X. nematophila and helps to manage stress or cause toxicity leading to programmed death of cells. Conclusion: The study provides insights into structural and functional features of novel toxin, XnMazF and provides an initial inference on control of X. nematophila growth regulated by TA systems.


1999 ◽  
Vol 19 (1) ◽  
pp. 495-504 ◽  
Author(s):  
John Sok ◽  
Xiao-Zhong Wang ◽  
Nikoleta Batchvarova ◽  
Masahiko Kuroda ◽  
Heather Harding ◽  
...  

ABSTRACT CHOP (also called GADD153) is a stress-inducible nuclear protein that dimerizes with members of the C/EBP family of transcription factors and was initially identified as an inhibitor of C/EBP binding to classic C/EBP target genes. Subsequent experiments suggested a role for CHOP-C/EBP heterodimers in positively regulating gene expression; however, direct evidence that this is the case has so far not been uncovered. Here we describe the identification of a positively regulated direct CHOP-C/EBP target gene, that encoding murine carbonic anhydrase VI (CA-VI). The stress-inducible form of the gene is expressed from an internal promoter and encodes a novel intracellular form of what is normally a secreted protein. Stress-induced expression of CA-VI is both CHOP and C/EBPβ dependent in that it does not occur in cells deficient in either gene. A CHOP-responsive element was mapped to the inducibleCA-VI promoter, and in vitro footprinting revealed binding of CHOP-C/EBP heterodimers to that site. Rescue of CA-VIexpression in c/ebpβ−/− cells by exogenous C/EBPβ and a shorter, normally inhibitory isoform of the protein known as LIP suggests that the role of the C/EBP partner is limited to targeting the CHOP-containing heterodimer to the response element and points to a preeminent role for CHOP in CA-VI induction during stress.


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