Cell Biology Commons^™

Biophysical Properties Of Cellular Membranes In Gram-Positive Bacterial Pathogens And Their Impact On Major Physiological Attributes And Virulence Determinants, Suranjana Sen

Theses and Dissertations

The cytoplasmic membrane of bacterial cells, forming an essential barrier from the surroundings, is a critical component of cellular physiology ensuring proper survival and maintenance of major cellular functions. The integrity of the membrane is an important feature that plays an essential role in the transport of solutes and nutrients through active and passive pathways, functions of membrane-associated proteins, electron transport and ATP synthesis, maintaining turgor pressure and combating environmental stresses, and thus is a crucial factor of a majority of cellular adaptations. The various biophysical properties affecting the integrity of this membrane are mainly determined by the composition and …

Expression, Localization, And Kinetic Characterization Of The Phospholipid Biosynthesis Enzyme Ctp: Phosphocholine Cytidylyltransferase From The Protozoan Parasite Leishmania Major, Justin Daniel Theodore Lange

Theses and Dissertations

The eukaryotic parasite Leishmania is the causative agent of the disease leishmaniasis. L. major is the most common of 21 species that causes visceral leishmaniasis in humans, and 30 that cause the same disease in other mammals. Visceral leishmaniasis causes fever, weight loss, and over a short amount of time, multiple organ failure, and has a 100% mortality rate within 2 years. This makes it the second largest parasitic killer in the world behind malaria. Over 90% of the worldâ??s cases of visceral leishmaniasis have been reported in underdeveloped countries of India, Bangladesh, Nepal, Sudan, Ethiopia and Brazil, with 500,000 …

Cell Wall Mutants In Arabidopsis Thaliana, Christy Jane Moore

Theses and Dissertations

Plant cell walls are versatile structures, playing important roles in communication, defense, organization and support. The importance of each of these functions varies by cell type, with specialized cells often utilizing one or two functions more than others. Trichomes, or leaf hairs, and hypocotyl cells for instance, exhibit distinct cell wall characteristics. Trichomes have developed very thick cell walls with several raised structures, known as papillae, on their surfaces. It is believed that these cells function in defense against predators, making it difficult to crawl on the leaf surface, and in protection against ultra violet radiation, through refraction of light …

Pemetrexed, A Modulator Of Amp-Activated Kinase Signaling And An Inhibitor Of Wild Type And Mutant P53, Stuti Agarwal

Theses and Dissertations

New drug discoveries and new approaches towards diagnosis and treatment have improved cancer therapeutics remarkably. One of the most influential and effective discoveries in the field of cancer therapeutics was antimetabolites, such as the antifolates. The interest in antifolates increased as some of the antifolates showed responses in cancers, such as mesothelioma, leukemia, and breast cancers. When pemetrexed (PTX) was discovered, our laboratory had established that the primary mechanism of action of pemetrexed is to inhibit thymidylate 22 synthase (TS) (E. Taylor et al., 1992). Preclinical studies have shown that PTX has a broad range of antitumor activity in human …

Interaction Between Atm Kinase And P53 In Determining Glioma Radiosensitivity, Syed F. Ahmad

Theses and Dissertations

Glioblastoma multiforme (GBM) is the most common primary brain tumor. Studies have shown that targeting the DNA damage response can sensitize cancer cells to DNA damaging agents. Ataxia telangiectasia mutated (ATM) is involved in signaling DNA double strand breaks. Our group has previously shown that ATM inhibitors (ATMi) sensitize GBM cells and tumors to ionizing radiation. This effect is greater when the tumor suppressor p53 is mutated.

The goals of this work include validation of a new ATM inhibitor, AZ32, and elucidation of how ATMi and p53 status interact to promote cell death after radiation. We propose that ATMi and …

Genetic Analysis Of Ton2 Dependent Processes In Microtubule Organization In Arabidopsis Thaliana, Samantha Nicole Atkinson

Theses and Dissertations

Microtubules carry out many functions within the cell. They're used during mitosis and meiosis to move chromosomes to opposite sides of the cell so that cell division can occur. They're also used as structural support for the cell and are involved in establishing the cell shape. Microtubules are also able to reorient from a longitudinal orientation to a transverse orientation in response to gibberellic acid and auxin (two hormones that are involved in cell elongation). The mechanism for how this reorientation occurs is unknown. The TONNEAU2 (TON2) protein is necessary for proper microtubule organization. We looked at how TON2 affects …

Localization And Functional Analysis Of Dictyostelium Discoideum Gtpases, Rabs And Rab2, Katherine V. Maringer

Theses and Dissertations

Dictyostelium discoideum is a simple eukaryotic amoeba that has proven useful in studying various aspects of endosomal and lysosomal membrane trafficking, as well as development. The Rab family of small molecular weight GTPases has been implemented in several cellular processes to include various vesicle trafficking roles, cell-cell signaling, and development. This study focuses on the localization and function of two Dictyostelium GTPases, RabS, and Rab2 which we hypothesized to both localize to the Golgi, and the contractile vacuole system. Expression of GFP-tagged DdRab2, and DdRabS proteins revealed similar localization to ER-Golgi membranes as well as the contractile vacuole system. Microscopic …

The Effect Of Lactic Acid On Mast Cell Function, Andrew J. Spence

Theses and Dissertations

This study shows for the first time the effect that L-(+)-lactic acid has on mast cell activation. Lactic acid is a byproduct of anaerobic glycolysis and is associated with inflammatory environments such as wounds, tumors and, asthma. In this study, pre-treatment with lactic acid altered cytokine production by bone marrow-derived mast cells (BMMC). Specifically, lactic acid enhanced cytokine secretion following IgE cross-linking, but decreased IL-33 mediated cytokine production. These effects were altered by genetic background, since C57BL/6 mast cells demonstrated the aforementioned result, but lactic acid had no effect on IgE-mediated cytokine production in 129/SvJ mast cells. The affected cytokines …

Isolation And Characterization Of Multipotent Lung Stem Cells From P53 Mutant Mice Models, Venkat Sundar Gadepalli

Theses and Dissertations

Recent advances in understanding lung biology have shown evidence for the existence of resident lung stem cells. Independent studies in identifying and characterizing these somatic lung stem cells have shown the potential role of these cells in lung repair and regeneration. Understanding the functional characteristics of these tissue resident stem/progenitor cells has gained much importance with increasing evidence of cancer stem cells, cells in a tumor tissue with stem cell characteristics. Lung cancer is most commonly characterized by loss of p53 function which results in uncontrolled cell divisions. Incidence of p53 point mutations is highest in lung cancer, with a …

The Osh Family Of Proteins And Their Role In Caloric Restriction-Mediated Lifespan Extension In The Budding Yeast Saccharomyces Cerevisiae, William Douglas Craft

Theses and Dissertations

Oxysterol-binding protein homolouges (OSH) have been implicated in mediating non-vesicular sterol transport. Caloric restriction (CR) down-regulates sterol synthesis in a variety of organisms, including the budding yeast Saccharomyces cerevisiae. OSH6, when up-regulated, extends replicative lifespan. In contrast, OSH5 up-regulation shortens replicative lifespan. In this thesis I obtained evidence to show that the deletion of OSH5 extends replicative lifespan in normal media. Deletion of OSH5 in the presence of caloric restriction blocks the lifespan-extending properties of the CR media. My data demonstrate that the total cellular sterol levels of the longevity mutants are indistinguishable from that of wild type. This suggests …

Molecular Analysis And Localization Of A Novel Dictyostelium Discoideum Rab Protein, Rabs, Katherine V. Maringer

Theses and Dissertations

Functional analysis and localization of the small GTPase RabS in the slime mold, Dictyostelium discoideum, was explored using cell lines that over-express a GFP tagged RabS protein. Based on homology to Rab1, Golgi association was explored. Immunofluoresence analysis of the intracellular localization of this GFP tagged protein revealed that this GFP-Rab had a partial co-localization with the contractile vacuole organelle system. Additionally, when the over-expressed RabS cell lines were exposed to selective biochemical inhibitors, the GFP-Tagged Rab localized with what can be assumed is the Golgi network. This dual localization of Golgi and CV may support a previously proposed connection …

The Effects Of A One-Tesla Magnet On Human Fibroblast Cell Growth, Ashley Chaplin

Theses and Dissertations

The controversy regarding the ill effects of electromagnetic fields began in 1979 when Nancy Wertheimer and Ed Leeper claimed to have found a connection between childhood leukemia and power lines. In 1997, a group of researchers led by Martha Linet, M. D., attempted to provide evidence that there was no link between cancer and electromagnetic fields. The study showed that the risk of acute lymphoblastic leukemia did not escalate with increasing electromagnetic field levels in the children's homes. When compared to the Earth's static magnetic field of 0.5 Gauss, these fields were extremely small. Within the past decade, magnets have …