6 results on '"V. Horova"'
Search Results
2. Localization of SARS-CoV-2 Capping Enzymes Revealed by an Antibody against the nsp10 Subunit.
- Author
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Horova V, Landova B, Hodek J, Chalupsky K, Krafcikova P, Chalupska D, Duchoslav V, Weber J, Boura E, and Klima M
- Subjects
- Antibodies, Monoclonal analysis, Humans, Methyltransferases analysis, Methyltransferases genetics, Protein Transport, RNA Caps metabolism, RNA, Viral metabolism, SARS-CoV-2 chemistry, SARS-CoV-2 genetics, Viral Nonstructural Proteins analysis, Viral Nonstructural Proteins genetics, Viral Regulatory and Accessory Proteins analysis, Viral Regulatory and Accessory Proteins genetics, COVID-19 virology, Methyltransferases metabolism, RNA Caps genetics, RNA, Viral genetics, SARS-CoV-2 enzymology, Viral Nonstructural Proteins metabolism, Viral Regulatory and Accessory Proteins metabolism
- Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease-19 pandemic. One of the key components of the coronavirus replication complex are the RNA methyltransferases (MTases), RNA-modifying enzymes crucial for RNA cap formation. Recently, the structure of the 2'- O MTase has become available; however, its biological characterization within the infected cells remains largely elusive. Here, we report a novel monoclonal antibody directed against the SARS-CoV-2 non-structural protein nsp10, a subunit of both the 2'- O RNA and N7 MTase protein complexes. Using this antibody, we investigated the subcellular localization of the SARS-CoV-2 MTases in cells infected with the SARS-CoV-2.
- Published
- 2021
- Full Text
- View/download PDF
3. Structural basis for hijacking of the host ACBD3 protein by bovine and porcine enteroviruses and kobuviruses.
- Author
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Smola M, Horova V, Boura E, and Klima M
- Subjects
- Animals, Cattle, Cell Line, Enterovirus Infections veterinary, Enterovirus Infections virology, Enteroviruses, Porcine genetics, HEK293 Cells, Humans, Kobuvirus genetics, Picornaviridae Infections veterinary, Picornaviridae Infections virology, Swine, Viral Proteins genetics, Viral Proteins metabolism, Virus Replication genetics, Adaptor Proteins, Signal Transducing metabolism, Enterovirus Infections metabolism, Enterovirus, Bovine pathogenicity, Enteroviruses, Porcine pathogenicity, Kobuvirus pathogenicity, Membrane Proteins metabolism, Picornaviridae Infections metabolism
- Abstract
Picornaviruses infect a wide range of mammals including livestock such as cattle and swine. As with other picornavirus genera such as Aphthovirus, there is emerging evidence of a significant economic impact of livestock infections caused by members of the genera Enterovirus and Kobuvirus. While the human-infecting enteroviruses and kobuviruses have been intensively studied during the past decades in great detail, research on livestock-infecting viruses has been mostly limited to the genomic characterization of the viral strains identified worldwide. Here, we extend our previous studies of the structure and function of the complexes composed of the non-structural 3A proteins of human-infecting enteroviruses and kobuviruses and the host ACBD3 protein and present a structural and functional characterization of the complexes of the following livestock-infecting picornaviruses: bovine enteroviruses EV-E and EV-F, porcine enterovirus EV-G, and porcine kobuvirus AiV-C. We present a series of crystal structures of these complexes and demonstrate the role of these complexes in facilitation of viral replication.
- Published
- 2020
- Full Text
- View/download PDF
4. Structures of kobuviral and siciniviral polymerases reveal conserved mechanism of picornaviral polymerase activation.
- Author
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Dubankova A, Horova V, Klima M, and Boura E
- Subjects
- Crystallography, X-Ray, Flow Cytometry, HeLa Cells, Humans, Hydrogen Bonding, Mutagenesis, Site-Directed, RNA-Dependent RNA Polymerase chemistry, RNA-Dependent RNA Polymerase genetics, Viral Proteins chemistry, Viral Proteins genetics, Kobuvirus enzymology, Picornaviridae enzymology, RNA-Dependent RNA Polymerase metabolism, Viral Proteins metabolism
- Abstract
RNA-dependent RNA polymerase 3D
pol is a key enzyme for the replication of picornaviruses. The viral genome is translated into a single polyprotein that is subsequently proteolytically processed into matured products. The 3Dpol enzyme arises from a stable 3CD precursor that has high proteolytic activity but no polymerase activity. Upon cleavage of the precursor the newly established N-terminus of 3Dpol is liberated and inserts itself into a pocket on the surface of the 3Dpol enzyme. The essential residue for this mechanism is the very first glycine that is conserved among almost all picornaviruses. However, kobuviruses and siciniviruses have a serine residue instead. Intrigued by this anomaly we sought to solve the crystal structure of these 3Dpol enzymes. The structures revealed a unique fold of the 3Dpol N-termini but the very first serine residues were inserted into a charged pocket in a similar manner as the glycine residue in other picornaviruses. These structures revealed a common underlying mechanism of 3Dpol activation that lies in activation of the α10 helix containing a key catalytical residue Asp238 that forms a hydrogen bond with the 2' hydroxyl group of the incoming NTP nucleotide., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
5. Convergent evolution in the mechanisms of ACBD3 recruitment to picornavirus replication sites.
- Author
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Horova V, Lyoo H, Różycki B, Chalupska D, Smola M, Humpolickova J, Strating JRPM, van Kuppeveld FJM, Boura E, and Klima M
- Subjects
- Adaptor Proteins, Signal Transducing chemistry, Adaptor Proteins, Signal Transducing genetics, Amino Acid Sequence, Crystallization, Crystallography, X-Ray, HEK293 Cells, Humans, Membrane Proteins chemistry, Membrane Proteins genetics, Models, Molecular, Mutation, Phosphotransferases (Alcohol Group Acceptor) genetics, Protein Binding, Protein Conformation, Sequence Homology, Viral Proteins chemistry, Viral Proteins genetics, Adaptor Proteins, Signal Transducing metabolism, Host-Pathogen Interactions, Membrane Proteins metabolism, Phosphotransferases (Alcohol Group Acceptor) metabolism, Picornaviridae physiology, Viral Proteins metabolism, Virus Replication
- Abstract
Enteroviruses, members of the family of picornaviruses, are the most common viral infectious agents in humans causing a broad spectrum of diseases ranging from mild respiratory illnesses to life-threatening infections. To efficiently replicate within the host cell, enteroviruses hijack several host factors, such as ACBD3. ACBD3 facilitates replication of various enterovirus species, however, structural determinants of ACBD3 recruitment to the viral replication sites are poorly understood. Here, we present a structural characterization of the interaction between ACBD3 and the non-structural 3A proteins of four representative enteroviruses (poliovirus, enterovirus A71, enterovirus D68, and rhinovirus B14). In addition, we describe the details of the 3A-3A interaction causing the assembly of the ACBD3-3A heterotetramers and the interaction between the ACBD3-3A complex and the lipid bilayer. Using structure-guided identification of the point mutations disrupting these interactions, we demonstrate their roles in the intracellular localization of these proteins, recruitment of downstream effectors of ACBD3, and facilitation of enterovirus replication. These structures uncovered a striking convergence in the mechanisms of how enteroviruses and kobuviruses, members of a distinct group of picornaviruses that also rely on ACBD3, recruit ACBD3 and its downstream effectors to the sites of viral replication., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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- View/download PDF
6. Inhibition of vacuolar ATPase attenuates the TRAIL-induced activation of caspase-8 and modulates the trafficking of TRAIL receptosomes.
- Author
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Horova V, Hradilova N, Jelinkova I, Koc M, Svadlenka J, Brazina J, Klima M, Slavik J, Hyrslova Vaculova A, and Andera L
- Subjects
- Apoptosis, CASP8 and FADD-Like Apoptosis Regulating Protein metabolism, Cell Line, Tumor, Death Domain Receptor Signaling Adaptor Proteins metabolism, Down-Regulation, Enzyme Activation, Humans, Hydrogen-Ion Concentration, Macrolides pharmacology, Protein Transport, Receptors, TNF-Related Apoptosis-Inducing Ligand metabolism, Signal Transduction drug effects, Sphingolipids physiology, Sphingomyelin Phosphodiesterase metabolism, Vacuolar Proton-Translocating ATPases metabolism, Antineoplastic Agents pharmacology, Caspase 8 metabolism, Endosomes metabolism, TNF-Related Apoptosis-Inducing Ligand pharmacology, Vacuolar Proton-Translocating ATPases antagonists & inhibitors
- Abstract
Tumour necrosis factor (TNF) related apoptosis inducing ligand (TRAIL), a membrane-bound ligand from the TNF family, has attracted significant attention due to its rather specific and effective ability to induce apoptotic death in various types of cancer cells via binding to and activating its pro-apoptotic death receptors. However, a significant number of primary cancer cells often develop resistance to TRAIL treatment, and the signalling platform behind this phenomenon is not fully understood. Upon blocking endosomal acidification by the vacuolar ATPase (V-ATPase) inhibitors bafilomycin A1 (BafA1) or concanamycin A, we observed a significantly reduced initial sensitivity of several, mainly colorectal, tumour cell lines to TRAIL-induced apoptosis. In cells pretreated with these inhibitors, the TRAIL-induced processing of caspase-8 and the aggregation and trafficking of the TRAIL receptor complexes were temporarily attenuated. Nuclear factor κB or mitogen activated protein/stress kinase signalling from the activated TRAIL receptors remained unchanged, and neither possible lysosomal permeabilization nor acid sphingomyelinase was involved in this process. The cell surface expression of TRAIL receptors and their TRAIL-induced internalization were not affected by V-ATPase inhibitors. The inhibitory effect of BafA1, however, was blunted by knockdown of the caspase-8 inhibitor cFLIP. Altogether, the data obtained provide the first evidence that endosomal acidification could represent an important regulatory node in the proximal part of TRAIL-induced pro-apoptotic signalling., (© 2013 FEBS.)
- Published
- 2013
- Full Text
- View/download PDF
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