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The present paper investigated the electrochemical behaviour of Schiff base and its zinc complex at a working electrode by cyclic voltammetry technique. In the phosphate and Britton-Robinson buffers, the electrochemical study of Schiff base was performed within various pH values 5-9. Cyclic voltammograms of the examined Schiff base exhibited irreversible and diffusion controlled waves at different sweep rates, which is associated with the two electron reduction process of azomethine group. The symmetry transfer coefficient (αn), the diffusion coefficient (D01/2) and rate constant (k°f,h) of the reactant species were calculated. Cyclic voltammetric study of zinc complex showed one electron diffusion controlled, quasi-reversible peaks at 50-250 mV/s sweep rates. Antimicrobial study of zinc complex showed that zinc complex found to be more potent than uncoordinated Schiff base.

Dysregulation of lipid metabolism is associated with cardiovascular/metabolic diseases, including atherosclerosis, liver diseases and type 2 diabetes mellitus (T2DM). Several miRNAs have been reported as regulators of different stages of lipid homeostasis, including cholesterol/fatty acid biosynthesis, degradation, transport, storage, and low-density (LDL) and high-density lipoprotein (HDL) formation. Indeed, various miRNAs are emerging as attractive therapeutic candidates for metabolic/cardiovascular disease (CVD). Here, we summarize the roles of miR-19b, miR-20a, miR-21, miR-27, miR-29, miR-34a, miR-144, miR-148a, and miR-199a in post-transcriptional regulation of genes involved in lipid homeostasis and their therapeutic potential. We also discuss experimental strategies for further development of these miRNAs as novel cardiometabolic therapeutics.

3-Hydroxy-3-methyl glutaryl-coenzyme A reductase (Hmgcr) encodes the rate-limiting enzyme in the cholesterol biosynthesis pathway. The regulation of Hmgcr in rat models of genetic hypertension (viz. Spontaneously Hypertensive Rat [SHR] and its normotensive control Wistar/Kyoto [WKY] strain) is unclear. Interestingly, Hmgcr transcript and protein levels are diminished in liver tissues of SHR as compared to WKY. This observation is consistent with the diminished plasma cholesterol level in SHR animals. However, the molecular basis of these apparently counter-intuitive findings remains completely unknown. Sequencing of the Hmgcr promoter in SHR and WKY strains reveals three variations: A-405G, C-62T and a 11 bp insertion (‐398_-388insTGCGGTCCTCC) in SHR. Among these variations, A-405G occurs at an evolutionarily-conserved site among many mammals. Moreover, SHR-Hmgcr promoter displays lower activity than WKY-Hmgcr promoter in various cell lines. Transient transfections of Hmgcr-promoter mutants and in silico analysis suggest altered binding of Runx3 and Srebf1 across A-405G site. On the other hand, C-62T and -398_-388insTGCGGTCCTCC variations do not appear to contribute to the reduced Hmgcr promoter activity in SHR as compared to WKY. Indeed, chromatin immunoprecipitation assays confirm differential binding of Runx3 and Srebf1 to Hmgcr promoter leading to reduced expression of Hmgcr in SHR as compared to WKY under basal as well as cholesterol-modulated conditions. Taken together, this study provides, for the first time, molecular basis for diminished Hmgcr expression in SHR animals, which may account for the reduced circulating cholesterol level in this widely-studied model for cardiovascular diseases.

Laser printers and writing instruments are being exploited by the forgers to produce fabricated documents. They often produce such documents by appending genuine signature on a blank sheet and later printing on it. Often these fabricated documents do not contain intersection of strokes and may pose a difficulty to forensic document examiners in analyzing cases related to such documents. Keeping in mind the limited research work done on nonintersecting strokes, the present study has been conducted with an aim to determine the sequence of nonintersecting strokes of gel pens and laser printers. Three hundred samples of nonintersecting strokes of gel pen ink and laser printing were prepared. Of these 300, 150 had laser-printed text below the gel pen strokes and the remaining 150 were prepared with gel pen stokes below the laser-printed text. The samples have been analyzed using Nikon SMZ 800N stereomicroscope. Three micro-conformation features, that is, pattern of toner distribution, ink distribution, and fiber distribution have been observed in the samples. The results demonstrate the successful establishment of sequence of nonintersecting strokes in case of gel pen and laser-printed documents by the determination of micro-conformation features.

Durability is one of the primary concern in new buildings and also for the old existing infrastructures. This paper deals with the durability properties of concrete containing sandstone slurry as a filler material. A significant quantity of sandstone slurry gets deposited, and their disposal problem becomes acuter. In order to utilize these wastes and to practice a sustainable construction, the ultimate solution is to use these types of sandstone slurry in concrete. Since durability plays an enormous role in maintaining the infrastructure for years, various tests such as compressive strength, flexural strength, water absorption, sulfate attack, acid attack, carbonation, DIN-Permeability, sorptivity are done to get the durability of the sandstone slurry mix in concrete. This paper presents the result of experimental research to examine the suitability of sandstone slurry as a partial replacement of total aggregates in cement concrete. It was observed that up to a certain level of substitution, compressive and flexural strength show a comparable result to that of control concrete. Also, it shows a good result with a controlled replacement towards acid-attack as well as sulfate attack and are equivalent to that of Portland cement concrete. Similar effect were also observed towards carbonation and permeability. From the results, it can be said that there is a promising future for the use of sandstone slurry as a partial replacement of total aggregate, which can lead to more significant environmental and sustainable benefits.

Concrete production has a lot of environmental impacts causing damage to the most fertile layer of the earth. Cement industry often uses unethical methods in obtaining resources by breaking river stones from the most alluring areas of the world for the production of cement concrete. Due to various environmental hazards associated with cement concrete production industries, most of the government re-forces and subsides the use of cement and also encourages to find a sustainable replacement material for the manufacture of cement concrete. Sandstones are a type of sedimentary rock which is composed of silt-sized minerals, rock grains and clay components. Some of the minerals like quartz and feldspar are the most occurred in earth surface and are found in sandstones. Since sandstones are highly porous when compared to magmatic rocks, they allow water to percolate and form aquifers and petroleum reservoirs. Even though sandstones were widely used in historical constructions around the globe, at present the use of such sedimentary rocks are not traditional in the field of building technology. There are many types of sandstones occurring in earth's surface and can be classified based on their elemental composition, clay content and sometimes based on their colour. Also, mining and quarrying generate a lot of these sandstone wastes which leads to excessive dumping without any utilisation. Although sandstones are a weaker type of aggregates that can be used in concrete, some of the studies have utilised them efficiently depending on the output needed for the use of such sedimentary materials. This paper presents the overview on the possible use of sandstones in cement concrete and some of the properties of such concrete in fresh and hardened states. Studies indicate that there is a promising future for the use of some selected sandstones in the production of cement concrete. The summary and information provided in this paper would provide new information and knowledge on the sustainable use of sandstone and its wastes for a greener concrete production.

Despite the well-known role of cystathionine γ-lyase (Cth) in cardiovascular pathophysiology, transcriptional regulation of Cth remains incompletely understood. Sequencing of the Cth promoter region in mouse models of genetic/essential hypertension (viz. Blood Pressure High [BPH], Blood Pressure Low [BPL] and Blood Pressure Normal [BPN] mice) identified several genetic variations. Transient transfections of BPH/BPL-Cth promoter-reporter plasmids into various cell types revealed higher promoter activity of BPL-Cth than that of BPH-Cth. Corroboratively, endogenous Cth mRNA levels in kidney and liver tissues were also elevated in BPL mice. Computational analysis of the polymorphic Cth promoter region predicted differential binding affinity of c-Rel, HOXA3 and IRF1 with BPL/BPH-Cth promoter domains. Over-expression of c-Rel/HOXA3/IRF1 modulated BPL/BPH-Cth promoter activities in a consistent manner. Gel shift assays using BPH/BPL-Cth-promoter oligonucleotides with/without binding sites for c-Rel/HOXA3/IRF1 displayed formation of specific complexes with c-Rel/HOXA3/IRF1; addition of antibodies to reaction mixtures resulted in supershifts/inhibition of Cth promoter-transcription factor complexes. Furthermore, chromatin immunoprecipitation (ChIP) assays proved differential binding of c-Rel, HOXA3 and IRF1 with the polymorphic promoter region of BPL/BPH-Cth. Tumor necrosis factor-α (TNF-α) reduced the activities of BPL/BPH-Cth promoters to different extents that were further declined by ectopic expression of IRF1; on the other hand, siRNA-mediated down-regulation of IRF1 rescued the TNF-α-mediated suppression of the BPL/BPH-Cth promoter activities. In corroboration, ChIP analysis revealed enhanced binding of IRF1 with BPH/BPL-Cth promoter following TNF-α treatment. BPL/BPH-Cth promoter activity was diminished upon exposure of hepatocytes and cardiomyoblasts to ischemia-like pathological condition due to reduced binding of c-Rel with BPL/BPH-Cth-promoter. Taken together, this study reveals the molecular basis for the differential expression of Cth in mouse models of essential hypertension under basal and pathophysiological conditions.

The comparative reaction efficiencies of currently used nucleophilic and electrophilic probes towards cysteine sulfenic acid have been thoroughly evaluated in two different settings – (i) a small molecule dipeptide based model and, (ii) a recombinant protein model. We further evaluated the stability of corresponding thioether and sulfoxide adducts under reducing conditions which are commonly encountered during proteomic protocols and in cell analysis. Powered by the development of new cyclic and linear C-nucleophiles, the unsurpassed efficiency in the capture of sulfenic acid under competitive conditions is achieved and thus holds great promise as highly potent tools for activity-based sulfenome profiling.

Concerns about off-target effects has motivated the development of reversible covalent inhibition strategies for targeting cysteine. However, such strategies have not been reported for the unique cysteine oxoform, sulfenic acid. Herein, we have designed and identified linear C-nucleophiles that react selectively with cysteine sulfenic acid. The resulting thioether adducts exhibit reversibility ranging from minutes to days under reducing conditions, showing the feasibility of tuning C-nucleophile reactivity across a wide range of time scales.

Oxidation of a protein cysteine thiol to sulfenic acid, termed S-sulfenylation, is a reversible post-translational modification that plays a crucial role in regulating protein function and is correlated with disease states. The majority of reaction-based small molecule and immunochemical probes used for detecting sulfenic acids are based on the 5,5-dimethyl-1,3-cyclohexanedione (dimedone) scaffold, which is selective, but suffers from low reactivity. In addition, mechanistic details and features that diminish or enhance nucleophile reactivity remain largely unknown. A significant hurdle to resolving the aforementioned issues has been the chemically unstable nature of small-molecule sulfenic acid models. Herein, we report a facile mass spectrometry-based assay and repurposed dipeptide-based model to screen a library of cyclic C-nucleophiles for reactivity with sulfenic acid under aqueous conditions. Observed rate constants for ~100 cyclic C-nucleophiles were obtained and, from this collection, we have identified novel compounds with more than 200-fold enhanced reactivity, as compared to dimedone. The increase in reactivity and retention of selectivity of these C-nucleophiles were validated in secondary assays, including a protein model for sulfenic acid. Together, this work represents a significant step toward developing new chemical reporters for detecting protein S-sulfenylation with superior kinetic resolution. The enhanced rates and varied composition of the C-nucleophiles should enable more comprehensive analyses of the sulfenome and serve as the foundation for reversible or irreversible nucleophilic covalent inhibitors that target oxidized cysteine residues in therapeutically important proteins.

Elevated expression of matrix metalloproteinase7 (MMP7) has been demonstrated to play a pivotal role in cancer invasion. The -181A→G (rs11568818) polymorphism in the MMP7 promoter modulates gene expression and possibly affects cancer progression. Here, we evaluated the impact of -181A→G polymorphism on MMP7 promoter activity and its association with gastric cancer risk in eastern Indian case-control cohorts (n = 520). The GG genotype as compared with the AA genotype was predisposed (p = 0.02; odds ratio = 1.9, 95% confidence interval = 1.1-3.3) to gastric cancer risk. Stratification analysis showed that tobacco addiction enhanced gastric cancer risk in GG subjects when compared with AA subjects (p = 0.03, odds ratio = 2.46, and 95% confidence interval = 1.07-5.68). Meta-analysis revealed that tobacco enhanced the risk for cancer more markedly in AG and GG carriers. Activity and expression of MMP7 were significantly higher in GG than in AA carriers. In support, MMP7 promoter-reporter assays showed greater transcriptional activity toward A to G transition under basal/nicotine-induced/cAMP-response element-binding protein (CREB) overexpressed conditions in gastric adenocarcinoma cells. Moreover, nicotine (a major component of tobacco) treatment significantly up-regulated MMP7 expression due to enhanced CREB phosphorylation followed by its nuclear translocation in gastric adenocarcinoma cells. Furthermore, chromatin immunoprecipitation experiments revealed higher binding of phosphorylated CREB with the -181G than the -181A allele. Altogether, specific binding of phosphorylated CREB to the G allele-carrying promoter enhances MMP7 gene expression that is further augmented by nicotine due to increased CREB phosphorylation and thereby increases the risk for gastric cancer.

Monoamine oxidase A (MAOA) plays important roles in the pathogenesis of several neurological and cardiovascular disorders. The mechanism of transcriptional regulation of MAOA under basal and pathological conditions, however, remains incompletely understood. Here, we report systematic identification and characterization of cis elements and transcription factors that govern the expression of MAOA gene. Extensive computational analysis of MAOA promoter, followed by 5?-promoter deletion/reporter assays, revealed that the -71/-40 bp domain was sufficient for its basal transcription. Gel-shift and chromatin immunoprecipitation assays provided evidence of interactions of the transcription factors GATA-binding protein 2 (GATA2), Sp1 and TATA-binding protein (TBP) with this proximal promoter region. Consistently, over-expression of GATA2, Sp1 and TBP augmented MAOA promoter activity in a coordinated manner. In corroboration, siRNA-mediated down-regulation of GATA2/Sp1/TBP repressed the endogenous MAOA expression as well as transfected MAOA promoter activity. Tumor necrosis factor-? and forskolin activated MAOA transcription that was reversed by Sp1 siRNA, in support, tumor necrosis factor-?- and forskolin-induced activities were enhanced by ectopic over-expression of Sp1. On the other hand, MAOA transcription was diminished upon exposure of neuroblasts or cardiac myoblasts to ischemia-like conditions because of reduced binding of GATA2/Sp1/TBP with MAOA promoter. In conclusion, this study revealed previously unknown roles of GATA2, Sp1 and TBP in modulating MAOA expression under basal as well as pathophysiological conditions such as inflammation and ischemia, thus providing new insights into the molecular basis of aberrant MAOA expression in neuronal/cardiovascular disease states. � 2015 International Society for Neurochemistry.

Targeted covalent inhibitors have emerged as a powerful approach in the drug discovery pipeline. Key to this process is the identification of signaling pathways (or receptors) specific to (or overexpressed in) disease cells. In this context, fragment-based ligand discovery (FBLD) has significantly expanded our view of the ligandable proteome and affords tool compounds for biological inquiry. To date, such covalent ligand discovery has almost exclusively employed cysteine-reactive small-molecule fragments. However, functional cysteine residues in proteins are often redox-sensitive and can undergo oxidation in cells. Such reactions are particularly relevant in diseases, like cancer, which are linked to excessive production of reactive oxygen species. Once oxidized, the sulfur atom of cysteine is much less reactive toward electrophilic groups used in the traditional FBLD paradigm. To address this limitation, we recently developed a novel library of diverse carbon-based nucleophile fragments that react selectively with cysteine sulfenic acid formed in proteins via oxidation or hydrolysis reactions. Here, we report analysis of sulfenic acid-reactive C-nucleophile fragments screened against a colon cancer cell proteome. Covalent ligands were identified for >1280 S-sulfenylated cysteines present in “druggable” proteins and orphan targets, revealing disparate reactivity profiles and target preferences. Among the unique ligand–protein interactions identified was that of a pyrrolidinedione nucleophile that reacted preferentially with protein tyrosine phosphatases. Fragment-based covalent ligand discovery with C-nucleophiles affords an expansive snapshot of the ligandable “redoxome” with significant implications for covalent inhibitor pharmacology and also affords new chemical tools to investigate redox-regulation of protein function.

Renalase, a novel monoamine oxidase, is emerging as an important regulator of cardiovascular, metabolic, and renal diseases. However, the mechanism of transcriptional regulation of this enzyme remains largely unknown. We undertook a systematic analysis of the renalase gene to identify regulatory promoter elements and transcription factors. Computational analysis coupled with transfection of human renalase promoter/luciferase reporter plasmids (5?-promoter-deletion constructs) into various cell types (HEK-293, IMR32, and HepG2) identified two crucial promoter domains at base pairs -485 to -399 and -252 to -150. Electrophoretic mobility shift assays using renalase promoter oligonucleotides with and without potential binding sites for transcription factors Sp1, STAT3, and ZBP89 displayed formation of specific complexes with HEK-293 nuclear proteins. Consistently, overexpression of Sp1, STAT3, and ZBP89 augmented renalase promoter activity; additionally, siRNA-mediated downregulation of Sp1, STAT3, and ZBP89 reduced the level of endogenous renalase transcription as well as the transfected renalase promoter activity. In addition, chromatin immunoprecipitation assays showed in vivo interactions of these transcription factors with renalase promoter. Interestingly, renalase promoter activity was augmented by nicotine and catecholamines; while Sp1 and STAT3 synergistically activated the nicotine-induced effect, Sp1 appeared to enhance epinephrine-evoked renalase transcription. Moreover, renalase transcript levels in mouse models of human essential hypertension were concomitantly associated with endogenous STAT3 and ZBP89 levels, suggesting crucial roles for these transcription factors in regulating renalase gene expression in cardiovascular pathological conditions. � 2014 American Chemical Society.

Owing to its labile nature, a new role for cysteine sulfenic acid (-SOH) modification has emerged. This oxidative modification modulates protein function by acting as a redox switch during cellular signaling. The identification of proteins that undergo this modification represents a methodological challenge, and its resolution remains a matter of current interest. The development of strategies to chemically modify cysteinyl-containing peptides for LC-MS/MS analysis has increased significantly within the past decade. The method of choice to selectively label sulfenic acid is based on the use of dimedone or its derivatives. For these chemical probes to be effective on a proteome-wide level, their reactivity toward -SOH must be high to ensure reaction completion. In addition, the presence of an adduct should not interfere with electrospray ionization, the efficiency of induced dissociation in MS/MS experiments, or with identification of Cys-modified peptides by automated database searching algorithms. Herein, we employ a targeted proteomics approach to study the electrospray ionization and fragmentation effects of different –SOH specific probes, and compared them to commonly used alkylating agents. We then extend our study to a whole proteome extract using shotgun proteomic approaches. These experiments enable us to demonstrate that dimedone adducts do not interfere with electrospray by suppressing the ionization nor impedes product ion assignment by automated search engines, which detect a + 138 Da increase from unmodified peptides. Collectively, these results suggest dimedone can be a powerful tool to identify sulfenic acid modifications by high-throughput shotgun proteomics of a whole proteome.

Background Reactive oxygen species-mediated cysteine sulfenic acid modification has emerged as an important regulatory mechanism in cell signaling. The stability of sulfenic acid in proteins is dictated by the local microenvironment and ability of antioxidants to reduce this modification. Several techniques for detecting this cysteine modification have been developed, including direct and in situ methods. Scope of review This review presents a historical discussion of sulfenic acid chemistry and highlights key examples of this modification in proteins. A comprehensive survey of available detection techniques with advantages and limitations is discussed. Finally, issues pertaining to rates of sulfenic acid formation, reduction, and chemical trapping methods are also covered. Major conclusions Early chemical models of sulfenic acid yielded important insights into the unique reactivity of this species. Subsequent pioneering studies led to the characterization of sulfenic acid formation in proteins. In parallel, the discovery of oxidant-mediated cell signaling pathways and pathological oxidative stress has led to significant interest in methods to detect these modifications. Advanced methods allow for direct chemical trapping of protein sulfenic acids directly in cells and tissues. At the same time, many sulfenic acids are short-lived and the reactivity of current probes must be improved to sample these species, while at the same time, preserving their chemical selectivity. Inhibitors with binding scaffolds can be rationally designed to target sulfenic acid modifications in specific proteins. General significance Ever increasing roles for protein sulfenic acids have been uncovered in physiology and pathology. A more complete understanding of sulfenic acid-mediated regulatory mechanisms will continue to require rigorous and new chemical insights. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn.

Although the transcript level of inducible heat shock protein 70.3 (Hsp70.3, also known as Hspa1a) is altered in various disease states, its transcriptional regulation remains incompletely understood. Here, we systematically analyzed the Hspa1a promoter to identify major cis elements and transcription factors that may govern the constitutive/inducible gene expression. Computational analyses coupled with extensive in vitro (promoter-reporter activity and electrophoretic mobility shift assays) and in vivo (chromatin immunoprecipitation assays) revealed interaction of several transcription factors with Hspa1a promoter motifs: HSF-1 (heat shock factor 1) at - 114/- 97 bp and - 788/- 777 bp, NF-Y (nuclear transcription factor Y) at - 73/- 58 bp, NF-?B (nuclear factor kappa B) at - 133/- 124 bp, and CREB (cAMP response element binding protein) at - 483/- 476 bp. Consistently, siRNA (small interfering RNA)-mediated down-regulation of each of these transcription factors caused substantial reduction of endogenous Hspa1a expression. Heat-shock-induced activation of Hspa1a was coordinately regulated by HSF-1 and NF-Y/NF-?B. The Hspa1a expression was augmented by TNF-? (tumor necrosis factor-alpha) and forskolin in NF-?B and CREB-dependent manners, respectively. NF-?B and CREB also activated Hspa1a transcription in cardiac myoblasts upon exposure to ischemia-like conditions. Taken together, this study discovered previously unknown roles for NF-?B and CREB to regulate Hspa1a expression and a coordinated action by several transcription factors for Hspa1a transactivation under heat-shock/ischemia-like conditions and thereby provided new insights into the mechanism of Hspa1a regulation. � 2013 Elsevier Ltd.

2,3-Diarylbenzofurans are efficiently generated by the cyclization of ortho-benzyloxybenzophenones using the hindered phosphazene base P 4 - t -Bu.

Language is a medium through which any individual can express his ideas or thoughts to others hence it is a way of communication. Forensic Linguistics is the application of the knowledge of the science of linguistics for the court of law. It comprises of various fields of language and linguistics and to apply them to help the law. In our research we have studied only few parameters like the time taken for the speaker to complete the sentence, its pitch, its intensity, time taken to spell certain words and the pause that a person gives between two sentences. There is a lot of similarity in the three recordings of the same sample. This shall be enough to say that the recordings are made by same person only. Though parameters needs to be studied to rule out the similarities and the differences but as this was a time bound project only these characters were feasible. The similarities can be identified without much effort. The time differences in recordings of same person are very minute which rounded off to the nearest zero. These results are inferred on the basis of linguistic analysis and spectrogram study and the conclusion was made.

Cysteine S-sulphenylation provides redox regulation of protein functions, but the global cellular impact of this transient post-translational modification remains unexplored. We describe a chemoproteomic workflow to map and quantify over 1,000 S-sulphenylation sites on more than 700 proteins in intact cells. Quantitative analysis of human cells stimulated with hydrogen peroxide or epidermal growth factor measured hundreds of site selective redox changes. Different cysteines in the same proteins displayed dramatic differences in susceptibility to S-sulphenylation. Newly discovered S-sulphenylations provided mechanistic support for proposed cysteine redox reactions and suggested novel redox mechanisms, including S-sulphenyl-mediated redox regulation of the transcription factor HIF1A by SIRT6. S-sulphenylation is favored at solvent-exposed protein surfaces and is associated with sequence motifs that are distinct from those for other thiol modifications. S-sulphenylations affect regulators of phosphorylation, acetylation and ubiquitylation, which suggest regulatory crosstalk between redox control and signalling pathways.

We describe a ribonucleic acid (RNA) reporter system for live-cell imaging of gene expression to detect changes in polymerase II activity on individual promoters in individual cells. The reporters use strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags) that can be expressed from a promoter of choice. For imaging, the cells are incubated with their ligands that are separately conjugated with one of the FRET pair, Cy3 and Cy5. The IMAGEtags were expressed in yeast from the GAL1, ADH1 or ACT1 promoters. Transcription from all three promoters was imaged in live cells and transcriptional increases from the GAL1 promoter were observed with time after adding galactose. Expression of the IMAGEtags did not affect cell proliferation or endogenous gene expression. Advantages of this method are that no foreign proteins are produced in the cells that could be toxic or otherwise influence the cellular response as they accumulate, the IMAGEtags are short lived and oxygen is not required to generate their signals. The IMAGEtag RNA reporter system provides a means of tracking changes in transcriptional activity in live cells and in real time.