Organisms Commons^™

Capsid Structure Of Dsrna Fungal Viruses, Daniel Luque, Carlos P. Mata, Nobuhiro Suzuki, Said A. Ghabrial, José R. Castón

Plant Pathology Faculty Publications

Most fungal, double-stranded (ds) RNA viruses lack an extracellular life cycle stage and are transmitted by cytoplasmic interchange. dsRNA mycovirus capsids are based on a 120-subunit T = 1 capsid, with a dimer as the asymmetric unit. These capsids, which remain structurally undisturbed throughout the viral cycle, nevertheless, are dynamic particles involved in the organization of the viral genome and the viral polymerase necessary for RNA synthesis. The atomic structure of the T = 1 capsids of four mycoviruses was resolved: the L-A virus of Saccharomyces cerevisiae (ScV-L-A), Penicillium chrysogenum virus (PcV), Penicillium stoloniferum virus F (PsV-F), and Rosellinia necatrix …

Contributions Of The Gp120 Variable Loops To Envelope Glycoprotein Trimer Stability In Primate Lentiviruses, Dane M. Bowder

School of Biological Sciences: Dissertations, Theses, and Student Research

Human Immunodeficiency Virus (HIV) is the etiological agent of AIDS and is responsible for the AIDS pandemic worldwide. According to UNAIDS, as of 2016, there were approximately 36.7 million people living with HIV globally, and 1.8 million new infections that year. While antiretroviral therapies and education continue to reduce these numbers, a preventative vaccine is still required to curb this epidemic. The envelope glycoprotein trimer of HIV, which is the sole protein on the surface of the virus and facilitates entry of the virus into host cells, is of keen interest to the HIV vaccine and drug-development field. Recently, the …

Evaluation Of A Human Papillomavirus Genotyping Assay For Cervical Cancer Screening In Tanzania, Kandali S. Kapie

School of Biological Sciences: Dissertations, Theses, and Student Research

Abstract: Mucosal high-risk Human papillomavirus (HR-HPV) has been identified as the primary factor in causing cervical cancer, the most common cancer in women of low and middle-income countries (LMICs). Cervical cancer screening, incorporating the HPV test shown to be more advantageous than screening by visual inspection with acetic acid (VIA) alone. However, due to resources constrain these countries could not afford the available HPV tests. We, therefore, validated a cost-effective Multiplex PCR HPV (mPCR) assay, a recently developed assay for detecting sixteen genital HPV, fourteen HR-HPV and 2 low-risk genotypes. We postulate that this HPV multiplex assay will be at …

Type 2 Bovine Viral Diarrhea Virus NPro Suppresses Type I Interferon Pathway Signaling In Bovine Cells And Augments Bovine Respiratory Syncytial Virus Replication, Abdulrahman Abdulaziz A. Alkheraif

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Bovine viral diarrhea virus (BVDV) and bovine respiratory syncytial virus (BRSV) infections contribute to the bovine respiratory disease complex (BRDC), which is a multi-factorial disorder involving co-infections of viruses and bacteria including mycoplasma. BRDC causes great economic losses to the United States feedlot industry. BVDV infection induces immunosuppression in infected animals. BVDV N^pro binds and degrades the transcription factor interferon regulatory factor-3 (IRF-3) and effectively blocks type I interferon (type I IFN) expression in host cells. BRSV nonstructural proteins, NS1 and NS2, block activation of IRF-3. In calves, concurrent infection with BVDV and BRSV resulted in more severe clinical …

Direct Cell-To-Cell Transmission Of Respiratory Viruses: The Fast Lanes, Nicolás P. Cifuentes-Muñoz, Rebecca Ellis Dutch, Roberto Cattaneo

Molecular and Cellular Biochemistry Faculty Publications

Virus particles protect genomes from hostile environments within and outside the host, eventually delivering these genomes to target tissues to initiate infection. Complex processes requiring significant energy and time are necessary to assemble these virus particles, but only a small portion of released virus will successfully infect new target cells (Fig 1A). While the science of virology has developed based on the isolation and purification of viral particles, it is becoming increasingly clear that direct cell-to-cell transmission of viruses and/or viral components is also highly relevant [1,2].

Direct cell-to-cell spread of infections has several advantages. The first is efficiency: genomic …

Snf1 Cooperates With The Cwi Mapk Pathway To Mediate The Degradation Of Med13 Following Oxidative Stress, Stephen D Willis, David C Stieg, Kai Li Ong, Ravina Shah, Alexandra K. Strich, Julianne H Grose, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Eukaryotic cells, when faced with unfavorable environmental conditions, mount either pro-survival or pro-death programs. The conserved cyclin C-Cdk8 kinase plays a key role in this decision. Both are members of the Cdk8 kinase module that, along with Med12 and Med13, associate with the core Mediator complex of RNA polymerase II. In Saccharomyces cerevisiae, oxidative stress triggers Med13 destruction, which releases cyclin C into the cytoplasm to promote mitochondrial fission and programmed cell death. The SCFGrr1 ubiquitin ligase mediates Med13 degradation dependent on the cell wall integrity pathway, MAPK Slt2. Here we show that the AMP kinase Snf1 activates a second …

Borrelia Burgdorferi Spovg Dna- And Rna-Binding Protein Modulates The Physiology Of The Lyme Disease Spirochete, Christina R. Savage, Brandon L. Jutras, Aaron Bestor, Kit Tilly, Patricia A. Rosa, Yvonne Tourand, Philip E. Stewart, Catherine A. Brissette, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The SpoVG protein of Borrelia burgdorferi, the Lyme disease spirochete, binds to specific sites of DNA and RNA. The bacterium regulates transcription of spoVG during the natural tick-mammal infectious cycle and in response to some changes in culture conditions. Bacterial levels of spoVG mRNA and SpoVG protein did not necessarily correlate, suggesting that posttranscriptional mechanisms also control protein levels. Consistent with this, SpoVG binds to its own mRNA, adjacent to the ribosome-binding site. SpoVG also binds to two DNA sites in the glpFKD operon and to two RNA sites in glpFKD mRNA; that operon encodes genes necessary for glycerol catabolism …

Fungal Endophytes In A Seed-Free Host: New Species That Demonstrate Unique Community Dynamics, Brett Steven Younginger

Dissertations and Theses

Fungal endophytes are highly diverse, cryptic plant endosymbionts that form asymptomatic infections within host tissue. They represent a large fraction of the millions of undescribed fungal taxa on our planet with some demonstrating mutualistic benefits to their hosts including herbivore and pathogen defense and abiotic stress tolerance. Other endophytes are latent saprotrophs or pathogens, awaiting host plant senescence to begin alternative stages of their life cycles. Most, however, are likely plant commensals with no observable benefits to their hosts while under study. Yet, when considering the context-dependence that may determine plant resistance to pathogen attack, the consortium of endophytes present …

What We Do Not Know About Fungal Cell Adhesion Molecules, Peter N. Lipke

Publications and Research

There has been extensive research on structure and function of fungal cell adhesion molecules, but the most of the work has been about adhesins in Candida albicans and Saccharomyces cerevisiae. These yeasts are members of a single ascomycete order, and adhesion molecules from the six other fungal phyla are only sparsely described in the literature. In these other phyla, most of the research is at the cellular level, rather than at the molecular level, so there has been little characterization of the adhesion molecules themselves. A catalog of known adhesins shows some common features: high Ser/Thr content, tandem repeats, N- …

Deletion Of Endo-Β-1,4-Xylanase Vmxyl1 Impacts The Virulence Of Valsa Mali In Apple Tree, Chunlei Yu, Ting Li, Xiangpeng Shi, Muhammad Saleem, Baohua Li, Wenxing Liang, Caixia Wang

Plant and Soil Sciences Faculty Publications

Valsa mali, a parasitic fungus, is a destructive pathogen of apple tree that causes heavy economic losses in China. The pathogen secretes various cell wall-degrading enzymes (CWDEs) that degrade plant cell-wall components, and thus facilitate its entry into host cells. Therefore, functional analysis of the genes encoding CWDEs is necessary to understand virulence of V. mali toward apple tree. Here, we identified and cloned an endo-β-1,4-xylanase gene, VmXyl1 in V. mali. The full-length cDNA of VmXyl1 is 1626 bp containing 5′- and 3′-non-coding regions, as well an open reading frame of 1320 bp that encodes a protein with …

A Time Course Study Of Rotavirus-Infected Intestinal Cells Treated With Stilbenoids And The Regulation Of Apoptosis, Rebecca D. Parr, Caleb M. Witcher, Rebekah Napier-Jameson, Hannah L. Wilson, Stormey Wisdom, Macie N. Mattila, Essence B. Strange, Josephine Taylor, Beatrice Clack, Fabricio Medina-Bolivar, Judith M. Ball

Faculty Publications

This is a time course study of virus –host interactions that are modified with the addition of two small natural products. They appear to effect virus replication and the host response to the infection.

Ictv Virus Taxonomy Profile: Hypoviridae, Nobuhiro Suzuki, Said A. Ghabrial, Kook-Hyung Kim, Michael Pearson, Shin-Yi L. Marzano, Hajime Yaegashi, Jiatao Xie, Lihua Guo, Hideki Kondo, Igor Koloniuk, Bradley I. Hillman, Ictv Report Consortium

Plant Pathology Faculty Publications

The Hypoviridae, comprising one genus, Hypovirus, is a family of capsidless viruses with positive-sense, ssRNA genomes of 9.1–12.7 kb that possess either a single large ORF or two ORFs. The ORFs appear to be translated from genomic RNA by non-canonical mechanisms, i.e. internal ribosome entry site-mediated and stop/restart translation. Hypoviruses have been detected in ascomycetous or basidiomycetous filamentous fungi, and are considered to be replicated in host Golgi-derived, lipid vesicles that contain their dsRNA as a replicative form. Some hypoviruses induce hypovirulence to host fungi, while others do not. This is a summary of the current ICTV report …

Nutritional Virulence Of Legionella Pneumophila., Ashley M. Best

Electronic Theses and Dissertations

Legionella pneumophila is an environment organism that parasitizes a wide range of protozoa. Growth within the environmental host primes L. pneumophila for infection of human alveolar macrophages when contaminated aerosols are inhaled. Intracellular replication within either host requires the establishment a replicative niche, known as the Legionella-containing vacuole (LCV). Biogenesis of the LCV depends on the type IVb translocation system, the Dot/Icm, to translocation >320 effectors into the host cytosol. Effectors are responsible for preventing lysosome fusion to the LCV, recruitment of ER-derived vesicles to the LCV, and modulation of a plethora of host processes to promote the intracellular …

Ketogenic Diet Enhances Neurovascular Function With Altered Gut Microbiome In Young Healthy Mice, David Ma, Amy C. Wang, Ishita Parikh, Stefan J. Green, Jared D. Hoffman, George Chlipala, M. Paul Murphy, Brent S. Sokola, Björn Bauer, Anika M. S. Hartz, Ai-Ling Lin

Sanders-Brown Center on Aging Faculty Publications

Neurovascular integrity, including cerebral blood flow (CBF) and blood-brain barrier (BBB) function, plays a major role in determining cognitive capability. Recent studies suggest that neurovascular integrity could be regulated by the gut microbiome. The purpose of the study was to identify if ketogenic diet (KD) intervention would alter gut microbiome and enhance neurovascular functions, and thus reduce risk for neurodegeneration in young healthy mice (12–14 weeks old). Here we show that with 16 weeks of KD, mice had significant increases in CBF and P-glycoprotein transports on BBB to facilitate clearance of amyloid-beta, a hallmark of Alzheimer’s disease (AD). These neurovascular …

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 mutant displayed …

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 …

In Vivo Structures Of The Helicobacter Pylori Cag Type Iv Secretion System, Yi-Wei Chang, Carrie L. Shaffer, Lee A. Rettberg, Debnath Ghosal, Grant J. Jensen

Veterinary Science Faculty Publications

The type IV secretion system (T4SS) is a versatile nanomachine that translocates diverse effector molecules between microbes and into eukaryotic cells. Here, using electron cryotomography, we reveal the molecular architecture of the Helicobacter pylori cag T4SS. Although most components are unique to H. pylori, the cag T4SS exhibits remarkable architectural similarity to other T4SSs. Our images revealed that, when H. pylori encounters host cells, the bacterium elaborates membranous tubes perforated by lateral ports. Sub-tomogram averaging of the cag T4SS machinery revealed periplasmic densities associated with the outer membrane, a central stalk, and peripheral wing-like densities. Additionally, we resolved pilus-like …

Paclitaxel Enhances Oncolytic Potential Of Herpes Simplex Virus Type-1 In Cancer Cells, Misagh Naderi

LSU Master's Theses

Taxanes are spindle poisons that bind to and stabilize microtubules resulting in mitotic arrest. Herpes simplex Typ-1 (HSV-1) virions utilize the microtubular network for intracellular transport during both virus entry and virus egress from infected cells. It has been reported previously that taxanes may synergize with oncolytic herpes simplex viruses in the treatment of experimental prostate and breast tumors in mice. Other reports have indicated that taxanes may inhibit viral replication in infected cells. In this study the previously characterized Oncolytic Herpes Simplex Virus type 1 (OSVP), which was constructed in Kousoulas lab was used in conjugation with paclitaxel (taxol) …

Characterization Of The Interaction Between R. Conorii And Human Host Vitronectin In Rickettsial Pathogenesis, Abigail Inez Fish

LSU Doctoral Dissertations

Spotted Fever Group Rickettsia are inoculated into the mammalian host during hematophagous arthropod feeding. Once in the bloodstream and during dissemination, the survival of these pathogens is dependent upon their ability to evade innate host defenses until a proper cellular target is reached. The establishment of a successful infection also relies on the ability of the bacteria to attach and invade target cells, as failure to do so results in destruction of the bacterium. Rickettsia conorii expresses an outer membrane protein, Adr1, which binds the multifunctional human glycoprotein, vitronectin, to promote resistance to complement mediated killing. Homologs of Adr1 are …

In Vitro Assay Development As An Alternative To The Use Of Laboratory Animals For Measuring Clostridium Perfingens Type C Toxoid, Lauren M. Wilmes

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Clostridium perfringens type C produces beta toxin, which is a primary virulence determinate that can cause necrotic enteritis in neonatal animals. Vaccines directed against C. perfringens toxins have shown to be efficacious in preventing disease. However, the production of a commercial vaccine requires not only an efficacious antigen, but also testing methods for quantifying antigens and potency on final product. This research was undertaken to fulfill a need for the reduction in small animal usage to produce and deliver vaccines. The current testing methods are performed in vivo according to the Code of Federal Regulations number 9 (9CFR) United …

Genetic And Molecular Mechanisms Underlying Symbiotic Specificity In Legume-Rhizobium Interactions, Qi Wang, Jinge Liu, Hongyan Zhu

Plant and Soil Sciences Faculty Publications

Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant. Establishment of a successful symbiosis requires the two symbiotic partners to be compatible with each other throughout the process of symbiotic development. However, incompatibility frequently occurs, such that a bacterial strain is unable to nodulate a particular host plant or forms nodules that are incapable of fixing nitrogen. Genetic and molecular mechanisms that regulate symbiotic specificity …

Recombinant Promoter (Muascsv8cp) Driven Totiviral Killer Protein 4 (Kp4) Imparts Resistance Against Fungal Pathogens In Transgenic Tobacco, Debasish Deb, Ankita Shrestha, Indu B. Maiti, Nrisingha Dey

Kentucky Tobacco Research and Development Center Faculty Publications

Development of disease-resistant plant varieties achieved by engineering anti-microbial transgenes under the control of strong promoters can suffice the inhibition of pathogen growth and simultaneously ensure enhanced crop production. For evaluating the prospect of such strong promoters, we comprehensively characterized the full-length transcript promoter of Cassava Vein Mosaic Virus (CsVMV; -565 to +166) and identified CsVMV8 (-215 to +166) as the highest expressing fragment in both transient and transgenic assays. Further, we designed a new chimeric promoter ‘MUASCsV8CP’ through inter-molecular hybridization among the upstream activation sequence (UAS) of Mirabilis Mosaic Virus (MMV; -297 to -38) and CsVMV8, as the core …

Comparative Analysis Of Microbial Sensing Molecules In Mucosal Tissues With Aging, Octavio A. Gonzalez, Sreenatha S. Kirakodu, Michael John Novak, A. J. Stromberg, L. Orraca, J. Gonzalez-Martinez, A. Burgos, Jeffrey L. Ebersole

Center for Oral Health Research Faculty Publications

Host-bacterial interactions at mucosal surfaces require recognition of the bacteria by host cells enabling targeted responses to maintain tissue homeostasis. It is now well recognized that an array of host-derived pattern recognition receptors (PRRs), both cell-bound and soluble, are critical to innate immune engagement of microbes via microbial-associated molecular patterns (MAMP). This report describes the use of a nonhuman primate model to evaluate changes in the expression of these sensing molecules related to aging in healthy gingival tissues. Macaca mulatta aged 3-24 years were evaluated clinically and gingival tissues obtained, RNA isolated and microarray analysis conducted for gene expression of …

Phaeophleospora Vochysiae Savi & Glienke Sp. Nov. Isolated From Vochysia Divergens Found In The Pantanal, Brazil, Produces Bioactive Secondary Metabolites, Daiani C. Savi, Khaled A. Shaaban, Francielly M. W. Gos, Larissa V. Ponomareva, Jon S. Thorson, Chirlei Glienke, Jürgen Rohr

Pharmaceutical Sciences Faculty Publications

Microorganisms associated with plants are highly diverse and can produce a large number of secondary metabolites, with antimicrobial, anti-parasitic and cytotoxic activities. We are particularly interested in exploring endophytes from medicinal plants found in the Pantanal, a unique and widely unexplored wetland in Brazil. In a bio-prospecting study, strains LGMF1213 and LGMF1215 were isolated as endophytes from Vochysia divergens, and by morphological and molecular phylogenetic analyses were characterized as Phaeophleospora vochysiae sp. nov. The chemical assessment of this species reveals three major compounds with high biological activity, cercoscosporin (1), isocercosporin (2) and the new compound 3-(sec-butyl)-6-ethyl-4,5-dihydroxy-2-methoxy-6-methylcyclohex-2-enone (3). …

Biophysical Approaches To Solve The Structures Of The Complex Glycan Shield Of Chloroviruses, Cristina De Castro, Garry Duncan, Domenico Garozzo, Antonio Molinaro, Luisa Sturiale, Michela Tonetti, James L. Van Etten

James Van Etten Publications

The capsid of Paramecium bursaria chlorella virus (PBCV-1) contains a heavily glycosylated major capsid protein, Vp54. The capsid protein contains four glycans, each N-linked to Asn. The glycan structures are unusual in many aspects: (1) they are attached by a β-glucose linkage, which is rare in nature; (2) they are highly branched and consist of 8–10 neutral monosaccharides; (3) all four glycoforms contain a dimethylated rhamnose as the capping residue of the main chain, a hyper-branched fucose residue and two rhamnose residues ''with opposite absolute configurations; (4) the four glycoforms differ by the nonstoichiometric presence of two monosaccharides, l-arabinose and …

Mrub_1199 & Mrub_2272 Of Meiothermus Ruber Are Orthologous Genes To The B0262 Gene In Escherichia Coli While Mrub_1200, Mrub_1201, Mrub_2015 & Mrub_2271 Are Not Orthologous To The B0262 Gene Coding For The Iron (Fe3+) Abc Transport System, Kumail Hussain, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

In this project we investigated the biological function of the genes Mrub_1199, Mrub_1200, Mrub_1201, Mrub_2015, Mrub_2271 and Mrub_2272 (KEGG map number 02010). We predict these genes encode components of an Iron (Fe3+) ATP Binding Cassette (ABC) transporter: 1) Mrub_1199 (DNA coordinates [1211595-1212572] on the reverse strand) encodes the permease component (aka transmembrane domain); and 2) Mrub_1200 (DNA coordinates [1212612-1214093] on the reverse strand) encodes the ATP-binding domain (aka nucleotide binding domain); and 3) Mrub_1201 (DNA coordinates [1214347-1215309] on the reverse strand) encodes the substrate binding protein (aka the periplasmic component); and Mrub_2015 ( DNA coordinates [2053963-2054949] on the reverse strand) …

Guidelines And Recommendations On Yeast Cell Death Nomenclature, Didac Carmona-Gutierrez, Maria Anna Bauer, Andreas Zimmermann, Andrés Aguilera, Nicanor Austriaco, Kathryn Ayscough, Rena Balzan, Shoshana Bar-Nun, Antonio Barrientos, Peter Belenky, Marc Blondel, Ralf J Braun, Michael Breitenbach, William C Burhans, Sabrina Büttner, Duccio Cavalieri, Michael Chang, Katrina F Cooper, Manuela Côrte-Real, Vítor Costa, Christophe Cullin, Ian Dawes, Jörn Dengjel, Martin B Dickman, Tobias Eisenberg, Birthe Fahrenkrog, Nicolas Fasel, Kai-Uwe Fröhlich, Ali Gargouri, Sergio Giannattasio, Paola Goffrini, Campbell W Gourlay, Chris M Grant, Michael T Greenwood, Nicoletta Guaragnella, Thomas Heger, Jürgen Heinisch, Eva Herker, Johannes M Herrmann, Sebastian Hofer, Antonio Jiménez-Ruiz, Helmut Jungwirth, Katharina Kainz, Dimitrios P Kontoyiannis, Paula Ludovico, Stéphen Manon, Enzo Martegani, Cristina Mazzoni, Lynn A Megeney, Chris Meisinger, Jens Nielsen, Thomas Nyström, Heinz D Osiewacz, Tiago F Outeiro, Hay-Oak Park, Tobias Pendl, Dina Petranovic, Stephane Picot, Peter Polčic, Ted Powers, Mark Ramsdale, Mark Rinnerthaler, Patrick Rockenfeller, Christoph Ruckenstuhl, Raffael Schaffrath, Maria Segovia, Fedor F Severin, Amir Sharon, Stephan J Sigrist, Cornelia Sommer-Ruck, Maria João Sousa, Johan M Thevelein, Karin Thevissen, Vladimir Titorenko, Michel B Toledano, Mick Tuite, F-Nora Vögtle, Benedikt Westermann, Joris Winderickx, Silke Wissing, Stefan Wölfl, Zhaojie J Zhang, Richard Y Zhao, Bing Zhou, Lorenzo Galluzzi, Guido Kroemer, Frank Madeo

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Elucidating the biology of yeast in its full complexity has major implications for science, medicine and industry. One of the most critical processes determining yeast life and physiology is cellular demise. However, the investigation of yeast cell death is a relatively young field, and a widely accepted set of concepts and terms is still missing. Here, we propose unified criteria for the definition of accidental, regulated, and programmed forms of cell death in yeast based on a series of morphological and biochemical criteria. Specifically, we provide consensus guidelines on the differential definition of terms including apoptosis, regulated necrosis, and autophagic …

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 the …

Genes For Membrane Transport Proteins: Not So Rare In Viruses, Timo Greiner, Anna Moroni, James L. Van Etten, Gerhard Thiel

James Van Etten Publications

Some viruses have genes encoding proteins with membrane transport functions. It is unknown if these types of proteins are rare or are common in viruses. In particular, the evolutionary origin of some of the viral genes is obscure, where other viral proteins have homologs in prokaryotic and eukaryotic organisms. We searched virus genomes in databases looking for transmembrane proteins with possible transport function. This effort led to the detection of 18 different types of putative membrane transport proteins indicating that they are not a rarity in viral genomes. The most abundant proteins are K+ channels. Their predicted structures vary between …

Size-Dependent Catalysis Of Chlorovirus Population Growth By A Messy Feeding Predator, John Delong, Zeina Al-Ameeli, Shelby Lyon, James L. Van Etten, David Dunigan

James Van Etten Publications

Many chloroviruses replicate in endosymbiotic zoochlorellae that are protected from infection by their symbiotic host. To reach the high virus concentrations that often occur in natural systems, a mechanism is needed to release zoochlorellae from their hosts. We demonstrate that the ciliate predator Didinium nasutum foraging on zoochlorellae-bearing Paramecium bursaria can release live zoochlorellae from the ruptured prey cell that can then be infected by chloroviruses. The catalysis process is very effective, yielding roughly 95% of the theoretical infectious virus yield as determined by sonication of P. bursaria. Chlorovirus activation is more effective with smaller Didinia, as larger …