Molecular Biology Commons^™

Decrypting Female Attractivity In Garter Snakes, Holly Rucker

Senior Honors Projects, 2010-2019

Pheromones are utilized by many species as sexual signals driving mate choice, and pheromone production in vertebrates hinges on sex hormone action. Female red-sided garter snakes (Thamnophis sirtalis parietalis) produce a skin-based sex pheromone used by males for mate detection and selection. Estradiol is necessary for pheromone production, yet the specific mechanisms within the skin are unknown. Central to this is the metabolism of testosterone to estradiol via the enzyme aromatase. It is hypothesized that female garter snakes synthesize estradiol locally in the skin and maintain pheromone production via tissue-specific regulation of aromatase. Further, I hypothesize that female …

Identification Of Pathways Required For The Survival Of Inversion(16) Acute Myeloid Leukemia, Yiqian Wang

Theses & Dissertations

Inversion of chromosome 16 [inv(16)] acute myeloid leukemia (AML) generates a fusion gene CBFB-MYH11. Approximately half of inv(16) AML patients eventually relapse mainly due to the existence of leukemia stem cells (LSCs). Previous work using a Cbfb-MYH11 knockin mouse model showed that the LSCs are enriched within CSF2RB^- population. Another gene upregulated by Cbfb-MYH11 encodes the cytokine receptor IL1RL1. Using Cbfb-MYH11 knockin mice, we showed that LSCs exist in multiple sub-populations defined by their immunophenotype, and IL1RL1 is expressed by cell populations with high LSC activity. We also found that treatment of IL-33, the ligand for IL1RL1, promoted …

The Role Of Ros In The Progression And Treatment Of Castration-Resistant Prostate Cancer, Dannah R. Miller

Theses & Dissertations

Prostate cancer is the second leading cause of cancer-related deaths in U.S. men, primarily due to the development of castration-resistant (CR) prostate cancer (PCa), of which there are no effective treatment options. Reactive oxygen species (ROS) plays a critical role in prostate carcinogenesis, including the progression of the CR PCa phenotype. ROS regulates both cell proliferation and apoptosis; a moderate increase in ROS can promote proliferation; however, a substantial rise in ROS levels will result in apoptosis. Oxidase p66Shc is elevated in clinical PCa cells and has been associated with a metastatic phenotype of CR PCa cells, promoting PCa cell …

Developing Targeted Therapy Against Pancreatic Cancer, Garima Kaushik

Theses & Dissertations

Not available.

Anti-Crispr Vs. Crispr: The Evolutionary Arms Race Between Microorganisms, Rachael M. St. Jacques

Masters Theses, 2010-2019

CRISPR arrays are a defense mechanism employed by bacteria against viral invaders. Cas proteins do the work in detecting, capturing, and integrating the viral DNA into the CRISPR array (Barrangou et al., 2007). Anti-CRISPR proteins are produced by phages, viruses that infect bacteria, to stop the bacterial host’s CRISPR-Cas complex from interrupting the phage life cycle (Bondy-Denomy, et al., 2015).

SEA-PHAGES is a course-based bacteriophage research network composed of 120 colleges and known at James Madison University as Viral Discovery. JMU uses the unsequenced Streptomyces griseus ATCC10137 as a host for bacteriophage discovery and propagation, and in this study we …

Assessing The Contribution Of Multiple Ascorbate Pathways To Abiotic Stress Tolerance Using Phenomic Approaches, Lucia Margarita Acosta Gamboa

Student Theses and Dissertations

L-Ascorbic acid (AsA, vitamin C) is an essential molecule that humans cannot synthesize; therefore, it must be acquired through dietary sources. Vitamin C has an important role in protecting organelles and cells against the damage caused by reactive oxygen species (ROS). In plants, AsA is synthesized by a complex metabolic network. Although progress has been made in the characterization of genes involved in some of these pathways, there is a gap in understanding which pathway(s) is/are activated in response to different stresses. The long term goal of this project is to assess the contribution of multiple ascorbate pathways to abiotic …

A Dedicated Chaperone Mediates The Safe Transfer Of Mitoribosomal Proteins To Their Site Of Assembly, Gabrielle Ashley Hillman

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. While remarkable progress has recently been made towards understanding the structure of mitoribosomes, the unique pathways and factors that facilitate their biogenesis remain largely unknown. This dissertation defines the physiological role of an evolutionarily conserved yeast protein called Mam33 in mitochondrial ribosome assembly. The biomedical relevance of this finding stems from the fact that mutations or changes in its expression of the human ortholog p32 result in mitochondrial dysfunction. In human patients, bi-allelic mutations cause severe multisystemic defects in mitochondrial energy metabolism, …

The Chelation Of Metal Ions By Vicibactin, A Siderophore Produced By Rhizobium Leguminosarum Atcc 14479, Joshua Stinnett

Undergraduate Honors Theses

Vicibactin is a small, high-affinity iron chelator produced by Rhizobium leguminosarum ATCC 14479. Previous work has shown that vicibactin is produced and secreted from the cell to sequester ferric iron from the environment during iron-deplete conditions. This ferric iron is then transported into the cell to be converted into ferrous iron. This study uses UV-Vis spectroscopy as well as ion trap-time of flight mass spectroscopy to determine that vicibactin does form a complex with copper(II) ions, however, at a much lower affinity than for iron(III). Stability tests have shown that the copper(II)-vicibactin complex is stable over time. The results of …

Transformation Of Model Organisms With Munc13-1 For Subcloning And Protein Harvesting, Grace Dittmar

Honors Theses

Exocytosis is the process by which cells release various molecules into the extracellular space. This mechanism is accomplished by membrane fusion, in which the membrane of the transport vesicle and that of the cell itself fuse to create one continuous membrane, allowing the release of the molecules inside the vesicle. A family of proteins, known as SNARE proteins, is responsible for facilitating membrane fusion. SNARE proteins form a complex between the vesicle membrane and the plasma membrane. For various cells, such as mast cells and neurons, exocytosis is essential to carry out their vital functions. Various accessory proteins are known …

The Dna Damage Response Gene Ddr48 Regulates Sterol Synthesis Genes To Confer Antifungal Resistance To The Pathogenic Fungus Histoplasma Capsulatum, Gabriella Reyes

Honors Theses

Histoplasma capsulatum is a dimorphic fungal pathogen that is endemic to the Ohio, Missouri, and Mississippi river valley regions. The fungus grows as a mold at environmental temperatures (25C) and transforms into a unicellular yeast upon inhalation by a mammalian host (37C). The mold to yeast shift is required for pathogenicity in host organisms, where the potentially fatal disease, histoplasmosis, can present. This study aims to characterize the DNA damage response protein DDR48 and the role that it plays in combating cellular stressors in H. capsulatum. We found that DDR48 is expressed strongly in the mold phase but expressed only …

The Effects Of Gibberellic Acid And Auxin Hormones On Heliotropism In Sunflowers, Brandon Bernardo, Hagop S. Atamian

Student Scholar Symposium Abstracts and Posters

Sunflowers are one of many different plant species that are able to track and face the sun in order to optimize the amount of sunlight they are exposed to. This process of orienting towards the sun is called Heliotropism. Sunflowers are able to effectively orient themselves towards the sun because the growth rate on the East and West side of the stem alternates depending on the time of day. At dawn, the East facing stem will grow at a faster rate than the West facing side, resulting in the flower orienting towards the West. This alternating and uneven growth is …

Glycine Receptor Expression Across Identified Retinal Ganglion Cell Types., Ian Scot Pyle

Electronic Theses and Dissertations

Retinal ganglion cells (RGCs) represent the culmination of all retinal signaling and their output forms the substrate for vision throughout the rest of the brain. About 40 different RGC types have been defined by differences in their visually evoked responses, morphology, and genetic makeup. These responses arise from interactions between inhibition and excitation throughout the retinal circuit (Franke et al., 2017; Masland, 2012; Sanes & Masland, 2015; Werblin, 2011). Unlike most other areas of the central nervous system (CNS), the retina utilizes both GABA and glycine inhibitory neurotransmitters to refine glutamatergic excitatory signals (Franke & Baden, 2017; Werblin, 2011; C. …

Development Of A Lectin-Fc Fusion Protein With Antiviral And Anti-Cancer Activity., Matthew William Dent

Electronic Theses and Dissertations

This thesis describes the development of a novel lectin-Fc fusion protein and its antiviral and anti-cancer activity. The molecule, Avaren-Fc (AvFc), is a fusion of a variant of the actinomycete lectin actinohivin (Avaren) and the Fc region of human IgG1, and is selective for the terminal α1,2-mannose residues found at the ends of high-mannose-type glycans that can be found on the surface of certain heavily glycosylated viruses and cancer cells. Here, AvFc was found to be able to neutralize simian immunodeficiency virus as well as Hepatitis C virus with nanomolar IC₅₀ values. Furthermore, AvFc recognizes a number of cell …

Paraoxonase 2 Is Critical For Non-Small Cell Lung Carcinoma Proliferation., Aaron Whitt

Electronic Theses and Dissertations

Non-small cell lung carcinoma (NSCLC) comprises 85% of lung cancer diagnoses and is plagued by drug resistance. Thus, elucidating the underlying mechanisms of NSCLC is paramount to expand future treatment options. Paraoxonase 2 (PON2), an intracellular enzyme with arylesterase and lactonase functions, has well-established anti-atherosclerotic activity. Recent studies show PON2 is overexpressed in a variety of tumors and confers drug resistance, although these interactions have not been thoroughly examined in NSCLC. Thus, we sought to investigate the role of PON2 in cellular proliferation using PON2-knockout mice, primary mouse cells, and NSCLC cell lines. Using these approaches, we demonstrate that PON2 …

Spatial Reorganization Of Histone-Like Nucleoid Structuring Proteins Caused By Silver Nanoparticles, Meaad Alqahtany

Graduate Theses and Dissertations

Silver nanoparticles (AgNPs) and ions (Ag+) can be the new generation of antibiotics due to their antimicrobial effects against bacteria and other microbes. Many studies have shown that AgNPs and suppress the growth of bacteria and damage the cell walls of the microbes; therefore, treating bacterial cells with AgNPs may be a promising method to terminate multi-resistant bacteria. In this work, the effect of AgNPs with two different surface coatings on the spatial reorganization of histone-like nucleoid structuring (H-NS) proteins in Escherichia coli bacteria was investigated using quantitative super-resolution fluorescence microscopy to understand the toxicity and antimicrobial mechanism of AgNPs. …

The Role And Regulation Of Alternative Polyadenylation In The Dna Damage Response, Michael R. Murphy

Dissertations, Theses, and Capstone Projects

Cellular homeostasis is achieved by the dynamic flux in gene expression. Post-transcriptional regulation of coding and non-coding RNA offers a fast method of adapting to a changing cellular environment, including deadenylation, microRNA (miRNA) pathway, and alternative polyadenylation (APA). In this dissertation, I explored some of the mechanisms involved in the post-transcriptional regulation of gene expression. The main hypothesis in these studies is that a single APA event after DNA damage is governed by specific conditions and factors outside of current known regulators of APA, and that the resultant transcript has a role in the DNA damage response (DDR). My aims …

Characterization Of Extracellular Vesicles From Human Diabetic Retinopathy Retinal Tissue In Vitro And From Urine Of Human Patients With Diabetic Retinopathy, Jason Mighty

Dissertations, Theses, and Capstone Projects

Diabetic Retinopathy (DR) is a neurovascular complication associated with diabetes mellitus that affects approximately 120 million people worldwide and its prevalence is expected to reach 190 million by 2030. DR diagnosis is accomplished with fundus ophthalmoscopy often when retinal damage and vision loss have already occurred. A group of biomarker being explored for early detection of diseases are extracellular vesicles (EVs), which are nanometer diameter lipid enclosed vesicles, released from all cell types and containing genetic cargo reflective of releasing cell state. EV biomarkers are currently being explored to help monitor disease predisposition, pathogenesis and response to treatment. While an …

The Role Of Parathyroid Hormone 1 Receptor (Pth1r) Signaling In Gastric Epithelial Homeostasis, Maram Maher Al-Hasan

Theses

In the stomach, the epithelial stem cells are responsible for glandular homeostasis. These stem cells continuously undergo cellular proliferation and differentiation to balance the death of senescent cells. Studies conducted on gastric cancers showed a significant increase in parathyroid hormone-like hormone (PTHLH). Moreover, both PTHLH along with parathyroid hormone (PTH) act as endogenous ligands for parathyroid hormone 1 receptor (PTH1R) which belongs to family B of G- protein-coupled receptors (GPCRs). This receptor functions by mediating many different signaling pathways and the most studied pathway is the stimulation of cyclic adenosine monophosphate (cAMP) as a second messenger.

There are very few …

An Investigation Into Clinically Relevant Determinants Of Azole Resistance In Candida Albicans, Andrew T. Nishimoto

Theses and Dissertations (ETD)

"Candida albicans is a commensal organism commonly colonizing the human gut and skin. As an opportunistic pathogen, it can cause persistent and serious infections in individuals with compromised immune systems, including the very young and elderly. Moreover, C. albicans can cause a wide spectrum of diseases ranging from superficial mucosal infections to life-threatening invasions of the organs and bloodstream. Candida species are the most common cause of invasive fungal disease, which is associated with high mortality and imposes a heavy toll on the healthcare system. Over the last 30 years, the azole antifungals have been a mainstay of antifungal therapy, …

Thiol-Based Misfolding: Linking Redox Balance To Cytosolic Proteostasis, Ford Amy

Dissertations and Theses (Open Access)

The eukaryotic cytosolic proteome is vulnerable to changes in proteostatic and redox balance caused by temperature, pH, oxidants and xenobiotics. Cysteine-containing proteins are especially at risk as the thiol side chain is subject to oxidation, adduction and chelation by thiol-reactive compounds. All of these thiol-modifiers have been demonstrated to induce the heat shock response and recruit protein chaperones to sites of presumed protein aggregation in the budding yeast Saccharomyces cerevisiae. However, endogenous targets of thiol stress toxicity responsible for these outcomes are largely unknown. Furthermore, I hypothesize proteins identified as redox-active are prone to misfolding and aggregation by thiol-specific …