Download or read book Studies on the Influenza Virus RNA Polymerase written by K. W. Tibbles and published by . This book was released on 1987 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of the Influenza Virus RNA Polymerase written by Vivian Carol Blok and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of the Structure and Function of the Influenza Virus RNA dependent RNA Polymerase written by Itziar Serna Martin and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of Viral and Cellular Factors in the Regulation of the Influenza Virus RNA dependent RNA Polymerase written by Ashley D. York and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influenza A case study written by The Open University and published by The Open University. This book was released on with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 6-hour free course explored the biology of influenza. Topics began with the virus itself, then all stages from infection through to treatment.

Download or read book Genetics of Influenza Viruses written by Peter Palese and published by Springer. This book was released on 1983 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advent of genetic engineering methods and improved biochemical tech niques, much has been learned about the replication of influenza viruses, their structure and their epidemiology. It appears that the time is ripe to review these efforts and to provide a molecular perspective of influenza virology. It is hoped that this book will stimulate our thinking, help us in designing new experiments, and possibly show avenues leading to the control of the diseases associated with influenza viruses. Peter Palese, New York, N. Y. August 1983 David W. Kingsbury, Memphis, Tenn. Contents List of Contributors. . . . . . . . . . . . . . . . . XV 1. The Evolution of Influenza Viral Genetics - A Perspective. By E. D. Kilbourne. . . . . . . . . . . . . . . . 1 I. Introduction. . . . . . . . . . . . . . . . . 1 II. The Development of Modern Influenza Viral Genetics 2 A. Early Evidence of Genetic Variation in the Laboratory 2 B. Application of Formal Genetic Techniques to Studies of Influenza Virus . . . . . . . 3 C. Genetic Markers. . . . . . . . . 3 D. Development of Plaquing Systems. . . 4 E. The Use of Conditional Lethal Mutants 5 F. New Approaches in Influenza Virus Genetics. 6 1. The Biochemical Identification of Viral Gene Products in the Unambiguous Definition of Viral Inheritance . . . 6 2. Mapping of the Influenza Virus Genome by Correlative Physico-Chemical and Biological Techniques. . . . . . 7 3. The Application of Molecular Biological Techniques to the Study of Viral Genetic Variation. . . . . . . . . 8 4. Oligonucleotide Mapping of Viral RNA's . . . . . . . 8 5. Contribution of Protein and RNA Sequencing to Influenza Viral Genetics-Intragenic Mapping . . . . . . . 8 III. Viral Genetics and the Understanding of Viral Virulence and Pathogenicity . . . . . . . . . . . . . . . . . . .

Download or read book DEVELOPMENT OF ANTIVIRAL AGENT written by Shuofeng Yuan and published by Open Dissertation Press. This book was released on 2017-01-26 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Development of Antiviral Agents Targeting the RNA Polymerase of Influenza Virus" by Shuofeng, Yuan, 袁碩峰, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The rapid mutability of influenza virus in conjunction with genomic reassortment between viral strains promotes the virus' ability to evade vaccines and to become resistant to antiviral drugs. Therefore, novel anti-influenza therapeutics utilizing new targets and creative strategies are essential. The RNA-dependent RNA polymerase of the virus consists of PA, PB1, and PB2 subunits. Biological and structural investigations of the functional domains of these subunits have broadened the target reservoir for drug screening. With the wealth of knowledge from these studies, identification of small-molecule inhibitors that specifically disrupt the polymerase assembly or abrogate polymerase activities has emerged as an innovative and promising approach. In an attempt to facilitate the discovery of antiviral agents that target viral polymerase, isolated functional domains such as the PA endonuclease domain, the PB2 cap-binding domain, and the PA-PB1 interaction domains were expressed as screening targets. Based on the biochemical and structural properties of individual targets, a variety of platforms were established for the effective screening of inhibitors, including systematic evolution of ligands by exponential enrichment (SELEX), fluorescence resonance energy transfer (FRET) assay, fluorescence polarization (FP) assay, and enzyme-linked immunosorbent assay (ELISA). The antiviral efficacies of selected inhibitors were examined in vitro and in vivo, followed by verification of their antiviral mechanisms. Clinical merits of selected inhibitors were further evaluated, focusing mainly on their cross-protection abilities among influenza virus subtypes and their potential synergetic antiviral effects when used in combination with other drugs. A number of small-molecule compounds, i.e. PA-30, ANA-0, PB2-19, PAC-3 and ANA-1, together with the aptamer PAN-2, were identified as potent inhibitors against the replication of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9, and H9N2, in Madin-Darby canine kidney (MDCK) cell cultures. The intranasal administration of the identified compounds enhanced survival rates and reduced lung viral loads in BALB/c mice infected with H1N1 virus. The docking analyses predicted the compounds targeting PA or PB2 interacted with enzyme active sites to abolish endonuclease or cap-binding activity of the polymerase, whereas the compound targeting the PA-PB1 interaction likely induced configurational changes that impeded polymerase assembly. In addition, the combined treatment of zanamivir with the PA- or PB2-targeted compounds exerted synergistic antiviral effects in vitro. This study underscores the medical importance of polymerase functional domains as druggable targets, which may be due to the fact that these targeted areas are not only highly conserved among virus subtypes but also key to viral fitness. The identified antivirals exhibit substantial promise for clinical applications and provide new additions to the arsenal of drugs that are already used for chemoprophylaxis and treatment of influenza. Importantly, the established screening platforms for PA endonuclease inhibitors, PB2 cap-binding inhibitors, and PA-PB1 interaction disrupters should advance the development of a category of anti-influenza drugs that target viral polymerase. DOI: 10.5353/th_b5699888 Subjects: Antiviral agents RNA po

Download or read book The Pathology of Influenza written by Milton C. Winternitz and published by . This book was released on 1920 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fluorescence Studies of Influenza RNA and RNA Polymerase written by Alexandra Iulia Tomescu and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influenza A Virus A Role for the RNA Polymerase in Viral Particle Assembly written by John F. Regan and published by . This book was released on 2005 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: Influenza is an RNA virus whose segmented genome is encapsidated into viral ribonucleoprotein complexes (vRNPs). Upon infection, the vRNPs migrate into the nucleus where transcription and replication take place. The vRNPs contain a RNA-dependent RNA polymerase that is responsible for viral transcription and replication. The polymerase is composed of three subunits, PB1, PB2, and PA. PBI has polymerase activity and PB2 is involved in viral transcription. The function of PA is unclear. To help elucidate the role of PA in the viral life cycle, 16 conserved regions of PA were targeted for alanine substitution. A plasmid-based transfection system was used to generate recombinant influenza particles bearing each mutation, which were tested for viral viability and the ability of each mutant polymerase to transcribe and replicate a reporter. Mutations in the N-terminus were not well tolerated and resulted in either non-viable or attenuated viruses. One of the mutants, J10, was capable of RNA synthesis, yet did not create viral particles capable of plaque formation in MDCK cells. Specifically, when compared to wild-type, this mutant synthesized 50+/-7% vRNA, 86+/-12% mRNA, and 128+/-18% cRNA. These levels are compatible with viability, as mutants J8 (27%) and J12 (23%), produced significantly less vRNA than J10, yet were viable by plaque assay. The mRNAs generated from J10 polymerase were found to be translationally-active, and both the mutant protein and its RNA products were appropriately localized in the cytoplasm, where influenza assembly occurs. Nevertheless, J10 failed to generate infectious particles from cells in a plasmid-based influenza assembly assay, and hemagglutinating material from the supernatants of such cells contained little or no nuclease-resistant genomic RNA. These findings suggest that PA has a previously unrecognized role in assembly or release of influenza virions, perhaps influencing core structure or the packaging of vRNAs or other essential components into nascent influenza particles.

Download or read book Functional Studies on the PB2 Subunit of the RNA Polymerase Complex of Influenza Viruses written by Simon M. Carr and published by . This book was released on 2005 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influenza Virus written by Yoshihiro Kawaoka and published by Humana Press. This book was released on 2016-08-23 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reports of influenza-like illnesses date back to the Middle Ages, and outbreaks of influenza likely afflicted humans long before that. Over the last half century, influenza virus research has led to the development of two classes of antivirals – ion channel and neuraminidase inhibitors. Recently, a method of the artificial generation of an influenza virus was established. This system has been instrumental in the development of novel influenza vaccines and in the understanding of viral pathogenicity and the functions of viral proteins. Influenza Virus: Methods and Protocols summarizes the current techniques that have made this progress possible, ranging from protocols for virus isolation, growth, and subtyping to procedures for the efficient generation of any influenza virus. Written in the successful Methods in Molecular BiologyTM series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and easily accessible, Influenza Virus: Methods and Protocols seeks to serve both professionals and novices with the techniques used in numerous laboratories around the world that are, thus, the building blocks that underpin almost all influenza virus research.

Download or read book Phosphorylation Controls Assembly and Activity of the Influenza Virus Replication Machinery written by Anthony Rohit Dawson and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Successful influenza virus replication requires that viral gene expression and genome replication are balanced during viral infection. Both of these tasks occur via the viral ribonucleoprotein (RNP) containing genomic RNA encapsidated by viral nucleoprotein (NP) and bound by the viral RNA-dependent RNA polymerase consisting of subunits PB1, PB2 and PA. RNP function is regulated by multiple host factors and post-translational modifications. In particular, studies presented here provide evidence that phosphorylation by host kinases controls the activities of all RNP proteins. The overall goal of this thesis is to define how host-mediated phosphorylation controls RNA synthesis of the influenza virus replication machinery. Initial studies sought to understand how RNP assembly is regulated. RNP assembly is required only for replication and assembly requires NP to oligomerizes along genomic RNA. We determined that phosphorylation of the oligomeric interface inhibits RNP assembly. These phosphorylation sites are conserved among influenza virus genera suggesting a common regulatory scheme. These studies also identified the host kinase PKC Îþ as a key modifier of NP and regulator of influenza virus RNA synthesis. Additional studies explored how phosphorylation controls the influenza virus polymerase. Each polymerase subunit possesses unique functions to enable transcription and genome replication. PB1 harbors the catalytic activity of the polymerase. We established that phosphorylation of PB1 controls both RNA binding and transcription by the viral polymerase. Moreover, prior studies determined that transcription by the polymerase occurs via a cap-snatching mechanism wherein the polymerase binds capped host mRNA, cleaves the 5' end to produce a short capped oligonucleotide, and uses the cleaved product to prime transcription of viral genes. The PB2 subunit harbors the required cap binding activity. We provide evidence that phosphorylation controls PB2 cap binding. The endonuclease activity required for cap snatching resides in PA. Experiments with PA phospho-mutants display severe defects in transcription, likely caused by impaired endonuclease activity. Some identified phosphorylated residues appear essential for total polymerase function, whereas the function of other phosphorylation events remains elusive. Thus, phosphorylation indirectly regulates genome replication through NP modifications and changes in RNP assembly, and directly regulates transcription and replication by modifying the polymerase. We also analyzed the phosphoproteome of synchronously influenza virus-infected cells. Viral phosphoproteins generally increase throughout infection commensurate with the abundance of these proteins, suggesting that viral protein phosphorylation does not change en masse to segregate functions of viral protein at discrete times during infection. In contrast, host phosphoprotein abundances show multiple patterns, potentially enabling key viral replication events. In sum, directed studies of specific phosphorylation events coupled with broad analysis of the host phosphoproteome during infection provide a larger framework to understand post translational control of the influenza virus replication cycle.

Download or read book Proteomic and Functional Studies of the Influenza A Virus PA X Protein written by Brittany Porter and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viral RNA endonuclease activity is required for influenza A virus (IAV) replication. This activity resides in the polymerase acidic (PA) protein, which assembles into viral RNA-dependent RNA polymerase (RdRp) complexes and cleaves nascent host pre-mRNAs proximal to 5'-m7G caps, creating primers for viral mRNA synthesis. A rare (+1) ribosomal frameshifting event during translation of the PA open reading frame (ORF) creates the polymerase acidic-X (PA-X) protein. PA-X retains the amino-terminal PA RNA endonuclease domain, but contains a novel short carboxy-terminus, dubbed the X-ORF. Accumulating evidence indicates PA-X is a host shutoff protein functioning in the nucleus, selectively cleaving RNAs transcribed by host RNA polymerase II (pol II) while sparing RNA pol I, III, and viral transcripts. The molecular mechanism for this specificity remains to be elucidated. I hypothesize that PA-X gains access to target RNAs by X-ORF-mediated interaction with host proteins. In this study, I used a proximity labeling proteomic method known as BioID to identify host proteins that interact with the X-ORF. In BioID, fusion of the bait protein to a promiscuous biotin ligase allows efficient biotinylation of lysine residues on nearby proteins. X-ORF baits subjected to BioID included a 61-amino acid variant from A/Puerto Rico/8/1934 (H1N1) and a truncated 41-amino acid variant from A/California/7/2009 (H1N1), as well as a mutant X-ORF lacking basic residues required for nuclear localization. Affinity-purified proteins were trypsinized, subjected to reductive dimethylation with stable isotope tags, and identified by mass spectrometry. Using quantitative analysis, 29 high-confidence candidate X-ORF-interacting proteins were identified. X-ORF interacting proteins were validated using a luciferase-based functional assay in cells where each candidate host gene was silenced by short-hairpin RNAs. Through this study, the cleavage factor I (CFIm) complex proteins, cleavage and polyadenylation specificity factor subunit 5 (CPSF5) and CPSF6, were identified as required for PA-X function. The CFIm complex is poorly characterized but is known to influence site selection for mRNA 3'-end cleavage and polyadenylation. My observations are concordant with the emerging model for PA-X host shutoff activity, which has been shown to require canonical mRNA 3'-end processing mechanisms.

Download or read book Avian Influenza Virus written by Erica Spackman and published by Springer Science & Business Media. This book was released on 2008-02-28 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the growing global fear of a major pandemic, avian influenza (AI) virus research has greatly increased in importance. In Avian Influenza Virus, an expert team of researchers and diagnosticians examine the fundamental, yet essential, virological methods for AI virus research and diagnostics as well as some of the newest molecular procedures currently used for basic and applied research. They present exciting, cutting-edge new methods that focus both on studying the virus itself and on work with avian hosts, an area greatly lacking in research.

Download or read book The Influenza Viruses and Influenza written by Edwin Dennis Kilbourne and published by . This book was released on 1975 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Domestic and International Impacts of the 2009 H1N1 Influenza A Pandemic written by Institute of Medicine and published by National Academies Press. This book was released on 2010-07-04 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: In March and early April 2009, a new, swine-origin 2009-H1N1 influenza A virus emerged in Mexico and the United States. During the first few weeks of surveillance, the virus spread by human-to-human transmission worldwide to over 30 countries. On June 11, 2009, the World Health Organization (WHO) raised the worldwide pandemic alert level to Phase 6 in response to the ongoing global spread of the novel influenza A (H1N1) virus. By October 30, 2009, the H1N1 influenza A had spread to 191 countries and resulted in 5,700 fatalities. A national emergency was declared in the United States and the swine flu joined SARS and the avian flu as pandemics of the 21st century. Vaccination is currently available, but in limited supply, and with a 60 percent effectiveness rate against the virus. The story of how this new influenza virus spread out of Mexico to other parts of North America and then on to Europe, the Far East, and now Australia and the Pacific Rim countries has its origins in the global interconnectedness of travel, trade, and tourism. Given the rapid spread of the virus, the international scientific, public health, security, and policy communities had to mobilize quickly to characterize this unique virus and address its potential effects. The World Health Organization and Centers for Disease Control have played critical roles in the surveillance, detection and responses to the H1N1 virus. The Domestic and International Impacts of the 2009-H1N1 Influenza A Pandemic: Global Challenges, Global Solutions aimed to examine the evolutionary origins of the H1N1 virus and evaluate its potential public health and socioeconomic consequences, while monitoring and mitigating the impact of a fast-moving pandemic. The rapporteurs for this workshop reported on the need for increased and geographically robust global influenza vaccine production capacities; enhanced and sustained interpandemic demand for seasonal influenza vaccines; clear "triggers" for pandemic alert levels; and accelerated research collaboration on new vaccine manufacturing techniques. This book will be an essential guide for healthcare professionals, policymakers, drug manufacturers and investigators.