Exogenous application of RNAs as a silencing tool for discovering gene function.

2021 ◽  
pp. 14-24
Author(s):  
Barbara Molesini ◽  
Tiziana Pandolfini
Keyword(s):  
Gene Expression ◽  
Gene Function ◽  
Rna Silencing ◽  
Target Genes ◽  
Specific Gene ◽  
Transcriptional Level ◽  
Fruit Setting ◽  
Organ Tissue ◽  
Specific Regulation ◽  
Time Specific

Abstract This chapter focuses on the importance of the RNA silencing technique in unraveling the function of genes by inhibiting gene expression at the post-transcriptional level, and is particularly appropriate for studying developmental processes such as fruit setting and growth that require a tight organ/tissue and time-specific regulation of the expression of target genes. Some methods used for establishing the function of a specific gene altering gene expression at either the genomic or post-transcriptional level are also presented.

New insights into promoter–enhancer communication mechanisms revealed by dynamic single-molecule imaging

2021 ◽  
Author(s):  
Jieru Li ◽  
Alexandros Pertsinidis
Keyword(s):  
Gene Expression ◽  
Single Molecule ◽  
Target Genes ◽  
Regulatory Elements ◽  
Specific Gene ◽  
Single Molecule Imaging ◽  
Cell Type ◽  
Regulatory Information ◽  
Cell Type Specific ◽  
Target Promoters

Establishing cell-type-specific gene expression programs relies on the action of distal enhancers, cis-regulatory elements that can activate target genes over large genomic distances — up to Mega-bases away. How distal enhancers physically relay regulatory information to target promoters has remained a mystery. Here, we review the latest developments and insights into promoter–enhancer communication mechanisms revealed by live-cell, real-time single-molecule imaging approaches.

scholarly journals Cross-Kingdom Regulation by Plant microRNAs Provides Novel Insight into Gene Regulation

2020 ◽  
Author(s):  
Abdul Fatah A Samad ◽  
Mohd Farizal Kamaroddin ◽  
Muhammad Sajad
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Current Knowledge ◽  
Circulatory System ◽  
Dietary Therapy ◽  
Transcriptional Level ◽  
Plant Mirnas ◽  
Health Issues ◽  
Plant Mirna ◽  
Potential Applications

ABSTRACT microRNAs (miRNAs) are well known as major players in mammalian and plant genetic systems that act by regulating gene expression at the post-transcriptional level. These tiny molecules can regulate target genes (mRNAs) through either cleavage or translational inhibition. Recently, the discovery of plant-derived miRNAs showing cross-kingdom abilities to regulate mammalian gene expression has prompted exciting discussions among researchers. After being acquired orally through the diet, plant miRNAs can survive in the digestive tract, enter the circulatory system, and regulate endogenous mRNAs. Here, we review current knowledge regarding the cross-kingdom mechanisms of plant miRNAs, related controversies, and potential applications of these miRNAs in dietary therapy, which will provide new insights for plant miRNA investigations related to health issues in humans.

scholarly journals Evaluation of Plant-Derived Promoters for Constitutive and Tissue-Specific Gene Expression in Potato

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1520
Author(s):  
Dmitry Miroshnichenko ◽  
Aleksey Firsov ◽  
Vadim Timerbaev ◽  
Oleg Kozlov ◽  
Anna Klementyeva ◽  
...  
Keyword(s):  
Gene Expression ◽  
Specific Activity ◽  
Expression Patterns ◽  
Camv 35S Promoter ◽  
35S Promoter ◽  
Specific Gene ◽  
Transcriptional Level ◽  
Promoter Strength ◽  
Tissue Specific ◽  
Camv 35S

Various plant-derived promoters can be used to regulate ectopic gene expression in potato. In the present study, four promoters derived from the potato genome have been characterized by the expression of identical cassettes carrying the fusion with the reporter β-glucuronidase (gusA) gene. The strengths of StUbi, StGBSS, StPat, and StLhca3 promoters were compared with the conventional constitutive CaMV 35S promoter in various organs (leaves, stems, roots, and tubers) of greenhouse-grown plants. The final amount of gene product was determined at the post-transcriptional level using histochemical analysis, fluorometric measurements, and Western blot analysis. The promoter strength comparison demonstrated that the StUbi promoter generally provided a higher level of constitutive β-glucuronidase accumulation than the viral CaMV 35S promoter. Although the StLhca3 promoter was predominantly expressed in a green tissue-specific manner (leaves and stems) while StGBSS and StPat mainly provided tuber-specific activity, a “promoter leakage” was also found. However, the degree of unspecific activity depended on the particular transgenic line and tissue. According to fluorometric data, the functional activity of promoters in leaves could be arranged as follows: StLhca3 > StUbi > CaMV 35S > StPat > StGBSS (from highest to lowest). In tubers, the higher expression was detected in transgenic plants expressing StPat-gusA fusion construct, and the strength order was as follows: StPat > StGBSS > StUbi > CaMV 35S > StLhca3. The observed differences between expression patterns are discussed considering the benefits and limitations for the usage of each promoter to regulate the expression of genes in a particular potato tissue.

scholarly journals The TEA Transcription Factor Tec1 Confers Promoter-Specific Gene Regulation by Ste12-Dependent and -Independent Mechanisms

2010 ◽  
Vol 9 (4) ◽  
pp. 514-531 ◽  
Author(s):  
Barbara Heise ◽  
Julia van der Felden ◽  
Sandra Kern ◽  
Mario Malcher ◽  
Stefan Brückner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcriptional Activation ◽  
Binding Sites ◽  
Target Genes ◽  
Specific Gene ◽  
Dependent Manner ◽  
A Genome ◽  
Regulated Gene Expression

ABSTRACT In Saccharomyces cerevisiae, the TEA transcription factor Tec1 is known to regulate target genes together with a second transcription factor, Ste12. Tec1-Ste12 complexes can activate transcription through Tec1 binding sites (TCSs), which can be further combined with Ste12 binding sites (PREs) for cooperative DNA binding. However, previous studies have hinted that Tec1 might regulate transcription also without Ste12. Here, we show that in vivo, physiological amounts of Tec1 are sufficient to stimulate TCS-mediated gene expression and transcription of the FLO11 gene in the absence of Ste12. In vitro, Tec1 is able to bind TCS elements with high affinity and specificity without Ste12. Furthermore, Tec1 contains a C-terminal transcriptional activation domain that confers Ste12-independent activation of TCS-regulated gene expression. On a genome-wide scale, we identified 302 Tec1 target genes that constitute two distinct classes. A first class of 254 genes is regulated by Tec1 in a Ste12-dependent manner and is enriched for genes that are bound by Tec1 and Ste12 in vivo. In contrast, a second class of 48 genes can be regulated by Tec1 independently of Ste12 and is enriched for genes that are bound by the stress transcription factors Yap6, Nrg1, Cin5, Skn7, Hsf1, and Msn4. Finally, we find that combinatorial control by Tec1-Ste12 complexes stabilizes Tec1 against degradation. Our study suggests that Tec1 is able to regulate TCS-mediated gene expression by Ste12-dependent and Ste12-independent mechanisms that enable promoter-specific transcriptional control.

scholarly journals Beyond the ENCODE project: using genomics and epigenomics strategies to study enhancer evolution

2013 ◽  
Vol 368 (1632) ◽  
pp. 20130022 ◽  
Author(s):  
Noboru Jo Sakabe ◽  
Marcelo A. Nobrega
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Expression Patterns ◽  
Dna Interaction ◽  
Regulatory Elements ◽  
Specific Gene ◽  
Genome Wide ◽  
Identify Transcription Factor ◽  
Specific Proteins ◽  
Species Specific

The complex expression patterns observed for many genes are often regulated by distal transcription enhancers. Changes in the nucleotide sequences of enhancers may therefore lead to changes in gene expression, representing a central mechanism by which organisms evolve. With the development of the experimental technique of chromatin immunoprecipitation (ChIP), in which discrete regions of the genome bound by specific proteins can be identified, it is now possible to identify transcription factor binding events (putative cis -regulatory elements) in entire genomes. Comparing protein–DNA binding maps allows us, for the first time, to attempt to identify regulatory differences and infer global patterns of change in gene expression across species. Here, we review studies that used genome-wide ChIP to study the evolution of enhancers. The trend is one of high divergence of cis -regulatory elements between species, possibly compensated by extensive creation and loss of regulatory elements and rewiring of their target genes. We speculate on the meaning of the differences observed and discuss that although ChIP experiments identify the biochemical event of protein–DNA interaction, it cannot determine whether the event results in a biological function, and therefore more studies are required to establish the effect of divergence of binding events on species-specific gene expression.

scholarly journals Epigenetic regulation of neural cell differentiation plasticity in the adult mammalian brain

2008 ◽  
Vol 105 (46) ◽  
pp. 18012-18017 ◽  
Author(s):  
Jun Kohyama ◽  
Takuro Kojima ◽  
Eriko Takatsuka ◽  
Toru Yamashita ◽  
Jun Namiki ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Epigenetic Modification ◽  
Mammalian Brain ◽  
Cytokine Signaling ◽  
Specific Gene ◽  
Neural Cells ◽  
Specific Gene Expression

Neural stem/progenitor cells (NSCs/NPCs) give rise to neurons, astrocytes, and oligodendrocytes. It has become apparent that intracellular epigenetic modification including DNA methylation, in concert with extracellular cues such as cytokine signaling, is deeply involved in fate specification of NSCs/NPCs by defining cell-type specific gene expression. However, it is still unclear how differentiated neural cells retain their specific attributes by repressing cellular properties characteristic of other lineages. In previous work we have shown that methyl-CpG binding protein transcriptional repressors (MBDs), which are expressed predominantly in neurons in the central nervous system, inhibit astrocyte-specific gene expression by binding to highly methylated regions of their target genes. Here we report that oligodendrocytes, which do not express MBDs, can transdifferentiate into astrocytes both in vitro (cytokine stimulation) and in vivo (ischemic injury) through the activation of the JAK/STAT signaling pathway. These findings suggest that differentiation plasticity in neural cells is regulated by cell-intrinsic epigenetic mechanisms in collaboration with ambient cell-extrinsic cues.

scholarly journals Carbohydrate Response Element Binding Protein Gene Expression Is Positively Regulated by Thyroid Hormone

Endocrinology ◽  
2009 ◽  
Vol 150 (7) ◽  
pp. 3417-3424 ◽  
Author(s):  
Koshi Hashimoto ◽  
Emi Ishida ◽  
Shunichi Matsumoto ◽  
Shuichi Okada ◽  
Masanobu Yamada ◽  
...  
Keyword(s):  
Gene Expression ◽  
Thyroid Hormone ◽  
Target Genes ◽  
Binding Protein ◽  
Gene Promoter ◽  
Direct Repeat ◽  
Transcriptional Level ◽  
Hepatic Lipogenesis ◽  
Response Element ◽  
Element Binding Protein

The molecular mechanism of thyroid hormone (TH) effects to fatty acid metabolism in liver is yet to be clear. The carbohydrate response element-binding protein (ChREBP) as well as sterol response element-binding protein (SREBP)-1c plays a pivotal role in hepatic lipogenesis. Both SREBP-1c and ChREBP are target genes of liver X receptors (LXRs). Because LXRs and TH receptors (TRs) cross talk mutually in many aspects of transcription, we examined whether TRs regulate the mouse ChREBP gene expression. In the current study, we demonstrated that TH up-regulated mouse ChREBP mRNA and protein expression in liver. Run-on and luciferase assays showed that TH and TR-β1 positively regulated the ChREBP gene transcription. The mouse ChREBP gene promoter contains two direct repeat-4 sites (LXRE1 and LXRE2) and EMSAs demonstrated that LXR-α and TR-β1 prefer to bind LXRE1 and LXRE2, respectively. The direct repeat-4 deletion and LXRE2 mutants of the promoter deteriorate the positive regulation by TR-β1, indicating that LXRE2 is functionally important for the regulation. We also showed that human ChREBP gene expression and promoter activities were up-regulated by TH. These data suggest that ChREBP mRNA expression is positively regulated by TR-β1 and TH at the transcriptional level in mammals. This novel observation indicates that TH fine-tunes hepatic lipogenesis via regulating SREBP-1c and ChREBP gene expression reciprocally.

scholarly journals MED14 and MED1 Differentially Regulate Target-Specific Gene Activation by the Glucocorticoid Receptor

2006 ◽  
Vol 20 (3) ◽  
pp. 560-572 ◽  
Author(s):  
Weiwei Chen ◽  
Inez Rogatsky ◽  
Michael J. Garabedian
Keyword(s):  
Glucocorticoid Receptor ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Leucine Zipper ◽  
Target Genes ◽  
Gene Activation ◽  
Specific Gene ◽  
Small Interfering Rnas ◽  
Mrna Induction ◽  
Specific Regulation

Abstract The Mediator subunits MED14 and MED1 have been implicated in transcriptional regulation by the glucocorticoid receptor (GR) by acting through its activation functions 1 and 2. To understand the contribution of these Mediator subunits to GR gene-specific regulation, we reduced the levels of MED14 and MED1 using small interfering RNAs in U2OS-hGR osteosarcoma cells and examined the mRNA induction by dexamethasone of four primary GR target genes, interferon regulatory factor 8 (IRF8), ladinin 1, IGF-binding protein 1 (IGFBP1), and glucocorticoid-inducible leucine zipper (GILZ). We found that the GR target genes differed in their requirements for MED1 and MED14. GR-dependent mRNA expression of ladinin 1 and IRF8 required both MED1 and MED14, whereas induction of IGFBP1 mRNA by the receptor was dependent upon MED14, but not MED1. In contrast, GILZ induction by GR was largely independent of MED1 and MED14, but required the p160 cofactor transcriptional intermediary factor 2. Interestingly, we observed higher GR occupancy at GILZ than at the IGFBP1 or IRF8 glucocorticoid response element (GREs). In contrast, recruitment of MED14 compared with GR at IGFBP1 and IRF8 was higher than that observed at GILZ. At GILZ, GR and RNA polymerase II were recruited to both the GRE and the promoter, whereas at IGFBP1, RNA polymerase II occupied the promoter, but not the GRE. Thus, MED14 and MED1 are used by GR in a gene-specific manner, and the requirement for the Mediator at GILZ may be bypassed by increased GR and RNA polymerase II occupancy at the GREs. Our findings suggest that modulation of the Mediator subunit activities would provide a mechanism for promoter selectivity by GR.

scholarly journals Growth-Rate Dependent And Nutrient-Specific Gene Expression Resource Allocation In Fission Yeast

2021 ◽  
Author(s):  
Istvan T. Kleijn ◽  
Amalia Martínez-Segura ◽  
François Bertaux ◽  
Malika Saint ◽  
Holger Kramer ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Rate ◽  
Resource Allocation ◽  
Fission Yeast ◽  
Metabolic Enzymes ◽  
Specific Gene ◽  
Specific Gene Expression ◽  
Rate Dependent ◽  
Specific Regulation ◽  
Yeast Genes

Cellular resources are limited and their relative allocation to gene expression programmes determines physiological states and global properties such as the growth rate. Quantitative studies using various growth conditions have singled out growth rate as a major physiological variable explaining relative protein abundances. Here, we used the simple eukaryote Schizosaccharomyces pombe to determine the importance of growth rate in explaining relative changes in protein and mRNA levels during growth on a series of non-limiting nitrogen sources. Although half of fission yeast genes were significantly correlated with the growth rate, this came alongside wide-spread nutrient-specific regulation. Proteome and transcriptome often showed coordinated regulation but with notable exceptions, such as metabolic enzymes. Genes positively correlated with growth rate participated in every level of protein production with the notable exception of RNA polymerase II, whereas those negatively correlated mainly belonged to the environmental stress response programme. Critically, metabolic enzymes, which represent ~55-70% of the proteome by mass, showed mainly condition-specific regulation. Specifically, many enzymes involved in glycolysis and NAD-dependent metabolism as well as the fermentative and respiratory pathways were condition-dependent and not consistently correlated with growth. In summary, we provide a rich account of resource allocation to gene expression in a simple eukaryote, advancing our basic understanding of the interplay between growth-rate dependent and nutrient-specific gene expression.

scholarly journals Bio Immune(G)ene Medicine and the Use of miRNAs to Regulate the Cell

2018 ◽  
Vol 1 (2) ◽  
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Allergic Diseases ◽  
Degradation Process ◽  
Transcriptional Level ◽  
Collateral Damage ◽  
Rna Molecules ◽  
The Past ◽  
Needed Information ◽  
Non Coding Rna

MicroRNAs (miRNAs or miRs) are a type of non-coding RNA molecules that regulate the gene expression in a negative way, by downregulating the gene expression mainly at the post-transcriptional level, either by the mRNA degradation process or the inhibition of the translation. The role that many miRNAs play in the pathogenesis of several diseases is well known, such as in the inflammation process, in several steps of the oncogenesis or the metabolism of several virus and bacteria among many others. One of the main limitations in the therapeutic use of miRNAs is the ability to reach the target, as well as doing so without causing any collateral damage. One microRNA can indeed regulate up to 200 target-genes, and one gene can be influenced by a lot of different microRNAs. This is the purpose of the Bio Immune(G)ene Medicine: to achieve the cell without harm, use all the molecular resources available, especially epigenetic with the microRNAs, and to restore the cell homeostasis. The Bio Immune(G)ene Medicine only seeks to play a regulatory biomimetic role, to give the cell the needed information for its own right regulation. Our experience in cell regulation for the past few years has shown the way to fight, for instance, against the deleterious effects of viruses or bacteria in the lymphocytes, also at the background of many autoimmune or allergic diseases, as well as to regulate many other pathological processes. To fulfil this purpose, nanobiotechnology is used to reach the targets; we thus introduce very low doses of miRNAs in nano compounds with the aim to promote the regulation of the main signalling pathways disturbed in a given pathology.

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