scholarly journals Identification and Characterization of ANAC042, a Transcription Factor Family Gene Involved in the Regulation of Camalexin Biosynthesis in Arabidopsis

2012 ◽  
Vol 25 (5) ◽  
pp. 684-696 ◽  
Author(s):  
Hirohisa Saga ◽  
Takumi Ogawa ◽  
Kosuke Kai ◽  
Hideyuki Suzuki ◽  
Yoshiyuki Ogata ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Mechanisms ◽  
Kinase Inhibitor ◽  
Alternaria Brassicicola ◽  
Limited Information ◽  
Transcription Factor Family ◽  
Gus Reporter ◽  
In The Wild ◽  
Dna Insertion ◽  
Reporter Assays

Camalexin is the major phytoalexin in Arabidopsis. An almost complete set of camalexin biosynthetic enzymes have been elucidated but only limited information is available regarding molecular mechanisms regulating camalexin biosynthesis. Here, we demonstrate that ANAC042, a member of the NAM, ATAF1/2, and CUC2 (NAC) transcription factor family genes, is involved in camalexin biosynthesis induction. T-DNA insertion mutants of ANAC042 failed to accumulate camalexin at the levels achieved in the wild type, and were highly susceptible to Alternaria brassicicola infection. The camalexin biosynthetic genes CYP71A12, CYP71A13, and CYP71B15/PAD3 were not fully induced in the mutants, indicating that the camalexin defects were at least partly a result of reduced expression levels of these P450 genes. β-Glucuronidase (GUS)-reporter assays demonstrated tissue-specific induction of ANAC042 in response to differential pathogen infections. Bacterial flagellin (Flg22) induced ANAC042 expression in the root-elongation zone, the camalexin biosynthetic site, and the induction was abolished in the presence of either a general kinase inhibitor (K252a), a Ca2+-chelator (BAPTA), or methyl jasmonate. The GUS-reporter assay revealed repression of the Flg22-dependent ANAC042 expression in the ethylene-insensitive ein2-1 background but not in sid2-2 plants defective for salicylic acid biosynthesis. We discuss ANAC042 as a key transcription factor involved in previously unknown regulatory mechanisms to induce phytoalexin biosynthesis in Arabidopsis.

scholarly journals Identification and characterization of the bZIP transcription factor family in yellowhorn

2020 ◽  
Vol 32 (1) ◽  
pp. 273-284 ◽  
Author(s):  
Qiaoying Chang ◽  
Xin Lu ◽  
Zhi Liu ◽  
Zhimin Zheng ◽  
Song Yu
Keyword(s):  
Transcription Factor ◽  
Leucine Zipper ◽  
Molecular Mechanisms ◽  
Bzip Transcription Factor ◽  
Biological Functions ◽  
Transcription Factor Family ◽  
Promoter Regions ◽  
Basic Leucine Zipper ◽  
Biotic Stresses ◽  
Bzip Transcription Factor Family

AbstractThe basic leucine zipper (bZIP) transcription factor family is one of the largest and most diverse families in plants, regulating plant growth and development and playing an essential role in response to abiotic and biotic stresses. However, little is known about the biological functions of bZIP proteins in yellowhorn (Xanthoceras sorbifolium). Recently, 64 XsbZIP genes were identified in the yellowhorn genome and found to be disproportionately distributed in linkage groups. The XsbZIP proteins clustered into 11 groups based on their phylogenetic relationships with AtbZIP, ZmbZIP and GmbZIP proteins. Five intron patterns in the basic and hinge regions and additional conserved motifs were defined, both supporting the group classification and possibly contributing to their functional diversity. Compared to tandem duplication, the segment duplication greatly contributed to the expansion of yellowhorn bZIP genes. In addition, most XsbZIP genes harbor several stress responsive cis-elements in their promoter regions. Moreover, the RNA-seq and qRT-PCR data indicated XsbZIP genes were extensively involved in response to various stresses, including salt (NaCl), cold and abscisic acid, with possibly different molecular mechanisms. These results provide a new understanding of the biological functions of bZIP transcription factors in yellowhorn.

Inhibitors Of Src Family and AKT Regulate The Activity Of CD20 Promoter

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1838-1838
Author(s):  
Beata Pyrzynska ◽  
Kamil Bojarczuk ◽  
Magdalena Winiarska ◽  
Jacek Bil ◽  
Nina Miazek ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Regulation ◽  
B Cells ◽  
Molecular Mechanisms ◽  
Kinase Inhibitor ◽  
Akt Kinase ◽  
Cd20 Antigen ◽  
Cd20 Expression ◽  
Anti Cd20 ◽  
Dasatinib Treatment

Abstract Introduction The monoclonal antibodies against CD20 antigen (rituximab and ofatumumab) have been developed and used in a clinic as a therapeutic strategy in B-cell malignancies. These antibodies eliminate B cells by triggering indirect effector mechanisms of the immune system, namely complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC), or immunophagocytosis. Unfortunately, in some patients the resistance to anti-CD20 therapy has been detected. Therefore the molecular mechanisms responsible for the therapy failure should be urgently elucidated. One of the major mechanisms responsible for the resistance to anti-CD20 therapy seems to be the reduced level of CD20 antigen on the surface of tumor B-cells. We have previously discovered that CD20 expression is strictly dependent on the activity of Src family tyrosine kinases and AKT kinase. We have noticed that treatment of B cells with Src family inhibitors or AKT inhibitors leads to a dose-dependent reduction of CD20 at both transcript and protein level. On the other hand the overexpression of constitutively active AKT (CA-AKT) leads to a significant increase in CD20 mRNA level. To uncover the transcriptional mechanisms governing the CD20 expression we employed the construct encoding the promoter region of CD20 cloned upstream of the firefly luciferase gene. The truncated and mutated versions of the CD20 promoter were used in the luciferase assays to elucidate the role of particular transcription factors binding sites in the regulation of CD20 expression. Objectives The aim of this study was to explore the molecular mechanisms governing the transcriptional regulation of CD20 expression in lymphoma cells as a potential explanation of the resistance to anti-CD20 therapy. Results In the initial experiments we observed a significant reduction of CD20 protein level in Raji cells treated with Src family tyrosine kinase inhibitor, dasatinib (Fig. 1A,B). This reduction correlated with the impaired binding of anti-CD20 monoclonal antibodies as estimated by FACS analysis. Quantitative PCR analysis revealed that the transcriptional regulation is the major mechanism responsible for the reduction of CD20 level upon dasatinib treatment (Fig. 1C). Consistently, the exogenously expressed CD20 under the control of CMV promoter was not sensitive to dasatinib treatment. To further elucidate the mechanism of transcriptional regulation of CD20 we performed the luciferase assays to estimate the activity of CD20 promoter and its truncated forms (Fig. 1D). Dasatinib or AKT kinase inhibitor (MK-2206) strongly decreased the activity of CD20 promoter (Fig. 1E,F) while the overexpression of CA-AKT partially blocked the inhibition caused by dasatinib (Fig. 1G). Using the truncated versions of the CD20 promoter we found that lack of the region (-313/-198) made the promoter insensitive to dasatinib treatment. Since this particular region is known to contain a putative Octamer transcription factor binding site (BAT-box, Thevenin et al., 1993), we introduced mutations in the BAT-box sequence. Although basal promoter activity was indeed decreased (Fig. 1H), dasatinib was equally effective in reducing the activity of both wild-type and mutated CD20 promoter. Collectively, our results indicate that Octamer transcription factor is an important regulator of basal CD20 expression, but it is not the major mediator of the effects caused by Src family inhibitors. Conclusions Our studies indicate that the Src family tyrosine kinases and AKT kinase are involved in the transcriptional regulation of CD20 antigen in lymphoma cells. The activity of CD20 promoter is significantly reduced upon treatment with Src family inhibitors, namely dasatinib. The particular region of CD20 promoter (-313/-198) was identified as the major region sensitive to dasatinib treatment. The transcriptional machinery responsible for the reduction of CD20 expression by dasatinib needs further investigation since the expected Octamer transcription factor does not mediate the effects caused by dasatinib. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Novel insights into expansion and functional diversification of MIR169 family in tomato

2019 ◽  
Author(s):  
Sombir Rao ◽  
Sonia Balyan ◽  
Sarita Jha ◽  
Saloni Mathur
Keyword(s):  
Rna Binding ◽  
Expression Profiles ◽  
Functional Diversification ◽  
Gus Reporter ◽  
New Variant ◽  
Depth Analysis ◽  
Tetratricopeptide Repeat Protein ◽  
In The Wild ◽  
Duplication Events ◽  
Reporter Assays

AbstractMIR169 family is an evolutionarily conserved miRNA family in plants. A systematic in-depth analysis of MIR169 family in tomato is lacking. We report eighteen miR169 precursors, annotating new loci for MIR169a, b and d, as well as four novel mature isoforms (MIR169f/g/h/i). The family has expanded by both tandem- and segmental-duplication events during evolution. A tandem-pair ‘MIR169b/b-1 and MIR169b-2/h’ is polycistronic in nature coding for three MIR169b isoforms and a new variant miR169h, that is evidently absent in the wild relatives S. pennellii and S. pimpinellifolium. Seven novel miR169 targets including RNA-binding-protein, protein-phosphatase, aminotransferase, chaperone, tetratricopeptide-repeat-protein, and transcription factors ARF-9B and SEPELLATA-3 were established by efficient target cleavage in presence of specific precursors as well as increased target abundance upon miR169 chelation by short-tandem-target-mimic construct in transient assays. Comparative antagonistic expression profiles of MIR169:target pairs suggest MIR169 family as ubiquitous regulator of various abiotic stresses (heat, cold, dehydration and salt) and developmental pathways. This regulation is partly brought about by acquisition of new promoters as demonstrated by promoterMIR169:GUS-reporter assays as well as differential processivity of different precursors and miRNA cleavage efficiencies. Thus, the current study augments the functional horizon of MIR169 family with applications for stress tolerance in crops.HighlightExpansion of MIR169 members by duplication and new mature forms, acquisition of new promoters, differential precursor-miRNA processivity and engaging novel targets increases the functional diversification of MIR169 in tomato. (29/30)

scholarly journals Down-Regulation of CK2α Leads toUp-Regulation of the Cyclin-Dependent Kinase Inhibitor p27KIP1 in Conditions Unfavorable for the Growth of Myoblast Cells

2020 ◽  
Vol 54 (6) ◽  
pp. 1177-1198
Keyword(s):  
Cell Cycle ◽  
Transcription Factor ◽  
Cell Growth ◽  
Knockout Mouse ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Kinase Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Cycle Progression ◽  
Cyclin Dependent Kinase Inhibitor

BACKGROUND/AIMS: Compelling evidence indicates that CK2α, which is one of the two catalytic isoforms of protein kinase CK2, is required for cell viability and plays an important role in cell proliferation and differentiation. While much is known on CK2 in the context of disease states, particularly cancer, its critical role in non-cancerous cell growth has not been extensively investigated. METHODS: In the present study, we have employed a cell line derived from rat heart with inducible down-regulation of CK2α and CK2α-knockout mouse tissue to identify CK2-mediated molecular mechanisms regulating cell growth. For this, we have performed Incucyte® live-cell analysis and applied flow cytometry, western blot, immunoprecipitation, immunohistochemistry, RT-qPCR and luciferase-based methods. RESULTS: Here, we show that lack of CK2α results in significantly delayed cell cycle progression through G1, inhibition of cyclin E-CDK2 complex, decreased phosphorylation of Rb protein at S795, and inactivation of E2F transcription factor. These events are accompanied by nuclear accumulation and up-regulation of the cyclin-dependent kinase inhibitor p27KIP1 in cells and CK2α-knockout mouse tissues. We found that increased levels of p27KIP1 are mainly attributable to post-translational modifications, namely phosphorylation at S10 and T197 amino acid residues catalyzed by Dyrk1B and AMPK, respectively, as silencing of FoxO3A transcription factor, which activates CDKN1B the gene coding for p27KIP1, does not result in markedly decreased expression levels of the corresponding protein. Interestingly, simultaneous silencing of CK2α and p27KIP1 significantly impairs cell cycle progression without increasing cell death. CONCLUSION: Taken together, our study sheds light on the molecular mechanisms controlling cell cycle progression through G1 phase when myoblasts proliferation potential is impaired by CK2α depletion. Our results suggest that elevated levels of p27KIP1,which follows CK2α depletion, contribute to delay the G1-to-S phase transition. Effects seen when p27KIP1 is down-regulated are independent of CK2α and reflect the protective role exerted by p27KIP1 under unfavorable cell growth conditions.

scholarly journals Genomic Organization of the B3-Domain Transcription Factor Family in Grapevine (Vitis vinifera L.) and Expression during Seed Development in Seedless and Seeded Cultivars

2019 ◽  
Vol 20 (18) ◽  
pp. 4553 ◽  
Author(s):  
Bilal Ahmad ◽  
Songlin Zhang ◽  
Jin Yao ◽  
Mati Ur Rahman ◽  
Muhammad Hanif ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Vitis Vinifera ◽  
Seed Development ◽  
Genomic Organization ◽  
Vitis Vinifera L ◽  
Limited Information ◽  
Transcription Factor Family ◽  
Cis Element ◽  
B3 Domain ◽  
Vegetative And Reproductive Growth

Members of the plant-specific B3-domain transcription factor family have important and varied functions, especially with respect to vegetative and reproductive growth. Although B3 genes have been studied in many other plants, there is limited information on the genomic organization and expression of B3 genes in grapevine (Vitis vinifera L.). In this study, we identified 50 B3 genes in the grapevine genome and analyzed these genes in terms of chromosomal location and syntenic relationships, intron–exon organization, and promoter cis-element content. We also analyzed the presumed proteins in terms of domain structure and phylogenetic relationships. Based on the results, we classified these genes into five subfamilies. The syntenic relationships suggest that approximately half of the genes resulted from genome duplication, contributing to the expansion of the B3 family in grapevine. The analysis of cis-element composition suggested that most of these genes may function in response to hormones, light, and stress. We also analyzed expression of members of the B3 family in various structures of grapevine plants, including the seed during seed development. Many B3 genes were expressed preferentially in one or more structures of the developed plant, suggesting specific roles in growth and development. Furthermore, several of the genes were expressed differentially in early developing seeds from representative seeded and seedless cultivars, suggesting a role in seed development or abortion. The results of this study provide a foundation for functional analysis of B3 genes and new resources for future molecular breeding of grapevine.

Transcription factor/DNA interactions visualized by electron spectroscopic imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 450-451
Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown
Keyword(s):  
Transcription Factor ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Phosphorus Content ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
Dna Backbone ◽  
Two Parameters ◽  
High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

scholarly journals TEAD4 modulated LncRNA MNX1-AS1 contributes to gastric cancer progression partly through suppressing BTG2 and activating BCL2

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
You Shuai ◽  
Zhonghua Ma ◽  
Weitao Liu ◽  
Tao Yu ◽  
Changsheng Yan ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Mechanistic Model ◽  
Ectopic Expression ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Tissue Samples ◽  
Reporter Assays

Abstract Background Gastric cancer (GC) is the third leading cause of cancer-related mortality globally. Long noncoding RNAs (lncRNAs) are dysregulated in obvious malignancies including GC and exploring the regulatory mechanisms underlying their expression is an attractive research area. However, these molecular mechanisms require further clarification, especially upstream mechanisms. Methods LncRNA MNX1-AS1 expression in GC tissue samples was investigated via microarray analysis and further determined in a cohort of GC tissues via quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. Cell proliferation and flow cytometry assays were performed to confirm the roles of MNX1-AS1 in GC proliferation, cell cycle regulation, and apoptosis. The influence of MNX1-AS1 on GC cell migration and invasion was explored with Transwell assays. A xenograft tumour model was established to verify the effects of MNX1-AS1 on in vivo tumourigenesis. The TEAD4-involved upstream regulatory mechanism of MNX1-AS1 was explored through ChIP and luciferase reporter assays. The mechanistic model of MNX1-AS1 in regulating gene expression was further detected by subcellular fractionation, FISH, RIP, ChIP and luciferase reporter assays. Results It was found that MNX1-AS1 displayed obvious upregulation in GC tissue samples and cell lines, and ectopic expression of MNX1-AS1 predicted poor clinical outcomes for patients with GC. Overexpressed MNX1-AS1 expression promoted proliferation, migration and invasion of GC cells markedly, whereas decreased MNX1-AS1 expression elicited the opposite effects. Consistent with the in vitro results, MNX1-AS1 depletion effectively inhibited the growth of xenograft tumour in vivo. Mechanistically, TEAD4 directly bound the promoter region of MNX1-AS1 and stimulated the transcription of MNX1-AS1. Furthermore, MNX1-AS1 can sponge miR-6785-5p to upregulate the expression of BCL2 in GC cells. Meanwhile, MNX1-AS1 suppressed the transcription of BTG2 by recruiting polycomb repressive complex 2 to BTG2 promoter regions. Conclusions Our findings demonstrate that MNX1-AS1 may be able to serve as a prognostic indicator in GC patients and that TEAD4-activatd MNX1-AS1 can promote GC progression through EZH2/BTG2 and miR-6785-5p/BCL2 axes, implicating it as a novel and potent target for the treatment of GC.

scholarly journals Molecular regulation of Snai2 in development and disease

2019 ◽  
Vol 132 (23) ◽  
Author(s):  
Wenhui Zhou ◽  
Kayla M. Gross ◽  
Charlotte Kuperwasser
Keyword(s):  
Transcription Factor ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Zinc Finger Protein ◽  
Main Role ◽  
Biological Processes ◽  
Developmental Defects ◽  
Mesenchymal Transition ◽  
Damage Repair

ABSTRACT The transcription factor Snai2, encoded by the SNAI2 gene, is an evolutionarily conserved C2H2 zinc finger protein that orchestrates biological processes critical to tissue development and tumorigenesis. Initially characterized as a prototypical epithelial-to-mesenchymal transition (EMT) transcription factor, Snai2 has been shown more recently to participate in a wider variety of biological processes, including tumor metastasis, stem and/or progenitor cell biology, cellular differentiation, vascular remodeling and DNA damage repair. The main role of Snai2 in controlling such processes involves facilitating the epigenetic regulation of transcriptional programs, and, as such, its dysregulation manifests in developmental defects, disruption of tissue homeostasis, and other disease conditions. Here, we discuss our current understanding of the molecular mechanisms regulating Snai2 expression, abundance and activity. In addition, we outline how these mechanisms contribute to disease phenotypes or how they may impact rational therapeutic targeting of Snai2 dysregulation in human disease.

scholarly journals Circular RNA mmu_circ_0005019 inhibits fibrosis of cardiac fibroblasts and reverses electrical remodeling of cardiomyocytes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Na Wu ◽  
Chengying Li ◽  
Bin Xu ◽  
Ying Xiang ◽  
Xiaoyue Jia ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cardiac Fibroblasts ◽  
Circular Rna ◽  
Protective Role ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Candidate Target ◽  
Paired Control ◽  
Reporter Assays ◽  
And Migration

Abstract Background Circular RNA (circRNA) have been reported to play important roles in cardiovascular diseases including myocardial infarction and heart failure. However, the role of circRNA in atrial fibrillation (AF) has rarely been investigated. We recently found a circRNA hsa_circ_0099734 was significantly differentially expressed in the AF patients atrial tissues compared to paired control. We aim to investigate the functional role and molecular mechanisms of mmu_circ_0005019 which is the homologous circRNA in mice of hsa_circ_0099734 in AF. Methods In order to investigate the effect of mmu_circ_0005019 on the proliferation, migration, differentiation into myofibroblasts and expression of collagen of cardiac fibroblasts, and the effect of mmu_circ_0005019 on the apoptosis and expression of Ito, INA and SK3 of cardiomyocytes, gain- and loss-of-function of cell models were established in mice cardiac fibroblasts and HL-1 atrial myocytes. Dual-luciferase reporter assays and RIP were performed to verify the binding effects between mmu_circ_0005019 and its target microRNA (miRNA). Results In cardiac fibroblasts, mmu_circ_0005019 showed inhibitory effects on cell proliferation and migration. In cardiomyocytes, overexpression of mmu_circ_0005019 promoted Kcnd1, Scn5a and Kcnn3 expression. Knockdown of mmu_circ_0005019 inhibited the expression of Kcnd1, Kcnd3, Scn5a and Kcnn3. Mechanistically, mmu_circ_0005019 exerted biological functions by acting as a miR-499-5p sponge to regulate the expression of its target gene Kcnn3. Conclusions Our findings highlight mmu_circ_0005019 played a protective role in AF development and might serve as an attractive candidate target for AF treatment.

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