scholarly journals Controlling gene expression with light: a multidisciplinary endeavour

2020 ◽  
Vol 48 (4) ◽  
pp. 1645-1659
Author(s):  
Denis Hartmann ◽  
Jefferson M. Smith ◽  
Giacomo Mazzotti ◽  
Razia Chowdhry ◽  
Michael J. Booth
Keyword(s):  
Gene Expression ◽  
Small Molecules ◽  
Cellular Damage ◽  
Biological Processes ◽  
Tissue Penetration ◽  
Spatiotemporal Resolution ◽  
Control Gene Expression ◽  
Diverse Field ◽  
Biological Methods

The expression of a gene to a protein is one of the most vital biological processes. The use of light to control biology offers unparalleled spatiotemporal resolution from an external, orthogonal signal. A variety of methods have been developed that use light to control the steps of transcription and translation of specific genes into proteins, for cell-free to in vivo biotechnology applications. These methods employ techniques ranging from the modification of small molecules, nucleic acids and proteins with photocages, to the engineering of proteins involved in gene expression using naturally light-sensitive proteins. Although the majority of currently available technologies employ ultraviolet light, there has been a recent increase in the use of functionalities that work at longer wavelengths of light, to minimise cellular damage and increase tissue penetration. Here, we discuss the different chemical and biological methods employed to control gene expression, while also highlighting the central themes and the most exciting applications within this diverse field.

scholarly journals Massively parallel in vivo CRISPR screening identifies RNF20/40 as epigenetic regulators of cardiomyocyte maturation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nathan J. VanDusen ◽  
Julianna Y. Lee ◽  
Weiliang Gu ◽  
Catalina E. Butler ◽  
Isha Sethi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genetic Screen ◽  
Forward Genetics ◽  
Epigenetic Mark ◽  
Biological Processes ◽  
Dynamic Changes ◽  
Forward Genetic Screen ◽  
High Resource ◽  
Organ Systems

AbstractThe forward genetic screen is a powerful, unbiased method to gain insights into biological processes, yet this approach has infrequently been used in vivo in mammals because of high resource demands. Here, we use in vivo somatic Cas9 mutagenesis to perform an in vivo forward genetic screen in mice to identify regulators of cardiomyocyte (CM) maturation, the coordinated changes in phenotype and gene expression that occur in neonatal CMs. We discover and validate a number of transcriptional regulators of this process. Among these are RNF20 and RNF40, which form a complex that monoubiquitinates H2B on lysine 120. Mechanistic studies indicate that this epigenetic mark controls dynamic changes in gene expression required for CM maturation. These insights into CM maturation will inform efforts in cardiac regenerative medicine. More broadly, our approach will enable unbiased forward genetics across mammalian organ systems.

scholarly journals Effects of Ubiquinol-10 on MicroRNA-146a Expression In Vitro and In Vivo

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Constance Schmelzer ◽  
Mitsuaki Kitano ◽  
Gerald Rimbach ◽  
Petra Niklowitz ◽  
Thomas Menke ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reactive Oxygen Species ◽  
Biological Processes ◽  
Oxygen Species ◽  
Moderate Reduction ◽  
Suppression Of Gene Expression ◽  
Fine Tune ◽  
Dependent Pathway

MicroRNAs (miRs) are involved in key biological processes via suppression of gene expression at posttranscriptional levels. According to their superior functions, subtle modulation of miR expression by certain compounds or nutrients is desirable under particular conditions. Bacterial lipopolysaccharide (LPS) induces a reactive oxygen species-/NF-κB-dependent pathway which increases the expression of the anti-inflammatory miR-146a. We hypothesized that this induction could be modulated by the antioxidant ubiquinol-10. Preincubation of human monocytic THP-1 cells with ubiquinol-10 reduced the LPS-induced expression level of miR-146a to 78.9±13.22%. In liver samples of mice injected with LPS, supplementation with ubiquinol-10 leads to a reduction of LPS-induced miR-146a expression to 78.12±21.25%. From these consistent in vitro and in vivo data, we conclude that ubiquinol-10 may fine-tune the inflammatory response via moderate reduction of miR-146a expression.

scholarly journals Increased Expression of CCN2 in the Red Flashing Light-Induced Myopia in Guinea Pigs

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hong Wang ◽  
Kang Zhuang ◽  
Lei Gao ◽  
Linna Zhang ◽  
Hongling Yang
Keyword(s):  
Gene Expression ◽  
Animal Model ◽  
Axial Length ◽  
Growth And Development ◽  
Visual Environment ◽  
Biological Processes ◽  
Cellular Functions ◽  
Ocular Growth ◽  
Flashing Light

Visual environment plays an important role in the occurrence of myopia. We previously showed that the different flashing lights could result in distinct effects on the ocular growth and development of myopia. CCN2 has been reported to regulate various cellular functions and biological processes. However, whether CCN2 signaling was involved in the red flashing light-induced myopia still remains unknown. In the present study, we investigated the effects of the red flashing lights exposure on the refraction and axial length of the eyesin vivoand then evaluated their effects on the expression of CCN2 and TGF-βin sclera tissues. Our data showed that the eyes exposed to the red flashing light became more myopic with a significant increase of the axial length and decrease of the refraction. Both CCN2 and TGF-β, as well as p38 MAPK and PI3K, were highly expressed in the sclera tissues exposed to the red flashing light. Both CCN2 and TGF-βwere found to have the same gene expression profilein vivo. In conclusion, our findings found that CCN2 signaling pathway plays an important role in the red flashing light-induced myopiain vivo. Moreover, our study establishes a useful animal model for experimental myopia research.

Engineered riboswitches control gene expression by small molecules

2005 ◽  
Vol 33 (3) ◽  
pp. 474-476 ◽  
Author(s):  
B. Suess
Keyword(s):  
Gene Expression ◽  
Small Molecules ◽  
Translational Control ◽  
Control Element ◽  
Structural Element ◽  
Conditional Gene Expression ◽  
Control Gene Expression ◽  
Communication Module ◽  
Ribosomal Binding Site ◽  
Form Addition

We have developed conditional gene expression systems based on engineered small-molecule-binding riboswitches. Tetracycline-dependent regulation can be imposed on an mRNA in yeast by inserting an aptamer in its 5′-untranslated region. Biochemical and genetic analyses determined that binding of the ligand tetracycline leads to a pseudoknot-like linkage within the aptamer structure, thereby inhibiting the initial steps of translation. A second translational control element was designed by combining a theophylline aptamer with a communication module for which a 1 nt slipping mechanism had been proposed. This structural element was inserted close to the bacterial ribosomal binding site at a position just interfering with translation in the non-ligand-bound form. Addition of the ligand then shifts the inhibitory element to a distance that permits efficient translation.

scholarly journals Overlapping and Unique Roles for C-Terminal Binding Protein 1 (CtBP1) and CtBP2 during Mouse Development

2002 ◽  
Vol 22 (15) ◽  
pp. 5296-5307 ◽  
Author(s):  
Jeffrey D. Hildebrand ◽  
Philippe Soriano
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Genetic Interaction ◽  
Binding Protein ◽  
Biological Processes ◽  
Vertebrate Development ◽  
Mouse Development ◽  
Axial Patterning ◽  
Wide Range

ABSTRACT The C-terminal binding protein (CtBP) family of proteins has been linked to multiple biological processes through their association with numerous transcription factors. We generated mice harboring mutations in both Ctbp1 and Ctbp2 to address the in vivo function of CtBPs during vertebrate development. Ctbp1 mutant mice are small but viable and fertile, whereas Ctbp2-null mice show defects in axial patterning and die by E10.5 due to aberrant extraembryonic development. Mice harboring various combinations of Ctbp1 and Ctbp2 mutant alleles exhibit dosage-sensitive defects in a wide range of developmental processes. The strong genetic interaction, as well as transcription assays with CtBP-deficient cells, indicates that CtBPs have overlapping roles in regulating gene expression. We suggest that the observed phenotypes reflect the large number of transcription factors whose activities are compromised in the absence of CtBP.

scholarly journals Enhancers predominantly regulate gene expression in vivo via transcription initiation

2019 ◽  
Author(s):  
Martin S. C. Larke ◽  
Takayuki Nojima ◽  
Jelena Telenius ◽  
Jacqueline A. Sharpe ◽  
Jacqueline A. Sloane-Stanley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
Genetically Engineered ◽  
Control Gene ◽  
Transcriptional Initiation ◽  
Pol Ii ◽  
Rna Molecules ◽  
Control Gene Expression

ABSTRACTGene transcription occurs via a cycle of linked events including initiation, promoter proximal pausing and elongation of RNA polymerase II (Pol II). A key question is how do transcriptional enhancers influence these events to control gene expression? Here we have used a new approach to quantify transcriptional initiation and pausing in vivo, while simultaneously identifying transcription start sites (TSSs) and pause-sites (TPSs) from single RNA molecules. When analyzed in parallel with nascent RNA-seq, these data show that differential gene expression is achieved predominantly via changes in transcription initiation rather than Pol II pausing. Using genetically engineered mouse models deleted for specific enhancers we show that these elements control gene expression via Pol II recruitment and/or initiation rather than via promoter proximal pause release. Together, our data show that enhancers, in general, control gene expression predominantly by Pol II recruitment and initiation rather than via pausing.

scholarly journals Engineering the smallest transcription factor: accelerated evolution of a 63-amino acid peptide dual activator-repressor

2019 ◽  
Author(s):  
Andreas K. Brödel ◽  
Rui Rodrigues ◽  
Alfonso Jaramillo ◽  
Mark Isalan
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Protein Gene ◽  
Control Gene ◽  
Bacteriophage Λ ◽  
Short Peptide ◽  
Amino Acid Peptide ◽  
Control Gene Expression ◽  
Accelerated Evolution

Transcription factors control gene expression in all life. This raises the question of what is the smallest protein that can support such activity. In nature, Cro from bacteriophage λ is the smallest known repressor (66 amino acids; a.a.) but activators are typically much larger (e.g. λ cI, 237 a.a.). Indeed, previous efforts to engineer a minimal activator from Cro resulted in no activity in vivo. In this study, we show that directed evolution results in a new Cro activator-repressor that functions as efficiently as λ cI, in vivo. To achieve this, we develop Phagemid-Assisted Continuous Evolution: PACEmid. We find that a peptide as small as 63-a.a. functions efficiently as an activator and/or repressor. To our knowledge, this is the smallest protein gene regulator reported to date, highlighting the capacity of transcription factors to evolve from very short peptide sequences.

scholarly journals Tissue Distribution of Doxycycline in Animal Models of Tuberculosis

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Martin Gengenbacher ◽  
Matthew D. Zimmerman ◽  
Jansy P. Sarathy ◽  
Firat Kaya ◽  
Han Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcriptional Control ◽  
Target Genes ◽  
Calcium Content ◽  
Tissue Penetration ◽  
Lung Lesions ◽  
Content Type ◽  
Clearance Kinetics

ABSTRACT Doxycycline, an FDA-approved tetracycline, is used in tuberculosis in vivo models for the temporal control of mycobacterial gene expression. In these models, animals are infected with recombinant Mycobacterium tuberculosis carrying genes of interest under transcriptional control of the doxycycline-responsive TetR-tetO unit. To minimize fluctuations of plasma levels, doxycycline is usually administered in the diet. However, tissue penetration studies to identify the minimum doxycycline content in food achieving complete repression of TetR-controlled genes in tuberculosis (TB)-infected organs and lesions have not been conducted. Here, we first determined the tetracycline concentrations required to achieve silencing of M. tuberculosis target genes in vitro. Next, we measured doxycycline concentrations in plasma, major organs, and lung lesions in TB-infected mice and rabbits and compared these values to silencing concentrations measured in vitro. We found that 2,000 ppm doxycycline supplemented in mouse and rabbit feed is sufficient to reach target concentrations in TB lesions. In rabbit chow, the calcium content had to be reduced 5-fold to minimize chelation of doxycycline and deliver adequate oral bioavailability. Clearance kinetics from major organs and lung lesions revealed that doxycycline levels fall below concentrations that repress tet promoters within 7 to 14 days after doxycycline is removed from the diet. In summary, we have shown that 2,000 ppm doxycycline supplemented in standard mouse diet and in low-calcium rabbit diet delivers concentrations adequate to achieve full repression of tet promoters in infected tissues of mice and rabbits.

Engineered riboswitches control gene expression by small molecules

2005 ◽  
Vol 2005 (Fall) ◽  
Author(s):  
Beatrix Suess ◽  
Shane Hanson ◽  
Michael Müller
Keyword(s):  
Gene Expression ◽  
Small Molecules ◽  
Control Gene ◽  
Control Gene Expression
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