Biochemistry, Biophysics, and Structural Biology Commons^™

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 …

Hsp70-Mediated Regulation Of Hsf1 Transcriptional Activity In Saccharomyces Cerevisiae, Sara Peffer

Dissertations and Theses (Open Access)

In eukaryotic cells, protein homeostasis and cellular fitness is promoted by the transcription factor heat shock factor 1 (HSF1) during exposure to proteotoxic stress. HSF1 controls the basal and stress-induced expression of molecular chaperones and other protective targets. Dynamic regulation of HSF1 involves the major heat shock proteins Hsp70 and Hsp90. Recent advances in the understanding of this regulatory circuit in Saccharomyces cerevisiae have shown that the Hsp70 Ssa1 acts as a sensor for some proteotoxic stresses and is capable of a direct interaction with Hsf1. This work continues to explore the complex regulatory interaction between Hsf1 and Ssa1. I …

The Role Of Gene Expression Noise In Mammalian Cell Survival, Kevin Farquhar

Dissertations and Theses (Open Access)

Drug resistance and metastasis remain obstacles to effective cancer treatment. A major challenge contributing to this problem is cellular heterogeneity. Even in the same environment, cells with identical genomes can display cell-to-cell differences in gene expression, also known as gene expression noise. Gene expression noise can vary in magnitude in a population or in fluctuation time scales, which is influenced by gene regulatory networks.

Currently, it is unclear how gene expression noise from gene regulatory networks contributes to drug survival outcomes in mammalian cells. An isogenic cell line with a noise-modulating genetic system tuned to the same mean is required. …

Development Of A High-Throughput System For Screening Of Anti-Prion Molecules, Katherine Do

Dissertations and Theses (Open Access)

The misfolded prion protein causes and transmits disease in both humans and animals. As other infectious agents, prions display strain variation, which can generate different pathological outcomes in affected individuals. Unfortunately, there are no known therapies for these diseases, which at present are invariably fatal. In this work, the Protein Misfolding Cyclic Amplification technology (PMCA, an in vitro test that replicates minimum quantities of infectious prions) has been modified to screen for small molecules inhibiting prion protein misfolding in a strain-specific manner. In order to approach a high-throughput PMCA system, technical aspects in PMCA has been optimized for application of …

Preparation Of A Flavonol Specific Glucosyltransferase Found In Grapefruit And Site-Directed Mutants For Protein Crystallization, Aaron Birchfield

Electronic Theses and Dissertations

This research was designed to determine the conditions necessary to remove c-myc and 6x-His tags from a flavonol specific glucosyltransferase found in grapefruit (CP3GT) using thrombin in preparation for crystallization. X-ray crystallography of CP3GT crystals may elucidate structural features that account for flavonol specificity in some glucosyltransferase enzymes. A thrombin cleavage site was inserted into WT CP3GT and one mutant. Recombinant CP3GT was expressed in yeast and purified. Optimal conditions for thrombin digestion were explored. Digestion with 100U of thrombin for 2 hours at 4^o C was optimal for removing tags from CP3GT. Storage at 4^o C for …

Cellular Localization Of Rad51d Mutant Proteins And The Application Of Art To Increase Scientific Literacy In America, Claire L. Chabot

Senior Theses

Ovarian cancers are the leading cause of death from cancer of the female reproductive system. Approximately 50% of ovarian cancers have defects in the homologous recombination (HR) DNA repair pathway that is required for the repair of DNA double-stranded breaks. The status of HR genes, such as BRCA1, BRCA2, and the RAD51 family, contributes to ovarian cancer development as well as treatment decisions regarding chemotherapy, radiation, and immunotherapy. The overarching goal of this project is to identify new insights into HR that can integrate with Precision Medicine Initiatives and align with the goals of the Cancer Moonshot 2020 Program. I …

Delineation Of Events In Centripetal Migration During Drosophila Oogenesis, Travis Tait Parsons

UNLV Theses, Dissertations, Professional Papers, and Capstones

All multicellular organisms initially start out as a single cell. This cell must use the genetic information encoded in its DNA to multiply in number and build itself into a complex multicellular organism. How this process occurs is the focus of developmental biology, a field that seeks to understand how a combination of genetic information and environmental conditions shape a cell from its beginnings as a zygote all the way to maturity. A fundamental part of this process is the ability of cells to work together in order to build complex tissues and organs. Cells achieve this coordination by using …

Hormone Signaling, Gene Expression, And Mitochondrial Hormone Receptor Expression In Avian Muscle (Cells), Kentu Rushadd Lassiter

Graduate Theses and Dissertations

Mitochondria are vital to the proper growth and function of muscle cells since they’re responsible for the majority of ATP production used for cellular energy. Previous studies have investigated how differences in mitochondrial function affects feed efficiency (FE) in broilers phenotyped for High and Low FE. Low FE broilers have been shown to have increased levels of reactive oxygen species (ROS), thus contributing to higher levels of oxidative stress and damage seen in these birds. Global gene and protein expression studies conducted on breast muscle of the High FE and Low FE phenotypes have suggested that differences in mitochondrial function …

Pre-Administration Of Medium Chain Triglycerides In Vivo Can Attenuate Or Block The Effects Of Recurrent Hypoglycemia, Dhanisha Nandigama

Biological Sciences

Hypoglycemia is a state of abnormally low blood glucose. Many patients who use insulin, primarily for the treatment of diabetes, experience multiple bouts of hypoglycemia, termed recurrent hypoglycemia (RH). Because RH impairs cognitive function and ability to appropriately respond to a subsequent episode of hypoglycemia, it is critical to develop treatments. One approach, which we have taken here, is to attempt to preserve neuronal fuel supply during a hypoglycemic episode. Medium-chain triglycerides are medium-chain fatty acid (MCT) esters of glycerol that can provide an alternative fuel source to the brain via ketones; the hippocampus is known to express transporters for …

Potential Interactions Between Glucocorticoid Receptors And L-Type Cav1.3 Ion Channels Expressed In Chinese Hamster Ovary (Cho) Cells, Mallory Soska

Undergraduate Distinction Papers

L-type calcium channels couple membrane depolarization to muscle contraction and aid in signal conduction between cells. Cav1.3 calcium channel isoform is expressed in neurons and endocrine cells. Nervous and endocrine tissues also express both Glucocorticoid (GR) and Mineralocorticoid receptors (MR) that are responsible for binding serum cortisol to induce immediate and long term changes within the cell. While neurons co-express both GRs and MRs, GR activation occurs in response to high concentrations of cortisol. There is a direct correlation between GR activation and the amplitude of calcium currents (Champeau, 2007). To determine potential interactions between the GR and the calcium …

Characterization Of The Perilipin 5 C-Terminus, Tim D. Clinton

Undergraduate Honors Thesis Projects

The crystallization of protein with subsequent X-Ray crystallography analysis is a powerful technique for uncovering a protein’s structure. This methodology is cutting edge and innovations are being made daily on how to best use the fundamentals of this technique for clearer characterizations. The protein Perilipin 5 could benefit from this technique as properties involving the structure of the molecule are still largely unknown. Knowing the structural aspects of perilipin 5 is important as several research efforts indicate that is a key factor in the regulation of lipolysis, or the breakdown of fats within a biological system. In the life sciences, …

Gamete Nuclear Migration In Animals And Plants, Umma Fatema, Mohammad F. Ali, Zheng Hu, Anthony J. Clark, Tomokazu Kawashima

Plant and Soil Sciences Faculty Publications

The migration of male and female gamete nuclei to each other in the fertilized egg is a prerequisite for the blending of genetic materials and the initiation of the next generation. Interestingly, many differences have been found in the mechanism of gamete nuclear movement among animals and plants. Female to male gamete nuclear movement in animals and brown algae relies on microtubules. By contrast, in flowering plants, the male gamete nucleus is carried to the female gamete nucleus by the filamentous actin cytoskeleton. As techniques have developed from light, electron, fluorescence, immunofluorescence, and confocal microscopy to live-cell time-lapse imaging using …

Peroxisomal Protein Defects Disrupt Coordinated Peroxisomal Processes And Affect Early Seedling Development Through Accumulating Toxic Catabolic Intermediates, Ying Li

Dissertations

Many peroxisomal proteins act in β-oxidation processes on a range of substrates. It is unclear how these proteins are coordinated to determine the flux of peroxisomal processes and meet the requirements for plant growth and development. Using mutant analysis and metabolic profiling, I examined proteins predicted to act in fatty acid and indole-butyric-acid (IBA) β-oxidation. ECH2 confers enoyl-CoA hydratase activity for the auxiliary β-oxidation of fatty acids with an even cis-unsaturated bond. ECH2 was suggested to function in IBA β-oxidation, as ech2 seedlings have altered IBA response. ech2 seedlings have reduced root length and cotyledon area. ech2 seedlings accumulate 3-hydroxyoctenoate …

Transcriptional Regulation Factors Of The Human Mitochondrial Aspartate/Glutamate Carrier Gene, Isoform 2 (Slc25a13): Usf1 As Basal Factor And Foxa2 As Activator In Liver Cells, Paolo Convertini, Simona Todisco, Francesco De Santis, Ilaria Pappalardo, Dominga Iacobazzi, Maria Antonietta Castiglione Morelli, Yvonne N. Fondufe-Mittendorf, Giuseppe Martelli, Ferdinando Palmieri, Vittoria Infantino

Molecular and Cellular Biochemistry Faculty Publications

Mitochondrial carriers catalyse the translocation of numerous metabolites across the inner mitochondrial membrane, playing a key role in different cell functions. For this reason, mitochondrial carrier gene expression needs tight regulation. The human SLC25A13 gene, encoding for the mitochondrial aspartate/glutamate carrier isoform 2 (AGC2), catalyses the electrogenic exchange of aspartate for glutamate plus a proton, thus taking part in many metabolic processes including the malate-aspartate shuttle. By the luciferase (LUC) activity of promoter deletion constructs we identified the putative promoter region, comprising the proximal promoter (−442 bp/−19 bp), as well as an enhancer region (−968 bp/−768 bp). Furthermore, with different …

A Polyphasic Approach In Understanding Green Algal Ecology, Blia Lor

Biology Theses

Pithophora and Cladophora are two representative genera of the order Cladophorales as filamentous Chlorophyta. These two genera are major contributors to the total algal biomass of littoral communities in freshwater and shallow marine water and have been reported as nuisance algae as they proliferate fast with the influx of nutrients. However, the wide geographical distribution and the overlap of plastic morphological characteristics between the two genera have complicated taxonomic identification at species level and phylogenetic studies. In the present study, a population of a monospecific, filamentous algal community was collected in Jewell, Georgia from the Ogeechee River. The monospecific, filamentous …

Mechanisms Of Oriented Cell Division And Their Roles In Tissue Development, Evan Blake Dewey

Biology ETDs

Properly executed cell division is crucial to development, maintenance, and longevity of multicellular organisms. Defects in both symmetric and asymmetric divisions can lead to improper developmental patterning, as well as genomic instability, disruption of tissue homeostasis, and cancer. Our research focuses on how regulators orchestrate proper cell divisions. Mushroom Body Defect (Mud) is one such regulator, and here we describe how Mud is regulated via the Hippo signaling pathway kinase Warts (Wts), showing Wts phosphorylates Mud to enhance interaction with the polarity protein Partner of Inscuteable, promoting spindle orientation activity. We next focus on another regulator, Shortstop (Shot), describing a …

Extracellular Vesicles As Biological Shuttles For Targeted Therapies., Stefania Raimondo, Gianluca Giavaresi, Aurelio Lorico, Riccardo Alessandro

College of Osteopathic Medicine (TUN) Publications and Research

The development of effective nanosystems for drug delivery represents a key challenge for the improvement of most current anticancer therapies. Recent progress in the understanding of structure and function of extracellular vesicles (EVs)-specialized membrane-bound nanocarriers for intercellular communication-suggests that they might also serve as optimal delivery systems of therapeutics. In addition to carrying proteins, lipids, DNA and different forms of RNAs, EVs can be engineered to deliver specific bioactive molecules to target cells. Exploitation of their molecular composition and physical properties, together with improvement in bio-techniques to modify their content are critical issues to target them to specific cells/tissues/organs. Here, …

Incorporation Of Egfr And Ron Receptors Into Nanodiscs, Cristina Flores-Cadengo

Biomedical Engineering ETDs

Understanding the structure-function relationship of membrane receptors is essential to comprehend the crosstalk between key signaling pathways. Aberrant trans-activation between receptors can lead to tumorigenesis. Two of these receptors known to be involved in cancer development are receptor tyrosine kinases (RTKs), RON (Recepteur d'Origine Nantais) and EGFR (Epidermal Growth Factor Receptor). There has been evidence of heterodimerization and crosstalk between these two receptors based on co-immunoprecipitation, however the structural requirements behind these interactions remain unknown. Structural studies could provide insights into these RTKs’ modes of dimerization and structure-function relationship. However, structural studies of full-length membrane proteins are often difficult due …

You Are What You Eat At Any Age: Carbon And Nitrogen Analysis Of Mummies From An Ancient Egyptian Necropolis, Stephen Funk, R. Paul Evans

Library/Life Sciences Undergraduate Poster Competition 2019

The BYU Egypt Project at Fag el-Gamus necropolis and adjacent Seila Pyramid has studied over 700 mummies excavated over the past 30 years. The necropolis includes an open area with densely located vertical burial shafts and a hill with horizontal burial shafts. The chronological and dietary history of the mummies was assessed using stable isotopy and 14C analysis of accessible biological samples.

Novel Insights Into The Multifaceted Roles Of Blm In The Maintenance Of Genome Stability, Vivek M. Shastri

USF Tampa Graduate Theses and Dissertations

Genomic instability is a hallmark of disorders in which DNA replication and repair genes are dysfunctional. The tumor suppressor RECQ helicase gene BLM encodes the 3’-5’ DNA Bloom syndrome helicase BLM, which plays important roles during DNA replication, recombination and repair to maintain genome stability. Mutations within BLM cause Bloom syndrome, an autosomal recessive disorder characterized by growth defects, immunodeficiency, >10-fold higher sister chromatid exchange compared to normal cells, and an increased predisposition to a wide range of cancers from an early age. Single nucleotide polymorphisms or SNPs in BLM have been reported to be associated with susceptibility to a …

Evaluating The Therapeutic Potential Of Crocin Against Diethylnitrosamine Induced Experimental Hepatocellular Carcinoma In Rats, Basma Ali Mustafa Awad

Theses

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer and the third cause of cancer-related death worldwide. Liver cancer is the result of repeated injuries to the liver triggered by different causes. Currently, sorafenib is the only drug U.S. Food and Drug Administration approved targeted therapy. Sorafenib, an oral multikinase inhibitor, which inhibits the proliferation of tumor cells and blocks angiogenesis. Sorafenib has been shown to treat early and mild HCC lesions and it helped increase the survival rates at one year, but for only 44% of patients. Chemotherapies are an important line of defense when it comes …