scholarly journals The tert-butylhydroquinone-mediated activation of the human thioredoxin gene reveals a novel promoter structure

2006 ◽  
Vol 398 (2) ◽  
pp. 269-277 ◽  
Author(s):  
Simone A. Osborne ◽  
Hye-Jin Kim Hawkes ◽  
Ben L. Baldwin ◽  
Kylie A. Alexander ◽  
Terje Svingen ◽  
...  

Thioredoxin is a redox-active protein that plays multiple roles in regulating cell growth, cell signalling and apoptosis. Here, we have demonstrated that a complex mechanism involving multiple regulatory elements is involved in the tBHQ [tert-butylhydroquinone or 2,5-di-(t-butyl)-1,4-hydroquinone]-mediated activation of the thioredoxin gene. Luciferase assays, utilizing various wild-type and mutated thioredoxin promoter fragments, revealed roles for the ORE (oxidative stress responsive element), ARE (antioxidant responsive element), three Sp1 (specificity protein 1)-binding sites and the TATA box in the activation of the thioredoxin gene by tBHQ. The ORE required the presence of the ARE to elicit its response, whereas the independent removal of three Sp1-binding sites and the TATA box also decreased activation of the thioredoxin gene, with mutation of the TATA box having the greatest effect. Real-time RT (reverse transcriptase)–PCR analysis also revealed varying roles for two TSSs (transcription start sites) in the activation of the thioredoxin gene by tBHQ. Transcription was initiated from both TSSs; however, different response rates and fold inductions were observed. Together, these results suggest that the thioredoxin gene is controlled by a novel arrangement of two overlapping core promoter regions, one containing a TATA box and the other TATA-less. Altering the intracellular levels of thioredoxin in a breast cancer cell line also influenced the induction of thioredoxin transcription in response to tBHQ. Stable transfections with a redox-inactive thioredoxin mutant produced 3.6 times higher induction levels of thioredoxin transcription compared with control cells, indicating an intrinsic form of control of promoter activity by the thioredoxin system itself.

1996 ◽  
Vol 43 (2) ◽  
pp. 369-377 ◽  
Author(s):  
J M Jankowski ◽  
P D Cannon ◽  
F Van der Hoorn ◽  
L D Wasilewska ◽  
N C Wong ◽  
...  

An in vitro transcription system from the trout testis nuclei was developed to study trout protamine gene expression. The protamine promoter contains, among others, two regulatory elements: 1) a cAMP-responsive element or CRE element (TGACGTCA) which is present in position 5' to TATA box, and 2) GC box (CCGCCC) which is present in position 3' to TATA box. The removal of the CRE-binding protein by titration (by the addition of appropriate oligonucleotides to the incubation mixture) resulted in a decrease in transcription of the protamine gene. These results were confirmed by experiments in which the pure CRE-binding factor (TPBP1) was used, as well as by those where a stimulatory effect of cAMP on protamine promoter transcription was observed. On the other hand, addition of oligonucleotides containing the GC-box sequence enhanced the protamine gene transcription indicating that the protein (Sp1 like) which binds to this sequence acts as a repressor of protamine gene expression. These results confirm the previously proposed model which suggested that the GC box played a role in negative regulation of the protamine gene expression. Involvement of some other factors in this process was also discussed.


2018 ◽  
Vol 3 (3) ◽  
pp. 77-86 ◽  
Author(s):  
Pedro Vera-Hernández ◽  
Marco Antonio Ortega-Ramírez ◽  
Marcelino Martínez Nuñez ◽  
Magali Ruiz-Rivas ◽  
Flor de Fátima Rosas-Cárdenas

Plants have developed physiological and molecular mechanisms to support and adapt to adverse environments. One response to abiotic stress is the accumulation of free proline (PRO). PRO can induce the expression of many genes, which have the proline-responsive element (PRE) in their promoters, nevertheless due to the complexity of interactions between stress factors and various molecular, biochemical and physiological phenomena it is still unclear whether a more efficient PRO accumulation can be considered a biomarker of tolerance in plants. In the present work, we evaluated the accumulation of PRO in two genotypes of sorghum with contrasting tolerance to cold stress. To explore the cause behind the accumulation of proline under cold stress conditions, we identified the Transcription Factors Binding Sites (TFBS) present in the promoter regions in the genes involved in the biosynthesis and degradation of proline in sorghum and other important crops, finding that the untranslated 3 'region P5CS gene contains different TFBS. We found TFBS that could allow the activation of genes involved in proline biosynthesis through the ornithine pathway under cold stress conditions, suggesting that ornithine route can be activated under cold stress conditions


Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 816
Author(s):  
Shuang Yang ◽  
Yan Deng ◽  
Da Chen ◽  
Shenqiang Hu ◽  
Yingying Zhang ◽  
...  

Anti-Müllerian hormone (AMH) is recognized as a reliable marker of ovarian reserve. However, the regulatory mechanism of goose AMH gene remains poorly understood. In the present study, both the full-length coding sequence (CDS) and promoter sequence of goose AMH have been cloned. Its CDS consisted of 2013 nucleotides encoding 670 amino acids and the amino acid sequence contained two structural domain: AMH-N and transforming growth factor beta (TGF-β) domain. The obtained promoter sequence spanned from the −2386 bp to its transcription start site (ATG). Core promoter regions and regulatory elements were identified as well as transcription factors were predicted in its promoter sequence. The luciferase activity was the highest spanning from the −331 to −1 bp by constructing deletion promoter reporter vectors. In CHO cells, the luciferase activity significantly increased by co-expression of AMH and GATA binding protein 4 (GATA-4), while that significantly decreased by mutating the binding sites of GATA-4 located in the −778 and −1477 bp. Results from quantitative real-time polymerase chain reaction (qPCR) indicated that levels of AMH mRNA in geese granulosa layers decreased gradually with the increasing follicular diameter. Taken together, it could be concluded that the transcriptional activity of AMH was activated by GATA-4 to inhibit the development of small follicles in goose.


2017 ◽  
Author(s):  
Mahmoud M. Ibrahim ◽  
Aslihan Karabacak ◽  
Alexander Glahs ◽  
Ena Kolundzic ◽  
Antje Hirsekorn ◽  
...  

AbstractDivergent transcription from promoters and enhancers is pervasive in many species, but it remains unclear if it is a general and passive feature of all eukaryotic cis regulatory elements. To address this, we define promoters and enhancers in C. elegans, D. melanogaster and H. sapiens using ATAC-Seq and investigate the determinants of their transcription initiation directionalities by analyzing genome-wide nascent, cap-selected, polymerase run-on assays. All three species initiate divergent transcription from separate core promoter sequences. Sequence asymmetry downstream of forward and reverse initiation sites, known to be important for termination and stability in H. sapiens, is unique in each species. Chromatin states of divergent promoters are not entirely conserved, but in all three species, the levels of histone modifications on the +1 nucleosome are independent from those on the -1 nucleosome, arguing for independent initiation events. This is supported by an integrative model of H3K4me3 levels and core promoter sequence that is highly predictive of promoter directionality and of two types of promoters: those with balanced initiation directionality and those with skewed directionality. Lastly, D. melanogaster enhancers display variation in chromatin architecture depending on enhancer location, and D. melanogaster promoter regions with dual enhancer/promoter potential are enriched for divergent transcription. Our results point to a high degree of variation in regulatory element transcription initiation directionality within and between metazoans, and to non-passive regulatory mechanisms of transcription initiation directionality in those species.


2017 ◽  
Author(s):  
Shira Weingarten-Gabbay ◽  
Ronit Nir ◽  
Shai Lubliner ◽  
Eilon Sharon ◽  
Yael Kalma ◽  
...  

ABSTRACTDespite its pivotal role in regulating transcription, our understanding of core promoter function, architecture, and cis-regulatory elements is lacking. Here, we devised a highthroughput assay to quantify the activity of ∼15,000 fully designed core promoters that we integrated and expressed from a fixed location within the human genome. We find that core promoters drive transcription unidirectionally, and that sequences originating from promoters exhibit stronger activity than sequences originating from enhancers. Testing multiple combinations and distances of core promoter elements, we observe a positive effect of TATA and Initiator, a negative effect of BREu and BREd, and a 10bp periodicity in the optimal distance between the TATA and the Initiator. By comprehensively screening TF binding-sites, we show that site orientation has little effect, that the effect of binding site number on expression is factor-specific, and that there is a striking agreement between the effect of binding site multiplicity in our assay and the tendency of the TF to appear in homotypic clusters throughout the genome. Overall, our results systematically assay the elements that drive expression in core- and proximal-promoter regions and shed light on organization principles of regulatory regions in the human genome.


Genome ◽  
2008 ◽  
Vol 51 (6) ◽  
pp. 399-408 ◽  
Author(s):  
Zong-Xiang Tang ◽  
Shu-Lan Fu ◽  
Zheng-Long Ren ◽  
Jian-Ping Zhou ◽  
Ben-Ju Yan ◽  
...  

To better understand the evolution of allopolyploids, 4 different combinations between wheat ( Triticum aestivum L.) and rye ( Secale cereale L.) including 12 F1 hybrids and 12 derived amphiploids were analyzed and compared with their direct parental plants by PCR analysis using 150 wheat SSR (single sequence repeat) markers and by FISH analysis using a rye-specific repetitive sequence (pSc200) as a probe. Nine SSR markers amplified rye-specific fragments whose sizes ranged from 471 bp to 1089 bp. These fragments contain regulatory elements and (or) promoters. Some of these fragments were amplified from all 24 progenies, while others were amplified from a subset of the progenies. The disappearance of rye-specific fragments from some progenies was caused by sequence elimination or DNA modification. Marker Xgwm320 amplified a new fragment (403 bp), a rye-specific tandem repeat, from some of the progenies. Twenty-eight SSR markers displayed microsatellite variation in progenies derived from ‘Chinese Spring’ × ‘Jinzhou-heimai’, but none of the 150 SSR markers displayed microsatellite variation in the progenies derived from the other three combinations. FISH signals of pSc200 were eliminated from one telomere/subtelomere of 4 chromosomes of ‘Kustro’ during allopolyploidization and expanded in amphiploids derived from ‘Chinese Spring’ × ‘AR106BONE’. Thus, allopolyploidization in wheat–rye can be accompanied by rapid variation of tandem repeats, regulatory elements, and promoter regions. The alterations of repetitive sequence pSc200 indicate coordination between the constituent genomes of the newly formed amphiploids. Different genetic backgrounds of parents appear to affect genome changes during allopolyploidization.


Fagopyrum ◽  
2018 ◽  
Vol 35 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Upasna Chettry ◽  
Lashaihun Dohtdong ◽  
N. K. Chrungoo

Multiple sequence alignment of 5’UTR of SSP genes from accessions of Fagopyrum esculentumrevealed the invariant nature of sequences with the transcription start site at P761and TATA box located -30bp upstream the TSS. Other cis-elements identified in the sequences included the legumin box (-581, -524, -184, -135, -91), the -131 prolamin box, DOF element (-718, -649, -540,-432, -272,-225, -128) and CAAT box (-692, -530, -475, -411, -282, -168, -54). Other elements identified included those involved in abscisic acid signallingviz., ABI3 at P-470,-95,-68,RAV1 at P-694and -543and AGL15 at P-671. A comparative analysis of regulatory elements of SSP gene promoters of distantly related species the presence of five cis-regulatory elements viz. TATA BOX, E-BOX, RY- element, CAAT box and the Endosperm box, which interplay in seed specific SSP gene expression. Other modulators influencing seed specific gene expression detected in the sequences included the  ABA-responsive elements ABI3, RAV1 and AGL15 which play an integral role in seed maturation. Identification of potential nucleosome binding sites in SSP gene promoters of Cicer arietinum, Brassica napus, B. campestris, Vicia faba, and Pisum sativumat positions 78, 635, 195, 112 and 152 respectively surmises the spatial fine tuning of SSP gene transcriptional regulation in these species. On the other hand, absence of nucleosome binding sites in the promoters of Fagopyrum esculentum, Zea mays, Avena sativa, Triticum aestivum and Oryza sativamay indicate relatively easier access of transcription factors to the proximal promoter, thereby providing higher level of gene expression.


Author(s):  
Dinku Senbeta ◽  
Mulugeta Kebede

Abstract Background In silico analysis of transcription start sites, promoter regions, transcription factors and their binding sites, and CpG islands for the Trametes hirsuta strain 072 genome were performed to understand the regulation mechanisms of gene expression and its genetic variations in the genomes. Therefore, a computational survey was carried out for the Trametes hirsuta strain 072 genome with the open reading frames from the National Center for Biotechnology Information database. Seventeen functional sequences were used to analyze promoter regions and their regulatory elements. Result The present study revealed that 94% of Trametes hirsuta strain 072 genes contained more than two TSSs. Among these identified TSSs, a TSS with the highest predictive score was considered to determine a promoter region of the genes. Moreover, a total of five common candidate motifs such as MotI, MotII, MotIII, MotIV, and MotV were identified. Among these motifs, motif IV was investigated as the common promoter motif for 41.17% of genes that serve as binding sites for transcription factors (TFs) involved in the expression regulation of Trametes hirsuta strain 072 genes. Motif IV was also compared to registered motifs in publically available databases to see if they are similar to known regulatory motifs for TF using TOMTOM web server. Hence, it was revealed that MotIV might serve as the binding site mainly for the leucine zipper TF gene family to regulate a gene expression of Trametes hirsuta strain 072. Regarding CpG island determination, it was concluded that there is no CpG island in both promoter and gene body regions of the Trametes hirsuta strain 072 genome. Conclusions This study provides a better insight into further molecular characterization which aimed to efficiently exploit a white rot fungus, Trametes hirsuta strain 072, for several biotechnological applications aimed to revitalize a severely contaminated environment.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Samuel N. Bogan ◽  
Sean P. Place

Abstract Background Antarctic fishes of the Notothenioidei suborder constitutively upregulate multiple inducible chaperones, a highly derived adaptation that preserves proteostasis in extreme cold, and represent a system for studying the evolution of gene frontloading. We screened for Hsf1-binding sites, as Hsf1 is a master transcription factor of the heat shock response, and highly-conserved non-coding elements within proximal promoters of chaperone genes across 10 Antarctic notothens, 2 subpolar notothens, and 17 perciform fishes. We employed phylogenetic models of molecular evolution to determine whether (i) changes in motifs associated with Hsf1-binding and/or (ii) relaxed purifying selection or exaptation at ancestral cis-regulatory elements coincided with the evolution of chaperone frontloading in Antarctic notothens. Results Antarctic notothens exhibited significantly fewer Hsf1-binding sites per bp at chaperone promoters than subpolar notothens and Serranoidei, the most closely-related suborder to Notothenioidei included in this study. 90% of chaperone promoters exhibited accelerated substitution rates among Antarctic notothens relative to other perciformes. The proportion of bases undergoing accelerated evolution (i) was significantly greater in Antarctic notothens than in subpolar notothens and Perciformes in 70% of chaperone genes and (ii) increased among bases that were more conserved among perciformes. Lastly, we detected evidence of relaxed purifying selection and exaptation acting on ancestrally conserved cis-regulatory elements in the Antarctic notothen lineage and its major branches. Conclusion A large degree of turnover has occurred in Notothenioidei at chaperone promoter regions that are conserved among perciform fishes following adaptation to the cooling of the Southern Ocean. Additionally, derived reductions in Hsf1-binding site frequency suggest cis-regulatory modifications to the classical heat shock response. Of note, turnover events within chaperone promoters were less frequent in the ancestral node of Antarctic notothens relative to younger Antarctic lineages. This suggests that cis-regulatory divergence at chaperone promoters may be greater between Antarctic notothen lineages than between subpolar and Antarctic clades. These findings demonstrate that strong selective forces have acted upon cis-regulatory elements of chaperone genes among Antarctic notothens.


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