scholarly journals Tracing the origins of SARS-COV-2 in coronavirus phylogenies: a review

2021 ◽  
Vol 19 (2) ◽  
pp. 769-785 ◽  
Author(s):  
Erwan Sallard ◽  
José Halloy ◽  
Didier Casane ◽  
Etienne Decroly ◽  
Jacques van Helden
Keyword(s):  
Sequence Analysis ◽  
Structure Function ◽  
Molecular Mechanisms ◽  
Laboratory Strain ◽  
Domestic Animals ◽  
Scientific Policy ◽  
Human Coronavirus ◽  
Viral Dissemination ◽  
Link Type ◽  
Intensive Breeding

AbstractSARS-CoV-2 is a new human coronavirus (CoV), which emerged in China in late 2019 and is responsible for the global COVID-19 pandemic that caused more than 97 million infections and 2 million deaths in 12 months. Understanding the origin of this virus is an important issue, and it is necessary to determine the mechanisms of viral dissemination in order to contain future epidemics. Based on phylogenetic inferences, sequence analysis and structure–function relationships of coronavirus proteins, informed by the knowledge currently available on the virus, we discuss the different scenarios on the origin—natural or synthetic—of the virus. The data currently available are not sufficient to firmly assert whether SARS-CoV2 results from a zoonotic emergence or from an accidental escape of a laboratory strain. This question needs to be solved because it has important consequences on the risk/benefit balance of our interactions with ecosystems, on intensive breeding of wild and domestic animals, on some laboratory practices and on scientific policy and biosafety regulations. Regardless of COVID-19 origin, studying the evolution of the molecular mechanisms involved in the emergence of pandemic viruses is essential to develop therapeutic and vaccine strategies and to prevent future zoonoses. This article is a translation and update of a French article published in Médecine/Sciences, August/September 2020 (10.1051/medsci/2020123).

Patulibacter medicamentivorans sp. nov., isolated from activated sludge of a wastewater treatment plant

2013 ◽  
Vol 63 (Pt_7) ◽  
pp. 2588-2593 ◽  
Author(s):  
Bárbara Almeida ◽  
Ivone Vaz-Moreira ◽  
Peter Schumann ◽  
Olga C. Nunes ◽  
Gilda Carvalho ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Sequence Analysis ◽  
Type Species ◽  
Gene Sequence ◽  
Treatment Plant ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Content Type ◽  
Link Type ◽  
Gene Sequence Analysis

A Gram-positive, aerobic, non-motile, non-endospore-forming rod-shaped bacterium with ibuprofen-degrading capacity, designated strain I11T, was isolated from activated sludge from a wastewater treatment plant. The major respiratory quinone was demethylmenaquinone DMK-7, C18 : 1 cis9 was the predominant fatty acid, phosphatidylglycerol was the predominant polar lipid, the cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid and the G+C content of the genomic DNA was 74.1 mol%. On the basis of 16S rRNA gene sequence analysis, the closest phylogenetic neighbours of strain I11T were Patulibacter ginsengiterrae CECT 7603T (96.8 % similarity), Patulibacter minatonensis DSM 18081T (96.6 %) and Patulibacter americanus DSM 16676T (96.6 %). Phenotypic characterization supports the inclusion of strain I11T within the genus Patulibacter (phylum Actinobacteria) . However, distinctive features and 16S rRNA gene sequence analysis suggest that is represents a novel species, for which the name Patulibacter medicamentivorans sp. nov. is proposed. The type strain is I11T ( = DSM 25962T = CECT 8141T).

scholarly journals Diversity of molecular mechanisms used by anti-CRISPR proteins: the tip of an iceberg?

2020 ◽  
Vol 48 (2) ◽  
pp. 507-516 ◽  
Author(s):  
Pierre Hardouin ◽  
Adeline Goulet
Keyword(s):  
Immune System ◽  
Structure Function ◽  
Defense Mechanisms ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Arms Race ◽  
Allosteric Inhibitors ◽  
Fundamental Knowledge ◽  
Attack And Defense ◽  
Fine Tune

Bacteriophages (phages) and their preys are engaged in an evolutionary arms race driving the co-adaptation of their attack and defense mechanisms. In this context, phages have evolved diverse anti-CRISPR proteins to evade the bacterial CRISPR–Cas immune system, and propagate. Anti-CRISPR proteins do not share much resemblance with each other and with proteins of known function, which raises intriguing questions particularly relating to their modes of action. In recent years, there have been many structure–function studies shedding light on different CRISPR–Cas inhibition strategies. As the anti-CRISPR field of research is rapidly growing, it is opportune to review the current knowledge on these proteins, with particular emphasis on the molecular strategies deployed to inactivate distinct steps of CRISPR–Cas immunity. Anti-CRISPR proteins can be orthosteric or allosteric inhibitors of CRISPR–Cas machineries, as well as enzymes that irreversibly modify CRISPR–Cas components. This repertoire of CRISPR–Cas inhibition mechanisms will likely expand in the future, providing fundamental knowledge on phage–bacteria interactions and offering great perspectives for the development of biotechnological tools to fine-tune CRISPR–Cas-based gene edition.

scholarly journals Pantoea coffeiphila sp. nov., cause of the ‘potato taste’ of Arabica coffee from the African Great Lakes region

2015 ◽  
Vol 65 (Pt_1) ◽  
pp. 23-29 ◽  
Author(s):  
Dominique Gueule ◽  
Gérard Fourny ◽  
Elisabeth Ageron ◽  
Anne Le Flèche-Matéos ◽  
Mathias Vandenbogaert ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Dna Hybridization ◽  
Type Strain ◽  
Novel Species ◽  
Gene Sequencing ◽  
Great Lakes Region ◽  
The Novel ◽  
Content Type ◽  
African Great Lakes ◽  
Link Type

Six isolates recovered from coffee seeds giving off a potato-like flavour were studied. Gene sequencing (rrs and rpoB) showed they belong to the genus Pantoea . By DNA–DNA hybridization, the isolates constituted a genomic species with less than 17 % relatedness to 96 strains representing enterobacterial species. Multilocus sequence analysis (gyrB, rpoB, atpD and infB genes) showed the isolates to represent a discrete species of the genus Pantoea . Nutritional versatility of the novel species was poor. The novel species is proposed as Pantoea coffeiphila sp.nov. and its type strain is Ca04T ( = CIP 110718T = DSM 28482T).

scholarly journals Transcriptional Regulation of Chitin Synthases by Calcineurin Controls Paradoxical Growth of Aspergillus fumigatus in Response to Caspofungin

2010 ◽  
Vol 54 (4) ◽  
pp. 1555-1563 ◽  
Author(s):  
Jarrod R. Fortwendel ◽  
Praveen R. Juvvadi ◽  
B. Zachary Perfect ◽  
Luise E. Rogg ◽  
John R. Perfect ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Molecular Mechanisms ◽  
Laboratory Strain ◽  
Chitin Synthase ◽  
High Dose ◽  
Paradoxical Effect ◽  
Paradoxical Response ◽  
Paradoxical Growth ◽  
High Concentrations ◽  
Calcineurin Signaling

ABSTRACT Attenuated activity of echinocandin antifungals at high concentrations, known as the “paradoxical effect,” is a well-established phenomenon in Candida albicans and Aspergillus fumigatus. In the yeast C. albicans, upregulation of chitin biosynthesis via the protein kinase C (PKC), high-osmolarity glycerol response (HOG), and Ca2+/calcineurin signaling pathways is an important cell wall stress response that permits growth in the presence of high concentrations of echinocandins. However, nothing is known of the molecular mechanisms regulating the mold A. fumigatus and its paradoxical response to echinocandins. Here, we show that the laboratory strain of A. fumigatus and five of seven clinical A. fumigatus isolates tested display various magnitudes of paradoxical growth in response to caspofungin. Interestingly, none of the eight strains showed paradoxical growth in the presence of micafungin or anidulafungin. Treatment of the ΔcnaA and ΔcrzA strains, harboring gene deletions of the calcineurin A subunit and the calcineurin-dependent transcription factor, respectively, with high concentrations of caspofungin revealed that the A. fumigatus paradoxical effect is calcineurin pathway dependent. Exploring a molecular role for CnaA in the compensatory chitin biosynthetic response, we found that caspofungin treatment resulted in increased chitin synthase gene expression, leading to a calcineurin-dependent increase in chitin synthase activity. Taken together, our data suggest a mechanistic role for A. fumigatus calcineurin signaling in the chitin biosynthetic response observed during paradoxical growth in the presence of high-dose caspofungin treatment.

scholarly journals How Not To Be in the Wrong Place at the Wrong Time: An Education Primer for Use with “Deposition of Centromeric Histone H3 Variant CENP-A/Cse4 into Chromatin Is Facilitated by Its C-Terminal Sumoylation”

Genetics ◽  
2020 ◽  
Vol 216 (2) ◽  
pp. 333-342
Author(s):  
Yee Mon Thu
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Diseases ◽  
Histone H3 ◽  
Model Organism ◽  
Post Translational Modification ◽  
Genetic Changes ◽  
Equal Distribution ◽  
Link Type ◽  
Histone H3 Variant ◽  
Big Picture

Recent work by Kentaro Ohkuni and colleagues exemplifies how a series of molecular mechanisms contribute to a cellular outcome—equal distribution of chromosomes. Failure to maintain structural and numerical integrity of chromosomes is one contributing factor in genetic diseases such as cancer. Specifically, the authors investigated molecular events surrounding centromeric histone H3 variant Cse4 deposition—a process important for chromosome segregation, using Saccharomyces cerevisiae as a model organism. This study illustrates an example of a post-translational modification—sumoylation—regulating a cellular process and the concept of genetic interactions (e.g., synthetic dosage lethality). Furthermore, the study highlights the importance of using diverse experimental approaches in answering a few key research questions. The authors used molecular biology techniques (e.g., qPCR), biochemical experiments (e.g., Ni-NTA/8His protein purification), as well as genetic approaches to understand the regulation of Cse4. At a big-picture level, the study reveals how genetic changes can lead to subsequent molecular and cellular changes.

scholarly journals Anticoagulant proteins from snake venoms: structure, function and mechanism

2006 ◽  
Vol 397 (3) ◽  
pp. 377-387 ◽  
Author(s):  
R. Manjunatha Kini
Keyword(s):  
Structure Function ◽  
Blood Coagulation ◽  
Snake Venom ◽  
Molecular Mechanisms ◽  
Cerebrovascular Diseases ◽  
Clot Formation ◽  
Snake Venoms ◽  
New Anticoagulants ◽  
Physiological Processes ◽  
Made In

Over the last several decades, research on snake venom toxins has provided not only new tools to decipher molecular details of various physiological processes, but also inspiration to design and develop a number of therapeutic agents. Blood circulation, particularly thrombosis and haemostasis, is one of the major targets of several snake venom proteins. Among them, anticoagulant proteins have contributed to our understanding of molecular mechanisms of blood coagulation and have provided potential new leads for the development of drugs to treat or to prevent unwanted clot formation. Some of these anticoagulants exhibit various enzymatic activities whereas others do not. They interfere in normal blood coagulation by different mechanisms. Although significant progress has been made in understanding the structure–function relationships and the mechanisms of some of these anticoagulants, there are still a number of questions to be answered as more new anticoagulants are being discovered. Such studies contribute to our fight against unwanted clot formation, which leads to death and debilitation in cardiac arrest and stroke in patients with cardiovascular and cerebrovascular diseases, arteriosclerosis and hypertension. This review describes the details of the structure, mechanism and structure–function relationships of anticoagulant proteins from snake venoms.

scholarly journals Retroposed New Genes Out of the X in Drosophila

2002 ◽  
Vol 12 (12) ◽  
pp. 1854-1859
Author(s):  
Esther Betrán ◽  
Kevin Thornton ◽  
Manyuan Long
Keyword(s):  
Population Genetics ◽  
Molecular Mechanisms ◽  
Sequence Data ◽  
Evolutionary Process ◽  
Significant Excess ◽  
Link Type ◽  
New Genes ◽  
Asymmetric Pattern ◽  
Unpublished Information

New genes that originated by various molecular mechanisms are an essential component in understanding the evolution of genetic systems. We investigated the pattern of origin of the genes created by retroposition in Drosophila. We surveyed the wholeDrosophila melanogaster genome for such new retrogenes and experimentally analyzed their functionality and evolutionary process. These retrogenes, functional as revealed by the analysis of expression, substitution, and population genetics, show a surprisingly asymmetric pattern in their origin. There is a significant excess of retrogenes that originate from the X chromosome and retropose to autosomes; new genes retroposed from autosomes are scarce. Further, we found that most of these X-derived autosomal retrogenes had evolved a testis expression pattern. These observations may be explained by natural selection favoring those new retrogenes that moved to autosomes and avoided the spermatogenesis X inactivation, and suggest the important role of genome position for the origin of new genes.[The sequence data from this study have been submitted to GenBank under accession nos. AY150701–AY150797. The following individuals kindly provided reagents, samples, or unpublished information as indicated in the paper: M.-L. Wu, F. Lemeunier, and P. Gibert.]

TERT Structure, Function, and Molecular Mechanisms

Telomerases ◽  
2012 ◽  
pp. 53-78 ◽  
Author(s):  
Emmanuel Skordalakes ◽  
Neal F. Lue
Keyword(s):  
Structure Function ◽  
Molecular Mechanisms
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