scholarly journals Elucidating the Influence of Chromosomal Architecture on Transcriptional Regulation in Prokaryotes – Observing Strong Local Effects of Nucleoid Structure on Gene Regulation

2020 ◽  
Vol 11 ◽  
Author(s):  
Thøger Jensen Krogh ◽  
Andre Franke ◽  
Jakob Møller-Jensen ◽  
Christoph Kaleta
Keyword(s):  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Local Effects ◽  
Chromosomal Architecture ◽  
Nucleoid Structure

scholarly journals Unique Role of Caffeine Compared to Other Methylxanthines (Theobromine, Theophylline, Pentoxifylline, Propentofylline) in Regulation of AD Relevant Genes in Neuroblastoma SH-SY5Y Wild Type Cells

2020 ◽  
Vol 21 (23) ◽  
pp. 9015
Author(s):  
Daniel Janitschke ◽  
Anna A. Lauer ◽  
Cornel M. Bachmann ◽  
Martin Seyfried ◽  
Heike S. Grimm ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Expression Patterns ◽  
Wild Type ◽  
Neuronal Function ◽  
Purine Base ◽  
Unique Role ◽  
Beneficial Effects ◽  
Other Substances

Methylxanthines are a group of substances derived from the purine base xanthine with a methyl group at the nitrogen on position 3 and different residues at the nitrogen on position 1 and 7. They are widely consumed in nutrition and used as pharmaceuticals. Here we investigate the transcriptional regulation of 83 genes linked to Alzheimer’s disease in the presence of five methylxanthines, including the most prominent naturally occurring methylxanthines—caffeine, theophylline and theobromine—and the synthetic methylxanthines pentoxifylline and propentofylline. Methylxanthine-regulated genes were found in pathways involved in processes including oxidative stress, lipid homeostasis, signal transduction, transcriptional regulation, as well as pathways involved in neuronal function. Interestingly, multivariate analysis revealed different or inverse effects on gene regulation for caffeine compared to the other methylxanthines, which was further substantiated by multiple comparison analysis, pointing out a distinct role for caffeine in gene regulation. Our results not only underline the beneficial effects of methylxanthines in the regulation of genes in neuroblastoma wild-type cells linked to neurodegenerative diseases in general, but also demonstrate that individual methylxanthines like caffeine mediate unique or inverse expression patterns. This suggests that the replacement of single methylxanthines by others could result in unexpected effects, which could not be anticipated by the comparison to other substances in this substance class.

Collective behavior in gene regulation: Post-transcriptional regulation and the temporal compartmentalization of cellular cycles

FEBS Journal ◽  
2008 ◽  
Vol 275 (10) ◽  
pp. 2364-2371 ◽  
Author(s):  
Maria C. Palumbo ◽  
Lorenzo Farina ◽  
Alberto De Santis ◽  
Alessandro Giuliani ◽  
Alfredo Colosimo ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Collective Behavior ◽  
Post Transcriptional Regulation

scholarly journals Impact and evolutionary determinants of Neanderthal introgression on transcriptional and post-transcriptional regulation

2019 ◽  
Author(s):  
Martin Silvert ◽  
Lluis Quintana-Murci ◽  
Maxime Rotival
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Regulatory Elements ◽  
Strong Impact ◽  
Modern Humans ◽  
Archaic Admixture ◽  
Archaic Introgression ◽  
Post Transcriptional Regulation ◽  
The Impact

AbstractArchaic admixture is increasingly recognized as an important source of diversity in modern humans, with Neanderthal haplotypes covering 1-3% of the genome of present-day Eurasians. Recent work has shown that archaic introgression has contributed to human phenotypic diversity, mostly through the regulation of gene expression. Yet, the mechanisms through which archaic variants alter gene expression, and the forces driving the introgression landscape at regulatory regions remain elusive. Here, we explored the impact of archaic introgression on transcriptional and post-transcriptional regulation, focusing on promoters and enhancers across 127 different tissues as well as microRNA-mediated regulation. Although miRNAs themselves harbor few archaic variants, we found that some of these variants may have a strong impact on miRNA-mediated gene regulation. Enhancers were by far the regulatory elements most affected by archaic introgression, with one third of the tissues tested presenting significant enrichments. Specifically, we found strong enrichments of archaic variants in adipose-related tissues and primary T cells, even after accounting for various genomic and evolutionary confounders such as recombination rate and background selection. Interestingly, we identified signatures of adaptive introgression at enhancers of some key regulators of adipogenesis, raising the interesting hypothesis of a possible adaptation of early Eurasians to colder climates. Collectively, this study sheds new light onto the mechanisms through which archaic admixture have impacted gene regulation in Eurasians and, more generally, increases our understanding of the contribution of Neanderthals to the regulation of acquired immunity and adipose homeostasis in modern humans.

scholarly journals Enhancer sharing promotes neighborhoods of transcriptional regulation across eukaryotes

2016 ◽  
Author(s):  
Porfirio Quintero-Cadena ◽  
Paul W. Sternberg
Keyword(s):  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Genome Size ◽  
Protein Complexes ◽  
Regulatory Elements ◽  
Scaling Factor ◽  
Specific Interactions ◽  
Physical Proximity ◽  
Transcriptional Promoters

Enhancers physically interact with transcriptional promoters, looping over distances that can span multiple regulatory elements. Given that enhancer-promoter (EP) interactions generally occur via common protein complexes, it is unclear whether EP pairing is predominantly deterministic or proximity guided. Here we present cross-organismic evidence suggesting that most EP pairs are compatible, largely determined by physical proximity rather than specific interactions. By re-analyzing transcriptome datasets, we find that the transcription of gene neighbors is correlated over distances that scale with genome size. We experimentally show that non-specific EP interactions can explain such correlation, and that EP distance acts as a scaling factor for the transcriptional influence of an enhancer. We propose that enhancer sharing is commonplace among eukaryotes, and that EP distance is an important layer of information in gene regulation.

scholarly journals Enhancer Sharing Promotes Neighborhoods of Transcriptional Regulation Across Eukaryotes

2016 ◽  
Vol 6 (12) ◽  
pp. 4167-4174 ◽  
Author(s):  
Porfirio Quintero-Cadena ◽  
Paul W Sternberg
Keyword(s):  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Genome Size ◽  
Protein Complexes ◽  
Regulatory Elements ◽  
Scaling Factor ◽  
Specific Interactions ◽  
Physical Proximity ◽  
Transcriptional Promoters

Abstract Enhancers physically interact with transcriptional promoters, looping over distances that can span multiple regulatory elements. Given that enhancer–promoter (EP) interactions generally occur via common protein complexes, it is unclear whether EP pairing is predominantly deterministic or proximity guided. Here, we present cross-organismic evidence suggesting that most EP pairs are compatible, largely determined by physical proximity rather than specific interactions. By reanalyzing transcriptome datasets, we find that the transcription of gene neighbors is correlated over distances that scale with genome size. We experimentally show that nonspecific EP interactions can explain such correlation, and that EP distance acts as a scaling factor for the transcriptional influence of an enhancer. We propose that enhancer sharing is commonplace among eukaryotes, and that EP distance is an important layer of information in gene regulation.

Non-canonical functions of the DNA methylome in gene regulation

2013 ◽  
Vol 451 (1) ◽  
pp. 13-23 ◽  
Author(s):  
James P. Reddington ◽  
Sari Pennings ◽  
Richard R. Meehan
Keyword(s):  
Dna Methylation ◽  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Polycomb Group ◽  
Epigenetic Mark ◽  
Regulation Of Transcription ◽  
Gene Promoters ◽  
Dna Modification ◽  
Dna Methylome ◽  
Genomic Regions

Methylation of the cytosine base in DNA, DNA methylation, is an essential epigenetic mark in mammals that contributes to the regulation of transcription. Several advances have been made in this area in recent years, leading to a leap forward in our understanding of how this pathway contributes to gene regulation during embryonic development, and the functional consequences of its perturbation in human disease. Critical to these advances is a comprehension of the genomic distribution of modified cytosine bases in unprecedented detail, drawing attention to genomic regions beyond gene promoters. In addition, we have a more complete understanding of the multifactorial manner by which DNA methylation influences gene regulation at the molecular level, and which genes rely directly on the DNA methylome for their normal transcriptional regulation. It is becoming apparent that a major role of DNA modification is to act as a relatively stable, and mitotically heritable, template that contributes to the establishment and maintenance of chromatin states. In this regard, interplay is emerging between DNA methylation and the PcG (Polycomb group) proteins, which act as evolutionarily conserved mediators of cell identity. In the present paper we review these aspects of DNA methylation, and discuss how a multifunctional view of DNA modification as an integral part of chromatin organization is influencing our understanding of this epigenetic mark's contribution to transcriptional regulation.

scholarly journals Arginine-Dependent Gene Regulation via the ArgR Repressor Is Species Specific in Chlamydia

2006 ◽  
Vol 188 (3) ◽  
pp. 919-927 ◽  
Author(s):  
Chris S. Schaumburg ◽  
Ming Tan
Keyword(s):  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Chlamydia Pneumoniae ◽  
Arginine Biosynthesis ◽  
Specific Mechanism ◽  
Regulatory Molecule ◽  
Chlamydial Species ◽  
The Family ◽  
Specific Manner ◽  
Species Specific

ABSTRACT Some, but not all, Chlamydia spp. are predicted to encode a homolog of ArgR, a master regulatory molecule that modulates arginine biosynthesis and catabolism in bacteria in response to intracellular arginine levels. While genes for arginine biosynthesis are apparently missing in Chlamydia, a putative arginine transport system encoded by glnP, glnQ, and artJ is present. We found that recombinant Chlamydia pneumoniae ArgR functions as an arginine-dependent aporepressor that bound specifically to operator sequences upstream of the glnPQ operon. ArgR was able to repress transcription in a promoter-specific manner that was dependent on the concentration of the corepressor l-arginine. We were able to locate ArgR operators upstream of glnPQ in C. pneumoniae and Chlamydophila caviae but not Chlamydia trachomatis, which corresponded to the predicted presence or absence of ArgR in these chlamydial species. Our findings indicate that only some members of the family Chlamydiaceae have an arginine-responsive mechanism of gene regulation that is predicted to control arginine uptake from the host cell. This is the first study to directly demonstrate a species-specific mechanism of transcriptional regulation in Chlamydia.

scholarly journals The ins and outs of FoxO shuttling: mechanisms of FoxO translocation and transcriptional regulation

2004 ◽  
Vol 380 (2) ◽  
pp. 297-309 ◽  
Author(s):  
Lars P. van der HEIDE ◽  
Marco F. M. HOEKMAN ◽  
Marten P. SMIDT
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Cell Death ◽  
Dna Repair ◽  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Transcription Factors ◽  
Protein Phosphorylation ◽  
Biological Processes ◽  
Forkhead Box

FoxO (forkhead box O; forkhead members of the O class) are transcription factors that function under the control of insulin/insulin-like signalling. FoxO factors have been associated with a multitude of biological processes, including cell-cycle, cell death, DNA repair, metabolism and protection from oxidative stress. Central to the regulation of FoxO factors is a shuttling system, which confines FoxO factors to either the nucleus or the cytosol. Shuttling of FoxO requires protein phosphorylation within several domains, and association with 14-3-3 proteins and the nuclear transport machinery. Description of the FoxO-shuttling mechanism contributes to the understanding of FoxO function in relation to signalling and gene regulation.

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