scholarly journals BrTCP7 Transcription Factor Is Associated with MeJA-Promoted Leaf Senescence by Activating the Expression of BrOPR3 and BrRCCR

2019 ◽  
Vol 20 (16) ◽  
pp. 3963 ◽  
Author(s):  
Yan-mei Xu ◽  
Xian-mei Xiao ◽  
Ze-xiang Zeng ◽  
Xiao-li Tan ◽  
Zong-li Liu ◽  
...  
Keyword(s):  
Leaf Senescence ◽  
Transcriptional Activity ◽  
Nuclear Protein ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Transient Expression Assay ◽  
Catabolic Genes ◽  
Meja Treatment ◽  
Mobility Shift Assay ◽  
Chlorophyll Catabolite

The plant hormone jasmonic acid (JA) has been recognized as an important promoter of leaf senescence in plants. However, upstream transcription factors (TFs) that control JA biosynthesis during JA-promoted leaf senescence remain unknown. In this study, we report the possible involvement of a TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) TF BrTCP7 in methyl jasmonate (MeJA)-promoted leaf senescence in Chinese flowering cabbage. Exogenous MeJA treatment reduced maximum quantum yield (Fv/Fm) and total chlorophyll content, accompanied by the increased expression of senescence marker and chlorophyll catabolic genes, and accelerated leaf senescence. To further understand the transcriptional regulation of MeJA-promoted leaf senescence, a class I member of TCP TFs BrTCP7 was examined. BrTCP7 is a nuclear protein and possesses trans-activation ability through subcellular localization and transcriptional activity assays. A higher level of BrTCP7 transcript was detected in senescing leaves, and its expression was up-regulated by MeJA. The electrophoretic mobility shift assay and transient expression assay showed that BrTCP7 binds to the promoter regions of a JA biosynthetic gene BrOPR3 encoding OPDA reductase3 (OPR3) and a chlorophyll catabolic gene BrRCCR encoding red chlorophyll catabolite reductase (RCCR), activating their transcriptions. Taken together, these findings reveal that BrTCP7 is associated with MeJA-promoted leaf senescence at least partly by activating JA biosynthesis and chlorophyll catabolism, thus expanding our knowledge of the transcriptional mechanism of JA-mediated leaf senescence.

scholarly journals Activation of the Transcription of BrGA20ox3 by a BrTCP21 Transcription Factor Is Associated with Gibberellin-Delayed Leaf Senescence in Chinese Flowering Cabbage during Storage

2019 ◽  
Vol 20 (16) ◽  
pp. 3860
Author(s):  
Xian-mei Xiao ◽  
Yan-mei Xu ◽  
Ze-xiang Zeng ◽  
Xiao-li Tan ◽  
Zong-li Liu ◽  
...  
Keyword(s):  
Transient Expression ◽  
Leaf Senescence ◽  
Biosynthetic Pathway ◽  
Transcript Level ◽  
Mobility Shift ◽  
Transient Expression Assay ◽  
Catabolic Genes ◽  
Mobility Shift Assay ◽  
Psii Quantum Yield ◽  
Senescence Associated Genes

Several lines of evidence have implicated the involvement of the phytohormone gibberellin (GA) in modulating leaf senescence in plants. However, upstream transcription factors (TFs) that regulate GA biosynthesis in association with GA-mediated leaf senescence remain elusive. In the current study, we report the possible involvement of a TEOSINTE BRANCHED1/CYCLOIDEA/PCF (TCP) TF BrTCP21 in GA-delayed leaf senescence in Chinese flowering cabbage. Exogenous GA3 treatment maintained a higher value of maximum PSII quantum yield (Fv/Fm) and total chlorophyll content, accompanied by the repression of the expression of senescence-associated genes and chlorophyll catabolic genes, which led to the delay of leaf senescence. A class I member of TCP TFs BrTCP21, was further isolated and characterized. The transcript level of BrTCP21 was low in senescing leaves, and decreased following leaf senescence, while GA3 could keep a higher expression level of BrTCP21. BrTCP21 was further found to be a nuclear protein and exhibit trans-activation ability through transient-expression analysis in tobacco leaves. Intriguingly, the electrophoretic mobility shift assay (EMSA) and transient expression assay illustrated that BrTCP21 bound to the promoter region of a GA biosynthetic gene BrGA20ox3, and activated its transcription. Collectively, these observations reveal that BrTCP21 is associated with GA-delayed leaf senescence, at least partly through the activation of the GA biosynthetic pathway. These findings expand our knowledge on the transcriptional mechanism of GA-mediated leaf senescence.

Olf-1-binding site: characterization of an olfactory neuron-specific promoter motif

1993 ◽  
Vol 13 (5) ◽  
pp. 3002-3014
Author(s):  
K Kudrycki ◽  
C Stein-Izsak ◽  
C Behn ◽  
M Grillo ◽  
R Akeson ◽  
...  
Keyword(s):  
Nuclear Protein ◽  
Consensus Sequence ◽  
Binding Motif ◽  
Sequence Motif ◽  
Olfactory Neuron ◽  
Sequence Motifs ◽  
Mobility Shift ◽  
Specific Expression ◽  
Mobility Shift Assay

We report characterization of several domains within the 5' flanking region of the olfactory marker protein (OMP) gene that may participate in regulating transcription of this and other olfactory neuron-specific genes. Analysis by electrophoretic mobility shift assay and DNase I footprinting identifies two regions that contain a novel sequence motif. Interactions between this motif and nuclear proteins were detected only with nuclear protein extracts derived from olfactory neuroepithelium, and this activity is more abundant in olfactory epithelium enriched in immature neurons. We have designated a factor(s) involved in this binding as Olf-1. The Olf-1-binding motif consensus sequence was defined as TCCCC(A/T)NGGAG. Studies with transgenic mice indicate that a 0.3-kb fragment of the OMP gene containing one Olf-1 motif is sufficient for olfactory tissue-specific expression of the reporter gene. Some of the other identified sequence motifs also interact specifically with olfactory nuclear protein extracts. We propose that Olf-1 is a novel, olfactory neuron-specific trans-acting factor involved in the cell-specific expression of OMP.

scholarly journals Olf-1-binding site: characterization of an olfactory neuron-specific promoter motif.

1993 ◽  
Vol 13 (5) ◽  
pp. 3002-3014 ◽  
Author(s):  
K Kudrycki ◽  
C Stein-Izsak ◽  
C Behn ◽  
M Grillo ◽  
R Akeson ◽  
...  
Keyword(s):  
Nuclear Protein ◽  
Consensus Sequence ◽  
Binding Motif ◽  
Sequence Motif ◽  
Olfactory Neuron ◽  
Sequence Motifs ◽  
Mobility Shift ◽  
Specific Expression ◽  
Mobility Shift Assay

We report characterization of several domains within the 5' flanking region of the olfactory marker protein (OMP) gene that may participate in regulating transcription of this and other olfactory neuron-specific genes. Analysis by electrophoretic mobility shift assay and DNase I footprinting identifies two regions that contain a novel sequence motif. Interactions between this motif and nuclear proteins were detected only with nuclear protein extracts derived from olfactory neuroepithelium, and this activity is more abundant in olfactory epithelium enriched in immature neurons. We have designated a factor(s) involved in this binding as Olf-1. The Olf-1-binding motif consensus sequence was defined as TCCCC(A/T)NGGAG. Studies with transgenic mice indicate that a 0.3-kb fragment of the OMP gene containing one Olf-1 motif is sufficient for olfactory tissue-specific expression of the reporter gene. Some of the other identified sequence motifs also interact specifically with olfactory nuclear protein extracts. We propose that Olf-1 is a novel, olfactory neuron-specific trans-acting factor involved in the cell-specific expression of OMP.

scholarly journals Transcriptional and Functional Analysis of the Neisseria gonorrhoeae Fur Regulon

2009 ◽  
Vol 192 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Lydgia A. Jackson ◽  
Thomas F. Ducey ◽  
Michael W. Day ◽  
Jeremy B. Zaitshik ◽  
Joshua Orvis ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Transcriptional Control ◽  
Cell Communication ◽  
Essential Element ◽  
Open Reading Frames ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Sequence Logos ◽  
Mobility Shift Assay

ABSTRACT To ensure survival in the host, bacteria have evolved strategies to acquire the essential element iron. In Neisseria gonorrhoeae, the ferric uptake regulator Fur regulates metabolism through transcriptional control of iron-responsive genes by binding conserved Fur box (FB) sequences in promoters during iron-replete growth. Our previous studies showed that Fur also controls the transcription of secondary regulators that may, in turn, control pathways important to pathogenesis, indicating an indirect role for Fur in controlling these downstream genes. To better define the iron-regulated cascade of transcriptional control, we combined three global strategies—temporal transcriptome analysis, genomewide in silico FB prediction, and Fur titration assays (FURTA)—to detect genomic regions able to bind Fur in vivo. The majority of the 300 iron-repressed genes were predicted to be of unknown function, followed by genes involved in iron metabolism, cell communication, and intermediary metabolism. The 107 iron-induced genes encoded hypothetical proteins or energy metabolism functions. We found 28 predicted FBs in FURTA-positive clones in the promoters and within the open reading frames of iron-repressed genes. We found lower levels of conservation at critical thymidine residues involved in Fur binding in the FB sequence logos of FURTA-positive clones with intragenic FBs than in the sequence logos generated from FURTA-positive promoter regions. In electrophoretic mobility shift assay studies, intragenic FBs bound Fur with a lower affinity than intergenic FBs. Our findings further indicate that transcription under iron stress is indirectly controlled by Fur through 12 potential secondary regulators.

scholarly journals Nucleolin stabilizes G-quadruplex structures folded by the LTR promoter and silences HIV-1 viral transcription

2015 ◽  
Vol 43 (18) ◽  
pp. 8884-8897 ◽  
Author(s):  
Elena Tosoni ◽  
Ilaria Frasson ◽  
Matteo Scalabrin ◽  
Rosalba Perrone ◽  
Elena Butovskaya ◽  
...  
Keyword(s):  
Transcriptional Activity ◽  
Cellular Protein ◽  
Spectrometric Analysis ◽  
Viral Transcription ◽  
Mobility Shift ◽  
Binding Preference ◽  
G Quadruplex ◽  
Mobility Shift Assay ◽  
Ltr Promoter ◽  
Hiv 1

Abstract Folding of the LTR promoter into dynamic G-quadruplex conformations has been shown to suppress its transcriptional activity in HIV-1. Here we sought to identify the proteins that control the folding of this region of proviral genome by inducing/stabilizing G-quadruplex structures. The implementation of electrophorethic mobility shift assay and pull-down experiments coupled with mass spectrometric analysis revealed that the cellular protein nucleolin is able to specifically recognize G-quadruplex structures present in the LTR promoter. Nucleolin recognized with high affinity and specificity the majority, but not all the possible G-quadruplexes folded by this sequence. In addition, it displayed greater binding preference towards DNA than RNA G-quadruplexes, thus indicating two levels of selectivity based on the sequence and nature of the target. The interaction translated into stabilization of the LTR G-quadruplexes and increased promoter silencing activity; in contrast, disruption of nucleolin binding in cells by both siRNAs and a nucleolin binding aptamer greatly increased LTR promoter activity. These data indicate that nucleolin possesses a specific and regulated activity toward the HIV-1 LTR promoter, which is mediated by G-quadruplexes. These observations provide new essential insights into viral transcription and a possible low mutagenic target for antiretroviral therapy.

scholarly journals HrpS Is a Global Regulator on Type III Secretion System (T3SS) and Non-T3SS Genes in Pseudomonas savastanoi pv. phaseolicola

2018 ◽  
Vol 31 (12) ◽  
pp. 1232-1243 ◽  
Author(s):  
Jingru Wang ◽  
Xiaolong Shao ◽  
Yingchao Zhang ◽  
Yanan Zhu ◽  
Pan Yang ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Binding Motif ◽  
Global Regulator ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Type Iii ◽  
Mobility Shift Assay ◽  
The Individual

The type III secretion system (T3SS) is the main machinery for Pseudomonas savastanoi and other gram-negative bacteria to invade plant cells. HrpR and HrpS form a hetero-hexamer, which activates the expression of HrpL, which induces all T3SS genes by binding to a ‘hrp box’ in promoters. However, the individual molecular mechanism of HrpR or HrpS has not been fully understood. Through chromatin immunoprecipitation coupled to high-throughput DNA sequencing, we found that HrpR, HrpS, and HrpL had four, 47, and 31 targets on the genome, respectively. HrpS directly bound to the promoter regions of a group of T3SS genes and non-T3SS genes. HrpS independently regulated these genes in a hrpL deletion strain. Additionally, a HrpS-binding motif (GTGCCAAA) was identified, which was verified by electrophoretic mobility shift assay and lux-reporter assay. HrpS also regulated motility and biofilm formation in P. savastanoi. The present study strongly suggests that HrpS alone can work as a global regulator on both T3SS and non-T3SS genes in P. savastanoi. [Formula: see text] Copyright © 2018 The Author(s). This is an open-access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Molecular regulation of the human IL-3 gene: inducible T cell-restricted expression requires intact AP-1 and Elf-1 nuclear protein binding sites.

1993 ◽  
Vol 178 (5) ◽  
pp. 1681-1692 ◽  
Author(s):  
L R Gottschalk ◽  
D M Giannola ◽  
S G Emerson
Keyword(s):  
T Cells ◽  
Transcription Factors ◽  
T Cell ◽  
Protein Binding ◽  
Binding Site ◽  
Binding Sites ◽  
Nuclear Protein ◽  
Mobility Shift ◽  
Nuclear Extracts ◽  
Mobility Shift Assay

Interleukin 3 (IL-3) is a hematopoietic stem-cell growth and differentiation factor that is expressed solely in activated T and NK cells. Studies to date have identified elements 5' to the IL-3 coding sequences that regulate its transcription, but the sequences that confer T cell-specific expression remain to be clearly defined. We have now identified DNA sequences that are required for T cell-restricted IL-3 gene transcription. A series of transient transfections performed with human IL-3-chloramphenicol acetyltransferase (CAT) reporter plasmids in T and non-T cells revealed that a plasmid containing 319 bp of 5' flanking sequences was active exclusively in T cells. Deletion analysis revealed that T cell specificity was conferred by a 49-bp fragment (bp -319 to -270) that included a potential binding site for AP-1 transcription factors 6 bp upstream of a binding site for Elf-1, a member of the Ets family of transcription factors. DNaseI footprint and electrophoretic mobility shift assay analyses performed with MLA-144 T cell nuclear extracts demonstrated that this 49-bp region contains a nuclear protein binding region that includes consensus AP-1 and Elf-1 binding sites. In addition, extracts prepared from purified human T cells contained proteins that bound to synthetic oligonucleotides corresponding to the AP-1 and Elf-1 binding sites. In vitro-transcribed and -translated Elf-1 protein bound specifically to the Elf-1 site, and Elf-1 antisera competed and super shifted nuclear protein complexes present in MLA-144 nuclear extracts. Moreover, addition of anti-Jun family antiserum in electrophoretic mobility shift assay reactions completely blocked formation of the AP-1-related complexes. Transient transfection studies in MLA-144 T cells revealed that constructs containing mutations in the AP-1 site almost completely abolished CAT activity while mutation of the Elf-1 site or the NF-IL-3 site, a previously described nuclear protein binding site (bp. -155 to -148) in the IL-3 promoter, reduced CAT activity to < 25% of the activity given by wild-type constructs. We conclude that expression of the human IL-3 gene requires the AP-1 and Elf-1 binding sites; however, unlike other previously characterized cytokine genes such as IL-2, the AP-1 and Elf-1 factors can bind independently in the IL-3 gene.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Transcript analysis reveals an extended regulon and the importance of protein–protein co-operativity for the Escherichia coli methionine repressor

2006 ◽  
Vol 396 (2) ◽  
pp. 227-234 ◽  
Author(s):  
Ferenc Marincs ◽  
Iain W. Manfield ◽  
Jonathan A. Stead ◽  
Kenneth J. Mcdowall ◽  
Peter G. Stockley
Keyword(s):  
Escherichia Coli ◽  
Gene Replacement ◽  
Dna Arrays ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Metabolic Role ◽  
Mobility Shift Assay

We have used DNA arrays to investigate the effects of knocking out the methionine repressor gene, metJ, on the Escherichia coli transcriptome. We assayed the effects in the knockout strain of supplying wild-type or mutant MetJ repressors from an expression plasmid, thus establishing a rapid assay for in vivo effects of mutations characterized previously in vitro. Repression is largely restricted to known genes involved in the biosynthesis and uptake of methionine. However, we identified a number of additional genes that are significantly up-regulated in the absence of repressor. Sequence analysis of the 5′ promoter regions of these genes identified plausible matches to met-box sequences for three of these, and subsequent electrophoretic mobility-shift assay analysis showed that for two such loci their repressor affinity is higher than or comparable with the known metB operator, suggesting that they are directly regulated. This can be rationalized for one of the loci, folE, by the metabolic role of its encoded enzyme; however, the links to the other regulated loci are unclear, suggesting both an extension to the known met regulon and additional complexity to the role of the repressor. The plasmid gene replacement system has been used to examine the importance of protein–protein co-operativity in operator saturation using the structurally characterized mutant repressor, Q44K. In vivo, there are detectable reductions in the levels of regulation observed, demonstrating the importance of balancing protein–protein and protein–DNA affinity.

scholarly journals Regulation of lactase–phlorizin hydrolase gene expression by the caudal-related homoeodomain protein Cdx-2

1997 ◽  
Vol 322 (3) ◽  
pp. 833-838 ◽  
Author(s):  
Jesper T. TROELSEN ◽  
Cathy MITCHELMORE ◽  
Nikolaj SPODSBERG ◽  
Anette M. JENSEN ◽  
Ove NORÉN ◽  
...  
Keyword(s):  
Gene Expression ◽  
Small Intestine ◽  
Binding Site ◽  
Electrophoretic Mobility Shift Assay ◽  
Gene Transcription ◽  
Transcriptional Activity ◽  
Nuclear Factor ◽  
Mobility Shift ◽  
Cis Element ◽  
Mobility Shift Assay

Lactase–phlorizin hydrolase is exclusively expressed in the small intestine and is often used as a marker for the differentiation of enterocytes. The cis-element CE-LPH1 found in the lactase–phlorizin hydrolase promoter has previously been shown to bind an intestinal-specific nuclear factor. By electrophoretic mobility-shift assay it was shown that the factor Cdx-2 (a homoeodomain-protein related to caudal) binds to a TTTAC sequence in the CE-LPH1. Furthermore it was demonstrated that Cdx-2 is able to activate reporter gene transcription by binding to CE-LPH1. A mutation in CE-LPH1, which does not affect Cdx-2 binding, results in a higher transcriptional activity, indicating that the CE-LPH1 site contains other binding site(s) in addition to the Cdx-2-binding site.

scholarly journals Regulation of Expression of the Epstein-Barr Virus BamHI-A Rightward Transcripts

2005 ◽  
Vol 79 (3) ◽  
pp. 1724-1733 ◽  
Author(s):  
Honglin Chen ◽  
Jian Huang ◽  
Frederick Y. Wu ◽  
Gangling Liao ◽  
Lindsey Hutt-Fletcher ◽  
...  
Keyword(s):  
B Cells ◽  
Epithelial Cells ◽  
Epstein Barr Virus ◽  
Promoter Regions ◽  
Mobility Shift ◽  
Regulation Of Expression ◽  
Barr Virus ◽  
Reporter Assays ◽  
Epstein Barr ◽  
Mobility Shift Assay

ABSTRACT The Epstein-Barr virus (EBV) BamHI-A rightward transcripts, or BARTs, are a family of mRNAs expressed in all EBV latency programs, including EBV-infected B cells in healthy carriers. Despite their ubiquitous expression, the regulation and biological function of BARTs are still unclear. In this study, the BART 5′ termini were characterized by using a procedure that selects capped, full-length mRNAs. Two TATA-less promoter regions, designated P1 and P2, were mapped. P1 had relatively high basal activity in both epithelial and B cells, whereas P2 exhibited higher activity in epithelial cells. Upon EBV infection of B cells, transcription from P1 was detected soon after infection, while expression from P2 was delayed. Promoter-reporter assays in transiently transfected cells revealed that P1 and P2 were differentially regulated. Interferon regulatory factor 7 (IRF7) and IRF5 negatively regulated P1 activity. c-Myc and C/EBP family members positively regulated P2. Regulation of P2 by C/EBPs was characterized by electrophoretic mobility shift assay, chromatin immunoprecipitation, and reporter assays. More-abundant BART expression in epithelial cells correlated with the relative expression of positive and negative regulators in these cells.

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