Download or read book The Role of Simian Virus 40 Large Tumor Antigen in Initiation of DNA Replication written by Beth Meryl Weiner and published by . This book was released on 1990 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Initiation of Simian Virus 40 SV40 DNA Replication written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well established that during initiation of SV40 DNA synthesis, a double hexamer of T antigen forms over the origin and acts as a bidirectional helicase. The subsequent events are much less clear. In fact, the structure on which DNA synthesis begins is not known, but has been hypothesized to be the double hexamer tightly associated with cellular initiation factors replication protein A (RPA), topoisomerase I (topo I) and more loosely with DNA polymerase & alpha;/primase (pol/prim). I now demonstrate that after a double hexamer forms over small origin fragments, a new structure consisting of a single hexamer associated with DNA is generated in an ATP dependent reaction from double hexamers. This structure, called the preinitiation complex (PIC), requires about 5 minutes to form whereas double hexamers are generated within 20 seconds. Importantly, PICs can associate with RPA and topo I whereas double hexamers, which have not been converted to PICs, can only bind to topo I. PICs are not simply T antigen hexamers associated with single-stranded DNA as the latter structures were shown not to bind RPA or topo I. Topo I can bind to an RPA-associated PIC, but RPA cannot bind to a topo I-associated PIC suggesting that the binding order is RPA then topo I. Importantly, DNA synthesis activity appears to be associated with the PICs but not with double hexamers. In this dissertation, a series of mutants with single-point substitutions in the helicase domain are generated to discover activities required for initiation of DNA replication. Four of these mutants (456 RA, 460ED, 462GA, and 499DA) are normal in their ability to hydrolyze ATP and are capable of associating into double hexamers in the presence of origin DNA. Furthermore, they possess normal ability to bind to single-stranded DNA. However, they fail to melt the early palindrome region of the origin. They also are severely impaired in unwinding origin-containing DNA fragments and in carrying out a helicase reaction with an M13 partial duplex DNA substrate. Interestingly, these mutants retain some ability to perform a helicase reaction with artificial replication forks, indicating that their intrinsic helicase activity is functional. Intriguingly, these mutants have almost completely lost their ability to bind to double-stranded DNA nonspecifically. Taken together, my data indicate that structural distortion and subsequent unwinding of the origin depend upon T antigen's ability to bind to DNA nonspecifically.

Download or read book Simian Virus 40 Large Tumor Antigen written by Robin Clark and published by . This book was released on 1986 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viruses and Human Disease written by Ellen G. Strauss and published by Elsevier. This book was released on 2007-09-21 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Completely revised and updated, the new edition of this groundbreaking text integrates basic virology with pathophysiological conditions to examine the connection between virology and human disease. Most virology textbooks focus on the molecular biology involved without adequate reference to physiology. This text focuses on viruses that infect humans, domestic animals and vertebrates and is based on extensive course notes from James Strauss' virology class at the California Institute of Technology taught for over 30 years. Expertly depicting in color the molecular structure and replication of each virus, it provides an excellent overview for students and professionals interested in viruses as agents of human disease. - Includes over 30% new material - virtually all of the figures and tables have been redrawn to include the latest information and the text has been extensively rewritten to include the most up-to-date information - Includes a new chapter on emerging and reemerging viral diseases such as avian flu, SARS, the spread of West Nile virus across America, and the continuing spread of Nipah virus in Southeast Asia - Further reading sections at the end of each chapter make it easy find key references - World maps depicting the current distribution of existing and newly emerging viruses are also incorporated into the text

Download or read book Simian Virus 40 DNA Replication written by Stephen Todd Smale and published by . This book was released on 1986 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book DNA Tumor Viruses written by Blossom Damania and published by Springer Science & Business Media. This book was released on 2008-12-19 with total page 805 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book focuses on the DNA viruses in the human population that are associated with cancers. It covers most of the viruses that are thought to contribute to human malignancy. This book represents a comprehensive review of the field of DNA tumor virology. Right now, while there are books out there that cover individual viruses that are also covered in this book, there is no single book that covers this topic comprehensively. This book is the first current, comprehensive review of its kind in the market.

Download or read book Mutational Analysis of the Origin Binding Domain of Simian Virus 40 Large T antigen Provides Insights Into Its Function in DNA Unwinding written by Erin C. Foster and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: DNA replication is an essential process of cell division required in order to maintain genomic integrity of all dividing cells. Although advancements have been made toward further understanding of this process, much is still unknown about the mechanisms underlying DNA replication, especially in mammalian systems. Eukaryotic DNA replication is a tightly regulated and complex process involving a myriad of proteins and numerous origins. Due to this complexity Simian Virus 40 (SV40) is used as a model system to simplify the investigation of the function of individual protein components. The replication of SV40 DNA employs one multifunctional viral protein, large T-antigen (T-ag). Many structural and genetic studies have provided a wealth of information about T-ag; however much remains unknown about the specific interactions between T-ag, DNA and replication factors and the precise sequence of events during replication. SV40 large T-ag is a multidomain protein that functions in origin recognition and unwinding events during initiation of SV40 DNA replication. The Origin Binding Domain (OBD) of T-ag plays a critical role during initiation to position T-ag on the origin through the use of a DNA binding motif consisting of A1 and B2 loops. After origin recognition, T-ag forms a double hexamer over the origin. Within each hexamer, the OBD adopts a lock washer structure where the origin recognizing A1 and B2 loops face towards the helicase domain and likely become unavailable for DNA binding. New surfaces of the OBD monomers are positioned along the DNA axis during hexamer formation. The role of the central channel of the OBD hexamer in DNA replication was investigated by analyzing the effects of mutations of residues lining the channel. All mutants showed binding defects with origin DNA and ssDNA especially at low protein concentrations, but only half were defective at supporting DNA replication in vitro. All mutants were normal in unwinding linear origin DNA fragments. However, replication defective mutants failed to unwind a small origin containing circular DNA whereas replication competent mutants did so normally. The presence of RPA and/or pol/prim restored circular DNA unwinding activity of compromised mutants probably by interacting with the separated DNA strands on the T-ag surface. The addition of RPA also recovered the ability of replication deficient mutants to support initiation and complete DNA replication in vitro. The addition of pol/prim resulted in the greatest recovery of mutant activity in minicircle unwinding and initiation. Compared to other polymerases tested, pol/prim was the only polymerase able to rescue mutant activity to WT levels indicated that this stimulation is specific to pol/prim. Of the four subunits of the pol/prim complex that could be responsible for stimulating mutant activity, the p180 subunit appeared to be active in recovering circular DNA unwinding. These results indicated a role for the OBD central channel in binding and threading ssDNA during unwinding of circular SV40 DNA. Mixing mutant and WT T-ag in minicircle unwinding assays suggested that only one monomer in an OBD hexamer was necessary for DNA unwinding. Results allowed for the development of a model of DNA threading through the T-ag complex illustrating how single stranded DNA could pass close to a trough generated by key residues in one monomer of the OBD hexamer.

Download or read book Human Polyomaviruses written by Ugo Moens and published by Nova Science Pub Incorporated. This book was released on 2009 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Human polyomaviruses are non-enveloped viruses with a circular double-stranded DNA genome of approximately 5,000 base pairs. The members BK virus and JC virus were first isolated in 1971 and are very common in the human population. Simian virus 40 (SV40), although originally isolated from rhesus macaques and accidentally introduced in the human population during massive poliovirus vaccination, may represent a third member of the polyomaviruses that can have man as a natural host. Primary infection with BK or/and JC virus occurs during early childhood. Subsequently, these viruses establish a seemingly life-long harmless latent infection. However, virus reactivation can occur especially in immunocompromised individuals and JC virus has been recognised as the cause of progressive multifocal leukoencephalopathy, while BK virus-associated interstitial nephritis has become an emerging complication in renal transplant patients. The genomes of human polyomaviruses encode two functional classes of proteins: the regulatory proteins large T-antigen, small t-antigen, and agnoprotein, and the structural proteins VP1, VP2 and VP3 that form the capsid. The regulatory proteins can modulate the expression and/or activity of cellular proteins involved in signal transduction, cell cycle regulation, and chromosomal functions. Therefore, they all possess oncogenic potential. Consistent with this, human polyomaviruses are capable of transforming human cells and inducing tumours in rodents, and are implicated in human malignancies. This book focuses on the etiological role of human polyomaviruses in cancer and highlights the mechanisms by which the viral regulatory proteins may contribute to neoplastic transformation of the infected host cells. Possible therapeutic strategies against these viruses will also be discussed.

Download or read book Small DNA Tumour Viruses written by Kevin Gaston and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this timely book leading scientists from around the world review current hot-topics in this area providing a fascinating overview of the molecular biology of these viruses and their interactions with the host. Topics covered include: HPV infections and the production of HPV virion stocks; viral oncoproteins and their functions; the replication and maintenance of viral genomes; virus induced alterations in cellular miRNAs; viral deregulation of DNA damage responses; the initiation of viral DNA replication; induction of genomic instability by viral oncoproteins; targeting of PML proteins and.

Download or read book Cellular Factors Regulating Transcription of the Simian Virus 40 Major Late Promoter written by Steven Robert Wiley and published by . This book was released on 1993 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparison of the DNA Sequences of Simian Virus 40 Required for the Synthesis of Early RNA and Viral DNA written by Gerald Zachary Hertz and published by . This book was released on 1986 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chromosome Biology written by Rudi Appels and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chromosome biology has been brought to a golden age by phenomenal advanced in molecular genetics and techniques. This is true in the plant arena, and it is becoming increasingly true in animal studies, where chromosomes are more difficult to work with. With advanced knowledge of transformation, scientists can tell exactly where a new element enters a chromosome. Conversely, molecular biologists can make large mistakes if they do not understand the behavior of chromosomes. Written by internationally recognized experts in the field, this book is the most authoritative work on the subject to date. Students of genetics, crop science and plant breeding, entomology, animal science, and related fields will benefit from this comprehensive and practical textbook.

Download or read book Handbook of Stem Cells written by Anthony Atala and published by Academic Press. This book was released on 2012-12-31 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt: New discoveries in the field of stem cells increasingly dominate the news and scientific literature revealing an avalanche of new knowledge and research tools that are producing therapies for cancer, heart disease, diabetes, and a wide variety of other diseases that afflict humanity. The Handbook of Stem Cells integrates this exciting area of life science, combining in two volumes the requisites for a general understanding of adult and embryonic stem cells. Organized in two volumes entitled Pluripotent Stem Cells and Cell Biology and Adult and Fetal Stem Cells, this work contains contributions from the world's experts in stem cell research to provide a description of the tools, methods, and experimental protocols needed to study and characterize stem cells and progenitor populations as well as a the latest information of what is known about each specific organ system. - Provides comprehensive coverage on this highly topical subject - Contains contributions by the foremost authorities and premiere names in the field of stem cell research - Companion website - http://booksite.elsevier.com/9780123859426/ - contains over 250 color figures in presentation format

Download or read book Cellular Endocrinology in Health and Disease written by Alfredo Ulloa-Aguirre and published by Academic Press. This book was released on 2021-02-19 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cellular Endocrinology in Health and Disease, Second Edition, describes the underlying basis of endocrine function, providing an important tool to understand the fundamentals of endocrine diseases. Delivering a comprehensive review of the basic science of endocrinology, from cell biology to human disease, this work explores and dissects the function of a number of cellular systems. The new edition provides an understanding of how endocrine glands function by integrating information resulting in biological effects on both local and systemic levels, also providing new information on the molecular physiopathogenesis of endocrine neoplasic cells. The new edition expands the most used chapters from the first edition and proposes a series of substitutions and additions to the table of contents. New chapters cover signaling, brown adipose tissue, hypothalamic cell models, cellular basis of insulin resistance, genetics and epigenetics of neuroendocrine tumors, and a series of chapters on endocrine-related cancer. Providing content that crosses disciplines, Cellular Endocrinology in Health and Disease, Second Edition, details how cellular endocrine function contributes to system physiology and mediates endocrine disorders. A methods section proves novel and useful approaches across research focus that will be attractive to medical students, residents, and specialists in the field of endocrinology, as well as to those interested in cellular regulation. Editors Alfredo Ulloa-Aguirre and Ya-Xiong Tao, experts in molecular and cellular aspects of endocrinology, deliver contributions carefully selected for relevance, impact, and clarity of expression from leading field experts Explores endocrine cells biology in normal and pathologic conditions Covers new aspects of endocrine cell function in distinct tissues Provides a view into the biological effect in local and systemic levels 15 new chapters covering the recent developments in the field

Download or read book Oral Head and Neck Oncology and Reconstructive Surgery E Book written by R. Bryan Bell and published by Elsevier Health Sciences. This book was released on 2017-08-25 with total page 967 pages. Available in PDF, EPUB and Kindle. Book excerpt: Oral, Head and Neck Oncology and Reconstructive Surgery is the first multidisciplinary text to provide readers with a system for managing adult head and neck cancers based upon stage. Using an evidence-based approach to the management and treatment of a wide variety of clinical conditions, the extensive experience of the author and contributors in head and neck surgery and oncology are highlighted throughout the text. This includes computer aided surgical simulation, intraoperative navigation, robotic surgery, endoscopic surgery, microvascular reconstructive surgery, molecular science, and tumor immunology. In addition, high quality photos and illustrations are included, which are easily accessible on mobile devices. - Management protocols and outcomes assessment provide clear guidelines for managing problems related to adult head and neck oncology and reconstructive surgery. - State-of-the art guidance by recognized experts details current techniques as well as technological advances in head and neck/cranio-maxillofacial surgery and oncology. - Evidence-based content details the latest diagnostic and therapeutic options for treating a wide-variety of clinical problems with an emphasis on surgical technique and outcomes. - Multidisciplinary approach reflects best practices in managing head and neck oncology and cranio-maxillofacial surgery. - 900 highly detailed images clearly demonstrate pathologies and procedures. - Designed for the modern classroom which lets you access important information anywhere through mobile tablets and smart phones.

Download or read book The Regulation of Simian Virus 40 Transcription written by Donald Charles Rio and published by . This book was released on 1983 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Leong s Manual of Diagnostic Antibodies for Immunohistology written by Runjan Chetty and published by Cambridge University Press. This book was released on 2016-11-28 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a unique A-Z guide to antibodies for immunohistology, this is an indispensable source for pathologists to ensure the correct application of immunohistochemistry in daily practice. Each entry includes commercial sources, clones, descriptions of stained proteins/epitopes, the full staining spectrum of normal and tumor tissues, staining pattern and cellular localization, the range of conditions of immunoreactivity, and pitfalls of the antibody's immunoprofile, giving pathologists a truly thorough quick-reference guide to sources, preparation and applications of specific antibodies. Appendices provide useful quick-reference tables of antibody panels for differential diagnoses, as well as summaries of diagnostic applications. Expanded from previous editions with over forty new entries, this handbook for diagnostic, therapeutic, prognostic and research applications of antibodies is an essential desktop book for practicing pathologists as well as researchers, residents and trainees.