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Articles 1 - 25 of 25

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Resistance From Afar: Distal Mutation V36m Allosterically Modulates The Active Site To Accentuate Drug Resistance In Hcv Ns3/4a Protease, Aysegul Ozen, Kuan-Hung Lin, Keith P. Romano, Davide Tavella, Alicia Newton, Christos J. Petropoulos, Wei Huang, Cihan Aydin, Celia A. Schiffer Dec 2018

Resistance From Afar: Distal Mutation V36m Allosterically Modulates The Active Site To Accentuate Drug Resistance In Hcv Ns3/4a Protease, Aysegul Ozen, Kuan-Hung Lin, Keith P. Romano, Davide Tavella, Alicia Newton, Christos J. Petropoulos, Wei Huang, Cihan Aydin, Celia A. Schiffer

University of Massachusetts Medical School Faculty Publications

Hepatitis C virus rapidly evolves, conferring resistance to direct acting antivirals. While resistance via active site mutations in the viral NS3/4A protease has been well characterized, the mechanism for resistance of non-active site mutations is unclear. R155K and V36M often co-evolve and while R155K alters the electrostatic network at the binding site, V36M is more than 13 Angstrom away. In this study the mechanism by which V36M confers resistance, in the context of R155K, is elucidated with drug susceptibility assays, crystal structures, and molecular dynamics (MD) simulations for three protease inhibitors: telaprevir, boceprevir and danoprevir. The R155K and R155K ...


Orbit: A New Paradigm For Genetic Engineering Of Mycobacterial Chromosomes, Kenan C. Murphy, Samantha J. Nelson, Subhalaxmi Nambi, Kadamba Papavinasasundaram, Christina E. Baer, Christopher M. Sassetti Dec 2018

Orbit: A New Paradigm For Genetic Engineering Of Mycobacterial Chromosomes, Kenan C. Murphy, Samantha J. Nelson, Subhalaxmi Nambi, Kadamba Papavinasasundaram, Christina E. Baer, Christopher M. Sassetti

Open Access Articles

Two efficient recombination systems were combined to produce a versatile method for chromosomal engineering that obviates the need to prepare double-stranded DNA (dsDNA) recombination substrates. A synthetic "targeting oligonucleotide" is incorporated into the chromosome via homologous recombination mediated by the phage Che9c RecT annealase. This oligonucleotide contains a site-specific recombination site for the directional Bxb1 integrase (Int), which allows the simultaneous integration of a "payload plasmid" that contains a cognate recombination site and a selectable marker. The targeting oligonucleotide and payload plasmid are cotransformed into a RecT- and Int-expressing strain, and drug-resistant homologous recombinants are selected in a single step ...


General Decapping Activators Target Different Subsets Of Inefficiently Translated Mrnas, Feng He, Alper Celik, Chan Wu, Allan Jacobson Dec 2018

General Decapping Activators Target Different Subsets Of Inefficiently Translated Mrnas, Feng He, Alper Celik, Chan Wu, Allan Jacobson

Open Access Articles

The Dcp1-Dcp2 decapping enzyme and the decapping activators Pat1, Dhh1, and Lsm1 regulate mRNA decapping, but their mechanistic integration is unknown. We analyzed the gene expression consequences of deleting PAT1, LSM1, or DHH1, or the DCP2 C-terminal domain, and found that: i) the Dcp2 C-terminal domain is an effector of both negative and positive regulation; ii) rather than being global activators of decapping, Pat1, Lsm1, and Dhh1 directly target specific subsets of yeast mRNAs and loss of the functions of each of these factors has substantial indirect consequences for genome-wide mRNA expression; and iii) transcripts targeted by Pat1, Lsm1, and ...


Potent Cas9 Inhibition In Bacterial And Human Cells By Acriic4 And Acriic5 Anti-Crispr Proteins, Jooyoung Lee, Aamir Mir, Alireza Edraki, Bianca Garcia, Nadia Amrani, Hannah E. Lou, Ildar Gainetdinov, April Pawluk, Raed Ibraheim, Xin D. Gao, Pengpeng Liu, Alan R. Davidson, Karen L. Maxwell, Erik J. Sontheimer Dec 2018

Potent Cas9 Inhibition In Bacterial And Human Cells By Acriic4 And Acriic5 Anti-Crispr Proteins, Jooyoung Lee, Aamir Mir, Alireza Edraki, Bianca Garcia, Nadia Amrani, Hannah E. Lou, Ildar Gainetdinov, April Pawluk, Raed Ibraheim, Xin D. Gao, Pengpeng Liu, Alan R. Davidson, Karen L. Maxwell, Erik J. Sontheimer

Open Access Articles

In their natural settings, CRISPR-Cas systems play crucial roles in bacterial and archaeal adaptive immunity to protect against phages and other mobile genetic elements, and they are also widely used as genome engineering technologies. Previously we discovered bacteriophage-encoded Cas9-specific anti-CRISPR (Acr) proteins that serve as countermeasures against host bacterial immunity by inactivating their CRISPR-Cas systems (A. Pawluk, N. Amrani, Y. Zhang, B. Garcia, et al., Cell 167:1829-1838.e9, 2016, https://doi.org/10.1016/j.cell.2016.11.017). We hypothesized that the evolutionary advantages conferred by anti-CRISPRs would drive the widespread occurrence of these proteins in nature (K ...


Deciphering The Molecular Basis Of Mycobacteria And Lipoglycan Recognition By The C-Type Lectin Dectin-2, Alexiane Decout, Devinder Kaur, Jerome Nigou Nov 2018

Deciphering The Molecular Basis Of Mycobacteria And Lipoglycan Recognition By The C-Type Lectin Dectin-2, Alexiane Decout, Devinder Kaur, Jerome Nigou

Open Access Articles

Dectin-2 is a C-type lectin involved in the recognition of several pathogens such as Aspergillus fumigatus, Candida albicans, Schistosoma mansonii, and Mycobacterium tuberculosis that triggers Th17 immune responses. Identifying pathogen ligands and understanding the molecular basis of their recognition is one of the current challenges. Purified M. tuberculosis mannose-capped lipoarabinomannan (ManLAM) was shown to induce signaling via Dectin-2, an activity that requires the (alpha1 --> 2)-linked mannosides forming the caps. Here, using isogenic M. tuberculosis mutant strains, we demonstrate that ManLAM is a bona fide and actually the sole ligand mediating bacilli recognition by Dectin-2, although M. tuberculosis produces a ...


Mutations In Influenza A Virus Neuraminidase And Hemagglutinin Confer Resistance Against A Broadly Neutralizing Hemagglutinin Stem Antibody, Kristina L. Prachanronarong, Aneth S. Canale, Ping Liu, Mohan Somasundaran, Shurong Hou, Yu-Ping Poh, Thomas Han, Quan Zhu, Nicholas Renzette, Konstantin B. Zeldovich, Timothy F. Kowalik, Nese Kurt Yilmaz, Jeffrey D. Jensen, Daniel N. Bolon, Wayne A. Marasco, Robert W. Finberg, Celia A. Schiffer, Jennifer P. Wang Oct 2018

Mutations In Influenza A Virus Neuraminidase And Hemagglutinin Confer Resistance Against A Broadly Neutralizing Hemagglutinin Stem Antibody, Kristina L. Prachanronarong, Aneth S. Canale, Ping Liu, Mohan Somasundaran, Shurong Hou, Yu-Ping Poh, Thomas Han, Quan Zhu, Nicholas Renzette, Konstantin B. Zeldovich, Timothy F. Kowalik, Nese Kurt Yilmaz, Jeffrey D. Jensen, Daniel N. Bolon, Wayne A. Marasco, Robert W. Finberg, Celia A. Schiffer, Jennifer P. Wang

Schiffer Lab Publications

Influenza A virus (IAV), a major cause of human morbidity and mortality, continuously evolves in response to selective pressures. Stem-directed, broadly neutralizing antibodies (sBnAbs) targeting influenza hemagglutinin (HA) are a promising therapeutic strategy, but neutralization escape mutants can develop. We used an integrated approach combining viral passaging, deep sequencing, and protein structural analyses to define escape mutations and mechanisms of neutralization escape in vitro for the F10 sBnAb. IAV was propagated with escalating concentrations of F10 over serial passages in cultured cells to select for escape mutations. Viral sequence analysis revealed three mutations in HA and one in neuraminidase (NA ...


Adapting Cell-Free Protein Synthesis As A Platform Technology For Education, Grace W. Chu, Max Z. Levine, Nicole E. Gregorio, Javin P. Oza Oct 2018

Adapting Cell-Free Protein Synthesis As A Platform Technology For Education, Grace W. Chu, Max Z. Levine, Nicole E. Gregorio, Javin P. Oza

STAR (STEM Teacher and Researcher) Presentations

Cell-free protein synthesis (CFPS) has emerged as an enabling biotechnology for research and biomanufacturing as it allows for the production of protein without the need for a living cell. Applications of CFPS include the construction of libraries for functional genomics and structural biology, the production of personalized medicine, and the expression of virus-like particles. The absence of a cell wall provides an open platform for direct manipulation of the reaction conditions and biological machinery. This project focuses on adapting the CFPS biotechnology to the classroom, making a hands-on bioengineering approach to learning protein synthesis accessible to students grades K-16 through ...


All-In-One Adeno-Associated Virus Delivery And Genome Editing By Neisseria Meningitidis Cas9 In Vivo, Raed Ibraheim, Chun-Qing Song, Aamir Mir, Nadia Amrani, Wen Xue, Erik J. Sontheimer Sep 2018

All-In-One Adeno-Associated Virus Delivery And Genome Editing By Neisseria Meningitidis Cas9 In Vivo, Raed Ibraheim, Chun-Qing Song, Aamir Mir, Nadia Amrani, Wen Xue, Erik J. Sontheimer

RNA Therapeutics Institute Publications

BACKGROUND: Clustered, regularly interspaced, short palindromic repeats (CRISPR) and CRISPR-associated proteins (Cas) have recently opened a new avenue for gene therapy. Cas9 nuclease guided by a single-guide RNA (sgRNA) has been extensively used for genome editing. Currently, three Cas9 orthologs have been adapted for in vivo genome engineering applications: Streptococcus pyogenes Cas9 (SpyCas9), Staphylococcus aureus Cas9 (SauCas9), and Campylobacter jejuni (CjeCas9). However, additional in vivo editing platforms are needed, in part to enable a greater range of sequences to be accessed via viral vectors, especially those in which Cas9 and sgRNA are combined into a single vector genome.

RESULTS: Here ...


An Asymmetric Centromeric Nucleosome, Yuichi Ichikawa, Noriko Saitoh, Paul D. Kaufman Aug 2018

An Asymmetric Centromeric Nucleosome, Yuichi Ichikawa, Noriko Saitoh, Paul D. Kaufman

Open Access Articles

Nucleosomes contain two copies of each core histone, held together by a naturally symmetric, homodimeric histone H3-H3 interface. This symmetry has complicated efforts to determine the regulatory potential of this architecture. Through molecular design and in vivo selection, we recently generated obligately heterodimeric H3s, providing a powerful tool for discovery of the degree to which nucleosome symmetry regulates chromosomal functions in living cells (Ichikawa et al., 2017). We now have extended this tool to the centromeric H3 isoform (Cse4/CENP-A) in budding yeast. These studies indicate that a single Cse4 N- or C-terminal extension per pair of Cse4 molecules is ...


Crystal Structure Of The Catalytic Domain Of Hiv-1 Restriction Factor Apobec3g In Complex With Ssdna, Atanu Maiti, Wazo Myint, Tapan Kanai, Krista Delviks-Frankenberry, Christina Sierra Rodriguez, Vinay K. Pathak, Celia A. Schiffer, Hiroshi Matsuo Jun 2018

Crystal Structure Of The Catalytic Domain Of Hiv-1 Restriction Factor Apobec3g In Complex With Ssdna, Atanu Maiti, Wazo Myint, Tapan Kanai, Krista Delviks-Frankenberry, Christina Sierra Rodriguez, Vinay K. Pathak, Celia A. Schiffer, Hiroshi Matsuo

Open Access Articles

The human APOBEC3G protein is a cytidine deaminase that generates cytidine to deoxy-uridine mutations in single-stranded DNA (ssDNA), and capable of restricting replication of HIV-1 by generating mutations in viral genome. The mechanism by which APOBEC3G specifically deaminates 5'-CC motifs has remained elusive since structural studies have been hampered due to apparently weak ssDNA binding of the catalytic domain of APOBEC3G. We overcame the problem by generating a highly active variant with higher ssDNA affinity. Here, we present the crystal structure of this variant complexed with a ssDNA substrate at 1.86 A resolution. This structure reveals atomic-level interactions ...


Role Of Protein Charge Density On Hepatitis B Virus Capsid Formation, Xinyu Sun, Dong Li, Zhaoshuai Wang, Panchao Yin, Rundong Hu, Rundong Hu, Hui Li, Qiao Liu, Yunyi Gao, Baiping Ren, Jie Zheng, Yinan Wei, Tianbo Liu Apr 2018

Role Of Protein Charge Density On Hepatitis B Virus Capsid Formation, Xinyu Sun, Dong Li, Zhaoshuai Wang, Panchao Yin, Rundong Hu, Rundong Hu, Hui Li, Qiao Liu, Yunyi Gao, Baiping Ren, Jie Zheng, Yinan Wei, Tianbo Liu

Chemistry Faculty Publications

The role of electrostatic interactions in the viral capsid assembly process was studied by comparing the assembly process of a truncated hepatitis B virus capsid protein Cp149 with its mutant protein D2N/D4N, which has the same conformational structure but four fewer charges per dimer. The capsid protein self-assembly was investigated under a wide range of protein surface charge densities by changing the protein concentration, buffer pH, and solution ionic strength. Lowering the protein charge density favored the capsid formation. However, lowering charge beyond a certain point resulted in capsid aggregation and precipitation. Interestingly, both the wild-type and D2N/D4N ...


Transmembrane Domains Of Highly Pathogenic Viral Fusion Proteins Exhibit Trimeric Association In Vitro, Stacy R. Webb, Stacy E. Smith, Michael G. Fried, Rebecca Ellis Dutch Apr 2018

Transmembrane Domains Of Highly Pathogenic Viral Fusion Proteins Exhibit Trimeric Association In Vitro, Stacy R. Webb, Stacy E. Smith, Michael G. Fried, Rebecca Ellis Dutch

Molecular and Cellular Biochemistry Faculty Publications

Enveloped viruses require viral fusion proteins to promote fusion of the viral envelope with a target cell membrane. To drive fusion, these proteins undergo large conformational changes that must occur at the right place and at the right time. Understanding the elements which control the stability of the prefusion state and the initiation of conformational changes is key to understanding the function of these important proteins. The construction of mutations in the fusion protein transmembrane domains (TMDs) or the replacement of these domains with lipid anchors has implicated the TMD in the fusion process. However, the structural and molecular details ...


Intron-Containing Rna From The Hiv-1 Provirus Activates Type I Interferon And Inflammatory Cytokines, Sean M. Mccauley, Kyusik Kim, Anetta Nowosielska, Ann Dauphin, Leonid Yurkovetskiy, William E. Diehl, Jeremy Luban Apr 2018

Intron-Containing Rna From The Hiv-1 Provirus Activates Type I Interferon And Inflammatory Cytokines, Sean M. Mccauley, Kyusik Kim, Anetta Nowosielska, Ann Dauphin, Leonid Yurkovetskiy, William E. Diehl, Jeremy Luban

Program in Molecular Medicine Publications and Presentations

HIV-1-infected people who take drugs that suppress viremia to undetectable levels are protected from developing AIDS. Nonetheless, these individuals have chronic inflammation associated with heightened risk of cardiovascular pathology. HIV-1 establishes proviruses in long-lived CD4+ memory T cells, and perhaps other cell types, that preclude elimination of the virus even after years of continuous antiviral therapy. Though the majority of proviruses that persist during antiviral therapy are defective for production of infectious virions, many are expressed, raising the possibility that the HIV-1 provirus or its transcripts contribute to ongoing inflammation. Here we found that the HIV-1 provirus activated innate immune ...


Primate Immunodeficiency Virus Vpx And Vpr Counteract Transcriptional Repression Of Proviruses By The Hush Complex, Leonid Yurkovetskiy, Mehmet Hakan Guney, Kyusik Kim, Shih Lin Goh, Sean M. Mccauley, Ann Dauphin, William E. Diehl, Jeremy Luban Apr 2018

Primate Immunodeficiency Virus Vpx And Vpr Counteract Transcriptional Repression Of Proviruses By The Hush Complex, Leonid Yurkovetskiy, Mehmet Hakan Guney, Kyusik Kim, Shih Lin Goh, Sean M. Mccauley, Ann Dauphin, William E. Diehl, Jeremy Luban

University of Massachusetts Medical School Faculty Publications

Drugs that inhibit HIV-1 replication and prevent progression to AIDS do not eliminate HIV-1 proviruses from the chromosomes of long-lived CD4+ memory T cells. To escape eradication by these antiviral drugs, or by the host immune system, HIV-1 exploits poorly defined host factors that silence provirus transcription. These same factors, though, must be overcome by all retroviruses, including HIV-1 and other primate immunodeficiency viruses, in order to activate provirus transcription and produce new virus. Here we show that Vpx and Vpr, proteins from a wide range of primate immunodeficiency viruses, activate provirus transcription in human CD4+ T cells. Provirus activation ...


Ras Hyperactivation Versus Overexpression: Lessons From Ras Dynamics In Candida Albicans, Vavilala A. Pratyusha, Guiliana Soraya Victoria, Mohammad Firoz Khan, Dominic T. Haokip, Bhawna Yadav, Nibedita Pal, Subhash Chandra Sethi, Priyanka Jain, Sneh Lata Singh, Sobhan Sen, Sneha Sudha Komath Mar 2018

Ras Hyperactivation Versus Overexpression: Lessons From Ras Dynamics In Candida Albicans, Vavilala A. Pratyusha, Guiliana Soraya Victoria, Mohammad Firoz Khan, Dominic T. Haokip, Bhawna Yadav, Nibedita Pal, Subhash Chandra Sethi, Priyanka Jain, Sneh Lata Singh, Sobhan Sen, Sneha Sudha Komath

Open Access Articles

Ras signaling in response to environmental cues is critical for cellular morphogenesis in eukaryotes. This signaling is tightly regulated and its activation involves multiple players. Sometimes Ras signaling may be hyperactivated. In C. albicans, a human pathogenic fungus, we demonstrate that dynamics of hyperactivated Ras1 (Ras1G13V or Ras1 in Hsp90 deficient strains) can be reliably differentiated from that of normal Ras1 at (near) single molecule level using fluorescence correlation spectroscopy (FCS). Ras1 hyperactivation results in significantly slower dynamics due to actin polymerization. Activating actin polymerization by jasplakinolide can produce hyperactivated Ras1 dynamics. In a sterol-deficient hyperfilamentous GPI mutant of C ...


Biochemical Analysis Of Dimethyl Suberimidate-Crosslinked Yeast Nucleosomes, Yuichi Ichikawa, Paul D. Kaufman Mar 2018

Biochemical Analysis Of Dimethyl Suberimidate-Crosslinked Yeast Nucleosomes, Yuichi Ichikawa, Paul D. Kaufman

Open Access Articles

Nucleosomes are the fundamental unit of eukaryotic chromosome packaging, comprised of 147 bp of DNA wrapped around two molecules of each of the core histone proteins H2A, H2B, H3, and H4. Nucleosomes are symmetrical, with one axis of symmetry centered on the homodimeric interaction between the C-termini of the H3 molecules. To explore the functional consequences of nucleosome symmetry, we designed an obligate pair of H3 heterodimers, termed H3X and H3Y, allowing us to compare cells with single or double H3 alterations. Our biochemical validation of the heterodimeric X-Y interaction included intra-nucleosomal H3 crosslinking using dimethyl suberimidate (DMS). Here, we ...


Transcriptome Profiling Of Neovascularized Corneas Reveals Mir-204 As A Multi-Target Biotherapy Deliverable By Raavs, Yi Lu, Phillip W. L. Tai, Jianzhong Ai, Dominic J. Gessler, Qin Su, Xieyi Yao, Qiang Zheng, Phillip D. Zamore, Xun Xu, Guangping Gao Mar 2018

Transcriptome Profiling Of Neovascularized Corneas Reveals Mir-204 As A Multi-Target Biotherapy Deliverable By Raavs, Yi Lu, Phillip W. L. Tai, Jianzhong Ai, Dominic J. Gessler, Qin Su, Xieyi Yao, Qiang Zheng, Phillip D. Zamore, Xun Xu, Guangping Gao

Open Access Articles

Corneal neovascularization (NV) is the major sight-threatening pathology caused by angiogenic stimuli. Current drugs that directly target pro-angiogenic factors to inhibit or reverse the disease require multiple rounds of administration and have limited efficacies. Here, we identify potential anti-angiogenic corneal microRNAs (miRNAs) and demonstrate a framework that employs discovered miRNAs as biotherapies deliverable by recombinant adeno-associated viruses (rAAVs). By querying differentially expressed miRNAs in neovascularized mouse corneas induced by alkali burn, we have revealed 39 miRNAs that are predicted to target more than 5,500 differentially expressed corneal mRNAs. Among these, we selected miR-204 and assessed its efficacy and therapeutic ...


Functional And Structural Mimicry Of A-Kinase Anchoring Proteins By Human Adenovirus E1a, Cason R. King Feb 2018

Functional And Structural Mimicry Of A-Kinase Anchoring Proteins By Human Adenovirus E1a, Cason R. King

Electronic Thesis and Dissertation Repository

As an obligate intracellular parasite, human adenovirus (HAdV) must utilize host factors for survival and replication. Early during infection, its multifunctional E1A protein interacts with an impressive range of cellular target proteins to exert control over the cellular environment. Through these virus-host interactions, E1A massively reprograms both viral and cellular transcription to activate the other HAdV genes, downregulate the host’s immune response, and induce the cell cycle. Consequently, E1A converts the infected cell into a compliant state more amenable for HAdV replication, resulting from its numerous protein-protein interactions. I sought to examine E1A’s interaction with cellular protein kinase ...


The Three-Fold Axis Of The Hiv-1 Capsid Lattice Is The Species-Specific Binding Interface For Trim5alpha, Damien Morger, Franziska Zosel, Martin Buhlmann, Sara Zuger, Maximilian Mittelviefhaus, Benjamin Schuler, Jeremy Luban, Markus G. Grutter Feb 2018

The Three-Fold Axis Of The Hiv-1 Capsid Lattice Is The Species-Specific Binding Interface For Trim5alpha, Damien Morger, Franziska Zosel, Martin Buhlmann, Sara Zuger, Maximilian Mittelviefhaus, Benjamin Schuler, Jeremy Luban, Markus G. Grutter

Open Access Articles

Rhesus TRIM5alpha (rhTRIM5alpha) potently restricts replication of human immunodeficiency virus type 1 (HIV-1). Restriction is mediated through direct binding of the C-terminal B30.2 domain of TRIM5alpha to the assembled HIV-1 capsid core. This host-pathogen interaction involves multiple capsid molecules within the hexagonal HIV-1 capsid lattice. However, the molecular details of this interaction and the precise site at which the B30.2 domain binds remain largely unknown. The human orthologue of TRIM5alpha (hsTRIM5alpha) fails to block infection by HIV-1 both in vivo and in vitro This is thought to be due to differences in binding to the capsid lattice. To ...


A Long Cytoplasmic Loop Governs The Sensitivity Of The Anti-Viral Host Protein Serinc5 To Hiv-1 Nef, Weiwei Dai, Yoshiko Usami, Yuanfei Wu, Heinrich G. Gottlinger Jan 2018

A Long Cytoplasmic Loop Governs The Sensitivity Of The Anti-Viral Host Protein Serinc5 To Hiv-1 Nef, Weiwei Dai, Yoshiko Usami, Yuanfei Wu, Heinrich G. Gottlinger

Open Access Articles

We recently identified the multipass transmembrane protein SERINC5 as an antiviral protein that can potently inhibit HIV-1 infectivity and is counteracted by HIV-1 Nef. We now report that the anti-HIV-1 activity, but not the sensitivity to Nef, is conserved among vertebrate SERINC5 proteins. However, a Nef-resistant SERINC5 became Nef sensitive when its intracellular loop 4 (ICL4) was replaced by that of Nef-sensitive human SERINC5. Conversely, human SERINC5 became resistant to Nef when its ICL4 was replaced by that of a Nef-resistant SERINC5. In general, ICL4 regions from SERINCs that exhibited resistance to a given Nef conferred resistance to the same ...


Early Epstein-Barr Virus Genomic Diversity And Convergence Toward The B95.8 Genome In Primary Infection, Eric R. Weiss, Susanna L. Lamers, Jennifer L. Henderson, Alexandre Melnikov, Mohan Somasundaran, Manuel Garber, Liisa K. Selin, Chad Nusbaum, Katherine Luzuriaga Jan 2018

Early Epstein-Barr Virus Genomic Diversity And Convergence Toward The B95.8 Genome In Primary Infection, Eric R. Weiss, Susanna L. Lamers, Jennifer L. Henderson, Alexandre Melnikov, Mohan Somasundaran, Manuel Garber, Liisa K. Selin, Chad Nusbaum, Katherine Luzuriaga

Garber Lab Publications

Over 90% of the world's population is persistently infected with Epstein-Barr virus. While EBV does not cause disease in most individuals, it is the common cause of acute infectious mononucleosis (AIM) and has been associated with several cancers and autoimmune diseases, highlighting a need for a preventive vaccine. At present, very few primary, circulating EBV genomes have been sequenced directly from infected individuals. While low levels of diversity and low viral evolution rates have been predicted for double-stranded DNA (dsDNA) viruses, recent studies have demonstrated appreciable diversity in common dsDNA pathogens (e.g., cytomegalovirus). Here, we report 40 full-length ...


Hiv-1 R5 Macrophage-Tropic Envelope Glycoprotein Trimers Bind Cd4 With High Affinity, While The Cd4 Binding Site On Non-Macrophage-Tropic, T-Tropic R5 Envelopes Is Occluded, Briana Quitadamo, Paul J. Peters, Alexander Repik, Olivia O'Connell, Zhongming Mou, Matthew Koch, Mohan Somasundaran, Robin M. Brody, Katherine Luzuriaga, Aaron Wallace, Shixia Wang, Shan Lu, Sean M. Mccauley, Jeremy Luban, Maria J. Duenas-Decamp, Maria Paz Paz Gonzalez-Perez, Paul R. Clapham Jan 2018

Hiv-1 R5 Macrophage-Tropic Envelope Glycoprotein Trimers Bind Cd4 With High Affinity, While The Cd4 Binding Site On Non-Macrophage-Tropic, T-Tropic R5 Envelopes Is Occluded, Briana Quitadamo, Paul J. Peters, Alexander Repik, Olivia O'Connell, Zhongming Mou, Matthew Koch, Mohan Somasundaran, Robin M. Brody, Katherine Luzuriaga, Aaron Wallace, Shixia Wang, Shan Lu, Sean M. Mccauley, Jeremy Luban, Maria J. Duenas-Decamp, Maria Paz Paz Gonzalez-Perez, Paul R. Clapham

Program in Molecular Medicine Publications and Presentations

HIV-1 R5 variants exploit CCR5 as a coreceptor to infect both T cells and macrophages. R5 viruses that are transmitted or derived from immune tissue and peripheral blood are mainly inefficient at mediating infection of macrophages. In contrast, highly macrophage-tropic (mac-tropic) R5 viruses predominate in brain tissue and can be detected in cerebrospinal fluid but are infrequent in immune tissue or blood even in late disease. These mac-tropic R5 variants carry envelope glycoproteins (Envs) adapted to exploit low levels of CD4 on macrophages to induce infection. However, it is unclear whether this adaptation is conferred by an increased affinity of ...


Studies Of Norspermidine Uptake In Drosophila Suggest The Existence Of Multiple Polyamine Transport Pathways, Michael Dieffenbach Jan 2018

Studies Of Norspermidine Uptake In Drosophila Suggest The Existence Of Multiple Polyamine Transport Pathways, Michael Dieffenbach

Honors Undergraduate Theses

Polyamines are a class of essential nutrients involved in many basic cellular processes such as gene expression, cell proliferation, and apoptosis. Without polyamines, cell growth is delayed or halted. Cancerous cells require an abundance of polyamines through a combination of synthesis and transport from the extracellular environment. An FDA-approved drug, D,L-α-difluoromethylornithine (DFMO), blocks polyamine synthesis but is ineffective at inhibiting cell growth due to polyamine transport. Thus, there is a need to develop drugs that inhibit polyamine transport to use in combination with DFMO. Surprisingly, little is known about the polyamine transport system in humans and other eukaryotes. Understanding ...


Discovery Of Bioactive Natural Products From Sugarcane, Rory Patrick Taylor Jan 2018

Discovery Of Bioactive Natural Products From Sugarcane, Rory Patrick Taylor

Theses

This research was undertaken to discover new potential products (with a focus on flavonoids) from sugarcane and sugar production by-products that have pharmaceutical, nutraceutical or functional food applications. Specifically, cytotoxic, antioxidant, anti-inflammatory/immune modulation and glycaemic index (GI) activities were surveyed. The results suggest that there are potentially novel anti-inflammatory and α-amylase inhibiting compound(s) present. These extracts or compounds may have use in the treatment of diabetes mellitus type 2 or inflammation-related diseases such as arthritis, multiple sclerosis and atherosclerosis. Further research such as compound identification and in vivo testing is warranted.


Testing Bacterial Antibiotic Production Under Carbohydrate And Protein Starvation, Briley Baird Jan 2018

Testing Bacterial Antibiotic Production Under Carbohydrate And Protein Starvation, Briley Baird

Honors Theses

Bacteria produce antibiotics when they are under stress, including starvation stress. Bacteria were tested under carbohydrate and protein starvation against Bacillus subtilis and Escherichia coli (due to the respective Gram positivity and negativity), in order to check for antibiotic production. The bacteria being tested were isolated by past Microbiology classes and stored in a -80°C freezer in the basement of Jones Science Center at Ouachita Baptist University. These test bacteria were grown on tryptic soy agar (TSA) to produce isolated bacterial colonies. Samples of isolated test colonies were then grown under conditions of carbohydrate starvation (M9 salts agar with ...