Microbiology Commons^™

The Leukemic Protein Core Binding Factor Beta (Cbfbeta)-Smooth-Muscle Myosin Heavy Chain Sequesters Cbfalpha2 Into Cytoskeletal Filaments And Aggregates, Neeraj Adya, Terryl Stacy, Nancy A. Speck, Pu Paul Liu

Dartmouth Scholarship

The fusion gene CBFB-MYH11 is generated by the chromosome 16 inversion associated with acute myeloid leukemias. This gene encodes a chimeric protein involving the core binding factor β (CBFβ) and the smooth-muscle myosin heavy chain (SMMHC). Mouse model studies suggest that this chimeric protein CBFβ-SMMHC dominantly suppresses the function of CBF, a heterodimeric transcription factor composed of DNA binding subunits (CBFα1 to 3) and a non-DNA binding subunit (CBFβ). This dominant suppression results in the blockage of hematopoiesis in mice and presumably contributes to leukemogenesis. We used transient-transfection assays, in combination with immunofluorescence and green fluorescent protein-tagged proteins, to monitor …

Identification And Characterization Of Spcu, A Chaperone Required For Efficient Secretion Of The Exou Cytotoxin, Viviane Finck-Barbançon, Timothy L. Yahr, Dara W. Frank

Dartmouth Scholarship

In recent studies, we have shown that Pseudomonas aeruginosa strains that are acutely cytotoxic in vitro damage the lung epithelium in vivo. Genetic analysis indicated that the factor responsible for acute cytotoxicity was controlled by ExsA and therefore was part of the exoenzyme S regulon. The specific virulence determinant responsible for epithelial damage in vivo and cytotoxicity in vitro was subsequently mapped to the exoU locus. The present studies are focused on a genetic characterization of the exoU locus. Northern blot analyses and complementation experiments indicated that a region downstream of exoU was expressed and that the expression of this …

Analysis Of Protein And Rna Interactions Of The Hiv-1 Rev Protein, John Francis

Loma Linda University Electronic Theses, Dissertations & Projects

The HIV-1 Rev protein enters the nucleus via it’s nuclear localization sequence/RNA binding domain and interacts with a ≈234 nt region of viral RNA, termed the Rev Response Element (RRE), which is located in the env region of unspliced and singly-spliced HIV-1 mRNA. The Rev nuclear export sequence (NES) then mediates translocation of the viral transcript to the cytoplasm, allowing for translation of viral structural genes and active virion formation. We report identification of two yeast nucleopore proteins, NUP49 and NUP100, that have been found to interact with Rev in vivo using the yeast two-hybrid system. NUP49 and NUP100 contain …

Fecal Bacteria Survival And Infiltration Through A Shallow Agricultural Soil: Timing And Tillage Effects, C. S. Stoddard, Mark S. Coyne, John H. Grove

Plant and Soil Sciences Faculty Publications

Human and livestock exposure to fecal pathogens via contaminated surface or groundwater is an important water quality concern for soils receiving animal wastes. The effects of manure application timing (spring or fall application) and soil management (no-tillage or conservation tillage) on fecal bacteria infiltration through shallow karst soils in central Kentucky (the Bluegrass region) have not been evaluated. We performed a field experiment to measure fecal coliforms and fecal streptococci in leachate from dairy manure-amended no-tillage and conservation tillage soils. Manure significantly increased fecal bacteria in leachate compared with unmanured treatments. After manure application, the leachate that collected in zero-tension …

The Seca Subunit Of Escherichia Coli Preprotein Translocase Is Exposed To The Periplasm, Jerry Eichler, William Wickner

Dartmouth Scholarship

SecA undergoes conformational changes during translocation, inserting domains into and across the membrane or enhancing the protease resistance of these domains. We now show that some SecA bound at SecYEG is accessible from the periplasm to a membrane-impermeant probe in cells with a permeabilized outer membrane but an intact plasma membrane.

Vertical Profiles Of Virus-Like Particles And Bacteria In The Water Column And Sediments Of Chesapeake Bay, Usa, Lisa A. Drake, Keun-Hyung Choi, A. G. Edward Haskell, Fred C. Dobbs

OES Faculty Publications

Vertical profiles of virus-like particles (VLPs) and bacteria were determined by near-synoptic sampling through the water column and 15 to 25 cm into the sediment at 5 stations across the mouth of Chesapeake Bay, USA. VLPs were about 10 times more abundant in the pore water (grand mean = 3.6 x 10(8) VLPs ml(-1)) than in the water column (grand mean = 3.8 x 10(7) VLPs ml(-1)). Similarly, bacteria counts were about 3 times higher in the pore water (grand mean = 6.5 x 10(6) bacteria ml(-1)) than in the water column (grand mean = 2.4 x 10(6) bacteria ml(-1)). …

Influence Of The Ccr2-V64i Polymorphism On Human Immunodeficiency Virus Type 1 Coreceptor Activity And On Chemokine Receptor Function Of Ccr2b, Ccr3, Ccr5, And Cxcr4, Benhur Lee, Benjamin J. Doranz, Shalini Rana, Yanji Yi, Mario Mellado, Jose M. R. Frade, Carlos Martinez-A., Stephen J. O'Brien, Michael Dean, Ronald G. Collman, Robert W. Doms

Biology Faculty Articles

The chemokine receptors CCR5 and CXCR4 are used by human immunodeficiency virus type 1 (HIV-1) in conjunction with CD4 to infect cells. In addition, some virus strains can use alternative chemokine receptors, including CCR2b and CCR3, for infection. A polymorphism in CCR2 (CCR2-V64I) is associated with a 2- to 4-year delay in the progression to AIDS. To investigate the mechanism of this protective effect, we studied the expression of CCR2b and CCR2b-V64I, their chemokine and HIV-1 coreceptor activities, and their effects on the expression and receptor activities of the major HIV-1 coreceptors. CCR2b and CCR2b-V64I were expressed at …

Characterization Of Metal-Regulated Genes In Pseudomonas Fluorescens, Melanie Pearson

Honors Theses

One side effect of today's industrialized world is increased levels of heavy metals in the environment. Many of these metals are necessary for biological function as trace elements, but at higher concentrations are toxic. Other metals, such as cadmium, are not beneficial at any level, and have only deleterious effects on living organisms. Cadmium is primarily thought to interfere with normal biological function of proteins. Human exposure to cadmium appears to primarily damage the kidneys, but may also affect the liver, lungs, immune system, and central nervous system. Bacteria, however, have developed several methods for handling toxic heavy metals: cation …

Cytoplasmic Assembly And Accumulation Of Human Immunodeficiency Virus Types 1 And 2 In Recombinant Human Colony-Stimulating Factor-1-Treated Human Monocytes: An Ultrastructural Study, Jan Marc Orenstein, Monte S. Meltzer, Terri Phipps, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Recombinant human colony-stimulating factor-1-treated human peripheral blood-derived monocytes-macrophages are efficient host cells for recovery of the human immunodeficiency virus (HIV) from blood leukocytes of patients with acquired immunodeficiency syndrome. These cells can be maintained as viable monolayers for intervals exceeding 3 months. Infection with HIV resulted in virus-induced cytopathic effects, accompanied by relatively high levels of released progeny virus, followed by a prolonged low-level release of virus from morphologically normal cells. In both acutely and chronically infected monocytes, viral particles were seen budding into and accumulating within cytoplasmic vacuoles. The number of intravacuolar virions far exceeded those associated with the …

Translation Of Random Transcripts Generated By Tdt: Potential Use In Polysome Peptide Libraries, Michael Lane Spencer

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science in Biology by Michael Lane Spencer on July 22, 1998.

The Physiology Of Life-History Trade-Offs: Experimental Analysis Of A Hormonally Induced Life-History Trade-Off In Gryllus Assimilis, Anthony J. Zera, Jason Potts, Kari Kobus

Anthony Zera Publications

Adult Gryllus assimilis given an analog of juvenile hormone exhibited reduced flight muscles and enlarged ovaries similar to those found in naturally occurring flightless individuals of species that are polymorphic for dispersal capability. Control and hormone-treated (flightless) G. assimilis did not differ in the amount of food consumed or assimilated on any of three diets that differed in nutrient quantity. Thus, enhanced ovarian growth of flightless individuals resulted from increased allocation of internal nutrients to reproduction (i.e., a trade-off) rather than from increased acquisition of nutrients. Compared with flight-capable controls, flightless G. assimilis also had reduced whole-organism respiration, reduced respiration …

Ultraviolet Radiation Triggers The Ribotoxic Stress Response In Mammalian Cells, Mihail S. Iordanov, David Pribnow, Jennifer L. Magun, Thanh-Hoai Dinh, Jean A. Pearson, Bruce E. Magun

CUP Faculty Research

The ribotoxic stress response, which is conserved between prokaryotes and eukaryotes, is a cellular reaction to cytotoxic interference with the function of the 3′-end of the large (23 S/28 S) ribosomal RNA. The 3′-end of the large rRNA is directly involved in the three sequential steps of translational elongation: the aminoacyl-tRNA binding, the peptidyl transfer, and the ribosomal translocation. In mammalian cells, the ribotoxic stress response involves activation of the stress-activated protein kinase/c-Jun NH₂-terminal kinase and the p38 mitogen-activated protein kinase and transcriptional induction of immediate early genes such as c-fos and c-jun. Active ribosomes …

Detection Of Mycobacterium Tuberculosis In Paraffin Embedded Intestinal Tissue Specimens By Polymerase Chain Reaction: Characterization Of Is6110 Element Negative Strains, Tariq Moatter, Shaper Mirza, Mohammad Shahid Siddiqui, Irshad Nabi Soomro

Department of Pathology and Laboratory Medicine

Tuberculosis is still one of the most widespread infection known to mankind. Although lung is the predominant site of disease, a sizeable population in Pakistan gets intestinal disease. Clinical presentation, radiologic and endoscopic examination provide clues to the diagnosis. However, a definitive diagnosis requires biopsy material with granulomas and/or caseation complemented by acid fast staining and culture. There are many occasions when biopsy material is scanty and even in some intestinal resection cases histologic evaluation fails to confirm or rule out tuberculosis. Therefore, an investigation was conducted to assess the efficacy of PCR in the detection of mycobacterial DNA in …

Igf-Ii Expression In Human Tumor Tissues And Human Igf-Ii Ribozyme Action, Zhaodong Xu

Loma Linda University Electronic Theses, Dissertations & Projects

Insulin-like growth factors (IGFs) are potent mitogens for a variety of cancer cells in vitro. In breast, prostate and neuroblastoma cancer cells, it has been suggested that IGF-II plays a paracrine/autocrine role. However, information on cell-type -specific IGF-II expression in vivo is limited. In situ hybridization and immunohistochemistry were carried out to determine the cell type expressing IGF-II in different tumor tissues. Both IGF-II mRNA and protein were localized to malignant cells, and expression in the stroma was minimal in all the tumors. The data are consistent with the hypothesis that cancer cell growth is regulated by IGF-II, and therefore …

Plant-Delivered Cholera Toxin B Subunit As An Immunomodulatory Molecule, Takeshi Arakawa

Loma Linda University Electronic Theses, Dissertations & Projects

The B subunit of cholera toxin (CTB) functions as an effective mucosal carrier molecule of chemically or genetically conjugated antigens. Orally delivered CTB or CTB fusion protein binds to G_M1-ganglioside receptor molecules located on cells in the gutassociated lymphoid tissues, the site of immunological induction. We have generated transgenic plants synthesizing CTB conjugated with vaccine antigens for food plant-based prevention of cholera and rotavirus toxin-induced diarrhea and for autoimmune diseases such as insulin-dependent diabetes mellitus (IDDM).

Mice fed with transgenic potato tubers synthesizing 0.3% of CTB as total tuber protein generated serum and mucosal antibodies with toxin neutralizing …

Biological Characterization Of Rev Variation In Equine Infectious Anemia Virus, Michael Belshan, Matthew E. Harris, Anne E. Shoemaker, Thomas J. Hope, Susan Carpenter

Nebraska Center for Virology: Faculty Publications

Sequence analysis identified significant variation in the second exon of equine infectious anemia virus (EIAV) rev. Functional analysis indicated that limited amino acid variation in Rev significantly altered the export activity of the protein but did not affect Rev-dependent alternative splicing. EIAV Rev can mediate export through two independent cis -acting Rev-responsive elements (RREs), and differences among Rev variants were more pronounced when both RREs were present. Variation in Rev may be an important mechanism for regulation of virus replication in vivo and may contribute to changes in clinical disease.

The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá

Biology Faculty Publications

The Biology of Xenopus presents a summary of current knowledge about a single genus resulting from a symposium held at the Zoological Society of London in September 1992. This approach to summarizing available information has also been taken for other taxa, such as Atelopus (Lotters, 1996). However, the task of compiling data for Xenopus is enormous relative to any other amphibian group, because Xenopus laevis has become a model system for molecular and development research (Cannatella and de Sa, 1993). Unfortunately, most of our knowledge of Xenopus is biased toward this single species. There are about 20 recognized species of …

Confocal Microscopy: A Powerful Tool For Biological Research, Amit Singh, K. P. Gopinathan

Biology Faculty Publications

Conventional light microscopy allows the observation of living as well as fixed cells and tissues to generate two-dimensional images. The out-of-focus information often obscures the ultrastructural details, especially in thick specimens with overlapping structures. The earliest available light microscopy visualized the objects in hydrated state in two-dimensions during their temporal development. The emergence of electron microscopy (EM) provided superb resolution of ultrastructural details, but it was applicable only for objects in the dehydrated state and thereby potentially introducing handling artifacts. The usefulness of optical methods, however, has been limited by the poor depth discrimination. Often, the fluorescence and reflectance images …

Localization Of Human Cytomegalovirus Structural Proteins To The Nuclear Matrix Of Infected Human Fibroblasts, V. Sanchez, Peter C. Angeletti, J. A. Engler, W. J. Britt

Nebraska Center for Virology: Faculty Publications

The intranuclear assembly of herpesvirus subviral particles remains an incompletely understood process. Previous studies have described the nuclear localization of capsid and tegument proteins as well as intranuclear tegumentation of capsid-like particles. The temporally and spatially regulated replication of viral DNA suggests that assembly may also be regulated by compartmentalization of structural proteins. We have investigated the intranuclear location of several structural and nonstructural proteins of human cytomegalovirus (HCMV). Tegument components including pp65 (ppUL83) and ppUL69 and capsid components including the major capsid protein (pUL86) and the small capsid protein (pUL48/49) were retained within the nuclear matrix (NM), whereas the …

Adenovirus Preterminal Protein Binds To The Cad Enzyme At Active Sites Of Viral Dna Replication On The Nuclear Matrix, Peter C. Angeletti, Jeffrey A. Engler

Nebraska Center for Virology: Faculty Publications

Adenovirus (Ad) replicative complexes form at discrete sites on the nuclear matrix (NM) via an interaction mediated by the precursor of the terminal protein (pTP). The identities of cellular proteins involved in these complexes have remained obscure. We present evidence that pTP binds to a multifunctional pyrimidine biosynthesis enzyme found at replication domains on the NM. Far-Western blotting identified proteins of 150 and 240 kDa that had pTP binding activity. Amino acid sequencing of the 150-kDa band revealed sequence identity to carbamyl phosphate synthetase I (CPS I) and a high degree of homology to the related trifunctional enzyme known as …

An Analysis Of Fecal Coliform Bacteria As A Water Quality Indicator, Janet Heyl Vail

Dissertations

The focus of this study is to assess the efficacy of fecal coliform bacteria as a microbiological water quality indicator. The scientific and educational context of fecal coliform bacteria is explored through analysis of large sets of water quality data, focused field monitoring projects, and review of commonly used resources for school-based and volunteer water-related studies. Analyzed data sets include long term sampling (10 years), multiple sites, daily samples, storm event samples, and other parameters monitored in parallel with bacteria. Special attention is given to data sets from Kent County, Michigan. A background reference site in Michigan unimpacted by humans …

Human Immunodeficiency Virus Neurotropism: An Analysis Of Viral Replication And Cytopathicity For Divergent Strains In Monocytes And Microglia, Anuja Ghorpade, Adeline Nukuna, Myhanh Che, Sherryl Haggerty, Yuri Persidsky, Eboni Carter, Leeroy Carhart, Laura Shafer, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Productive replication of human immunodeficiency virus type 1 (HIV-1) in brain macrophages and microglia is a critical component of viral neuropathogenesis. However, how virus-macrophage interactions lead to neurological disease remains incompletely understood. Possibly, a differential ability of virus to replicate in brain tissue macrophages versus macrophages in other tissues underlies HIV-1 neurovirulence. To these ends, we established systems for the isolation and propagation of pure populations of human microglia and then analyzed the viral life cycles of divergent HIV-1 strains in these cells and in cultured monocytes by using identical viral inocula and indicator systems. The HIV-1 isolates included those …

Role Of The Β-Chemokine Receptors Ccr3 And Ccr5 In Human Immunodeficiency Virus Type 1 Infection Of Monocytes And Microglia, Anuja Ghorpade, Meng Qi Xia, Bradley T. Hyman, Yuri Persidsky, Adeline Nukuna, Paul Bock, Myhanh Che, Janae Limoges, Howard Gendelman, Charles R. Mackay

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus type 1 (HIV-1) infection in mononuclear phagocyte lineage cells (monocytes, macrophages, and microglia) is a critical component in the pathogenesis of viral infection. Viral replication in macrophages serves as a reservoir, a site of dissemination, and an instigator for neurological sequelae during HIV-1 disease. Recent studies demonstrated that chemokine receptors are necessary coreceptors for HIV-1 entry which determine viral tropism for different cell types. To investigate the relative contribution of the β -chemokine receptors CCR3 and CCR5 to viral infection of mononuclear phagocytes we utilized a panel of macrophage-tropic HIV-1 strains (from blood and brain tissue) to …

Human Immunodeficiency Virus Neurotropism: An Analysis Of Viral Replication And Cytopathicity For Divergent Strains In Monocytes And Microglia, Anuja Ghorpade, Adeline Nukuna, Myhanh Che, Sheryl Haggerty, Yuri Persidsky, Eboni Carter, Leeroy Carhart, Laura Shafer, Howard Gendelman

Nebraska Center for Virology: Faculty Publications

Productive replication of human immunodeficiency virus type 1 (HIV-1) in brain macrophages and microglia is a critical component of viral neuropathogenesis. However, how virus-macrophage interactions lead to neurological disease remains incompletely understood. Possibly, a differential ability of virus to replicate in brain tissue macrophages versus macrophages in other tissues underlies HIV-1 neurovirulence. To these ends, we established systems for the isolation and propagation of pure populations of human microglia and then analyzed the viral life cycles of divergent HIV-1 strains in these cells and in cultured monocytes by using identical viral inocula and indicator systems. The HIV-1 isolates included those …

A Cell Cycle-Regulated Adenine Dna Methyltransferase From Caulobacter Crescentus Processively Methylates Gantc Sites On Hemimethylated Dna, Craig Stephens, Anthony J. Berdis, Irene Lee, James K. Coward, Rachel Wright, Lucy Shapiro, Stephen J. Benkovic

Biology

The kinetic properties of an adenine DNA methyltransferase involved in cell cycle regulation of Caulobacter crescentus have been elucidated by using defined unmethylated or hemimethylated DNA (DNAHM) substrates. Catalytic efficiency is significantly enhanced with a DNAHM substrate. Biphasic kinetic behavior during methyl incorporation is observed when unmethylated or DNAHM substrates are used, indicating that a step after chemistry limits enzyme turnover and is most likely the release of enzyme from methylated DNA product. The enzyme is thermally inactivated at 30 degrees C within 20 min; this process is substantially decreased in the presence of saturating concentrations of DNAHM, suggesting that …

Predicting Prognosis In Lung Cancer: Use Of Proliferation Marker, Ki67 Monoclonal Antibody, I N. Soomro, J Holmes, W F. Whimster

Department of Pathology and Laboratory Medicine

An investigation was carried out to assess the prognostic significance of proliferation marker Ki67 in a group of lung cancer patients treated by surgery (limited disease). Tissue was not available for Ki67 immunostaining in inoperable group. The diagnosis is established by bronchial biopsy which does not carry enough tissue for frozen section and counting. This study is supplemented by estimating the prognostic significance of histological sub-types in the operable group and in a group of inoperable patients with extensive disease. These are usually treated by radiotherapy and/or chemotherapy. In all, 267 patients were studied including 105 treated by surgery. These …

Prevalence Of Broad-Host-Range Lytic Bacteriophages Of Sphaerotilus Natans, Escherichia Coli, And Pseudomonas Aeruginosa, Ellen C. Jensen, Holly S. Schrader, Brenda Rieland, Thomas L. Thompson, Kit W. Lee, Kenneth W. Nickerson, Tyler A. Kokjohn

Papers in Microbiology

Two bacteriophage collections were examined with regard to their ability to form plaques on multiple bacterial host species. Nine of 10 phages studied were found to be broad-host-range bacteriophages. These phages fell into two groups. Group 1, the SN series, was isolated from sewage treatment plant samples with Sphaerotilus natans ATCC 13338 as a host. The DNAs of these bacteriophages contained modified bases and were insensitive to cleavage by type I and II restriction endonucleases. The efficiency of plating of these bacteriophages was changed only slightly on the alternate host. Group 2, the BHR series, was isolated by a two-host …

Loss Of Cellular K+ Mimics Ribotoxic Stress, Mihail S. Iordanov, Bruce E. Magun

CUP Faculty Research

The tumor promoter palytoxin has been found to activate the stress-activated protein kinase/c-Jun NH₂-terminal kinase 1 (SAPK/JNK1), and it also potentiates, as demonstrated here, the p38/HOG1 mitogen-activated protein kinase and the upstream activator of SAPK/JNK1, SEK1/MKK4. In search of possible mechanisms for both the cytotoxicity and the activation of stress kinases by palytoxin, we found that palytoxin is a potent inhibitor of cellular protein synthesis. The inhibition of translation by palytoxin does not result from its direct binding to the translational apparatus. We have previously demonstrated that ribotoxic stressors (Iordanov, M. S., Pribnow, D., Magun, J. L., Dinh, …

Vh Gene Usage In Vha2 Allotype-Producing B Cells From Mutant Alicia Rabbits, Anusorn Boonthum

Dissertations

No abstract provided.

Cytoskeletal Association Of An Esterase In Dictyostelium Discoideum, Catherine P. Chia, Lothar Bomblies, Kristy K. Taylor

Papers in Microbiology

A 70-kDa glycoprotein, gp70, was found enriched in the detergentinsoluble cytoskeletal fraction of axenically grown Dictyostelium discoideum cells. Its N-terminal amino acid sequence identified it as “crystal protein” (L. Bomblies et al., 1990, J. Cell Biol. 110, 669– 679). This finding was corroborated when antibody to crystal protein cross-reacted with gp70 and its deglycosylated form. The postulated esterase activity of gp70/crystal protein was verified through comparative enzyme assays of extracts derived from cells that either overexpressed or lacked gp70. Gp70 cosedimented with cytoskeletons on sucrose gradients, suggesting an interaction with the cytoskeleton. Coisolation of gp70 with detergent-extracted cells, observed by …