RNA switches regulate initiation of translation in bacteria

2008 ◽  
Vol 389 (5) ◽  
Author(s):  
Stefano Marzi ◽  
Pierre Fechter ◽  
Clément Chevalier ◽  
Pascale Romby ◽  
Thomas Geissmann
Keyword(s):  
Conformational Changes ◽  
Regulatory Proteins ◽  
Environmental Cues ◽  
Structural Elements ◽  
Direct Effects ◽  
Regulate Gene Expression ◽  
Initiation Of Translation ◽  
Rna Switches ◽  
Non Coding Rnas ◽  
Living Organisms

AbstractA large variety of RNA-based mechanisms have been uncovered in all living organisms to regulate gene expression in response to internal and external changes, and to rapidly adapt cell growth in response to these signals. In bacteria, structural elements in the 5′ leader regions of mRNAs have direct effects on translation initiation of the downstream coding sequences. The docking and unfolding of these mRNAs on the 30S subunit are critical steps in the initiation process directly modulating and timing translation. Structural elements can also undergo conformational changes in response to environmental cues (i.e., temperature sensors) or upon binding of a variety oftrans-acting factors, such as metabolites, non-coding RNAs or regulatory proteins. These RNA switches can temporally regulate translation, leading either to repression or to activation of protein synthesis.

scholarly journals Regulatory and Functional Involvement of Long Non-Coding RNAs in DNA Double-Strand Break Repair Mechanisms

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1506
Author(s):  
Angelos Papaspyropoulos ◽  
Nefeli Lagopati ◽  
Ioanna Mourkioti ◽  
Andriani Angelopoulou ◽  
Spyridon Kyriazis ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Strand Break ◽  
Dna Double Strand Breaks ◽  
End Joining ◽  
Dsb Repair ◽  
Repair Mechanisms ◽  
Non Coding Rnas ◽  
Repair Pathways ◽  
Non Homologous End Joining ◽  
Living Organisms

Protection of genome integrity is vital for all living organisms, particularly when DNA double-strand breaks (DSBs) occur. Eukaryotes have developed two main pathways, namely Non-Homologous End Joining (NHEJ) and Homologous Recombination (HR), to repair DSBs. While most of the current research is focused on the role of key protein players in the functional regulation of DSB repair pathways, accumulating evidence has uncovered a novel class of regulating factors termed non-coding RNAs. Non-coding RNAs have been found to hold a pivotal role in the activation of DSB repair mechanisms, thereby safeguarding genomic stability. In particular, long non-coding RNAs (lncRNAs) have begun to emerge as new players with vast therapeutic potential. This review summarizes important advances in the field of lncRNAs, including characterization of recently identified lncRNAs, and their implication in DSB repair pathways in the context of tumorigenesis.

scholarly journals MicroRNA profiles of dry secretions through the first three weeks of the dry period from Holstein cows

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ellie J. Putz ◽  
Austin M. Putz ◽  
Hyeongseon Jeon ◽  
John D. Lippolis ◽  
Hao Ma ◽  
...  
Keyword(s):  
Regression Models ◽  
Transition Period ◽  
Mirna Profile ◽  
Random Regression ◽  
Q Value ◽  
Dry Period ◽  
Regulate Gene Expression ◽  
Intramammary Infections ◽  
Non Coding Rnas ◽  
Insight Into

AbstractIn dairy cows, the period from the end of lactation through the dry period and into the transition period, requires vast physiological and immunological changes critical to mammary health. The dry period is important to the success of the next lactation and intramammary infections during the dry period will adversely alter mammary function, health and milk production for the subsequent lactation. MicroRNAs (miRNAs) are small non-coding RNAs that can post transcriptionally regulate gene expression. We sought to characterize the miRNA profile in dry secretions from the last day of lactation to 3, 10, and 21 days post dry-off. We identified 816 known and 80 novel miRNAs. We found 46 miRNAs whose expression significantly changed (q-value < 0.05) over the first three weeks of dry-off. Additionally, we examined the slopes of random regression models of log transformed normalized counts and cross analyzed the 46 significantly upregulated and downregulated miRNAs. These miRNAs were found to be associated with important components of pregnancy, lactation, as well as inflammation and disease. Detailing the miRNA profile of dry secretions through the dry-off period provides insight into the biology at work, possible means of regulation, components of resistance and/or susceptibility, and outlets for targeted therapy development.

scholarly journals Molecular Insights into the Fungus-Specific Serine/Threonine Protein Phosphatase Z1 in Candida albicans

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
Emily Chen ◽  
Meng S. Choy ◽  
Katalin Petrényi ◽  
Zoltán Kónya ◽  
Ferenc Erdődi ◽  
...  
Keyword(s):  
Candida Albicans ◽  
High Mortality ◽  
Protein Phosphatase ◽  
Cyclic Peptide ◽  
Fungal Infections ◽  
The United States ◽  
Mortality Rates ◽  
Regulatory Proteins ◽  
Structural Elements ◽  
Novel Targets

ABSTRACT The opportunistic pathogen Candida is one of the most common causes of nosocomial bloodstream infections. Because candidemia is associated with high mortality rates and because the incidences of multidrug-resistant Candida are increasing, efforts to identify novel targets for the development of potent antifungals are warranted. Here, we describe the structure and function of the first member of a family of protein phosphatases that is specific to fungi, protein phosphatase Z1 (PPZ1) from Candida albicans . We show that PPZ1 not only is active but also is as susceptible to inhibition by the cyclic peptide inhibitor microcystin-LR as its most similar human homolog, protein phosphatase 1α (PP1α [GLC7 in the yeast Saccharomyces cerevisiae ]). Unexpectedly, we also discovered that, despite its 66% sequence identity to PP1α, the catalytic domain of PPZ1 contains novel structural elements that are not present in PP1α. We then used activity and pulldown assays to show that these structural differences block a large subset of PP1/GLC7 regulatory proteins from effectively binding PPZ1, demonstrating that PPZ1 does not compete with GLC7 for its regulatory proteins. Equally important, these unique structural elements provide new pockets suitable for the development of PPZ1-specific inhibitors. Together, these studies not only reveal why PPZ1 does not negatively impact GLC7 activity in vivo but also demonstrate that the family of fungus-specific phosphatases—especially PPZ1 from C. albicans —are highly suitable targets for the development of novel drugs that specifically target C. albicans without cross-reacting with human phosphatases. IMPORTANCE Candida albicans is a medically important human pathogen that is the most common cause of fungal infections in humans. In particular, approximately 46,000 cases of health care-associated candidiasis occur each year in the United States. Because these infections are associated with high mortality rates and because multiple species of Candida are becoming increasingly resistant to antifungals, there are increasing efforts to identify novel targets that are essential for C. albicans virulence. Here we use structural and biochemical approaches to elucidate how a member of a fungus-specific family of enzymes, serine/threonine phosphatase PPZ1, functions in C. albicans . We discovered multiple unique features of PPZ1 that explain why it does not cross-react with, and in turn compete for, PP1-specific regulators, a long-standing question in the field. Most importantly, however, these unique features identified PPZ1 as a potential target for the development of novel antifungal therapeutics that will provide new, safe, and potent treatments for candidiasis in humans.

MicroRNAs: role in cardiovascular biology and disease

2008 ◽  
Vol 114 (12) ◽  
pp. 699-706 ◽  
Author(s):  
Chunxiang Zhang
Keyword(s):  
Cardiovascular Diseases ◽  
Target Genes ◽  
Future Research ◽  
Cardiovascular Development ◽  
Biological Functions ◽  
Lesion Formation ◽  
Regulate Gene Expression ◽  
Proliferation And Apoptosis ◽  
Cardiovascular Biology ◽  
Non Coding Rnas

miRNAs (microRNAs) comprise a novel class of endogenous, small, non-coding RNAs that negatively regulate gene expression via degradation or translational inhibition of their target mRNAs. Recent studies have demonstrated that miRNAs are highly expressed in the cardiovascular system. Although we are currently in the initial stages of understanding how this novel class of gene regulators is involved in cardiovascular biological functions, a growing body of exciting evidence suggests that miRNAs are important regulators of cardiovascular cell differentiation, growth, proliferation and apoptosis. Moreover, miRNAs are key modulators of both cardiovascular development and angiogenesis. Consequently, dysregulation of miRNA function may lead to cardiovascular diseases. Indeed, several recent reports have demonstrated that miRNAs are aberrantly expressed in diseased hearts and vessels. Modulating these aberrantly expressed miRNAs has significant effects on cardiac hypertrophy, vascular neointimal lesion formation and cardiac arrhythmias. Identifying the roles of miRNAs and their target genes and signalling pathways in cardiovascular disease will be critical for future research. miRNAs may represent a new layer of regulators for cardiovascular biology and a novel class of therapeutic targets for cardiovascular diseases.

scholarly journals The Dynamic Life of Virus Capsids

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 618
Author(s):  
Michael B. Sherman ◽  
Hong Q. Smith ◽  
Thomas J. Smith
Keyword(s):  
Immune System ◽  
Small Molecules ◽  
Conformational Changes ◽  
Environmental Cues ◽  
Virus Capsids ◽  
P Domain ◽  
Single Polypeptide ◽  
Dynamic Structures ◽  
The Moment ◽  
The Right

Protein-shelled viruses have been thought as “tin cans” that merely carry the genomic cargo from cell to cell. However, through the years, it has become clear that viruses such as rhinoviruses and caliciviruses are active and dynamic structures waiting for the right environmental cues to deliver their genomic payload to the host cell. In the case of human rhinoviruses, the capsid has empty cavities that decrease the energy required to cause conformational changes, resulting in the capsids “breathing”, waiting for the moment when the receptor binds for it to release its genome. Most strikingly, the buried N-termini of VP1 and VP4 are transiently exposed during this process. A more recent example of a “living” protein capsid is mouse norovirus (MNV). This family of viruses have a large protruding (P) domain that is loosely attached to the shell via a single-polypeptide tether. Small molecules found in the gut, such as bile salts, cause the P domains to rotate and collapse onto the shell surface. Concomitantly, bile alters the conformation of the P domain itself from one that binds antibodies to one that recognizes receptors. In this way, MNV appears to use capsid flexibility to present one face to the immune system and a completely different one to attack the host tissue. Therefore, it appears that even protein-shelled viruses have developed an impressive array of tricks to dodge our immune system and efficiently attack the host.

scholarly journals The Osteoporosis/Microbiota Linkage: The Role of miRNA

2020 ◽  
Vol 21 (23) ◽  
pp. 8887 ◽  
Author(s):  
Massimo De Martinis ◽  
Lia Ginaldi ◽  
Alessandro Allegra ◽  
Maria Maddalena Sirufo ◽  
Giovanni Pioggia ◽  
...  
Keyword(s):  
Dynamic Equilibrium ◽  
Treatment Strategies ◽  
Therapeutic Agents ◽  
Osteoporosis Prevention ◽  
Regulate Gene Expression ◽  
Molecular Biotechnology ◽  
Non Coding Rnas ◽  
The Relationship ◽  
Complementary Mechanism

Hundreds of trillions of bacteria are present in the human body in a mutually beneficial symbiotic relationship with the host. A stable dynamic equilibrium exists in healthy individuals between the microbiota, host organism, and environment. Imbalances of the intestinal microbiota contribute to the determinism of various diseases. Recent research suggests that the microbiota is also involved in the regulation of the bone metabolism, and its alteration may induce osteoporosis. Due to modern molecular biotechnology, various mechanisms regulating the relationship between bone and microbiota are emerging. Understanding the role of microbiota imbalances in the development of osteoporosis is essential for the development of potential osteoporosis prevention and treatment strategies through microbiota targeting. A relevant complementary mechanism could be also constituted by the permanent relationships occurring between microbiota and microRNAs (miRNAs). miRNAs are a set of small non-coding RNAs able to regulate gene expression. In this review, we recapitulate the physiological and pathological meanings of the microbiota on osteoporosis onset by governing miRNA production. An improved comprehension of the relations between microbiota and miRNAs could furnish novel markers for the identification and monitoring of osteoporosis, and this appears to be an encouraging method for antagomir-guided tactics as therapeutic agents.

The Role of miR-210 in the Biological System: A Current Overview

2019 ◽  
Vol 84 (6) ◽  
pp. 233-239
Author(s):  
Xu Hui ◽  
Hisham Al-Ward ◽  
Fahmi Shaher ◽  
Chun-Yang Liu ◽  
Ning Liu
Keyword(s):  
Gene Expression ◽  
Regulation Of Gene Expression ◽  
Low Oxygen ◽  
Cellular Functions ◽  
Regulate Gene Expression ◽  
System A ◽  
Non Coding Rnas ◽  
Post Transcriptional Regulation ◽  
A Current

<b><i>Background:</i></b> MicroRNAs (miRNAs) represent a group of non-coding RNAs measuring 19–23 nucleotides in length and are recognized as powerful molecules that regulate gene expression in eukaryotic cells. miRNAs stimulate the post-transcriptional regulation of gene expression via direct or indirect mechanisms. <b><i>Summary:</i></b> miR-210 is highly upregulated in cells under hypoxia, thereby revealing its significance to cell endurance. Induction of this mRNA expression is an important feature of the cellular low-oxygen response and the most consistent and vigorous target of HIF. <b><i>Key Message:</i></b> miR-210 is involved in many cellular functions under the effect of HIF-1α, including the cell cycle, DNA repair, immunity and inflammation, angiogenesis, metabolism, and macrophage regulation. It also plays an important regulatory role in T-cell differentiation and stimulation.

scholarly journals MicroRNAs in Daphnia magna identified and characterized by deep sequencing, genome mapping and manual curation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dag H. Coucheron ◽  
Marcin W. Wojewodzic ◽  
Thomas Bøhn
Keyword(s):  
Daphnia Magna ◽  
Deep Sequencing ◽  
Rna Silencing ◽  
Genome Mapping ◽  
Regulation Of Gene Expression ◽  
Environmental Cues ◽  
Water Flea ◽  
Manual Curation ◽  
Non Coding Rnas ◽  
Post Transcriptional Regulation

Abstract MicroRNAs (miRNAs) are small non-coding RNAs that function in RNA silencing and post-transcriptional regulation of gene expression in most organisms. The water flea, Daphnia magna is a key model to study phenotypic, physiological and genomic responses to environmental cues and miRNAs can potentially mediate these responses. By using deep sequencing, genome mapping and manual curations, we have characterised the miRNAome of D. magna. We identified 66 conserved miRNAs and 13 novel miRNAs; all of these were found in the three studied life stages of D. magna (juveniles, subadults, adults), but with variation in expression levels between stages. Forty-one of the miRNAs were clustered into 13 genome clusters also present in the D. pulex genome. Most miRNAs contained sequence variants (isomiRs). The highest expressed isomiRs were 3′ template variants with one nucleotide deletion or 3′ non-template variants with addition of A or U at the 3′ end. We also identified offset RNAs (moRs) and loop RNAs (loRs). Our work extends the base for further work on all species (miRNA, isomiRs, moRNAs, loRNAs) of the miRNAome of Daphnia as biomarkers in response to chemical substances and environment cues, and underline age dependency.

scholarly journals Crystal structure of the capsular polysaccharide synthesizing protein CapE of Staphylococcus aureus

2013 ◽  
Vol 33 (3) ◽  
Author(s):  
Takamitsu Miyafusa ◽  
Jose M. M. Caaveiro ◽  
Yoshikazu Tanaka ◽  
Martin E. Tanner ◽  
Kouhei Tsumoto
Keyword(s):  
Staphylococcus Aureus ◽  
Conformational Changes ◽  
Capsular Polysaccharide ◽  
Site Directed Mutagenesis ◽  
Structural Elements ◽  
Contact Interface ◽  
Protein Subunits ◽  
Polysaccharide Synthesis ◽  
Substrate Binding Domain ◽  
Primary Sequence Alignment

Enzymes synthesizing the bacterial CP (capsular polysaccharide) are attractive antimicrobial targets. However, we lack critical information about the structure and mechanism of many of them. In an effort to reduce that gap, we have determined three different crystal structures of the enzyme CapE of the human pathogen Staphylococcus aureus. The structure reveals that CapE is a member of the SDR (short-chain dehydrogenase/reductase) super-family of proteins. CapE assembles in a hexameric complex stabilized by three major contact surfaces between protein subunits. Turnover of substrate and/or coenzyme induces major conformational changes at the contact interface between protein subunits, and a displacement of the substrate-binding domain with respect to the Rossmann domain. A novel dynamic element that we called the latch is essential for remodelling of the protein–protein interface. Structural and primary sequence alignment identifies a group of SDR proteins involved in polysaccharide synthesis that share the two salient features of CapE: the mobile loop (latch) and a distinctive catalytic site (MxxxK). The relevance of these structural elements was evaluated by site-directed mutagenesis.

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