scholarly journals The Distinctive Regulation of Cyanobacterial Glutamine Synthetase

Life ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 52 ◽  
Author(s):  
Paul Bolay ◽  
M. Muro-Pastor ◽  
Francisco Florencio ◽  
Stephan Klähn
Keyword(s):  
Glutamine Synthetase ◽  
Gene Expression Regulation ◽  
Feedback Inhibition ◽  
Current Knowledge ◽  
Transcriptional Level ◽  
Distinctive Features ◽  
Small Proteins ◽  
Regulatory Systems ◽  
Covalent Modifications ◽  
Post Transcriptional Regulation

Glutamine synthetase (GS) features prominently in bacterial nitrogen assimilation as it catalyzes the entry of bioavailable nitrogen in form of ammonium into cellular metabolism. The classic example, the comprehensively characterized GS of enterobacteria, is subject to exquisite regulation at multiple levels, among them gene expression regulation to control GS abundance, as well as feedback inhibition and covalent modifications to control enzyme activity. Intriguingly, the GS of the ecologically important clade of cyanobacteria features fundamentally different regulatory systems to those of most prokaryotes. These include the interaction with small proteins, the so-called inactivating factors (IFs) that inhibit GS linearly with their abundance. In addition to this protein interaction-based regulation of GS activity, cyanobacteria use alternative elements to control the synthesis of GS and IFs at the transcriptional level. Moreover, cyanobacteria evolved unique RNA-based regulatory mechanisms such as glutamine riboswitches to tightly tune IF abundance. In this review, we aim to outline the current knowledge on the distinctive features of the cyanobacterial GS encompassing the overall control of its activity, sensing the nitrogen status, transcriptional and post-transcriptional regulation, as well as strain-specific differences.

scholarly journals Bacterial tRNA 2′-O-methylation is dynamically regulated under stress conditions and modulates innate immune response

2020 ◽  
Vol 48 (22) ◽  
pp. 12833-12844
Author(s):  
Adeline Galvanin ◽  
Lea-Marie Vogt ◽  
Antonia Grober ◽  
Isabel Freund ◽  
Lilia Ayadi ◽  
...  
Keyword(s):  
Gene Expression Regulation ◽  
Current Knowledge ◽  
Protein Translation ◽  
Stress Conditions ◽  
Transcriptional Level ◽  
Trna Modification ◽  
Rna Modifications ◽  
Swarming Motility ◽  
E Coli ◽  
Response To Stress

Abstract RNA modifications are a well-recognized way of gene expression regulation at the post-transcriptional level. Despite the importance of this level of regulation, current knowledge on modulation of tRNA modification status in response to stress conditions is far from being complete. While it is widely accepted that tRNA modifications are rather dynamic, such variations are mostly assessed in terms of total tRNA, with only a few instances where changes could be traced to single isoacceptor species. Using Escherichia coli as a model system, we explored stress-induced modulation of 2′-O-methylations in tRNAs by RiboMethSeq. This analysis and orthogonal analytical measurements by LC-MS show substantial, but not uniform, increase of the Gm18 level in selected tRNAs under mild bacteriostatic antibiotic stress, while other Nm modifications remain relatively constant. The absence of Gm18 modification in tRNAs leads to moderate alterations in E. coli mRNA transcriptome, but does not affect polysomal association of mRNAs. Interestingly, the subset of motility/chemiotaxis genes is significantly overexpressed in ΔTrmH mutant, this corroborates with increased swarming motility of the mutant strain. The stress-induced increase of tRNA Gm18 level, in turn, reduced immunostimulation properties of bacterial tRNAs, which is concordant with the previous observation that Gm18 is a suppressor of Toll-like receptor 7 (TLR7)-mediated interferon release. This documents an effect of stress induced modulation of tRNA modification that acts outside protein translation.

scholarly journals MicroRNAs as monitoring markers for right-sided heart failure and congestive hepatopathy

2021 ◽  
Vol 14 (2) ◽  
pp. 142-147
Author(s):  
Ruxandra Florentina Ionescu ◽  
◽  
Sanda Maria Cretoiu ◽  
◽  
Keyword(s):  
Heart Failure ◽  
Cardiovascular Diseases ◽  
Current Knowledge ◽  
Mechanisms Of Action ◽  
Transcriptional Level ◽  
Accurate Assessment ◽  
Regulate Gene Expression ◽  
Non Coding Rnas ◽  
Post Transcriptional Regulation ◽  
Congestive Hepatopathy

The last decades showed a worrying increase in the evolution of cardiovascular diseases towards different stages of heart failure (HF), as a stigma of the western lifestyle. MicroRNAs (miRNAs), non-coding RNAs, which are approximately 22-nucleotide long, were shown to regulate gene expression at the post-transcriptional level and play a role in the pathogenesis and progression of HF. miRNAs research is of high interest nowadays, as these molecules display mechanisms of action that can influence the course of evolution of common chronic diseases, including HF. The potential of post-transcriptional regulation by miRNAs concerning the diagnosis, management, and therapy for HF represents a new promising approach in the accurate assessment of cardiovascular diseases. This review aims to assess the current knowledge of miRNAs in cardiovascular diseases, especially right-sided heart failure and hepatomegaly. Moreover, attention is focused on their role as potential molecular biomarkers and more promising aspects involving miRNAs as future therapeutic targets in the pathophysiology of HF.

The DEAH helicase DHX36 and its role in G-quadruplex-dependent processes

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Philipp Schult ◽  
Katrin Paeschke
Keyword(s):  
Current Knowledge ◽  
Future Research ◽  
Transcriptional Level ◽  
Cellular Functions ◽  
Multiple Functions ◽  
Open Questions ◽  
G Quadruplex ◽  
Cellular Pathways ◽  
Nucleic Acid Structures ◽  
Dependent Processes

AbstractDHX36 is a member of the DExD/H box helicase family, which comprises a large number of proteins involved in various cellular functions. Recently, the function of DHX36 in the regulation of G-quadruplexes (G4s) was demonstrated. G4s are alternative nucleic acid structures, which influence many cellular pathways on a transcriptional and post-transcriptional level. In this review we provide an overview of the current knowledge about DHX36 structure, substrate specificity, and mechanism of action based on the available models and crystal structures. Moreover, we outline its multiple functions in cellular homeostasis, immunity, and disease. Finally, we discuss the open questions and provide potential directions for future research.

Mechanisms involved in developmental programming of hypertension and renal diseases. Gender differences

2014 ◽  
Vol 18 (2) ◽  
Author(s):  
Analia Lorena Tomat ◽  
Francisco Javier Salazar
Keyword(s):  
Metabolic Diseases ◽  
Current Knowledge ◽  
Adult Life ◽  
Developmental Programming ◽  
Renal Diseases ◽  
Future Studies ◽  
Functional Changes ◽  
Regulatory Systems ◽  
Increased Risk ◽  
Renal Changes

AbstractA substantial body of epidemiological and experimental evidence suggests that a poor fetal and neonatal environment may “program” susceptibility in the offspring to later development of cardiovascular, renal and metabolic diseases.This review focuses on current knowledge from the available literature regarding the mechanisms linking an adverse developmental environment with an increased risk for cardiovascular, renal and metabolic diseases in adult life. Moreover, this review highlights important sex-dependent differences in the adaptation to developmental insults.Developmental programming of several diseases is secondary to changes in different mechanisms inducing important alterations in the normal development of several organs that lead to significant changes in birth weight. The different diseases occurring as a consequence of an adverse environment during development are secondary to morphological and functional cardiovascular and renal changes, to epigenetic changes and to an activation of several hormonal and regulatory systems, such as angiotensin II, sympathetic activity, nitric oxide, COX2-derived metabolites, oxidative stress and inflammation. The important sex-dependent differences in the developmental programming of diseases seem to be partly secondary to the effects of sex hormones. Recent studies have shown that the progression of these diseases is accelerated during aging in both sexes.The cardiovascular, renal and metabolic diseases during adult life that occur as a consequence of several insults during fetal and postnatal periods are secondary to multiple structural and functional changes. Future studies are needed in order to prevent the origin and reduce the incidence and consequences of developmental programmed diseases.

scholarly journals Matrix Metalloproteinases: A Review

1993 ◽  
Vol 4 (2) ◽  
pp. 197-250 ◽  
Author(s):  
H. Birkedal-Hansen ◽  
W.G.I. Moore ◽  
M.K. Bodden ◽  
L.J. Windsor ◽  
B. Birkedal-Hansen ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Matrix Metalloproteinases ◽  
Current Knowledge ◽  
Periodontal Diseases ◽  
Present Review ◽  
Transcriptional Level ◽  
Substrate Specificities ◽  
Pathological Conditions ◽  
Final Segment ◽  
Extracellular Level

Matrix metalloproteinases (MMPs) are a family of nine or more highly homologous Zn++endopeptidases that collectively cleave most if not all of the constituents of the extracellular matrix. The present review discusses in detail the primary structures and the overlapping yet distinct substrate specificities of MMPs as well as the mode of activation of the unique MMP precursors. The regulation of MMP activity at the transcriptional level and at the extracellular level (precursor activation, inhibition of activated, mature enzymes) is also discussed. A final segment of the review details the current knowledge of the involvement of MMP in specific developmental or pathological conditions, including human periodontal diseases.

The Salivary miRNome: A Promising Biomarker of Disease

MicroRNA ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Sara Tomei ◽  
Harshitha Shobha Manjunath ◽  
Selvasankar Murugesan ◽  
Souhaila Al Khodor
Keyword(s):  
Current Knowledge ◽  
Transcriptional Level ◽  
Biological Processes ◽  
Circulating Mirnas ◽  
Disease Pathogenesis ◽  
Technical Aspects ◽  
Recent Developments ◽  
Health And Disease ◽  
Non Coding Rnas

: MicroRNAs (miRNAs) are non-coding RNAs ranging from 18-24 nucleotides also known to regulate the human genome mainly at the post-transcriptional level. MiRNAs were shown to play an important role in most biological processes such as apoptosis and in the pathogenesis of many diseases such as cardiovascular diseases and cancer. Recent developments of advanced molecular high-throughput technologies have enhanced our knowledge of miRNAs. MiRNAs can now be discovered, interrogated, and quantified in various body fluids, and hence can serve as diagnostic and therapeutic markers for many diseases. While most studies use blood as a sample source to measure circulating miRNAs as possible biomarkers for disease pathogenesis, fewer studies have assessed the role of salivary miRNAs in health and disease. This review aims at providing an overview of the current knowledge of the salivary miRNome, addressing the technical aspects of saliva sampling and highlighting the applicability of miRNA screening to clinical practice.

Transcriptome-wide m6A detection with DART-Seq

2019 ◽  
Author(s):  
Kate D. Meyer
Keyword(s):  
Gene Expression Regulation ◽  
Preparation Method ◽  
Current Knowledge ◽  
Cross Reactivity ◽  
High Variability ◽  
Library Preparation ◽  
Rna Seq ◽  
Generation Sequencing ◽  
Library Preparation Method

Abstract m6A is the most abundant internal mRNA modification and plays diverse roles in gene expression regulation. Much of our current knowledge about m6A has been driven by recent advances in the ability to detect this mark transcriptome-wide. Antibody-based approaches have been the method of choice for global m6A mapping studies. These methods rely on m6A antibodies to immunoprecipitate methylated RNAs, followed by next-generation sequencing to identify m6A-containing transcripts1,2. While these methods enabled the first identification of m6A sites transcriptome-wide and have dramatically improved our ability to study m6A, they suffer from several limitations. These include requirements for high amounts of input RNA, costly and time-consuming library preparation, high variability across studies, and m6A antibody cross-reactivity with other modifications. Here, we describe DART-Seq (deamination adjacent to RNA modification targets), an antibody-free method for global m6A detection. In DART-Seq, the C to U deaminating enzyme, APOBEC1, is fused to the m6A-binding YTH domain. This fusion protein is then introduced to cellular RNA either through overexpression in cells or with in vitro assays, and subsequent deamination of m6A-adjacent cytidines is then detected by RNA sequencing to identify m6A sites. DART-Seq can successfully map m6A sites throughout the transcriptome using as little as 10 nanograms of total cellular RNA, and it is compatible with any standard RNA-seq library preparation method.

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.

RNA Modifications in the Central Nervous System

2020 ◽  
Author(s):  
Dan Ohtan Wang
Keyword(s):  
Gene Expression ◽  
Cell Function ◽  
Gene Expression Regulation ◽  
Spinal Injury ◽  
Regulation Of Gene Expression ◽  
Modified Nucleosides ◽  
Rna Modifications ◽  
The Central Nervous System ◽  
Post Transcriptional Regulation ◽  
The Brain

Epitranscriptomics, a recently emerged field to investigate post-transcriptional regulation of gene expression through enzyme-mediated RNA modifications, is rapidly evolving and integrating with neuroscience. Using a rich repertoire of modified nucleosides and strategically positioning them to the functionally important and evolutionarily conserved regions of the RNA, epitranscriptomics dictates RNA-mediated cell function. The new field is quickly changing our view of the genetic geography in the brain during development and plasticity, impacting major functions from cortical neurogenesis, circadian rhythm, learning and memory, to reward, addiction, stress, stroke, and spinal injury, etc. Thus understanding the molecular components and operational rules of this pathway is becoming a key for us to decipher the genetic code for brain development, function, and disease. What RNA modifications are expressed in the brain? What RNAs carry them and rely on them for function? Are they dynamically regulated? How are they regulated and how do they contribute to gene expression regulation and brain function? This chapter summarizes recent advances that are beginning to answer these questions.

scholarly journals Regulatory landscape of the Hox transcriptome

2018 ◽  
Vol 62 (11-12) ◽  
pp. 693-704 ◽  
Author(s):  
Ana Casaca ◽  
Gabriel M. Hauswirth ◽  
Heidi Bildsoe ◽  
Moisés Mallo ◽  
Edwina McGlinn
Keyword(s):  
Translational Control ◽  
Noncoding Rna ◽  
Current Knowledge ◽  
Developmental Systems ◽  
Rna Regulation ◽  
Polycistronic Transcription ◽  
Hox Protein ◽  
Post Transcriptional Regulation ◽  
Protein Output ◽  
Cluster Gene

Precise regulation of Hox gene activity is essential to achieve proper control of animal embryonic development and to avoid generation of a variety of malignancies. This is a multilayered process, including complex polycistronic transcription, RNA processing, microRNA repression, long noncoding RNA regulation and sequence-specific translational control, acting together to achieve robust quantitative and qualitative Hox protein output. For many such mechanisms, the Hox cluster gene network has turned out to serve as a paradigmatic model for their study. In this review, we discuss current knowledge of how the different layers of post-transcriptional regulation and the production of a variety of noncoding RNA species control Hox output, and how this shapes formation of developmental systems that are reproducibly patterned by complex Hox networks.

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