1,212 research outputs found
Acetylation of E2 by P300 Mediates Topoisomerase Entry at the Papillomavirus Replicon
No full textHuman papillomavirus (HPV) E2 proteins are integral for the transcription of viral genes and the replication and maintenance of viral genomes in host cells. E2 recruits the viral DNA helicase E1 to the origin. A lysine (K111), highly conserved among almost all papillomavirus (PV) E2 proteins, is a target for P300 (EP300) acetylation and is critical for viral DNA replication (E. J. Quinlan, S. P. Culleton, S. Y. Wu, C. M. Chiang, et al., J Virol 87:1497-1507, 2013, https://doi.org/10.1128/JVI.02771-12; Y. Thomas and E. J. Androphy, J Virol 92:e01912-17, 2018, https://doi.org/10.1128/JVI.01912-17). Since the viral genome exists as a covalently closed circle of double-stranded DNA, topoisomerase 1 (Topo1) is thought to be required for progression of the replication forks. Due to the specific effect of K111 mutations on DNA unwinding (Y. Thomas and E. J. Androphy, J Virol 92:e01912-17, 2018, https://doi.org/10.1128/JVI.01912-17), we demonstrate that the E2 protein targets Topo1 to the viral origin, and this depends on acetylation of K111. The effect was corroborated by functional replication assays, in which higher levels of P300, but not its homolog CBP, caused enhanced replication with wild-type E2 but not the acetylation-defective K111 arginine mutant. These data reveal a novel role for lysine acetylation during viral DNA replication by regulating topoisomerase recruitment to the replication origin.IMPORTANCE Human papillomaviruses affect an estimated 75% of the sexually active adult population in the United States, with 5.5 million new cases emerging every year. More than 200 HPV genotypes have been identified; a subset of them are linked to the development of cancers from these epithelial infections. Specific antiviral medical treatments for infected individuals are not available. This project examines the mechanisms that control viral genome replication and may allow the development of novel therapeutics
Review of the book John Locke: The philosopher as Christian virtuoso, by Victor Nuovo
No full textDr. Elliot Rossiter (Douglas College) reviews the book John Locke: The Philosopher as Christian Virtuoso by Victor Nuovo (2017).Final article published.contemporary applied ethicsphilosophyearly modern philosophyhistory of ethics and economic
Effect of Tyrosine Phosphorylation of HPV31 E2 on Replication
No full textBackground
The HPV early E2 protein is an essential regulatory protein involved in HPV replication and transcription that is encoded by all papillomaviruses. Phosphorylation of E2 at Y102 inhibits viral replication, and an additional phosphorylation site at Y87 was recently identified through mass spectrometry. This project aimed to characterize E2 proteins encoding mutations at Y87 that abrogate phosphorylation. In parallel, we aimed to identify the kinase responsible for E2 phosphorylation at Y87. The Androphy lab previously has published that FGFR tyrosine kinases effect HPV replication, but there may be other kinases which act upon E2. Tyk2 is a tyrosine kinase regulated by the viral protein E6 and highly expressed in keratinocytes. We want to determine if Tyk2 is involved in regulation of E2 through phosphorylation.
Experimental Design
We will co-express Tyk2 and E2 in 293TT cells and through immunoprecipitations determine if Tyk2 binds E2. Using an in-vitro replication assay, viral proteins E2 and E1 will be overexpressed along with Tyk2 to determine if Tyk2 effects replication. We will make HPV genomes with Y87E/Y87F mutations through site-directed mutagenesis. Expression of mutant E2 will be examined through transfection of cells and western blot analysis.
Results
E2 harboring 87 to glutamic acid (Y87E) or phenylalanine (Y87F) mutations produces soluble protein, but 87E inhibits replication. Tyk2 expression stabilizes E2 suggesting it binds E2.
Potential impact
It is important to understanding the mechanisms underlying a virus’ replication cycle for future targeted treatments against infection
William E. Hoy, letter to Mr. Ralph Elliot Lin Weber, July 8, 1943, with envelope and newspaper articles
No full textThis letter was sent from William E. Hoy to Mr. Ralph Elliot Lin Weber and is dated July 8, 1943. The letter recounts information about the only baseball game where Hoy, a deaf athlete, was at-bat against Taylor, also a deaf athlete. Mentioned in the letter is a typewritten play by play of the same game, copied from the Enquirer of May 17, 1902. Also included is an envelope and newspaper articles. The envelope, from International League Information, is addressed to Ralph E Lin Weber and has handwritten lists of players of N.Y. and Cincinnati. The newspaper articles are from the Dayton Daily News and the Cincinnati Enquirer and feature pictures of William E. Hoy, the author of the letter
Letter from Frank E. Gannett to William Elliot Griffis, September 14, 1912
No full textThanks Griffis for copy of A Modern Pioneer and attaches a newspaper clipping of a review of the book from the Star-Gazette.Enclosed with Elmira Star-Gazette newspaper clipping, Dr. Griffis author of book on KoreaThis project was funded by a grant from the Overseas Korean Cultural Heritage Foundation, Seoul, Korea.Youngmee Yu Cho and Sungmin Park are responsible for the transcription and annotation of the letters
Locke and the Jesuits on law and politics
No full textDr. Elliot Rossiter (Douglas College) contributed the chapter "Locke and the Jesuits on law and politics" (2019).Final book published
How the discovery of ISS-N1 led to the first medical therapy for spinal muscular atrophy
No full textSpinal muscular atrophy (SMA), a prominent genetic disease of infant mortality, is caused by low levels of survival motor neuron (SMN) protein owing to deletions or mutations of the SMN1 gene. SMN2, a nearly identical copy of SMN1 present in humans, cannot compensate for the loss of SMN1 due to predominant skipping of exon 7 during pre-mRNA splicing. With the recent FDA approval of nusinersen (Spinraza™), the potential for correction of SMN2 exon 7 splicing as a SMA therapy has been affirmed. Nusinersen is an antisense oligonucleotide that targets intronic splicing silencer N1 (ISS-N1) discovered in 2004 at the University of Massachusetts Medical School. ISS-N1 has emerged as the model target for testing the therapeutic efficacy of antisense oligonucleotides using different chemistries as well as different mouse models of SMA. Here we provide a historical account of events that led to the discovery of ISS-N1 and describe the impact of independent validations that raised the profile of ISS-N1 as one of the most potent antisense targets for the treatment of a genetic disease. Recent approval of nusinersen provides a much-needed boost for antisense technology that is just beginning to realize its potential. Beyond treating SMA, the ISS-N1 target offers myriad potentials for perfecting various aspects of the nucleic-acid-based technology for the amelioration of the countless number of pathological conditions.This is a manuscript of an article published as Singh, Natalia N., Matthew D. Howell, Elliot J. Androphy, and Ravindra N. Singh. "How the discovery of ISS-N1 led to the first medical therapy for spinal muscular atrophy." Gene therapy 24, no. 9 (2017): 520. doi: 10.1038/gt.2017.34. Posted with permission.</p
Quantitative Analysis of Novel Chemical and shRNA Based Methods to Increase Survival of Motor Neuron Protein Levels
No full textSpinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder that is the leading genetic cause of infantile death. SMA is caused by homozygous deletion or mutation of the survival of motor neuron 1 gene (SMN1). The SMN2 gene is nearly identical to SMN1, however is alternatively spliced. The close relationship to SMN1 results in SMN2 being a very power genetic modifier of SMA disease severity and a target for therapies. In this study we attempt to characterize novel chemical compounds identified as potential activators of the SMN2 gene. Additionally, we sought to determine the regulatory role individual HDAC proteins use to control expression of full length protein from the SMN2 gene. We used quantitative PCR to determine the effects of novel compounds and shRNA silencing of individual HDACs on the steady state levels of a SMN2-luciferase reporter transcripts. We determined that the compounds identified in multiple reporter high throughput screens increased SMN protein levels via transcriptional activation of the SMN2 gene. Other compounds identified in the same screen functioned post-transcriptionally, possibly stabilizing the SMN protein itself by decreasing degradation. Furthermore, we determined that reduction of individual HDAC proteins was sufficient to increase SMN protein levels in a transgenic reporter system. Knockdown of class I HDAC proteins preferentially activated the reporter by increased promoter transcription. Silencing of class II HDAC proteins maintained transcriptional activity; however silencing of HDAC 5 and 6 also appeared to enhance inclusion of an alternatively spliced exon. This collective work defines a quantitative RNA based protocol to determine mechanism of SMN reporter increase in response to any chosen treatment method. Additionally, this work highlights HDAC proteins 2 and 6 as excellent investigative targets. These data are important to the basic understanding of SMN expression regulation and the refinements of current therapeutic compounds as well as the development of novel SMA therapeutics.Interdisciplinary Graduate Progra
hAda3 degradation by papillomavirus type 16 E6 correlates with abrogation of the p14ARF-p53 pathway and efficient immortalization of human mammary epithelial cells
No full textTwo activities of human papillomavirus type 16 E6 (HPV16 E6) are proposed to contribute to the efficient immortalization of human epithelial cells: the degradation of p53 protein and the induction of telomerase. However, the requirement for p53 inactivation has been debated. Another E6 target is the hAda3 protein, a p53 coactivator and a component of histone acetyltransferase complexes. We have previously described the role of hAda3 and p53 acetylation in p14ARF-induced human mammary epithelial cell (MEC) senescence (P. Sekaric, V. A. Shamanin, J. Luo, and E. J. Androphy, Oncogene 26:6261-6268, 2007). In this study, we analyzed a set of HPV16 E6 mutants for the ability to induce hAda3 degradation. E6 mutants that degrade hAda3 but not p53 could abrogate p14ARF-induced growth arrest despite the presence of normal levels of p53 and efficiently immortalized MECs. However, two E6 mutants that previously were reported to immortalize MECs with low efficiency were found to be defective for both p53 and hAda3 degradation. We found that these immortal MECs select for reduced p53 protein levels through a proteasome-dependent mechanism. The findings strongly imply that the inactivation of the p14ARF-p53 pathway, either by the E6-mediated degradation of p53 or hAda3 or by cellular adaptation, is required for MEC immortalization
Elliot Merrick (1905-1997)
No full text... Elliot Merrick, Labrador author and traveler, died on 22 April 1997, less than three weeks before his 92nd birthday. Toward the end of his life, he would joke that he was so old that he\u27d become "historical". In fact, he was one of the last surviving links with pioneer Labrador - a place that makes the present-day Labrador of jet overflights and nickel mines seem like another country. ... Elliot Merrick made no contribution to science; his trips did not result in new maps being drawn up, and he did not make any major or even minor archaeological finds. But his books about Labrador will live on to enthral future generations of readers with the magic of the North
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