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Book The Herpes Simplex Virus Virion Host Shutoff Protein is Targeted to MRNA Cleavage Sites Through Interactions with Components of the Host Translational Apparatus

Download or read book The Herpes Simplex Virus Virion Host Shutoff Protein is Targeted to MRNA Cleavage Sites Through Interactions with Components of the Host Translational Apparatus written by Lora Ann Shiflett and published by . This book was released on 2010 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: The virion host shutoff protein (Vhs) is a herpes simplex virus (HSV) protein involved in early shutoff of the host cell. It is a component of the infecting virion, located in the tegument region, that works by rapidly degrading both viral and cellular messenger RNA (mRNA). in vivo and within infected cells, Vhs is selective for degrading messenger RNA opposed to non-messenger RNA. This dissertation sought to examine Vhs cleavage of an mRNA that utilizes the cap-dependent scanning mechanism for translation initiation and to see if cleavage was connected to early events of translation initiation. mRNA encoding HSV-1 thymidine kinase (pBK2) was used for the majority of the experiments, and studies were designed to map the cut sites produced by Vhs in a rabbit reticulocyte lysate (RRL) system. Additional experiments investigated whether Vhs was selective for degrading certain types of mRNAs over others, particularly IRES-containing mRNAs. Studies revealed that Vhs specifically cleaves pBK2 mRNA within the first 300 bases from the 5' cap, and these cut sites are close to and slightly upstream from the first three AUG codons of the sequence. The proximity of the cutting to the AUG codons led to speculations that early events of translation initiation might be involved in Vhs degradation of mRNA. This was found to be true, where data revealed that blocking early stages such as (1) recruitment of translation initiation factors to the 5' cap and/or (2) ATP hydrolysis RNA helicase activity important for unwinding RNA secondary structure and the scanning process hinder Vhs cleavage. However, blocking later stages of translation initiation only had a modest effect on RNase activity. Results also found that a 5' cap analog inhibits Vhs site-specific cleavage of mRNA at regions near the 5' cap. Interestingly, a cap appears to be required for Vhs production of specific cleavage sites within the first 300 bases of the transcript. Work went on to study whether there was a difference between Vhs cleavage of circularized RNA that normally experiences cap-dependent scanning and circularized RNA that initiates translation in a cap-independent manner. Results indicated that Vhs requires a free 5' end for specific cleavage of mRNA that undergoes cap-dependent scanning. However, Vhs does not require a free 5' end to specifically cleave a circular RNA that utilizes cap-independent methods for translation initiation. Mutational work, with pBK2 mutants which contained mutations in or surrounding the AUG codon, further supported a mechanism for Vhs cleavage that involved Vhs association with the scanning complex to reach some of its preferred cut sites. Mutating the first AUG to a non-AUG inhibited Vhs specific cleavage of pBK2 mRNA at a region just upstream from the AUG codon. Additionally, mutating bases surrounding the AUG codon to put it in an optimal context enhanced cleavage at regions near the start codon. Inserting a stable hairpin near the 5' cap to block scanning also reduced Vhs cleavage at prominent sites within the first 300 bases of the transcript. To conclude, this work provides several indications that Vhs associates with components of the translational apparatus to access at least some of its cut sites.

Book Studies of the Virion Host Shutoff Function of Herpes Simplex Virus

Download or read book Studies of the Virion Host Shutoff Function of Herpes Simplex Virus written by Annette Schmidt Pak and published by . This book was released on 1992 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Translation Initiation Factors EIF4B and EIF4H Stimulate the Ribonuclease Activity of the Virion Host Shutoff Protein of Herpes Simplex Virus 1

Download or read book Translation Initiation Factors EIF4B and EIF4H Stimulate the Ribonuclease Activity of the Virion Host Shutoff Protein of Herpes Simplex Virus 1 written by Rosalyn C. Doepker and published by . This book was released on 2004 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Characterization of the Role of Herpes Simplex Virus Protein VP16 in Viral Gene Expression Through Interactions with the Virion Host Shutoff Protein VHS and HCF 1 microform

Download or read book Characterization of the Role of Herpes Simplex Virus Protein VP16 in Viral Gene Expression Through Interactions with the Virion Host Shutoff Protein VHS and HCF 1 microform written by Jozo Knez and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2003 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Herpes Simplex Virus 1 (HSV1) VP16 transcriptionally activates viral immediate-early (IE) genes, through the formation of a multi-protein structure termed the VP16-induced complex (VIC). VIC is comprised of cellular transcription factors Oct-1 and HCF-1. In addition, VP16 is a pre-formed, structural protein that has a critical role in virion assembly. At least one aspect of its role at late times post-infection includes the downregulation of the virion host shutoff protein (vhs); which functions to indiscriminately degrade mRNA.

Book The Role of Tegument Proteins and the Dynamic Interplay They Have with One Another Throughout the Course of Herpes Simplex Virus Type 1 Infections

Download or read book The Role of Tegument Proteins and the Dynamic Interplay They Have with One Another Throughout the Course of Herpes Simplex Virus Type 1 Infections written by Ekaette Francis Mbong and published by . This book was released on 2012 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Herpes simplex virus type 1 (HSV-1) is a neurotropic virus affecting up to 98% of the adult population. Central to this report is the proteinaceous layer termed the tegument found within the HSV-1 virion. The tegument is composed of>20 different viral proteins of varying stoichiometries. Tegument proteins are delivered to the host cell upon infection, providing this virus an advantage early in its replication cycle. Tegument proteins also function at late times in infection when they are synthesized at high levels. One of the most abundant tegument proteins is VP22, encoded by the U_L 49 gene, with over 2000 copies per virion. The studies described herein provided much insight into how VP22 promotes the HSV-1 replication cycle. We found the absence of VP22 during infection resulted in decreased mRNA levels at early times and decreased protein synthesis at late times. These results were distinct and separable with respect to both the genes affected and the timing during infection. Because U_L 49^- infections often result in secondary, compensatory mutations in the gene encoding vhs, we examined the effects of one such mutation as well as the role of vhs's RNase activity on protein synthesis in the presence and absence of VP22. Our results indicated secondary mutations that decreased vhs's RNase activity compensated for the lack of VP22 during HSV-1 infections. Further analyses indicated the absence of VP22 resulted in decreased translation efficiency independent of mRNA abundance, the result of cleavage of the 5' UTRs of viral mRNAs. In separate studies we focused on the tegument protein encoded by the U_L21 gene. Although much is known about the role of this protein at late times in infection, very little was known about its role at early times in HSV-1 infections. We found the absence of pUL21 resulted in decreased levels of several immediate early mRNAs, and their corresponding proteins, at early times in infection. Although HSV-1 establishes a persistent infection, and is therefore incurable, we have made several novel findings that contribute important knowledge to the herpesvirus field and will hopefully aid in the development of new therapeutics.

Book Proceedings of the National Academy of Sciences of the United States of America

Download or read book Proceedings of the National Academy of Sciences of the United States of America written by National Academy of Sciences (U.S.). and published by . This book was released on 2007 with total page 1164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Molecular Virology

    Molecular Virology

    Book Details:
  • Author : Susanne Modrow
  • Publisher : Springer
  • Release : 2013-09-18
  • ISBN : 9783642207174
  • Pages : 0 pages

Download or read book Molecular Virology written by Susanne Modrow and published by Springer. This book was released on 2013-09-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives a comprehensive overview on the knowledge of virus infection relevant for humans and animals. For each virus family the molecular details of the virus particle and the viral replication cycle are described. In the case of virus types with relevance for human and/or animal health the data on molecular biology, genetics and virus-cell interaction are combined with those concerning, pathogenesis, epidemiology, clinics, prevention and therapy.

Book Prokaryotic and Eukaryotic Heat Shock Proteins in Infectious Disease

Download or read book Prokaryotic and Eukaryotic Heat Shock Proteins in Infectious Disease written by A. Graham Pockley and published by Springer Science & Business Media. This book was released on 2009-11-10 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prokaryotic and Eukaryotic Heat Shock Proteins in Infectious Disease provides the most current review of the literature relating to the role and influence of heat shock (stress) proteins on the establishment, progression and resolution of infectious disease. Written by leaders in the field of heat shock proteins (HSP) and their biological and immunological properties, the contributors provide a fascinating insight into the complex relationship between, and the involvement of prokaryotic and eukaryotic HSP in disease states. It has been known for some considerable time that heat shock proteins from prokaryotic organisms are immunodominant molecules that are intimately involved in the induction of potential protective inflammatory responses, and this aspect of HSP biology is updated herein. In addition to regulating heat shock protein gene expression, the transcription factor HSF1 also appears to play an important role in regulating immune responses to infection. Heat shock proteins are now known to influence infectious disease processes in a number of diverse ways: they are involved in the propagation of prions, the replication and morphogenesis of viruses, and the resistance of parasites to chemotherapy. These proteins also appear to be important mediators of bacteria-host interactions and inflammation, the latter via interactions with cell surface molecules and structures such as Toll-like receptors and lipid rafts. Heat shock proteins can be expressed on the surface of infected cells, and this is likely to provide a target for the innate immune response. Elevated levels of circulating HSP are present in infectious diseases and these proteins might therefore regulate inflammatory responses to pathogenic challenge on a systemic basis. Heat shock proteins are also implicated in the impact of genital tract infections on the reproductive outcome, as well as in the local and systemic consequences of periodontal disease. Fever-range temperatures can induce the expression of heat shock proteins, and the final chapter in the book examines the influence of fever-range hyperthermia on a variety of cells and the organization of plasma membranes. This book is an essential read for graduates and postgraduates in Biology, pro- and eukaryotic Biochemistry, Immunology, Microbiology, Inflammatory and Infectious Disease, and Pathology.

Book Genetics Abstracts

Download or read book Genetics Abstracts written by and published by . This book was released on 2001 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Principles of Virology Volume 1

Download or read book Principles of Virology Volume 1 written by Jane Flint and published by John Wiley & Sons. This book was released on 2020-11-03 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: Principles of Virology, the leading virology textbook in use, is an extremely valuable and highly informative presentation of virology at the interface of modern cell biology and immunology. This text utilizes a uniquely rational approach by highlighting common principles and processes across all viruses. Using a set of representative viruses to illustrate the breadth of viral complexity, students are able to under-stand viral reproduction and pathogenesis and are equipped with the necessary tools for future encounters with new or understudied viruses. This fifth edition was updated to keep pace with the ever-changing field of virology. In addition to the beloved full-color illustrations, video interviews with leading scientists, movies, and links to exciting blogposts on relevant topics, this edition includes study questions and active learning puzzles in each chapter, as well as short descriptions regarding the key messages of references of special interest. Volume I: Molecular Biology focuses on the molecular processes of viral reproduction, from entry through release. Volume II: Pathogenesis and Control addresses the interplay between viruses and their host organisms, on both the micro- and macroscale, including chapters on public health, the immune response, vaccines and other antiviral strategies, viral evolution, and a brand new chapter on the therapeutic uses of viruses. These two volumes can be used for separate courses or together in a single course. Each includes a unique appendix, glossary, and links to internet resources. Principles of Virology, Fifth Edition, is ideal for teaching the strategies by which all viruses reproduce, spread within a host, and are maintained within populations. This edition carefully reflects the results of extensive vetting and feedback received from course instructors and students, making this renowned textbook even more appropriate for undergraduate and graduate courses in virology, microbiology, and infectious diseases.