Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
1.
Cell Rep ; 37(2): 109806, 2021 10 12.
Article in English | MEDLINE | ID: covidwho-1466094

ABSTRACT

Tactical disruption of protein synthesis is an attractive therapeutic strategy, with the first-in-class eIF4A-targeting compound zotatifin in clinical evaluation for cancer and COVID-19. The full cellular impact and mechanisms of these potent molecules are undefined at a proteomic level. Here, we report mass spectrometry analysis of translational reprogramming by rocaglates, cap-dependent initiation disruptors that include zotatifin. We find effects to be far more complex than simple "translational inhibition" as currently defined. Translatome analysis by TMT-pSILAC (tandem mass tag-pulse stable isotope labeling with amino acids in cell culture mass spectrometry) reveals myriad upregulated proteins that drive hitherto unrecognized cytotoxic mechanisms, including GEF-H1-mediated anti-survival RHOA/JNK activation. Surprisingly, these responses are not replicated by eIF4A silencing, indicating a broader translational adaptation than currently understood. Translation machinery analysis by MATRIX (mass spectrometry analysis of active translation factors using ribosome density fractionation and isotopic labeling experiments) identifies rocaglate-specific dependence on specific translation factors including eEF1ε1 that drive translatome remodeling. Our proteome-level interrogation reveals that the complete cellular response to these historical "translation inhibitors" is mediated by comprehensive translational landscape remodeling.


Subject(s)
Protein Biosynthesis/drug effects , Protein Synthesis Inhibitors/pharmacology , Animals , Benzofurans/pharmacology , Cell Line, Tumor , Eukaryotic Initiation Factor-4A/drug effects , Eukaryotic Initiation Factor-4A/metabolism , Humans , Male , Mice , Mice, Inbred NOD , Primary Cell Culture , Protein Biosynthesis/physiology , Proteomics/methods , Ribosomes/metabolism , Transcriptome/drug effects , Transcriptome/genetics , Triterpenes/pharmacology
2.
Cell Rep ; 37(3): 109841, 2021 10 19.
Article in English | MEDLINE | ID: covidwho-1439922

ABSTRACT

Nonstructural protein 1 (nsp1) is a coronavirus (CoV) virulence factor that restricts cellular gene expression by inhibiting translation through blocking the mRNA entry channel of the 40S ribosomal subunit and by promoting mRNA degradation. We perform a detailed structure-guided mutational analysis of severe acute respiratory syndrome (SARS)-CoV-2 nsp1, revealing insights into how it coordinates these activities against host but not viral mRNA. We find that residues in the N-terminal and central regions of nsp1 not involved in docking into the 40S mRNA entry channel nonetheless stabilize its association with the ribosome and mRNA, both enhancing its restriction of host gene expression and enabling mRNA containing the SARS-CoV-2 leader sequence to escape translational repression. These data support a model in which viral mRNA binding functionally alters the association of nsp1 with the ribosome, which has implications for drug targeting and understanding how engineered or emerging mutations in SARS-CoV-2 nsp1 could attenuate the virus.


Subject(s)
COVID-19/genetics , Gene Expression Regulation, Viral , SARS-CoV-2/genetics , Viral Nonstructural Proteins/metabolism , Anisotropy , COVID-19/immunology , DNA Mutational Analysis , Female , Gene Expression Profiling , Green Fluorescent Proteins/metabolism , HEK293 Cells , Humans , Kinetics , Mutation , Phenotype , Point Mutation , Protein Biosynthesis , Protein Domains , RNA Stability , Ribosome Subunits, Small, Eukaryotic/metabolism , Ribosomes/metabolism
3.
Commun Biol ; 4(1): 715, 2021 06 10.
Article in English | MEDLINE | ID: covidwho-1387495

ABSTRACT

While SARS-CoV-2 is causing modern human history's most serious health crisis and upending our way of life, clinical and basic research on the virus is advancing rapidly, leading to fascinating discoveries. Two studies have revealed how the viral virulence factor, nonstructural protein 1 (Nsp1), binds human ribosomes to inhibit host cell translation. Here, we examine the main conclusions on the molecular activity of Nsp1 and its role in suppressing innate immune responses. We discuss different scenarios potentially explaining how the viral RNA can bypass its own translation blockage and speculate on the suitability of Nsp1 as a therapeutic target.


Subject(s)
Host-Pathogen Interactions/physiology , Ribosomes/virology , SARS-CoV-2/pathogenicity , Viral Nonstructural Proteins/metabolism , 5' Untranslated Regions , Gene Expression Regulation, Viral , Humans , Immunity, Innate , Protein Biosynthesis , RNA, Messenger/metabolism , Ribosomes/metabolism , SARS-CoV-2/genetics , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics
4.
ACS Chem Biol ; 16(8): 1469-1481, 2021 08 20.
Article in English | MEDLINE | ID: covidwho-1387143

ABSTRACT

The programmed -1 ribosomal frameshifting element (PFSE) of SARS-CoV-2 is a well conserved structured RNA found in all coronaviruses' genomes. By adopting a pseudoknot structure in the presence of the ribosome, the PFSE promotes a ribosomal frameshifting event near the stop codon of the first open reading frame Orf1a during translation of the polyprotein pp1a. Frameshifting results in continuation of pp1a via a new open reading frame, Orf1b, that produces the longer pp1ab polyprotein. Polyproteins pp1a and pp1ab produce nonstructural proteins NSPs 1-10 and NSPs 1-16, respectively, which contribute vital functions during the viral life cycle and must be present in the proper stoichiometry. Both drugs and sequence alterations that affect the stability of the -1 programmed ribosomal frameshifting element disrupt the stoichiometry of the NSPs produced, which compromise viral replication. For this reason, the -1 programmed frameshifting element is considered a promising drug target. Using chaperone assisted RNA crystallography, we successfully crystallized and solved the three-dimensional structure of the PFSE. We observe a three-stem H-type pseudoknot structure with the three stems stacked in a vertical orientation stabilized by two triple base pairs at the stem 1/stem 2 and stem 1/stem 3 junctions. This structure provides a new conformation of PFSE distinct from the bent conformations inferred from midresolution cryo-EM models and provides a high-resolution framework for mechanistic investigations and structure-based drug design.


Subject(s)
Crystallography/methods , Frameshifting, Ribosomal/physiology , Molecular Chaperones , RNA, Viral/metabolism , SARS-CoV-2/metabolism , Humans , Models, Molecular , Nucleic Acid Conformation , RNA, Viral/genetics , Ribosomes/metabolism , SARS-CoV-2/genetics , Viral Proteins/chemistry , Viral Proteins/genetics , Viral Proteins/metabolism , Virus Replication/physiology
5.
mBio ; 12(3): e0142321, 2021 06 29.
Article in English | MEDLINE | ID: covidwho-1280400

ABSTRACT

The catalytic subunit of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA-dependent RNA polymerase (RdRp) Nsp12 has a unique nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain that transfers nucleoside monophosphates to the Nsp9 protein and the nascent RNA. The NiRAN and RdRp modules form a dynamic interface distant from their catalytic sites, and both activities are essential for viral replication. We report that codon-optimized (for the pause-free translation in bacterial cells) Nsp12 exists in an inactive state in which NiRAN-RdRp interactions are broken, whereas translation by slow ribosomes and incubation with accessory Nsp7/8 subunits or nucleoside triphosphates (NTPs) partially rescue RdRp activity. Our data show that adenosine and remdesivir triphosphates promote the synthesis of A-less RNAs, as does ppGpp, while amino acid substitutions at the NiRAN-RdRp interface augment activation, suggesting that ligand binding to the NiRAN catalytic site modulates RdRp activity. The existence of allosterically linked nucleotidyl transferase sites that utilize the same substrates has important implications for understanding the mechanism of SARS-CoV-2 replication and the design of its inhibitors. IMPORTANCE In vitro interrogations of the central replicative complex of SARS-CoV-2, RNA-dependent RNA polymerase (RdRp), by structural, biochemical, and biophysical methods yielded an unprecedented windfall of information that, in turn, instructs drug development and administration, genomic surveillance, and other aspects of the evolving pandemic response. They also illuminated the vast disparity in the methods used to produce RdRp for experimental work and the hidden impact that this has on enzyme activity and research outcomes. In this report, we elucidate the positive and negative effects of codon optimization on the activity and folding of the recombinant RdRp and detail the design of a highly sensitive in vitro assay of RdRp-dependent RNA synthesis. Using this assay, we demonstrate that RdRp is allosterically activated by nontemplating phosphorylated nucleotides, including naturally occurring alarmone ppGpp and synthetic remdesivir triphosphate.


Subject(s)
Adenosine Triphosphate/analogs & derivatives , Antiviral Agents/pharmacology , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Guanosine Tetraphosphate/pharmacology , SARS-CoV-2/drug effects , Adenosine Triphosphate/pharmacology , COVID-19/drug therapy , Catalytic Domain/physiology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Humans , Ribosomes/metabolism
6.
Int J Mol Sci ; 22(12)2021 Jun 17.
Article in English | MEDLINE | ID: covidwho-1273459

ABSTRACT

The SARS-CoV-2 Spike glycoprotein (S protein) acquired a unique new 4 amino acid -PRRA- insertion sequence at amino acid residues (aa) 681-684 that forms a new furin cleavage site in S protein as well as several new glycosylation sites. We studied various statistical properties of the -PRRA- insertion at the RNA level (CCUCGGCGGGCA). The nucleotide composition and codon usage of this sequence are different from the rest of the SARS-CoV-2 genome. One of such features is two tandem CGG codons, although the CGG codon is the rarest codon in the SARS-CoV-2 genome. This suggests that the insertion sequence could cause ribosome pausing as the result of these rare codons. Due to population variants, the Nextstrain divergence measure of the CCU codon is extremely large. We cannot exclude that this divergence might affect host immune responses/effectiveness of SARS-CoV-2 vaccines, possibilities awaiting further investigation. Our experimental studies show that the expression level of original RNA sequence "wildtype" spike protein is much lower than for codon-optimized spike protein in all studied cell lines. Interestingly, the original spike sequence produces a higher titer of pseudoviral particles and a higher level of infection. Further mutagenesis experiments suggest that this dual-effect insert, comprised of a combination of overlapping translation pausing and furin sites, has allowed SARS-CoV-2 to infect its new host (human) more readily. This underlines the importance of ribosome pausing to allow efficient regulation of protein expression and also of cotranslational subdomain folding.


Subject(s)
RNA, Viral/metabolism , Ribosomes/metabolism , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Animals , Base Sequence , COS Cells , COVID-19/pathology , COVID-19/virology , Chlorocebus aethiops , Codon Usage , HEK293 Cells , Humans , Mutagenesis , SARS-CoV-2/isolation & purification , Sequence Alignment , Spike Glycoprotein, Coronavirus/metabolism
7.
Science ; 372(6548): 1306-1313, 2021 06 18.
Article in English | MEDLINE | ID: covidwho-1228853

ABSTRACT

Programmed ribosomal frameshifting is a key event during translation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA genome that allows synthesis of the viral RNA-dependent RNA polymerase and downstream proteins. Here, we present the cryo-electron microscopy structure of a translating mammalian ribosome primed for frameshifting on the viral RNA. The viral RNA adopts a pseudoknot structure that lodges at the entry to the ribosomal messenger RNA (mRNA) channel to generate tension in the mRNA and promote frameshifting, whereas the nascent viral polyprotein forms distinct interactions with the ribosomal tunnel. Biochemical experiments validate the structural observations and reveal mechanistic and regulatory features that influence frameshifting efficiency. Finally, we compare compounds previously shown to reduce frameshifting with respect to their ability to inhibit SARS-CoV-2 replication, establishing coronavirus frameshifting as a target for antiviral intervention.


Subject(s)
Frameshifting, Ribosomal , RNA, Viral/genetics , Ribosomes/ultrastructure , SARS-CoV-2/genetics , Viral Proteins/biosynthesis , Animals , Antiviral Agents/pharmacology , Codon, Terminator , Coronavirus RNA-Dependent RNA Polymerase/biosynthesis , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Coronavirus RNA-Dependent RNA Polymerase/genetics , Cryoelectron Microscopy , Fluoroquinolones/pharmacology , Frameshifting, Ribosomal/drug effects , Genome, Viral , Humans , Image Processing, Computer-Assisted , Models, Molecular , Nucleic Acid Conformation , Open Reading Frames , Protein Folding , RNA, Messenger/chemistry , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Ribosomal, 18S/chemistry , RNA, Ribosomal, 18S/genetics , RNA, Ribosomal, 18S/metabolism , RNA, Viral/chemistry , RNA, Viral/metabolism , Ribosomal Proteins/metabolism , Ribosomes/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Viral Proteins/chemistry , Viral Proteins/genetics , Virus Replication/drug effects
8.
Nature ; 594(7862): 240-245, 2021 06.
Article in English | MEDLINE | ID: covidwho-1225510

ABSTRACT

The coronavirus SARS-CoV-2 is the cause of the ongoing pandemic of COVID-191. Coronaviruses have developed a variety of mechanisms to repress host mRNA translation to allow the translation of viral mRNA, and concomitantly block the cellular innate immune response2,3. Although several different proteins of SARS-CoV-2 have previously been implicated in shutting off host expression4-7, a comprehensive picture of the effects of SARS-CoV-2 infection on cellular gene expression is lacking. Here we combine RNA sequencing, ribosome profiling and metabolic labelling of newly synthesized RNA to comprehensively define the mechanisms that are used by SARS-CoV-2 to shut off cellular protein synthesis. We show that infection leads to a global reduction in translation, but that viral transcripts are not preferentially translated. Instead, we find that infection leads to the accelerated degradation of cytosolic cellular mRNAs, which facilitates viral takeover of the mRNA pool in infected cells. We reveal that the translation of transcripts that are induced in response to infection (including innate immune genes) is impaired. We demonstrate this impairment is probably mediated by inhibition of nuclear mRNA export, which prevents newly transcribed cellular mRNA from accessing ribosomes. Overall, our results uncover a multipronged strategy that is used by SARS-CoV-2 to take over the translation machinery and to suppress host defences.


Subject(s)
COVID-19/metabolism , COVID-19/virology , Host-Pathogen Interactions , Protein Biosynthesis , SARS-CoV-2/pathogenicity , 5' Untranslated Regions/genetics , COVID-19/genetics , COVID-19/immunology , Cell Line , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate/genetics , Protein Biosynthesis/genetics , RNA Stability , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Viral/metabolism , Ribosomes/metabolism , Viral Nonstructural Proteins/metabolism
9.
Methods Mol Biol ; 2203: 231-238, 2020.
Article in English | MEDLINE | ID: covidwho-729910

ABSTRACT

Ribopuromycylation enables the visualization and quantitation of translation on a cellular level by immunofluorescence or in total using standard western blotting. This technique uses ribosome catalyzed puromycylation of nascent chains followed by immobilization on the ribosome by antibiotic chain elongation inhibitor emetine. Detection of puromycylated ribosome-bound nascent chains can then be achieved using a puromycin-specific antibody.


Subject(s)
Coronavirus/genetics , Puromycin/pharmacology , Coronavirus Infections , Fluorescent Antibody Technique , Host-Pathogen Interactions , Humans , Protein Biosynthesis , Ribosomes/drug effects , Ribosomes/metabolism
10.
Int J Mol Sci ; 22(7)2021 Mar 25.
Article in English | MEDLINE | ID: covidwho-1154425

ABSTRACT

The global COVID-19 pandemic caused by SARS-CoV-2 has resulted in over 2.2 million deaths. Disease outcomes range from asymptomatic to severe with, so far, minimal genotypic change to the virus so understanding the host response is paramount. Transcriptomics has become incredibly important in understanding host-pathogen interactions; however, post-transcriptional regulation plays an important role in infection and immunity through translation and mRNA stability, allowing tight control over potent host responses by both the host and the invading virus. Here, we apply ribosome profiling to assess post-transcriptional regulation of host genes during SARS-CoV-2 infection of a human lung epithelial cell line (Calu-3). We have identified numerous transcription factors (JUN, ZBTB20, ATF3, HIVEP2 and EGR1) as well as select antiviral cytokine genes, namely IFNB1, IFNL1,2 and 3, IL-6 and CCL5, that are restricted at the post-transcriptional level by SARS-CoV-2 infection and discuss the impact this would have on the host response to infection. This early phase restriction of antiviral transcripts in the lungs may allow high viral load and consequent immune dysregulation typically seen in SARS-CoV-2 infection.


Subject(s)
Cytokines/genetics , RNA Processing, Post-Transcriptional , Ribosomes/metabolism , Ribosomes/virology , SARS-CoV-2/immunology , Transcription Factors/genetics , Animals , Antiviral Agents/antagonists & inhibitors , Cell Line, Tumor , Chlorocebus aethiops , Computational Biology , Cytokines/metabolism , Epithelial Cells/immunology , Epithelial Cells/virology , Gene Expression Profiling , Host Microbial Interactions , Humans , Immunity, Innate/genetics , Lung/immunology , Lung/virology , RNA, Messenger/metabolism , RNA-Seq , Ribosomes/genetics , SARS-CoV-2/metabolism , Transcription Factors/metabolism , Transcriptome , Vero Cells
11.
Pharm Res ; 38(3): 473-478, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-1117456

ABSTRACT

The COVID-19 pandemic has left scientists and clinicians no choice but a race to find solutions to save lives while controlling the rapid spreading. Messenger RNA (mRNA)-based vaccines have become the front-runners because of their safety profiles, precise and reproducible immune response with more cost-effective and faster production than other types of vaccines. However, the physicochemical properties of naked mRNA necessitate innovative delivery technologies to ferry these 'messengers' to ribosomes inside cells by crossing various barriers and subsequently induce an immune response. Intracellular delivery followed by endosomal escape represents the key strategies for cytoplasmic delivery of mRNA vaccines to the target. This Perspective provides insights into how state-of-the-art nanotechnology helps break the delivery barriers and advance the development of mRNA vaccines. The challenges remaining and future perspectives are outlined.


Subject(s)
COVID-19 Vaccines/therapeutic use , COVID-19/prevention & control , Cytoplasm/metabolism , Drug Carriers , Lipids/chemistry , Nanoparticles , Ribosomes/metabolism , Vaccines, Synthetic/therapeutic use , Animals , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/pharmacokinetics , Drug Compounding , Humans , Nanomedicine , Vaccines, Synthetic/chemistry
12.
Nucleic Acids Res ; 49(7): e40, 2021 04 19.
Article in English | MEDLINE | ID: covidwho-1050155

ABSTRACT

Generation of conditional knockout (cKO) and various gene-modified cells is laborious and time-consuming. Here, we established an all-in-one cKO system, which enables highly efficient generation of cKO cells and simultaneous gene modifications, including epitope tagging and reporter gene knock-in. We applied this system to mouse embryonic stem cells (ESCs) and generated RNA helicase Ddx1 cKO ESCs. The targeted cells displayed endogenous promoter-driven EGFP and FLAG-tagged DDX1 expression, and they were converted to Ddx1 KO via FLP recombinase. We further established TetFE ESCs, which carried a reverse tetracycline transactivator (rtTA) expression cassette and a tetracycline response element (TRE)-regulated FLPERT2 cassette in the Gt(ROSA26)Sor locus for instant and tightly regulated induction of gene KO. By utilizing TetFE Ddx1F/F ESCs, we isolated highly pure Ddx1F/F and Ddx1-/- ESCs and found that loss of Ddx1 caused rRNA processing defects, thereby activating the ribosome stress-p53 pathway. We also demonstrated cKO of various genes in ESCs and homologous recombination-non-proficient human HT1080 cells. The frequency of cKO clones was remarkably high for both cell types and reached up to 96% when EGFP-positive clones were analyzed. This all-in-one cKO system will be a powerful tool for rapid and precise analyses of gene functions.


Subject(s)
DEAD-box RNA Helicases/metabolism , Gene Knockout Techniques/methods , RNA, Ribosomal/metabolism , Animals , Cell Line , Embryonic Stem Cells , Fibroblasts , Gene Expression , Gene Knock-In Techniques , Humans , Mice , Mice, Inbred C57BL , RNA Processing, Post-Transcriptional , Ribosomes/metabolism
13.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Article in English | MEDLINE | ID: covidwho-1042832

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a beta-CoV that recently emerged as a human pathogen and is the causative agent of the COVID-19 pandemic. A molecular framework of how the virus manipulates host cellular machinery to facilitate infection remains unclear. Here, we focus on SARS-CoV-2 NSP1, which is proposed to be a virulence factor that inhibits protein synthesis by directly binding the human ribosome. We demonstrate biochemically that NSP1 inhibits translation of model human and SARS-CoV-2 messenger RNAs (mRNAs). NSP1 specifically binds to the small (40S) ribosomal subunit, which is required for translation inhibition. Using single-molecule fluorescence assays to monitor NSP1-40S subunit binding in real time, we determine that eukaryotic translation initiation factors (eIFs) allosterically modulate the interaction of NSP1 with ribosomal preinitiation complexes in the absence of mRNA. We further elucidate that NSP1 competes with RNA segments downstream of the start codon to bind the 40S subunit and that the protein is unable to associate rapidly with 80S ribosomes assembled on an mRNA. Collectively, our findings support a model where NSP1 proteins from viruses in at least two subgenera of beta-CoVs associate with the open head conformation of the 40S subunit to inhibit an early step of translation, by preventing accommodation of mRNA within the entry channel.


Subject(s)
COVID-19/genetics , COVID-19/metabolism , COVID-19/virology , RNA, Messenger/metabolism , Ribosomes/metabolism , SARS-CoV-2/metabolism , Viral Nonstructural Proteins/metabolism , Eukaryotic Initiation Factors/metabolism , Humans , Pandemics , Peptide Chain Initiation, Translational/genetics , Protein Biosynthesis , Protein Processing, Post-Translational , RNA, Messenger/genetics , RNA, Viral/genetics , Ribosomal Proteins/genetics , Ribosomal Proteins/metabolism , Ribosome Subunits, Small, Eukaryotic/metabolism , Ribosomes/genetics , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , Viral Nonstructural Proteins/genetics
14.
J Proteome Res ; 19(11): 4275-4290, 2020 11 06.
Article in English | MEDLINE | ID: covidwho-974861

ABSTRACT

SARS-CoV-2 (COVID-19) has infected millions of people worldwide, with lethality in hundreds of thousands. The rapid publication of information, both regarding the clinical course and the viral biology, has yielded incredible knowledge of the virus. In this review, we address the insights gained for the SARS-CoV-2 proteome, which we have integrated into the Viral Integrated Structural Evolution Dynamic Database, a publicly available resource. Integrating evolutionary, structural, and interaction data with human proteins, we present how the SARS-CoV-2 proteome interacts with human disorders and risk factors ranging from cytokine storm, hyperferritinemic septic, coagulopathic, cardiac, immune, and rare disease-based genetics. The most noteworthy human genetic potential of SARS-CoV-2 is that of the nucleocapsid protein, where it is known to contribute to the inhibition of the biological process known as nonsense-mediated decay. This inhibition has the potential to not only regulate about 10% of all biological transcripts through altered ribosomal biology but also associate with viral-induced genetics, where suppressed human variants are activated to drive dominant, negative outcomes within cells. As we understand more of the dynamic and complex biological pathways that the proteome of SARS-CoV-2 utilizes for entry into cells, for replication, and for release from human cells, we can understand more risk factors for severe/lethal outcomes in patients and novel pharmaceutical interventions that may mitigate future pandemics.


Subject(s)
Betacoronavirus , Coronavirus Infections , Host-Pathogen Interactions , Pandemics , Pneumonia, Viral , Proteome , Ribosomes , COVID-19 , Coronavirus Infections/genetics , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Databases, Genetic , Gene Expression Profiling , Humans , Pneumonia, Viral/genetics , Pneumonia, Viral/metabolism , Pneumonia, Viral/virology , Proteome/genetics , Proteome/metabolism , Ribosomes/genetics , Ribosomes/metabolism , Ribosomes/virology , SARS-CoV-2 , Transcriptome , Viral Proteins
15.
Med Hypotheses ; 144: 110245, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-753093

ABSTRACT

(1) Background: RNA viruses and especially coronaviruses could act inside host cells not only by building their own proteins, but also by perturbing the cell metabolism. We show the possibility of miRNA-like inhibitions by the SARS-CoV-2 concerning for example the hemoglobin and type I interferons syntheses, hence highly perturbing oxygen distribution in vital organs and immune response as described by clinicians; (2) Hypothesis: We hypothesize that short RNA sequences (about 20 nucleotides in length) from the SARS-CoV-2 virus genome can inhibit the translation of human proteins involved in oxygen metabolism, olfactory perception and immune system. (3) Methods: We compare RNA subsequences of SARS-CoV-2 protein S and RNA-dependent RNA polymerase genes to mRNA sequences of beta-globin and type I interferons; (4) Results: RNA subsequences longer than eight nucleotides from SARS-CoV-2 genome could hybridize subsequences of the mRNA of beta-globin and of type I interferons; (5) Conclusions: Beyond viral protein production, COVID-19 might affect vital processes like host oxygen transport and immune response.


Subject(s)
COVID-19/virology , Interferon Type I/metabolism , MicroRNAs/metabolism , Oxygen/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , beta-Globins/metabolism , COVID-19/drug therapy , COVID-19/metabolism , Genome, Viral , Hemoglobins/metabolism , Humans , Immune System , Open Reading Frames , Pandemics , Protein Interaction Mapping , RNA, Messenger/metabolism , Ribosomes/metabolism , Smell , Virus Replication
16.
Nature ; 589(7840): 125-130, 2021 01.
Article in English | MEDLINE | ID: covidwho-752477

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing coronavirus disease 2019 (COVID-19) pandemic1. To understand the pathogenicity and antigenic potential of SARS-CoV-2 and to develop therapeutic tools, it is essential to profile the full repertoire of its expressed proteins. The current map of SARS-CoV-2 coding capacity is based on computational predictions and relies on homology with other coronaviruses. As the protein complement varies among coronaviruses, especially in regard to the variety of accessory proteins, it is crucial to characterize the specific range of SARS-CoV-2 proteins in an unbiased and open-ended manner. Here, using a suite of ribosome-profiling techniques2-4, we present a high-resolution map of coding regions in the SARS-CoV-2 genome, which enables us to accurately quantify the expression of canonical viral open reading frames (ORFs) and to identify 23 unannotated viral ORFs. These ORFs include upstream ORFs that are likely to have a regulatory role, several in-frame internal ORFs within existing ORFs, resulting in N-terminally truncated products, as well as internal out-of-frame ORFs, which generate novel polypeptides. We further show that viral mRNAs are not translated more efficiently than host mRNAs; instead, virus translation dominates host translation because of the high levels of viral transcripts. Our work provides a resource that will form the basis of future functional studies.


Subject(s)
Gene Expression Profiling , Genome, Viral/genetics , Open Reading Frames/genetics , Protein Biosynthesis , SARS-CoV-2/genetics , Viral Proteins/biosynthesis , Viral Proteins/genetics , Animals , Cell Line , Humans , Molecular Sequence Annotation , Peptides/genetics , Peptides/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism , Ribosomes/metabolism , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Viral Proteins/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...