Cell and Developmental Biology Commons^™

The Highly Conserved Layer-3 Component Of The Hiv-1 Gp120 Inner Domain Is Critical For Cd4-Required Conformational Transitions, Anik Désormeaux, Mathieu Coutu, Halima Medjahed, Beatriz Pacheco, Alon Herschhorn, Christopher Gu, Shi-Hua Xiang, Youdong Mao, Joseph Sodroski, Andrés Finzi

Nebraska Center for Virology: Faculty Publications

The trimeric envelope glycoprotein (Env) of human immunodeficiency virus type 1 (HIV-1) mediates virus entry into host cells. CD4 engagement with the gp120 exterior envelope glycoprotein subunit represents the first step during HIV-1 entry. CD4-induced conformational changes in the gp120 inner domain involve three potentially flexible topological layers (layers 1, 2, and 3). Structural rearrangements between layer 1 and layer 2 have been shown to facilitate the transition of the envelope glycoprotein trimer from the unliganded to the CD4-bound state and to stabilize gp120-CD4 interaction. However, our understanding of CD4-induced conformational changes in the gp120 inner domain remains incomplete. Here, …

Analysis Of Primary Resistance Mutations To Hiv-1 Entry Inhibitors In Therapy Naive Subtype C Hiv-1 Infected Mother– Infant Pairs From Zambia, Hongyan Guo, Chang Liu, Bin Liu, Charles Wood, Xiaohong Kong

Nebraska Center for Virology: Faculty Publications

Background—Small molecular CCR5 inhibitors represent a new class of drugs for treating HIV-1 infection. The evaluation of the primary resistance mutations associated with entry inhibitors during HIV-1 perinatal transmission is required because they may have a profound impact on the clinical management in MTCT.

Objectives—To evaluate the primary resistance mutations to maraviroc and vicriviroc during perinatal transmission and analyze the sensitivity of Env derived from mother–infant pairs to maraviroc.

Study design—Nine MIPs infected by subtype C HIV-1 were recruited to analyze the prevalence and transmission of primary resistance mutations to maraviroc and vicriviroc. Moreover, Env derived from six MIPs were …

Early Childhood Infection Of Kaposi’S Sarcoma-Associated Herpesvirus In Zambian Households: A Molecular Analysis, Landon Olp, Danielle M. Shea, Maxine K. White, Clement Gondwe, Chipepo Kankasa, Charles Wood

Nebraska Center for Virology: Faculty Publications

Sub-Saharan Africa is endemic for Kaposi’s sarcoma-associated herpesvirus (KSHV) and there is a high rate of early childhood infection; however, the transmission sources are not well characterized. We examined household members as potential KSHV transmission sources to young children in the KSHV-endemic country of Zambia. To this end, we enrolled and followed Zambian households with at least one KSHV-seropositive child and collected longitudinal buccal swab samples. KSHV burden was evaluated and K1 sequences from the children were determined and analyzed for differences to K1 sequences from household members. The K1 sequences were also analyzed for evolution over time. We generated …

A Dysfunctional Tricarboxylic Acid Cycle Enhances Fitness Of Staphylococcus Epidermidis During Β-Lactam Stress, Vinai Chittenzham Thomas, Lauren Kinkhead, Ashley Janssen, Carolyn Schaeffer, Keith Woods, Jill Lindgren, Johnathan Peaster, Sujata Chaudhari, Marat Sadykov, Joselyn Jones, Sameh Mohamadi Abdelghani, Matthew Zimmerman, Kenneth W. Bayles, Greg Somerville, Paul Fey

School of Veterinary and Biomedical Sciences: Faculty Publications

A recent controversial hypothesis suggested that the bactericidal action of antibiotics is due to the generation of endogenous reactive oxygen species (ROS), a process requiring the citric acid cycle (tricarboxylic acid [TCA] cycle). To test this hypothesis, we assessed the ability of oxacillin to induce ROS production and cell death in Staphylococcus epidermidis strain 1457 and an isogenic citric acid cycle mutant. Our results confirm a contributory role for TCA-dependent ROS in enhancing susceptibility of S. epidermidis toward β-lactam antibiotics and also revealed a propensity for clinical isolates to accumulate TCA cycle dysfunctions presumably as a way to tolerate these …

Manipulation Of Cellular Processing Bodies And Their Constituents By Viruses, Asit K. Pattnaik, Phat X. Dinh

School of Veterinary and Biomedical Sciences: Faculty Publications

The processing bodies (PBs) are a form of cytoplasmic aggregates that house the cellular RNA decay machinery as well as many RNA-binding proteins and mRNAs. The PBs are constitutively present in eukaryotic cells and are involved in maintaining cellular homeostasis by regulating RNA metabolism, cell signaling, and survival. Virus infections result in modification of the PBs and their constituents. Many viruses induce compositionally altered PBs, while many others use specific components of the PBs for their replication. PB constituents are also known to restrict virus replication by a variety of mechanisms. Further, continuing studies in this rapidly emerging field of …

Characterization Of A Serologic Marker Candidate For Development Of A Live-Attenuated Diva Vaccine Against Porcine Reproductive And Respiratory Syndrome Virus, Hiep Vu, Byungjoon Kwon, Marcelo De Lima, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

DIVA (differentiating infected from vaccinated animals) vaccines have proven extremely useful for control and eradication of infectious diseases in livestock. We describe here the characterization of a serologic marker epitope, so-called epitope-M201, which can be a potential target for development of a live-attenuated DIVA vaccine against porcine reproductive and respiratory syndrome virus (PRRSV). Epitope-M201 is located at the carboxyl terminus (residues 161-174) of the viral M protein. The epitope is highly immunodominant and well-conserved among type-II PRRSV isolates. Rabbit polyclonal antibodies prepared against this epitope are non-neutralizing; thus, the epitope does not seem to contribute to the protective immunity against …

Trex1 Regulates Lysosomal Biogenesis And Interferon-Independent Activation Of Antiviral Genes, Maroof Hasan, James Koch, Dinesh Rakheja, Asit K. Pattnaik, James Brugarolas, Igor Dozmorov, Beth Levine, Edward K. Wakeland, Min Ae Lee-Kirsch, Nan Yan

School of Veterinary and Biomedical Sciences: Faculty Publications

Innate immune sensing of viral nucleic acids triggers type I interferon (IFN) production, which activates interferon-stimulated genes (ISGs) and directs a multifaceted antiviral response. ISGs can also be activated through IFN-independent pathways, although the precise mechanisms remain elusive. Here we found that the cytosolic exonuclease Trex1 regulates the activation of a subset of ISGs independently of IFN. Both Trex1−/− mouse and TREX1-mutant human cells express high levels of antiviral genes and are refractory to viral infections. The IFN-independent activation of antiviral genes in Trex1−/− cells requires STING, TBK1 and IRF3 and IRF7. We also found that Trex1-deficient cells display expanded …

Influence Of Therapeutic Ceftiofur Treatments Of Feedlot Cattle On Fecal And Hide Prevalences Of Commensal Escherichia Coli Resistant To Expanded-Spectrum Cephalosporins, And Molecular Characterization Of Resistant Isolates, John W. Schmidt, Dee Griffin, Larry A. Kuehn, Dayna M. Brichta-Harhay

School of Veterinary and Biomedical Sciences: Faculty Publications

In the United States, the bla_CMY-2 gene contained within incompatibility type A/C (IncA/C) plasmids is frequently identified in extended-spectrum-cephalosporin-resistant (ESC^r) Escherichia coli strains from both human and cattle sources. Concerns have been raised that therapeutic use of ceftiofur in cattle may increase the prevalence of ESC^r E. coli. We report that herd ESC^r E. coli fecal and hide prevalences throughout the residency of cattle at a feedlot, including during the period of greatest ceftiofur use at the feedlot, were either not significantly different (P≥0.05) or significantly less (Pr E. coli shedding that follows ceftiofur …

Complete Closed Genome Sequences Of Mannheimia Haemolytica Serotypes A1 And A6, Isolated From Cattle, Gregory P. Harhay, Sergey Koren, Adam M. Phillippy, D. Scott Mcvey, Jennifer Kuszak, Michael L. Clawson, Dayna M. Harhay, Michael P. Heaton, Carol G. Chitko-Mckown, Timothy P. L. Smith

School of Veterinary and Biomedical Sciences: Faculty Publications

Mannheimia haemolytica is a respiratory pathogen affecting cattle and related ruminants worldwide. M. haemolytica is commonly associated with bovine respiratory disease complex (BRDC), a polymicrobial multifactorial disease.Wepresent the first two complete closed genome sequences of this species, determined using an automated assembly pipeline requiring no manual finishing.

Deep Sequencing And Genome-Wide Analysis Reveals The Expansion Of Microrna Genes In The Gall Midge Mayetiola Destructor, Chitvan Khajuria, Christie E. Williams, Mustapha El Bouhssini, R. Jeff Whitworth, Stephen Richards, Jeffrey J. Stuart, Ming-Shun Chen

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: MicroRNAs (miRNAs) are small non-coding RNAs that play critical roles in regulating post transcriptional gene expression. Gall midges encompass a large group of insects that are of economic importance and also possess fascinating biological traits. The gall midge Mayetiola destructor, commonly known as the Hessian fly, is a destructive pest of wheat and model organism for studying gall midge biology and insect – host plant interactions.

Results: In this study, we systematically analyzed miRNAs from the Hessian fly. Deep-sequencing a Hessian fly larval transcriptome led to the identification of 89 miRNA species that are either identical or very …

Development And Evaluation Of A Replicon Particle Vaccine Expressing The E2 Glycoprotein Of Bovine Viral Diarrhea Virus (Bvdv) In Cattle, John Dustin Loy, Jill Gander, Mark Mogler, Ryan Vander Veen, Julia Ridpath, Delbert Hank Harris, Kurt Kamrud

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Bovine viral diarrhea virus is one of the most significant and costly viral pathogens of cattle worldwide. Alphavirus-derived replicon particles have been shown to be safe and highly effective vaccine vectors against a variety of human and veterinary pathogens. Replicon particles are non-propagating, DIVA compatible, and can induce both humoral and cell mediated immune responses. This is the first experiment to demonstrate that Alphavirus-based replicon particles can be utilized in a standard prime/boost vaccination strategy in calves against a commercially significant bovine pathogen.

Findings: Replicon particles that express bovine viral diarrhea virus sub-genotype 1b E2 glycoprotein were …

Glutaredoxin 2 (Grx2) Knockout Increases Sensitivity To Oxidative Stress In Mouse Lens Epithelial Cells, Hongli Wu, Liren Lin, Frank Giblin, Ye-Sheh Ho, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

Glutaredoxin belongs to the oxidoreductase family with cytosolic glutaredoxin 1 (Grx1) and mitochondrial gluraredoxin 2 (Grx2) isoforms. Of the two isozymes, the function of Grx2 is not well understood. This paper studied the effect of Grx2 deletion on cellular function using primary lens epithelial cell cultures isolated from Grx2 gene knockout (KO) and wild type (WT) mice. We found that both cell types showed similar growth patterns and morphology, and comparable mitochondrial glutathione pool and complex I activity. Cells with deleted Grx2 did not show affected Grx1 or thioredoxin (Trx) expression but exhibited high sensitivity to oxidative stress. Under treatment …

Ultraviolet Radiation–Induced Cataract In Mice: The Effect Of Age And The Potential Biochemical Mechanism, Jie Zhang, Hong Yan, Stefan Lofgren, Xiaoli Tian, Marjorie F. Lou

School of Veterinary and Biomedical Sciences: Faculty Publications

PURPOSE. To study the effect of age on the morphologic and biochemical alterations induced by in vivo exposure of ultraviolet radiation (UV).

METHODS. Young and old C57BL/6 mice were exposed to broadband UVBþUVA and euthanized after 2 days. Another batch of UV-exposed young mice was monitored for changes after 1, 2, 4, and 8 days. Age-matched nonexposed mice served as controls. Lens changes were documented in vivo by slit-lamp biomicroscopy and dark field microscopy photographs ex vivo. Lens homogenates were analyzed for glutathione (GSH) level, and the activities of thioredoxin (Trx), thioltransferase (TTase), and glyceraldehyde-3-phosphate dehydrogenase (G3PD). Glutathionylated lens proteins …

Melanopsin Mediates Retrograde Visual Signaling In The Retina, Dao-Qi Zhang, Michael A. Belenky, Patricia J. Sollars, Gary E. Pickard, Douglas G. Mcmahon

School of Veterinary and Biomedical Sciences: Faculty Publications

The canonical flow of visual signals proceeds from outer to inner retina (photoreceptors→bipolar cells→ganglion cells). However, melanopsin-expressing ganglion cells are photosensitive and functional sustained light signaling to retinal dopaminergic interneurons persists in the absence of rods and cones. Here we show that the sustained-type light response of retinal dopamine neurons requires melanopsin and that the response is mediated by AMPA-type glutamate receptors, defining a retrograde retinal visual signaling pathway that fully reverses the usual flow of light signals in retinal circuits.

Peptoid Based Slide Coatings For Disease Detection Via Elisa Microarray Analysis, Melissa Lea Hebert

Graduate Theses and Dissertations

Poly-N-substituted glycines (peptoids) are a very versatile family of synthetic molecules that can be customized for any number of applications. In this study, we chose to use peptoids as a foundation for sandwich ELISA microarray analysis with a long term goal of creating an early detection device for complex diseases such as cancer. The peptoids were designed to self-assemble into microspheres to be used in coatings on the surface of the microarray substrates to increase the surface area available for antibody attachment. This increased antibody density would lead to an increase in the microarray analysis sensitivity and dynamic range. Studies …

Pv1 Down-Regulation Via Shrna Inhibits The Growth Of Pancreatic Adenocarcinoma Xenografts, Sophie J. Deharvengt, Dan Tse, Olga Sideleva, Caitlin Mcgarry, Jason R. Gunn, Daniel S. Longnecker, Catherine Carriere, Radu V. Stan

Dartmouth Scholarship

PV1 is an endothelial-specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour-bearing mice by single-dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down-regulation by shRNAs inhibits the growth of established tumours derived from two …

Environmental Friendly Synthesis, Characterization Of Surface Modifiable Starch Encapsulated Gold Nanoparticles With Bactericidal And Catalytic Activity, Dillon Pender

Mahurin Honors College Capstone Experience/Thesis Projects

In the present study, we report the green synthesis of gold nanoparticles (GNPs), using potato starch as a reducing as well as a stabilizing agent in an aqueous buffer medium. The resulting starch-GNPs (St-GNPs) were near spherical in shape with an average diameter of 15 ± 5 nm. In this approach, St-GNPs were characterized and investigated for their antibacterial properties against both gram negative (Escherichia coli) and gram positive (Staphylococcus epidermidis) bacteria. These St-GNPs were found to possess significant dose dependent antibacterial activity against bacteria. Also, St-GNPs showed a significant catalytic activity and can easily be …

Regulation Of Protein Degradation In The Heart By Amp-Activated Protein Kinase, Kedryn K. Baskin

Dissertations and Theses (Open Access)

The degradation of proteins by the ubiquitin proteasome system is essential for cellular homeostasis in the heart. An important regulator of metabolic homeostasis is AMP-activated protein kinase (AMPK). During nutrient deprivation, AMPK is activated and intracellular proteolysis is enhanced through the ubiquitin proteasome system (UPS). Whether AMPK plays a role in protein degradation through the UPS in the heart is not known. Here I present data in support of the hypothesis that AMPK transcriptionally regulates key players in the UPS, which, under extreme conditions can be detrimental to the heart. The ubiquitin ligases MAFbx /Atrogin-1 and MuRF1, key regulators of …

Characterization Of Species C Human Adenovirus Serotype 6 (Ad6), Eric A. Weaver, Reeti Khare, Mathew L. Hillestad, Donna Palmer, Philip Ng, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Adenovirus serotype (Ad5) is the most studied Ad. Ad1, 2, and 6 are also members of species C Ad and are presumed to have biologies similar to Ad5. In this work, we have compared the ability of Ad1, 2, 5, and 6 to infect liver and muscle after intravenous and intramuscular injection. We found that Ad6 was surprisingly the most potent at liver gene delivery and that Ad1 and Ad2 were markedly weaker than Ad5 and 6. To understand these differences, we sequenced the Ad6 genome. This revealed that the Ad6 fiber protein is surprisingly three shaft repeats shorter than …

Heme Oxygenase-1 Regulates The Immune Response To Influenza Virus Infection And Vaccination In Aged Mice, Nathan W. Cummins, Eric A. Weaver, Shannon M. May, Anthony J. Croatt, Oded Foreman, Richard B. Kennedy, Gregory A. Poland, Michael A. Barry, Karl A. Nath, Andrew D. Badley

Nebraska Center for Virology: Faculty Publications

Underlying mechanisms of individual variation in severity of influenza infection and response to vaccination are poorly understood. We investigated the effect of reduced heme oxygenase-1 (HO-1) expression on vaccine response and outcome of influenza infection. HO-1-deficient and wild-type (WT) mice (kingdom, Animalia; phylum, Chordata; genus/species, Mus musculus) were infected with influenza virus A/PR/8/34 with or without prior vaccination with an adenoviral-based influenza vaccine. A genome-wide association study evaluated the expression of single-nucleotide polymorphisms (SNPs) in the HO-1 gene and the response to influenza vaccination in healthy humans. HO-1-deficient mice had decreased survival after influenza infection compared to WT mice (median …

The Mechanical Behavior Of Mutant K14-R125p Keratin Bundles And Networks In Neb-1 Keratinocytes, Daniel R. Beriault, Oualid Haddad, John V. Mccuaig, Zachary J. Robinson, David Russell, E. Birgitte Lane, Douglas S. Fudge

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Epidermolysis bullosa simplex (EBS) is an inherited skin-blistering disease that is caused by dominant mutations in the genes for keratin K5 or K14 proteins. While the link between keratin mutations and keratinocyte fragility in EBS patients is clear, the exact biophysical mechanisms underlying cell fragility are not known. In this study, we tested the hypotheses that mutant K14-R125P filaments and/or networks in human keratinocytes are mechanically defective in their response to large-scale deformations. We found that mutant filaments and networks exhibit no obvious defects when subjected to large uniaxial strains and have no negative effects on the ability of human …

Effective Non-Viral Delivery Of Sirna To Acute Myeloid Leukemia Cells With Lipid-Substituted Polyethylenimines, Breanne Landry

Pharmacy Faculty Articles and Research

Use of small interfering RNA (siRNA) is a promising approach for AML treatment as the siRNA molecule can be designed to specifically target proteins that contribute to aberrant cell proliferation in this disease. However, a clinical-relevant means of delivering siRNA molecules must be developed, as the cellular delivery of siRNA is problematic. Here, we report amphiphilic carriers combining a cationic polymer (2 kDa polyethyleneimine, PEI2) with lipophilic moieties to facilitate intracellular delivery of siRNA to AML cell lines. Complete binding of siRNA by the designed carriers was achieved at a polymer:siRNA ratio of ~0.5 and led to siRNA/polymer complexes of …

Triticum Mosaic Poacevirus Enlists P1 Rather Than Hc-Pro To Suppress Rna Silencing-Mediated Host Defense, Satyanarayana Tatineni, Feng Qu, Ruhui Li, Thomas Jack Morris, Roy French

Nebraska Center for Virology: Faculty Publications

Triticum mosaic virus (TriMV) is the type species of the newly established Poacevirus genus in the family Potyviridae. In this study, we demonstrate that in contrast to the helper component- proteinase (HC-Pro) of Potyvirus species, the P1 proteins of TriMV and Sugarcane steak mosaic poacevirus function in suppression of RNA silencing (SRS). TriMV P1 effectively suppressed silencing induced by single- or double-stranded RNAs (ss/ds RNAs), and disrupted the systemic spread of silencing signals at a step after silencing signal production. Interestingly, contrary to enhanced SRS activity of potyviral HC-Pro by co-expression with P1, the presence of TriMV HC-Pro reduced …

Identification Of Molecular Determinants From Moloney Leukemia Virus 10 Homolog (Mov10) Protein For Virion Packaging And Anti-Hiv-1 Activity, Aierken Abudu, Xiaojun Wang, Ying Dang, Tao Zhou, Shi-Hua Xiang, Yong -Hui Zheng

Nebraska Center for Virology: Faculty Publications

Background: MOV₁₀ inhibits HIV-1 replication after being packaged.

Results: A Gag binding plus all but one of seven helicase domains are required for MOV^₁₀ packaging. Nearly all residues are required for anti-HIV-1 activity. Conclusion: Gag binding is not sufficient for MOV₁₀ packaging, and multiple discontinuous domains regulate MOV₁₀ activity.

Significance: These findings uncover a new packaging mechanism and provide new insights into MOV₁₀ antiviral activity.

One-Pot Regioselective Synthesis Of Tetrahydroindazolones And Evaluation Of Their Anti-Proliferative And Src Kinase Inhibitory Activities, V. Kameshwara Rao, Bhupender S. Chhikara, Rakesh Tiwari, Amir Nasrolahi Shirazi, Keykavous Parang, Anil Kumar

Pharmacy Faculty Articles and Research

A number of 2-substituted tetrahydroindazolones were synthesized by three-component condensation reaction of 1,3- diketones, substituted hydrazines, benzaldehydes, and Yb(OTf)3 as a catalyst in [bmim][BF4] ionic liquid using a simple, efficient, and economical one-pot method. The synthesized tetrahydroindazolones were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), human ovarian adenocarcinoma (SK-OV-3), and c-Src kinase activity. 3,4-Dichlorophenyl tetrahydroindazolone derivative (15) inhibited the cell proliferation of HT-29 and SK-OV-3 cells by 62% and 58%, respectively. 2,3-Diphenylsubstituted tetrahydroindazolone derivatives, 19, 25, and 33, inhibited the cell proliferation of HT-29 cells by 6572% at a concentration of 50 μM. In general, the …

Dynamics Of Envelope Evolution In Clade C Shiv-Infected Pig-Tailed Macaques During Disease Progression Analyzed By Ultra-Deep Pyrosequencing, For Yue Tso, Damien C. Tully, Sandra Gonzalez, Christopher Quince, On Ho, Patricia Polacino, Ruth M. Ruprecht, Shiu-Lok Hu, Charles Wood

Nebraska Center for Virology: Faculty Publications

Understanding the evolution of the human immunodeficiency virus type 1 (HIV-1) envelope during disease progression can provide tremendous insights for vaccine development, and simian-human immunodeficiency virus (SHIV) infection of nonhuman primate provides an ideal platform for such studies. A newly developed clade C SHIV, SHIV-1157ipd3N4, which was able to infect rhesus macaques, closely resembled primary HIV-1 in transmission and pathogenesis, was used to infect several pig-tailed macaques. One of the infected animals subsequently progressed to AIDS, whereas one remained a nonprogressor. The viral envelope evolution in the infected animals during disease progression was analyzed by a bioinformatics approach using ultra-deep …

Genetics And Cancer, Sachin Puri

A with Honors Projects

Genes' effect in body and relationship with cancer. Role in cell cycle and angiogenesis.

Higher Il-6 And Il6:Igf Ratio In Patients With Barth Syndrome, Lori D. Wilson, Sadeeka Al-Majid, Cyril Rakovski, Christina D. Schwindt

Mathematics, Physics, and Computer Science Faculty Articles and Research

Background: Barth Syndrome (BTHS) is a serious X-linked genetic disorder associated with mutations in the tafazzin gene (TAZ, also called G4.5). The multi-system disorder is primarily characterized by the following pathologies: cardiac and skeletal myopathies, neutropenia, growth delay, and exercise intolerance. Although growth anomalies have been widely reported in BTHS, there is a paucity of research on the role of inflammation and the potential link to alterations in growth factors levels in BTHS patients.

Methods: Plasma from 36 subjects, 22 patients with Barth Syndrome (0.5 - 24 yrs) and 14 healthy control males (8 - 21 yrs) was …

Chloroviruses: Not Your Everyday Plant Virus, James L. Van Etten, David D. Dunigan

Nebraska Center for Virology: Faculty Publications

Viruses infecting higher plants are among the smallest viruses known and typically have four to ten protein-encoding genes. By contrast, many viruses that infect algae (classified in the virus family Phycodnaviridae) are among the largest viruses found to date and have up to 600 protein- encoding genes. This brief review focuses on one group of plaque-forming phycodnaviruses that infect unicellular chlorella-like green algae. The prototype chlorovirus PBCV-1 has more than 400 protein-encoding genes and 11 tRNA genes. About 40% of the PBCV-1 encoded proteins resemble proteins of known function including many that are completely unexpected for a virus. In many …

Molecular Genetic And Biochemical Characterization Of The Vaccinia Virus I3 Protein, The Replicative Single-Stranded Dna Binding Protein, Matthew D. Greseth, Kathleen A. Boyle, Matthew S. Bluma, Bethany Unger, Matthew S. Wiebe, Jamaria A. Soares-Martins, Nadi T. Wickramasekera, James Wahlberg, Paula Traktman

Nebraska Center for Virology: Faculty Publications

Vaccinia virus, the prototypic poxvirus, efficiently and faithfully replicates its approximately 200-kb DNA genome within the cytoplasm of infected cells. This intracellular localization dictates that vaccinia virus encodes most, if not all, of its own DNA replication machinery. Included in the repertoire of viral replication proteins is the I3 protein, which binds to single-stranded DNA (ssDNA) with great specificity and stability and has been presumed to be the replicative ssDNA binding protein (SSB). We substantiate here that I3 colocalizes with bromodeoxyuridine (BrdU)-labeled nascent viral genomes and that these genomes accumulate in cytoplasmic factories that are delimited by membranes derived from …