Life Sciences Commons^™

The Identification Of Small Molecule Inhibitors To Candida Albicans Phosphatidylserine Synthase, Yue Zhou

Doctoral Dissertations

Candida albicans phosphatidylserine (PS) synthase, encoded by the CHO1 gene, has been identified as a potential drug target for new antifungals against systemic candidiasis due to its importance in virulence, absence in the host and conservation among fungal pathogens. This dissertation is focused on the identification of inhibitors for this membrane enzyme. Cho1 has two substrates: cytidyldiphosphate-diacylglycerol (CDP-DAG) and serine. Previous studies identified a conserved CDP-alcohol phosphotransferase (CAPT) binding motif present within Cho1, and here we revealed that mutations in all but one conserved amino acid within the CAPT motif resulted in decreased Cho1. For serine, we have predicted a …

Characterization Of Lignin Structural Variability And The Associated Application In Genome Wide Association Studies, Nathan D. Bryant

Doctoral Dissertations

Poplar (Populus sp.) is a promising biofuel feedstock due to advantageous features such as fast growth, the ability to grow on marginal land, and relatively low lignin content. However, there is tremendous variability associated with the composition of biomass. Understanding this variability, especially in lignin, is crucial to developing and implementing financially viable, integrated biorefineries. Although lignin is typically described as being comprised of three primary monolignols (syringyl, guaiacyl, p-hydroxyphenyl), it is a highly irregular biopolymer that can incorporate non-canonical monolignols. It is also connected by a variety of interunit linkages, adding to its complexity. Secondary cell wall …

The Development Of Tailored Amphiphilic Copolymers For Detergent-Free Integral Membrane Protein Extraction, Cameron Edward Workman

Doctoral Dissertations

Integral membrane proteins are prolific targets for the design, development, and delivery of pharmaceuticals. In fact, over 60% of all currently available drugs target these proteins to accomplish their therapeutic effect. However, integral membrane proteins remain the least characterized class of all proteins, accounting for only ~2% of all solved protein structures. One of the primary reasons for this low number of solved protein structures is that many membrane proteins lose their native conformation when extracted using conventional methods (e.g. detergents), convoluting accurate structure determination. In contrast, amphiphilic styrene-maleic acid copolymers (SMAs) were recently discovered to readily isolate membrane proteins …

Characterization Of Arabidopsis Eukaryotic Translation Initiation Factor 2Α (Eif2Α) Mutants, Mark Edens

Masters Theses

Plants are stationary organisms that are charged with overcoming a multitude of biotic and abiotic stresses. The eukaryotic translation initiation factor 2 (eIF2) is responsible for charging the P-site of the forming 80S ribosome with the initiator methionyl-tRNA. Thus, eIF2 is a protein of utmost consequence in the growth and development of organisms. The eIF2 protein is also a mediator of global translational regulation in the eukaryotic integrated stress response (ISR), where the α-subunit is phosphorylated by protein kinases, such as the kinase GCN2. Here, five eIF2α allele mutants in Arabidopsis were found to be deleterious to plant growth, development, …

A Novel Transmembrane Ligand Inhibits T Cell Receptor Activation, Yujie Ye

Doctoral Dissertations

T lymphocytes (T cells) play essential roles in the adaptive immune system. Each mature T cell expresses one type of functional T cell receptor (TCR). The TCR recognizes antigens bound to the major histocompatibility complex (MHC) in antigen presenting cells. The resulting stimulation signal crosses the transmembrane domain of TCR and initiates downstream signaling cascades. The human immune system relies on TCRs to recognize a variety of pathogens. Normally, TCR can distinguish the self-antigens from pathogenic antigens. However, dysfunction or aberrant expression of TCRs causes different inflammatory and autoimmune diseases, which afflict millions of people annually (Chapter I). Current treatments …

Investigating The Role Of Dullard And Tmem-188 In Lipid Droplet Biogenesis In Mammalian Cells, Mia Kaitlin Buono

Chancellor’s Honors Program Projects

No abstract provided.

Mutations In The N-Terminus Of The Mod(Mdg4) Btb Domain Reveal An Unexpected Role Of Mod(Mdg4) In Chromosome Segregation In Female Meiosis, Gwyneth D E Walker, Bruce D. Mckee

Chancellor’s Honors Program Projects

No abstract provided.

Erecta Family Genes Regulate The Shoot Apical Meristem And Organ Formation, Daniel A. Degennaro

Doctoral Dissertations

Plants are sessile and must adjust their organ growth to their environments. A reservoir of stem cells in the shoot apical meristem (SAM) supplies cells for differentiation into organs. The SAM must balance organ production with stem cell maintenance. The ERECTA family (ERfs) encodes the leucine-rich repeat receptor-like kinases ERECTA (ER), ERECTA-LIKE 1 (ERL1), and ERL2. ERf signaling regulates organ initiation and stem cell maintenance. Results presented in this work include the following:

1) WUSCHEL (WUS) and CLAVATA3 (CLV3) make up a negative feedback loop to maintain SAM size. WUS and CLV3 expression localization is critical for …

Influence Of Physical Variability Of Highly Weathered Sedimentary Rock On Nitrate In Area 3 Of The Enigma Field Research Site At Y-12, Erin Kelly

Masters Theses

Uranium processing and waste storage in unlined waste ponds leached contaminants into the groundwater at Y-12, Oak Ridge, Tennessee, from the 1950s to 1980s. Groundwater wells near the S-3 ponds have had the highest nitrate concentrations of groundwater anywhere in the world (>10,000 mg/L). For reference, the maximum contaminant level for nitrate in drinking water set by the U.S. Environmental Protection Agency is 10 mg/L. Since 2012, the ENIGMA (Ecosystems and Networks Integrated with Genes and Molecular Assemblies) group has been characterizing, monitoring, and conducting field experiments to understand the interactions between contaminants, microbes, and the subsurface. The goals …

60. Epfl Genes And Their Role In Flower Development In Arabidopsis Thaliana, Rachael Deboe

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Flowers are composed of four floral organ types: sepals, petals, stamens, and a pistil. In Arabidopsis thaliana, the ERECTA family leucine rich repeat receptor like kinases (LRR-RLKs) have been shown to regulate plant morphology. Epidermal Patterning Factor-Like (EPFL) genes encode for small secretory proteins that are ligands for ERECTA Family (ERf) receptors. It is suspected that EPFL’s act as a signal to coordinate proper lateral organ number, patterning, and spacing. ERf mutants have significant defects in flower development, including difficulty forming anther lobes and pistils, yet little is known about how individual EPFL ligands contribute to ERf signaling. In order …

A Tissue Specific Transcriptomic, Proteomic And Phospho-Proteomic Atlas Of The Translational Machinery Of Arabidopsis Thaliana, Abdullah Salim

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Gene expression encompasses the flow of genetic information from DNA to mRNA (transcription) and from mRNA to protein (translation) along with the regulatory mechanisms underlying these processes. Omics technologies offer a powerful toolset with which to study gene expression at each of these stages. A recently published dataset integrating transcriptomic, proteomic and phospho-proteomic measurements from 30 Arabidopsis thaliana tissues provides a unique resource to explore gene expression.¹ The translational machinery (the ribosome, and its initiation, elongation, and termination factors) are a core component in gene expression. Defects in translation can be lethal or lead to major developmental defects and …

The Hidden Life Of Tropical Roots: Functional Root Traits And Their Response To Climatic Disturbances, Daniela Yaffar

Doctoral Dissertations

Roots play a critical role in plant nutrition, and terrestrial carbon cycling. However, they are often understudied compared to their aboveground counterparts; especially in the tropics, where more carbon is cycled than in any other ecosystem. Some tropical forests, like in Puerto Rico, are more represented in scientific studies than others. However, this information is sparse, complicating the interpretation of root trait patterns. Trees in Puerto Rico have adapted mechanisms for withstanding hurricane disturbances, including in their roots. Additionally, as many tropical forests, some in Puerto Rico have low available phosphorus (P); thus, trees rely on root traits to enhance …

Engineering Modularity Of Ester Biosynthesis Across Biological Scales, Hyeongmin Seo

Doctoral Dissertations

Metabolic engineering and synthetic biology enable controlled manipulation of whole-cell biocatalysts to produce valuable chemicals from renewable feedstocks in a rapid and efficient manner, helping reduce our reliance on the conventional petroleum-based chemical synthesis. However, strain engineering process is costly and time-consuming that developing economically competitive bioprocess at industrial scale is still challenging. To accelerate the strain engineering process, modular cell engineering has been proposed as an innovative approach that harnesses modularity of metabolism for designing microbial cell factories. It is important to understand biological modularity and to develop design principles for effective implementation of modular cell engineering. In this …

Computer Simulations Of Biological Systems: From Protein Dynamics To Drug Discovery, Rupesh Agarwal

Doctoral Dissertations

Computational biophysics methods such as molecular dynamics (MD) simulations are often used in combination with experimental techniques like neutron scattering, NMR, and FTIR to explore protein conformational landscapes. With the improvements in experimental techniques, there is also a need to continually optimize the MD forcefield parameters to make precise predictions that match experimental results. To complement many of these experiments, an accurate model of deuteration is frequently required, but has been elusive. In our work, we developed a novel method to capture isotope effects in classical MD simulations by re-parameterization of the bonded terms of the CHARMM forcefield using quantum …

Using Second Harmonic Generation To Study Gram-Positive Bacterial Membranes, Lindsey N. Miller

Doctoral Dissertations

Understanding how small-molecules, such as drugs, interact with bacterial membranes can quickly unravel into much more perplexing questions. No two bacterial species are alike, especially when comparing their membrane compositions which can even be altered by incorporating fatty acids from their surrounding environment into their lipid-membrane composition. To further complicate the comparison, discrete alterations in small-molecule structures can result in vastly different membrane-interaction outcomes, giving rise to the need for more "label-free" studies when analyzing drug mechanisms. The work presented in this dissertation highlights the benefits to using nonlinear spectroscopy and microscopy techniques for probing small-molecule interactions in living bacteria. …

The Current Neuroscientific Understanding Of Alzheimer's Disease, Rachel A. Brandes

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Alzheimer’s disease is a degenerative neurological illness characterized by the deterioration of brain regions implicated in memory and cognitive function. While researchers have yet to find a cure or effective treatment, they have gained a better understanding of its pathology and development. Through years of neuroscience research, scientists have discovered much of what happens in the brain during Alzheimer’s disease onset and how this causes its symptoms; many hypotheses regarding this aspect of the illness involve temporal lobe atrophy, neurofibrillary tangles, and amyloid plaques. Although Alzheimer’s disease affects millions of people every day, it seems that most are unaware of …

Characterization Of Tmx Transmembrane Protein In Bacillus Subtilis And Its Effects On Antibiotic Resistance, Membrane Permeability, And Membrane Fluidity, Henna Zaver

Chancellor’s Honors Program Projects

No abstract provided.

Crosstalk Between Rho-Family Gtpases At The Division Site During Cytokinesis, Emma Nicole Koory

Chancellor’s Honors Program Projects

No abstract provided.

Investigating The Effects Of Excitotoxic Stimuli On The Suprachiasmatic Nucleus, Rachel A. Brandes

Chancellor’s Honors Program Projects

No abstract provided.

Cell Separation Delay And Membrane Trafficking Defects In Cdc42 Gap Mutants, Haylee Young

Chancellor’s Honors Program Projects

No abstract provided.

Effect Of Turmeric On The Promoter Activity Of The Cyp6a8 Gene Of Drosophila Melanogaster, Alexa Stroh

Chancellor’s Honors Program Projects

No abstract provided.

Circadian Rhythmicity And Neurodevelopment Of Disco And Grim Mutations In Drosophila Melanogaster, John Patrick Story

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

The death gene grim and its pathway for apoptosis has been studied extensively in Drosophila Melanogaster. The effects of grim mutations on circadian neurodevelopment and locomotor assays have yet to be investigated. Mutations in the gene disconnected (disco) has been shown to disrupt the normal development of the circadian circuitry, specifically the small ventro-lateral neurons (s-LNv’s). Which has shown to severely decrease rhythmicity during free-running periods. Alternatively, we have observed an increase in rhythmicity during free-running periods in grim mutations. Our goal is to investigate the neurodevelopment of the circadian circuitry and their associated locomotor activities in these Drosophila mutations.

Design And Development Of A Quartz Crystal Microbalance Immunosensor For Exosomes, Wesley Cox

Chancellor’s Honors Program Projects

No abstract provided.

Investigation For Novel Anti-Apoptotic Factors In The Neurons Of Drosophila Melanogaster, Haylie Rachel Lam

Chancellor’s Honors Program Projects

No abstract provided.

Constitutive Expression Of Thioglucoside Glucohydrolase 1 (Tgg1) Decreases Intercellular Trafficking In Arabidopsis Thaliana, Alessandro Francesco Sarno

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Plasmodesmata (PD) are pores that traverse plant cell walls, providing a route for intercellular trafficking of essential metabolites, nutrients, and signaling molecules between adjacent plant cells, thereby aiding communication. The increased size exclusion limit 2 (ise2) mutant of Arabidopsis thaliana has an increased abundance of branched PD, as well as a greater flux of intercellular trafficking. A search for proteins that interact with ISE2 identified THIOGLUCOSIDE GLUCOHYDROLASE 2 (a myrosinase). A. thaliana also encodes a second, closely-related myrosinase, TGG1. Myrosinases are enzymes that catalyze the hydrolysis of glucosinolates, a type of secondary metabolite that are amino acid derivatives. The breakdown …

Design And Synthesis Of Analogs Of Myo-Inositol, Serine, And Cysteine To Enable Chemical Biology Studies, Tanei J. Ricks

Doctoral Dissertations

Phosphorylated myo-inositol compounds including inositol phosphates (InsPs) as well as the phosphatidylinositol polyphosphate lipids (PIP_ns) are critical biomolecules that regulate many of the most important biological processes and pathways. They are aberrant in many disease states due to their regulatory function. The same is true of the phospholipid phosphatidylserine (PS) which can serve as a marker to begin apoptosis. However, the full scope of activities of these structures is not clear, particularly since techniques that enable global detection and analysis of the production of these compounds spatially and temporally are lacking. With all of these obstacles in …

Detection, Diversity, And Evolution Of Fungal Nitric Oxide Reductases (P450nor), Steven Adam Higgins

Doctoral Dissertations

Nitrous oxide (N₂O) is a gas responsible for significant ozone layer depletion and contributes to greenhouse effects in Earth’s atmosphere. N₂O is primarily generated by denitrification, whereby nitrate (NO_3-) or nitrite (NO_2-) is converted to gaseous N₂O or N2. Teragram quantities of N₂O are emitted annually from agricultural soils treated with nitrogenous fertilizers due to the activity of soil microbiota. Although bacteria and fungi harbor genes permitting denitrification, fungi lack NosZ, an enzyme responsible for reducing N₂O into inert N2 gas. Historically, scientists have linked fungi …

The Crowding Effects Of Rmlc On R67 And Chromosomal Dihydrofolate Reductase Enzymes, Michael A. Craig

Chancellor’s Honors Program Projects

No abstract provided.

A Study On The Interactions Of Trehalose With Model Folate Compounds, Carolyn R Ware

Chancellor’s Honors Program Projects

No abstract provided.

Effects Of Nicotine On The Cyp6a8 Gene Promoter Of Drosophila Melanogaster, Leslie M. Stroud

Chancellor’s Honors Program Projects

No abstract provided.