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1.
Proc Natl Acad Sci U S A ; 117(29): 17195-17203, 2020 07 21.
Article in English | MEDLINE | ID: covidwho-624792

ABSTRACT

The vast majority of intracellular protein targets are refractory toward small-molecule therapeutic engagement, and additional therapeutic modalities are needed to overcome this deficiency. Here, the identification and characterization of a natural product, WDB002, reveals a therapeutic modality that dramatically expands the currently accepted limits of druggability. WDB002, in complex with the FK506-binding protein (FKBP12), potently and selectively binds the human centrosomal protein 250 (CEP250), resulting in disruption of CEP250 function in cells. The recognition mode is unprecedented in that the targeted domain of CEP250 is a coiled coil and is topologically featureless, embodying both a structural motif and surface topology previously considered on the extreme limits of "undruggability" for an intracellular target. Structural studies reveal extensive protein-WDB002 and protein-protein contacts, with the latter being distinct from those seen in FKBP12 ternary complexes formed by FK506 and rapamycin. Outward-facing structural changes in a bound small molecule can thus reprogram FKBP12 to engage diverse, otherwise "undruggable" targets. The flat-targeting modality demonstrated here has the potential to expand the druggable target range of small-molecule therapeutics. As CEP250 was recently found to be an interaction partner with the Nsp13 protein of the SARS-CoV-2 virus that causes COVID-19 disease, it is possible that WDB002 or an analog may exert useful antiviral activity through its ability to form high-affinity ternary complexes containing CEP250 and FKBP12.


Subject(s)
Actinobacteria/genetics , Genome, Bacterial , Protein Interaction Domains and Motifs/drug effects , Small Molecule Libraries/pharmacology , Tacrolimus Binding Protein 1A/chemistry , Tacrolimus Binding Protein 1A/metabolism , Actinobacteria/metabolism , Amino Acid Sequence , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/metabolism , Autoantigens/genetics , Autoantigens/metabolism , Calcineurin/genetics , Calcineurin/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Evolution, Molecular , HEK293 Cells , Humans , Models, Molecular , Protein Conformation , Sequence Homology , Sirolimus/chemistry , Sirolimus/metabolism , Small Molecule Libraries/chemistry , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism
2.
Nat Commun ; 11(1): 4235, 2020 08 25.
Article in English | MEDLINE | ID: covidwho-738373

ABSTRACT

Bats are presumed reservoirs of diverse coronaviruses (CoVs) including progenitors of Severe Acute Respiratory Syndrome (SARS)-CoV and SARS-CoV-2, the causative agent of COVID-19. However, the evolution and diversification of these coronaviruses remains poorly understood. Here we use a Bayesian statistical framework and a large sequence data set from bat-CoVs (including 630 novel CoV sequences) in China to study their macroevolution, cross-species transmission and dispersal. We find that host-switching occurs more frequently and across more distantly related host taxa in alpha- than beta-CoVs, and is more highly constrained by phylogenetic distance for beta-CoVs. We show that inter-family and -genus switching is most common in Rhinolophidae and the genus Rhinolophus. Our analyses identify the host taxa and geographic regions that define hotspots of CoV evolutionary diversity in China that could help target bat-CoV discovery for proactive zoonotic disease surveillance. Finally, we present a phylogenetic analysis suggesting a likely origin for SARS-CoV-2 in Rhinolophus spp. bats.


Subject(s)
Chiroptera/virology , Coronavirus Infections/veterinary , Coronavirus/genetics , Evolution, Molecular , Zoonoses/transmission , Animals , Bayes Theorem , Betacoronavirus/classification , Betacoronavirus/genetics , Biodiversity , China , Chiroptera/classification , Coronavirus/classification , Coronavirus Infections/transmission , Coronavirus Infections/virology , Humans , Pandemics , Phylogeny , Phylogeography , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , Zoonoses/virology
3.
J Virol ; 94(12)2020 06 01.
Article in English | MEDLINE | ID: covidwho-736044

ABSTRACT

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that recently emerged in China is thought to have a bat origin, as its closest known relative (BatCoV RaTG13) was described previously in horseshoe bats. We analyzed the selective events that accompanied the divergence of SARS-CoV-2 from BatCoV RaTG13. To this end, we applied a population genetics-phylogenetics approach, which leverages within-population variation and divergence from an outgroup. Results indicated that most sites in the viral open reading frames (ORFs) evolved under conditions of strong to moderate purifying selection. The most highly constrained sequences corresponded to some nonstructural proteins (nsps) and to the M protein. Conversely, nsp1 and accessory ORFs, particularly ORF8, had a nonnegligible proportion of codons evolving under conditions of very weak purifying selection or close to selective neutrality. Overall, limited evidence of positive selection was detected. The 6 bona fide positively selected sites were located in the N protein, in ORF8, and in nsp1. A signal of positive selection was also detected in the receptor-binding motif (RBM) of the spike protein but most likely resulted from a recombination event that involved the BatCoV RaTG13 sequence. In line with previous data, we suggest that the common ancestor of SARS-CoV-2 and BatCoV RaTG13 encoded/encodes an RBM similar to that observed in SARS-CoV-2 itself and in some pangolin viruses. It is presently unknown whether the common ancestor still exists and, if so, which animals it infects. Our data, however, indicate that divergence of SARS-CoV-2 from BatCoV RaTG13 was accompanied by limited episodes of positive selection, suggesting that the common ancestor of the two viruses was poised for human infection.IMPORTANCE Coronaviruses are dangerous zoonotic pathogens; in the last 2 decades, three coronaviruses have crossed the species barrier and caused human epidemics. One of these is the recently emerged SARS-CoV-2. We investigated how, since its divergence from a closely related bat virus, natural selection shaped the genome of SARS-CoV-2. We found that distinct coding regions in the SARS-CoV-2 genome evolved under conditions of different degrees of constraint and are consequently more or less prone to tolerate amino acid substitutions. In practical terms, the level of constraint provides indications about which proteins/protein regions are better suited as possible targets for the development of antivirals or vaccines. We also detected limited signals of positive selection in three viral ORFs. However, we warn that, in the absence of knowledge about the chain of events that determined the human spillover, these signals should not be necessarily interpreted as evidence of an adaptation to our species.


Subject(s)
Betacoronavirus/genetics , Evolution, Molecular , Selection, Genetic , Amino Acid Sequence , Animals , Betacoronavirus/classification , Chiroptera/virology , Coronavirus Infections/virology , Genome, Viral/genetics , Humans , Models, Molecular , Open Reading Frames/genetics , Pandemics , Phylogeny , Pneumonia, Viral/virology , Viral Proteins/chemistry , Viral Proteins/genetics
4.
Vet Microbiol ; 247: 108777, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-733593

ABSTRACT

Coronaviruses (CoVs) cause disease in a range of agricultural and companion animal species, and can be important causes of zoonotic infections. In humans, several coronaviruses circulate seasonally. Recently, a novel zoonotic CoV named SARS-CoV-2 emerged from a bat reservoir, resulting in the COVID-19 pandemic. With a focus on felines, we review here the evidence for SARS-CoV-2 infection in cats, ferrets and dogs, describe the relationship between SARS-CoV-2 and the natural coronaviruses known to infect these species, and provide a rationale for the relative susceptibility of these species to SARS-CoV-2 through comparative analysis of the ACE-2 receptor.


Subject(s)
Cat Diseases/virology , Coronavirus Infections/veterinary , Dog Diseases/virology , Evolution, Molecular , Pandemics/veterinary , Pneumonia, Viral/veterinary , Zoonoses/transmission , Animals , Betacoronavirus , Cats/virology , Dogs/virology , Ferrets/virology , Humans , Peptidyl-Dipeptidase A/metabolism , Receptors, Virus/genetics , Zoonoses/virology
5.
Virol J ; 17(1): 131, 2020 08 27.
Article in English | MEDLINE | ID: covidwho-733041

ABSTRACT

BACKGROUND: The Covid19 infection is caused by the SARS-CoV-2 virus, a novel member of the coronavirus (CoV) family. CoV genomes code for a ORF1a / ORF1ab polyprotein and four structural proteins widely studied as major drug targets. The genomes also contain a variable number of open reading frames (ORFs) coding for accessory proteins that are not essential for virus replication, but appear to have a role in pathogenesis. The accessory proteins have been less well characterized and are difficult to predict by classical bioinformatics methods. METHODS: We propose a computational tool GOFIX to characterize potential ORFs in virus genomes. In particular, ORF coding potential is estimated by searching for enrichment in motifs of the X circular code, that is known to be over-represented in the reading frames of viral genes. RESULTS: We applied GOFIX to study the SARS-CoV-2 and related genomes including SARS-CoV and SARS-like viruses from bat, civet and pangolin hosts, focusing on the accessory proteins. Our analysis provides evidence supporting the presence of overlapping ORFs 7b, 9b and 9c in all the genomes and thus helps to resolve some differences in current genome annotations. In contrast, we predict that ORF3b is not functional in all genomes. Novel putative ORFs were also predicted, including a truncated form of the ORF10 previously identified in SARS-CoV-2 and a little known ORF overlapping the Spike protein in Civet-CoV and SARS-CoV. CONCLUSIONS: Our findings contribute to characterizing sequence properties of accessory genes of SARS coronaviruses, and especially the newly acquired genes making use of overlapping reading frames.


Subject(s)
Betacoronavirus/genetics , Genome, Viral , Open Reading Frames , SARS Virus/genetics , Viral Regulatory and Accessory Proteins/genetics , Animals , Codon , Computational Biology , Evolution, Molecular , Genes, Viral , Humans , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Viral Matrix Proteins/genetics , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Regulatory and Accessory Proteins/chemistry
6.
BMC Res Notes ; 13(1): 398, 2020 Aug 27.
Article in English | MEDLINE | ID: covidwho-733023

ABSTRACT

OBJECTIVE: In December 2019 a novel coronavirus (SARS-CoV-2) that is causing the current COVID-19 pandemic was identified in Wuhan, China. Many questions have been raised about its origin and adaptation to humans. In the present work we performed a genetic analysis of the Spike glycoprotein (S) of SARS-CoV-2 and other related coronaviruses (CoVs) isolated from different hosts in order to trace the evolutionary history of this protein and the adaptation of SARS-CoV-2 to humans. RESULTS: Based on the sequence analysis of the S gene, we suggest that the origin of SARS-CoV-2 is the result of recombination events between bat and pangolin CoVs. The hybrid SARS-CoV-2 ancestor jumped to humans and has been maintained by natural selection. Although the S protein of RaTG13 bat CoV has a high nucleotide identity with the S protein of SARS-CoV-2, the phylogenetic tree and the haplotype network suggest a non-direct parental relationship between these CoVs. Moreover, it is likely that the basic function of the receptor-binding domain (RBD) of S protein was acquired by the SARS-CoV-2 from the MP789 pangolin CoV by recombination and it has been highly conserved.


Subject(s)
Betacoronavirus/genetics , Coronaviridae/genetics , Recombination, Genetic , Spike Glycoprotein, Coronavirus/genetics , Adaptation, Biological/genetics , Animals , Binding Sites/genetics , Chiroptera/virology , Eutheria/virology , Evolution, Molecular , Furin/metabolism , Host Specificity , Humans , Peptidyl-Dipeptidase A/metabolism , Phylogeny , Selection, Genetic , Spike Glycoprotein, Coronavirus/metabolism
7.
PLoS One ; 15(8): e0238490, 2020.
Article in English | MEDLINE | ID: covidwho-732989

ABSTRACT

SARS-CoV-2 is still rampaging throughout the world while the many evolutionary studies on it are simultaneously springing up. Researchers have simply utilized the public RNA-seq data to find out the so-called SNPs in the virus genome. The evolutionary analyses were largely based on these mutations. Here, we claim that we reliably detected A-to-G RNA modifications in the RNA-seq data of SARS-CoV-2 with high signal to noise ratios, presumably caused by the host's deamination enzymes. Intriguingly, since SARS-CoV-2 is an RNA virus, it is technically impossible to distinguish SNPs and RNA modifications from the RNA-seq data alone without solid evidence, making it difficult to tell the evolutionary patterns behind the mutation spectrum. Researchers should clarify their biological significance before they automatically regard the mutations as SNPs or RNA modifications. This is not a problem for DNA organisms but should be seriously considered when we are investigating the RNA viruses.


Subject(s)
Betacoronavirus/genetics , Evolution, Molecular , Polymorphism, Single Nucleotide , RNA, Viral/genetics , Base Sequence , Coronavirus Infections , Humans , Mutation Rate , Pandemics , Pneumonia, Viral , RNA-Seq
8.
Sci Rep ; 10(1): 14031, 2020 08 20.
Article in English | MEDLINE | ID: covidwho-724696

ABSTRACT

The COVID-19 pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), was declared on March 11, 2020 by the World Health Organization. As of the 31st of May, 2020, there have been more than 6 million COVID-19 cases diagnosed worldwide and over 370,000 deaths, according to Johns Hopkins. Thousands of SARS-CoV-2 strains have been sequenced to date, providing a valuable opportunity to investigate the evolution of the virus on a global scale. We performed a phylogenetic analysis of over 1,225 SARS-CoV-2 genomes spanning from late December 2019 to mid-March 2020. We identified a missense mutation, D614G, in the spike protein of SARS-CoV-2, which has emerged as a predominant clade in Europe (954 of 1,449 (66%) sequences) and is spreading worldwide (1,237 of 2,795 (44%) sequences). Molecular dating analysis estimated the emergence of this clade around mid-to-late January (10-25 January) 2020. We also applied structural bioinformatics to assess the potential impact of D614G on the virulence and epidemiology of SARS-CoV-2. In silico analyses on the spike protein structure suggests that the mutation is most likely neutral to protein function as it relates to its interaction with the human ACE2 receptor. The lack of clinical metadata available prevented our investigation of association between viral clade and disease severity phenotype. Future work that can leverage clinical outcome data with both viral and human genomic diversity is needed to monitor the pandemic.


Subject(s)
Betacoronavirus/chemistry , Coronavirus Infections/epidemiology , Evolution, Molecular , Pneumonia, Viral/epidemiology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Base Sequence , Betacoronavirus/pathogenicity , Child , Child, Preschool , Computer Simulation , Coronavirus Infections/virology , Female , Genome, Viral/genetics , Humans , Infant , Male , Middle Aged , Mutation, Missense , Pandemics , Peptidyl-Dipeptidase A/metabolism , Phylogeny , Pneumonia, Viral/virology , Protein Conformation , Spike Glycoprotein, Coronavirus/metabolism , Virulence/genetics , Young Adult
9.
Med Sci (Paris) ; 36(8-9): 783-796, 2020.
Article in French | MEDLINE | ID: covidwho-706965

ABSTRACT

SARS-CoV-2 is a new human coronavirus (CoV), which emerged in People's Republic of China at the end of 2019 and is responsible for the global Covid-19 pandemic that caused more than 540 000 deaths in six months. Understanding the origin of this virus is an important issue and it is necessary to determine the mechanisms of its dissemination in order to be able to contain new epidemics. Based on phylogenetic inferences, sequence analysis and structure-function relationships of coronavirus proteins, informed by the knowledge currently available, we discuss the different scenarios evoked to account for the origin - natural or synthetic - of the virus. On the basis of currently available data, it is impossible to determine whether SARS-CoV-2 is the result of a natural zoonotic emergence or an accidental escape from experimental strains. Regardless of its origin, the study of the evolution of the molecular mechanisms involved in the emergence of this pandemic virus is essential to develop therapeutic and vaccine strategies.


Subject(s)
Betacoronavirus/genetics , Communicable Diseases, Emerging/virology , Coronavirus Infections/virology , Coronavirus/classification , Evolution, Molecular , Pandemics , Phylogeny , Pneumonia, Viral/virology , RNA, Viral/genetics , Amino Acid Sequence , Animals , Betacoronavirus/classification , Betacoronavirus/isolation & purification , Biohazard Release , China/epidemiology , Coronaviridae Infections/transmission , Coronaviridae Infections/veterinary , Coronaviridae Infections/virology , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Disease Reservoirs , Gain of Function Mutation , Genome, Viral , HIV/genetics , Host Specificity , Humans , Mammals/virology , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Reassortant Viruses/genetics , Sequence Alignment , Sequence Homology, Amino Acid , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/physiology , Zoonoses
10.
Virol J ; 17(1): 117, 2020 07 29.
Article in English | MEDLINE | ID: covidwho-684739

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection has spread rapidly across the world and become an international public health emergency. Both SARS-CoV-2 and SARS-CoV belong to subfamily Coronavirinae in the family Coronaviridae of the order Nidovirales and they are classified as the SARS-like species while belong to different cluster. Besides, viral structure, epidemiology characteristics and pathological characteristics are also different. We present a comprehensive survey of the latest coronavirus-SARS-CoV-2-from investigating its origin and evolution alongside SARS-CoV. Meanwhile, pathogenesis, cardiovascular disease in COVID-19 patients, myocardial injury and venous thromboembolism induced by SARS-CoV-2 as well as the treatment methods are summarized in this review.


Subject(s)
Betacoronavirus , Coronavirus Infections , Pandemics , Pneumonia, Viral , Antiviral Agents/therapeutic use , Asymptomatic Infections , Betacoronavirus/chemistry , Betacoronavirus/classification , Betacoronavirus/pathogenicity , Betacoronavirus/physiology , Comorbidity , Coronavirus Infections/drug therapy , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Coronavirus Infections/pathology , Coronavirus Infections/therapy , Disease Susceptibility , Evolution, Molecular , Genome, Viral , Humans , Immunization, Passive , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Pneumonia, Viral/pathology , Pneumonia, Viral/therapy , Receptors, Virus/metabolism , SARS Virus/chemistry , SARS Virus/classification , SARS Virus/pathogenicity , SARS Virus/physiology , Viral Proteins/chemistry
11.
J Infect Dis ; 222(2): 223-233, 2020 06 29.
Article in English | MEDLINE | ID: covidwho-656287

ABSTRACT

Severe acute respiratory syndrome coronavirus (SARS-CoV) was discovered as a novel pathogen in the 2002-2003 SARS epidemic. The emergence and disappearance of this pathogen have brought questions regarding its source and evolution. Within the genome sequences of 281 SARS-CoVs, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and SARS-related CoVs (SARSr-CoVs), a ~430 bp genomic region (from 27 701 bp to 28 131 bp in AY390556.1) with regular variations was investigated. This ~430 bp region overlaps with the ORF8 gene and is prone to deletions and nucleotide substitutions. Its complexity suggested the need for a new genotyping method for coronaviruses related to SARS-similar coronaviruses (SARS-CoV, SARSr-CoV, and SARS-CoV-2). Bat SARSr-CoV presented 3 genotypes, of which type 0 is only seen in bat SARSr-CoV, type I is present in SARS in the early phase, and type II is found in all SARS-CoV-2. This genotyping also shows potential usage in distinguishing the SARS-similar coronaviruses from different hosts and geographic areas. This genomic region has important implications for predicting the epidemic trend and studying the evolution of coronavirus.


Subject(s)
Betacoronavirus/genetics , Genome, Viral , SARS Virus/genetics , Viral Matrix Proteins/genetics , Animals , Base Sequence , Chiroptera/virology , Eutheria/virology , Evolution, Molecular , Genes, Viral , Genetic Variation , Humans , Open Reading Frames , Phylogeny , Sequence Alignment , Sequence Deletion , Spike Glycoprotein, Coronavirus/genetics , Viverridae/virology
12.
J Transl Med ; 18(1): 275, 2020 07 07.
Article in English | MEDLINE | ID: covidwho-655214

ABSTRACT

BACKGROUND: The Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) outbreak originating in Wuhan, China, has raised global health concerns and the pandemic has now been reported on all inhabited continents. Hitherto, no antiviral drug is available to combat this viral outbreak. METHODS: Keeping in mind the urgency of the situation, the current study was designed to devise new strategies for drug discovery and/or repositioning against SARS-CoV-2. In the current study, RNA-dependent RNA polymerase (RdRp), which regulates viral replication, is proposed as a potential therapeutic target to inhibit viral infection. RESULTS: Evolutionary studies of whole-genome sequences of SARS-CoV-2 represent high similarity (> 90%) with other SARS viruses. Targeting the RdRp active sites, ASP760 and ASP761, by antiviral drugs could be a potential therapeutic option for inhibition of coronavirus RdRp, and thus viral replication. Target-based virtual screening and molecular docking results show that the antiviral Galidesivir and its structurally similar compounds have shown promise against SARS-CoV-2. CONCLUSIONS: The anti-polymerase drugs predicted here-CID123624208 and CID11687749-may be considered for in vitro and in vivo clinical trials.


Subject(s)
Betacoronavirus/enzymology , Computational Biology , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Molecular Targeted Therapy , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , RNA Replicase/metabolism , Amino Acid Sequence , Betacoronavirus/isolation & purification , Drug Evaluation, Preclinical , Evolution, Molecular , Humans , Ligands , Molecular Docking Simulation , Pandemics , Phylogeny , RNA Replicase/chemistry , Thermodynamics
13.
Virus Res ; 287: 198098, 2020 10 02.
Article in English | MEDLINE | ID: covidwho-653575

ABSTRACT

To investigate the evolutionary and epidemiological dynamics of the current COVID-19 outbreak, a total of 112 genomes of SARS-CoV-2 strains sampled from China and 12 other countries with sampling dates between 24 December 2019 and 9 February 2020 were analyzed. We performed phylogenetic, split network, likelihood-mapping, model comparison, and phylodynamic analyses of the genomes. Based on Bayesian time-scaled phylogenetic analysis with the best-fitting combination models, we estimated the time to the most recent common ancestor (TMRCA) and evolutionary rate of SARS-CoV-2 to be 12 November 2019 (95 % BCI: 11 October 2019 and 09 December 2019) and 9.90 × 10-4 substitutions per site per year (95 % BCI: 6.29 × 10-4-1.35 × 10-3), respectively. Notably, the very low Re estimates of SARS-CoV-2 during the recent sampling period may be the result of the successful control of the pandemic in China due to extreme societal lockdown efforts. Our results emphasize the importance of using phylodynamic analyses to provide insights into the roles of various interventions to limit the spread of SARS-CoV-2 in China and beyond.


Subject(s)
Betacoronavirus/classification , Betacoronavirus/genetics , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Genome, Viral , Genomics , Phylogeny , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , China/epidemiology , Disease Outbreaks , Evolution, Molecular , Genomics/methods , Humans , Pandemics
14.
J Transl Med ; 18(1): 278, 2020 07 09.
Article in English | MEDLINE | ID: covidwho-652087

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome (SARS) has been initiating pandemics since the beginning of the century. In December 2019, the world was hit again by a devastating SARS episode that has so far infected almost four million individuals worldwide, with over 200,000 fatalities having already occurred by mid-April 2020, and the infection rate continues to grow exponentially. SARS coronavirus 2 (SARS-CoV-2) is a single stranded RNA pathogen which is characterised by a high mutation rate. It is vital to explore the mutagenic capability of the viral genome that enables SARS-CoV-2 to rapidly jump from one host immunity to another and adapt to the genetic pool of local populations. METHODS: For this study, we analysed 2301 complete viral sequences reported from SARS-CoV-2 infected patients. SARS-CoV-2 host genomes were collected from The Global Initiative on Sharing All Influenza Data (GISAID) database containing 9 genomes from pangolin-CoV origin and 3 genomes from bat-CoV origin, Wuhan SARS-CoV2 reference genome was collected from GeneBank database. The Multiple sequence alignment tool, Clustal Omega was used for genomic sequence alignment. The viral replicating enzyme, 3-chymotrypsin-like cysteine protease (3CLpro) that plays a key role in its pathogenicity was used to assess its affinity with pharmacological inhibitors and repurposed drugs such as anti-viral flavones, biflavanoids, anti-malarial drugs and vitamin supplements. RESULTS: Our results demonstrate that bat-CoV shares > 96% similar identity, while pangolin-CoV shares 85.98% identity with Wuhan SARS-CoV-2 genome. This in-depth analysis has identified 12 novel recurrent mutations in South American and African viral genomes out of which 3 were unique in South America, 4 unique in Africa and 5 were present in-patient isolates from both populations. Using state of the art in silico approaches, this study further investigates the interaction of repurposed drugs with the SARS-CoV-2 3CLpro enzyme, which regulates viral replication machinery. CONCLUSIONS: Overall, this study provides insights into the evolving mutations, with implications to understand viral pathogenicity and possible new strategies for repurposing compounds to combat the nCovid-19 pandemic.


Subject(s)
Betacoronavirus/enzymology , Computer Simulation , Coronavirus Infections/virology , Cysteine Endopeptidases/metabolism , DNA Replication , Drug Repositioning , Geography , Pneumonia, Viral/virology , Viral Nonstructural Proteins/metabolism , Betacoronavirus/genetics , Evolution, Molecular , Genome, Viral , Humans , Molecular Docking Simulation , Mutation/genetics , Mutation Rate , Pandemics , Phylogeny , Virus Assembly
16.
Postgrad Med J ; 96(1137): 408-411, 2020 Jul.
Article in English | MEDLINE | ID: covidwho-639885

ABSTRACT

All animal life on earth is thought to have a common origin and have common genetic mechanisms. Evolution has enabled differentiation of species. Pathogens likewise have evolved within various species and mostly come to a settled dynamic equilibrium such that co-existence results (pathogens ideally should not kill their hosts). Problems arise when pathogens jump species because the new host had not developed any resistance. These infections from related species are known as zoonoses. COVID-19 is the latest example of a virus entering another species but HIV (and various strains of influenza) were previous examples.


Subject(s)
Disease Outbreaks/statistics & numerical data , HIV Infections/transmission , HIV-1/pathogenicity , Simian Acquired Immunodeficiency Syndrome/transmission , Simian Immunodeficiency Virus/pathogenicity , Zoonoses/transmission , Animals , Betacoronavirus/genetics , Betacoronavirus/pathogenicity , Coronavirus Infections/transmission , Coronavirus Infections/virology , Evolution, Molecular , HIV Infections/virology , HIV-1/genetics , Humans , Pandemics , Phylogeny , Pneumonia, Viral/transmission , Pneumonia, Viral/virology , Primates/virology , Simian Acquired Immunodeficiency Syndrome/virology , Simian Immunodeficiency Virus/genetics , Zoonoses/virology
17.
Genes (Basel) ; 11(7)2020 07 07.
Article in English | MEDLINE | ID: covidwho-639723

ABSTRACT

The pandemic caused by the spread of SARS-CoV-2 has led to considerable interest in its evolutionary origin and genome structure. Here, we analyzed mutation patterns in 34 human SARS-CoV-2 isolates and a closely related RaTG13 isolated from Rhinolophus affinis (a horseshoe bat). We also evaluated the CpG dinucleotide contents in SARS-CoV-2 and other human and animal coronavirus genomes. Out of 1136 single nucleotide variations (~4% divergence) between human SARS-CoV-2 and bat RaTG13, 682 (60%) can be attributed to C>U and U>C substitutions, far exceeding other types of substitutions. An accumulation of C>U mutations was also observed in SARS-CoV2 variants that arose within the human population. Globally, the C>U substitutions increased the frequency of codons for hydrophobic amino acids in SARS-CoV-2 peptides, while U>C substitutions decreased it. In contrast to most other coronaviruses, both SARS-CoV-2 and RaTG13 exhibited CpG depletion in their genomes. The data suggest that C-to-U conversion mediated by C deamination played a significant role in the evolution of the SARS-CoV-2 coronavirus. We hypothesize that the high frequency C>U transitions reflect virus adaptation processes in their hosts, and that SARS-CoV-2 could have been evolving for a relatively long period in humans following the transfer from animals before spreading worldwide.


Subject(s)
Betacoronavirus/genetics , Cytosine/metabolism , Evolution, Molecular , SARS Virus/genetics , Uracil/metabolism , Animals , Base Sequence , Betacoronavirus/classification , Betacoronavirus/isolation & purification , Chiroptera/virology , CpG Islands , Humans , Phylogeny , Polymorphism, Single Nucleotide , SARS Virus/classification , SARS Virus/isolation & purification , Spike Glycoprotein, Coronavirus/genetics
18.
J Virol ; 94(18)2020 08 31.
Article in English | MEDLINE | ID: covidwho-639615

ABSTRACT

C3A is a subclone of the human hepatoblastoma HepG2 cell line with strong contact inhibition of growth. We fortuitously found that C3A was more susceptible to human coronavirus HCoV-OC43 infection than HepG2, which was attributed to the increased efficiency of virus entry into C3A cells. In an effort to search for the host cellular protein(s) mediating the differential susceptibility of the two cell lines to HCoV-OC43 infection, we found that ArfGAP with dual pleckstrin homology (PH) domains 2 (ADAP2), gamma-interferon-inducible lysosome/endosome-localized thiolreductase (GILT), and lymphocyte antigen 6 family member E (LY6E), the three cellular proteins identified to function in interference with virus entry, were expressed at significantly higher levels in HepG2 cells. Functional analyses revealed that ectopic expression of LY6E, but not GILT or ADAP2, in HEK 293 cells inhibited the entry of HCoV-O43. While overexpression of LY6E in C3A and A549 cells efficiently inhibited the infection of HCoV-OC43, knockdown of LY6E expression in HepG2 significantly increased its susceptibility to HCoV-OC43 infection. Moreover, we found that LY6E also efficiently restricted the entry mediated by the envelope spike proteins of other human coronaviruses, including the currently pandemic SARS-CoV-2. Interestingly, overexpression of serine protease TMPRSS2 or amphotericin treatment significantly neutralized the IFN-inducible transmembrane 3 (IFITM3) restriction of human coronavirus (CoV) entry, but did not compromise the effect of LY6E on the entry of human coronaviruses. The work reported herein thus demonstrates that LY6E is a critical antiviral immune effector that controls CoV infection and pathogenesis via a mechanism distinct from other factors that modulate CoV entry.IMPORTANCE Virus entry into host cells is one of the key determinants of host range and cell tropism and is subjected to the control of host innate and adaptive immune responses. In the last decade, several interferon-inducible cellular proteins, including IFITMs, GILT, ADAP2, 25CH, and LY6E, had been identified to modulate the infectious entry of a variety of viruses. Particularly, LY6E was recently identified as a host factor that facilitates the entry of several human-pathogenic viruses, including human immunodeficiency virus, influenza A virus, and yellow fever virus. Identification of LY6E as a potent restriction factor of coronaviruses expands the biological function of LY6E and sheds new light on the immunopathogenesis of human coronavirus infection.


Subject(s)
Antigens, Surface/metabolism , Betacoronavirus/physiology , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Coronavirus/physiology , Host-Pathogen Interactions , Pneumonia, Viral/metabolism , Pneumonia, Viral/virology , Virus Internalization , Amino Acid Sequence , Amphotericin B/pharmacology , Betacoronavirus/drug effects , Cell Line , Coronavirus/drug effects , Coronavirus Infections/epidemiology , Disease Susceptibility , Evolution, Molecular , GPI-Linked Proteins/metabolism , Humans , Pandemics , Pneumonia, Viral/epidemiology , Protein Sorting Signals , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism
19.
Nat Struct Mol Biol ; 27(8): 763-767, 2020 08.
Article in English | MEDLINE | ID: covidwho-640223

ABSTRACT

SARS-CoV-2 is thought to have emerged from bats, possibly via a secondary host. Here, we investigate the relationship of spike (S) glycoprotein from SARS-CoV-2 with the S protein of a closely related bat virus, RaTG13. We determined cryo-EM structures for RaTG13 S and for both furin-cleaved and uncleaved SARS-CoV-2 S; we compared these with recently reported structures for uncleaved SARS-CoV-2 S. We also biochemically characterized their relative stabilities and affinities for the SARS-CoV-2 receptor ACE2. Although the overall structures of human and bat virus S proteins are similar, there are key differences in their properties, including a more stable precleavage form of human S and about 1,000-fold tighter binding of SARS-CoV-2 to human receptor. These observations suggest that cleavage at the furin-cleavage site decreases the overall stability of SARS-CoV-2 S and facilitates the adoption of the open conformation that is required for S to bind to the ACE2 receptor.


Subject(s)
Betacoronavirus/genetics , Host-Pathogen Interactions/genetics , Peptidyl-Dipeptidase A/chemistry , Receptors, Virus/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Animals , Betacoronavirus/metabolism , Betacoronavirus/ultrastructure , Binding Sites , Chiroptera/virology , Coronavirus Infections/virology , Cryoelectron Microscopy , Evolution, Molecular , Furin/chemistry , Gene Expression , HEK293 Cells , Humans , Models, Molecular , Pandemics , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/virology , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Protein Isoforms/chemistry , Protein Isoforms/genetics , Protein Isoforms/metabolism , Protein Stability , Proteolysis , Receptors, Virus/genetics , Receptors, Virus/metabolism , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Structural Homology, Protein
20.
Int J Mol Sci ; 21(12)2020 Jun 26.
Article in English | MEDLINE | ID: covidwho-627906

ABSTRACT

The recently emerged SARS-CoV-2 is the cause of the global health crisis of the coronavirus disease 2019 (COVID-19) pandemic. No evidence is yet available for CoV infection into hosts upon zoonotic disease outbreak, although the CoV epidemy resembles influenza viruses, which use sialic acid (SA). Currently, information on SARS-CoV-2 and its receptors is limited. O-acetylated SAs interact with the lectin-like spike glycoprotein of SARS CoV-2 for the initial attachment of viruses to enter into the host cells. SARS-CoV-2 hemagglutinin-esterase (HE) acts as the classical glycan-binding lectin and receptor-degrading enzyme. Most ß-CoVs recognize 9-O-acetyl-SAs but switched to recognizing the 4-O-acetyl-SA form during evolution of CoVs. Type I HE is specific for the 9-O-Ac-SAs and type II HE is specific for 4-O-Ac-SAs. The SA-binding shift proceeds through quasi-synchronous adaptations of the SA-recognition sites of the lectin and esterase domains. The molecular switching of HE acquisition of 4-O-acetyl binding from 9-O-acetyl SA binding is caused by protein-carbohydrate interaction (PCI) or lectin-carbohydrate interaction (LCI). The HE gene was transmitted to a ß-CoV lineage A progenitor by horizontal gene transfer from a 9-O-Ac-SA-specific HEF, as in influenza virus C/D. HE acquisition, and expansion takes place by cross-species transmission over HE evolution. This reflects viral evolutionary adaptation to host SA-containing glycans. Therefore, CoV HE receptor switching precedes virus evolution driven by the SA-glycan diversity of the hosts. The PCI or LCI stereochemistry potentiates the SA-ligand switch by a simple conformational shift of the lectin and esterase domains. Therefore, examination of new emerging viruses can lead to better understanding of virus evolution toward transitional host tropism. A clear example of HE gene transfer is found in the BCoV HE, which prefers 7,9-di-O-Ac-SAs, which is also known to be a target of the bovine torovirus HE. A more exciting case of such a switching event occurs in the murine CoVs, with the example of the ß-CoV lineage A type binding with two different subtypes of the typical 9-O-Ac-SA (type I) and the exclusive 4-O-Ac-SA (type II) attachment factors. The protein structure data for type II HE also imply the virus switching to binding 4-O acetyl SA from 9-O acetyl SA. Principles of the protein-glycan interaction and PCI stereochemistry potentiate the SA-ligand switch via simple conformational shifts of the lectin and esterase domains. Thus, our understanding of natural adaptation can be specified to how carbohydrate/glycan-recognizing proteins/molecules contribute to virus evolution toward host tropism. Under the current circumstances where reliable antiviral therapeutics or vaccination tools are lacking, several trials are underway to examine viral agents. As expected, structural and non-structural proteins of SARS-CoV-2 are currently being targeted for viral therapeutic designation and development. However, the modern global society needs SARS-CoV-2 preventive and therapeutic drugs for infected patients. In this review, the structure and sialobiology of SARS-CoV-2 are discussed in order to encourage and activate public research on glycan-specific interaction-based drug creation in the near future.


Subject(s)
Betacoronavirus/metabolism , Coronavirus Infections/virology , Evolution, Molecular , Host Microbial Interactions/physiology , Pneumonia, Viral/virology , Receptors, Virus/metabolism , Virus Internalization , Acetylesterase/metabolism , Animals , Betacoronavirus/genetics , Binding Sites , Cell Line , Coronavirus/genetics , Esterases , Gene Transfer, Horizontal , Glycosaminoglycans/metabolism , Hemagglutinins, Viral/genetics , Humans , Lectins/metabolism , Pandemics , Polysaccharides , Receptors, Virus/chemistry , Sialic Acids/chemistry , Sialic Acids/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/physiology , Torovirus , Viral Fusion Proteins/genetics
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