scholarly journals Activity and Function Studies of The Promoter Cis-Acting Elements of The Key Enzymes in Saponins Biosynthesis of DS From Panax Notoginseng

Author(s):  
Yujie Zheng ◽  
Rongyu Shao ◽  
Pengguo Xia ◽  
Zongsuo Liang ◽  
Kaijing Yan

Abstract Background:Panax notoginseng is a traditional Chinese medicine for the treatment of blood diseases, in which saponins were the main active components. Dammarenediol synthase (DS) is a key enzyme in the saponin synthesis pathway of P. notoginseng.The promoter is an important region to regulate gene expression, and the study of the promoter sequence provides important evidence for revealing the mechanism of gene expression regulation. Methods: However, there was still little research on the promoter function of P. notoginseng. In this study, the 1382 bp promoter upstream of DS from P. notoginseng was cloned and sequenced. The promoter sequence was analyzed by online databases. The plant expression vector fused with the β-glucuronidase gene was constructed, transferred into Agrobacterium tumefaciens. Then tobacco was injected, and its response to exogenous hormones (gibberellin and abscisic acid) was studied by transient expression to verify its unique action elements. Results: The results showed that the tobacco leaves transferred with DS promoter had significantly increased GUS protease activity after spraying GA and ABA, indicating that both DS promoter can specifically and significantly respond to exogenous GA and ABA signal. Conclusions: These findings will help us to better understand the regulatory mechanisms of the upstream region of the DS gene and provide a basis for future research on the interaction of cis-acting elements of promoters with related transcription factors.

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 417-423
Author(s):  
Wayne K Versaw ◽  
Robert L Metzenberg

Abstract A transgenic position effect that causes activator-independent gene expression has been described previously for three Neurospora crassa phosphate-repressible genes. We report analogous findings for two additional positively regulated genes, qa-2  + and ars-1  +, indicating that such position effects are not limited to genes involved in phosphorus metabolism. In addition, we have characterized a number of mutants that display activator-independent gene expression. Each of these mutants contains a chromosomal rearrangement with one breakpoint located in the 5’-upstream region of the affected gene. This suggests that the rearrangements are associated with activator-independent gene expression and that these cis-acting mutations may represent a position effect similar to that responsible for rendering some transgenes independent of their transcriptional activators. We suggest that positively regulated genes in N.  crassa are normally held in a transcriptionally repressed state by a cis-acting mechanism until specifically activated. Disruption of this cis-acting mechanism, either by random integration of a gene by transformation or by chromosomal rearrangement, renders these genes independent or partly independent of the transcriptional activator on which they normally depend.


Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5201
Author(s):  
Emanuele Vitale ◽  
Mila Gugnoni ◽  
Alessia Ciarrocchi

The control of gene expression at a transcriptional level requires a widespread landscape of regulatory elements. Central to these regulatory circuits are enhancers (ENHs), which are defined as cis-acting DNA elements able to increase the transcription of a target gene in a distance- and orientation-independent manner. ENHs are not independent functional elements but work in a complex and dynamic cooperative network, constituting the building blocks of multimodular domains of gene expression regulation. The information from each of these elements converges on the target promoter, contributing to improving the precision and sharpness of gene modulation. ENHs’ interplay varies in its nature and extent, ranging from an additive to redundant effect depending on contexts. Moving from super-enhancers that drive the high expression levels of identity genes, to shadow-enhancers, whose redundant functions contribute to buffering the variation in gene expression, this review aims to describe the different modalities of ENHs’ interaction and their role in the regulation of complex biological processes like cancer development.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Bai ◽  
Haijiao Liu ◽  
Jianying Pan ◽  
Shiyan Zhang ◽  
Yixin Guo ◽  
...  

The root of Panax notoginseng (Burk.), in which saponins are the major active components, is a famous traditional Chinese medicine used to stop bleeding and to decrease inflammation and heart disease. Inflorescence removal increases the yield and quality of P. notoginseng, but the underlying molecular mechanisms are unknown. Here, the differences between inflorescence-removal treatment and control groups of P. notoginseng were compared using transcriptomics and metabolomics analyses. Illumina sequencing of cDNA libraries prepared from the rhizomes, leaves and roots of the two groups independently identified 6,464, 4,584, and 7,220 differentially expressed genes (DEG), respectively. In total, 345 differentially expressed transcription factors (TFs), including MYB and WRKY family members, were induced by the inflorescence-removal treatment. Additionally, 215 DEGs involved in saponin terpenoid backbone biosynthetic pathways were identified. Most genes involved in the mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathways were activated by inflorescence removal. The co-expression analysis showed that the low expression levels of flavonoid biosynthesis-related genes (e.g., C4H and F3H) decreased the biosynthesis and accumulation of some flavonoids after inflorescence removal. The results not only provide new insights into the fundamental mechanisms underlying the poorly studied inflorescence-removal process in P. notoginseng and other rhizome crops, but they also represent an important resource for future research on gene functions during inflorescence-removal treatments and the reproductive stage.


Author(s):  
Elena Panagiotopoulou ◽  
Celeste Peiris ◽  
Daniel Hayes

Abstract Despite the high prevalence of self-harm among young people, as well as their extensive use of mobile apps for seeking support with their mental healthcare, it is unclear whether the design of mobile apps aimed at targeting self-harm is underpinned by behavior change techniques (BCTs). To systematically analyze and identify (a) what BCTs and (b) what theories are present in self-harm apps for young people in an attempt to understand their active components. Systematic searches in Apple store, followed by thorough screening, were conducted to identify free mobile apps targeting self-harm in young people. Five apps met the inclusion criteria and were used by trained researchers, who coded identified features against the BCT Taxonomy V1. Despite the majority of apps being underpinned by principles of Dialectical Behavior Therapy (DBT), no other information is available about specific theories underpinning these apps. Nineteen of the 93 BCTs were identified across the five apps. The most frequently used BCT was “Distraction” (54.2%), offering ideas for activities to distract users from self-harming. Other techniques that were used often were “Social Support (unspecified)” (27.0%) and “Behavior Substitution” (10.6%). This study provides the first analysis of BCTs present in mental health apps which are designed to target the reduction of self-harm in young people. Future research is needed to evaluate the effectiveness of the apps, as well as assess the effectiveness of the BCTs present.


2021 ◽  
Vol 22 (5) ◽  
pp. 2599
Author(s):  
Mégane Collobert ◽  
Ozvan Bocher ◽  
Anaïs Le Nabec ◽  
Emmanuelle Génin ◽  
Claude Férec ◽  
...  

About 8% of the human genome is covered with candidate cis-regulatory elements (cCREs). Disruptions of CREs, described as “cis-ruptions” have been identified as being involved in various genetic diseases. Thanks to the development of chromatin conformation study techniques, several long-range cystic fibrosis transmembrane conductance regulator (CFTR) regulatory elements were identified, but the regulatory mechanisms of the CFTR gene have yet to be fully elucidated. The aim of this work is to improve our knowledge of the CFTR gene regulation, and to identity factors that could impact the CFTR gene expression, and potentially account for the variability of the clinical presentation of cystic fibrosis as well as CFTR-related disorders. Here, we apply the robust GWAS3D score to determine which of the CFTR introns could be involved in gene regulation. This approach highlights four particular CFTR introns of interest. Using reporter gene constructs in intestinal cells, we show that two new introns display strong cooperative effects in intestinal cells. Chromatin immunoprecipitation analyses further demonstrate fixation of transcription factors network. These results provide new insights into our understanding of the CFTR gene regulation and allow us to suggest a 3D CFTR locus structure in intestinal cells. A better understand of regulation mechanisms of the CFTR gene could elucidate cases of patients where the phenotype is not yet explained by the genotype. This would thus help in better diagnosis and therefore better management. These cis-acting regions may be a therapeutic challenge that could lead to the development of specific molecules capable of modulating gene expression in the future.


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