Molecular Biology 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 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 …

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 …

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 …

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 …

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

Chancellor’s Honors Program Projects

No abstract provided.

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.

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

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 …

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.

Electron Transport To Photosystem I By Soluble Carriers: Evolution Of The Interacting Pair, Khoa Dang Nguyen

Doctoral Dissertations

Oxygenic photosynthesis is driven via sequential action of Photosystem II (PSII) and (PSI) reaction centers via the Z-­‐scheme. Both of these pigment– membrane protein complexes are found in cyanobacteria, algae, and plants. PSI, unlike PSII, is remarkably stable and does not undergo limiting photo-­‐damage. This stability, as well as other fundamental structural differences, makes PSI the most attractive reaction centers for applied photosynthetic applications. These applied applications exploit the efficient light harvesting and high quantum yield of PSI where the isolated PSI particles are redeployed providing electrons directly as a photocurrent or, via a coupled catalyst to yield H2. Here, …

Modification Of Carbohydrate Active Enzymes In Switchgrass (Panicum Virgatum L.) To Improve Saccharification And Biomass Yields For Biofuels, Jonathan Duran Willis

Doctoral Dissertations

The natural recalcitrance of plant cell walls is a major commercial hurdle for plant biomass to be converted into a viable energy source as alternative to fossil fuels. To circumvent this hurdle manipulation of carbohydrate enzymes active in the cellulose and hemicellulose portions of the plant cell wall can be utilized to improve feedstocks. Production of cellulolytic enzymes by plants have been evaluated for reducing the cost associated with lignocellulosic biofuels. Plants have successfully served as bioreactors producing bacterial and fungal glycosyl hydrolases, which have altered plant growth to improve saccharification. A bioprospecting opportunity lies with the utilization of insect …

Characterization Of An Ethylene Receptor In Synechocystis Sp. Pcc 6803, Randy Francis Lacey

Doctoral Dissertations

In plants, ethylene functions as a hormone regulating many growth and developmental processes. Ethylene receptors in plants resemble bacterial two-component signaling systems. Because of this it, ethylene receptors are thought to have been acquired by gene transfer from the cyanobacterial endosymbiont that lead to the development of the chloroplast. However, prior to this work, functional ethylene receptors were thought to only be found in green plants. Here, we show that the cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis) contains a functional ethylene receptor, SynEtr1. SynEtr1 contains a predicted ethylene binding domain, a photosensory cyanobacteriochrome (CBCR) domain, and a histidine …

Modulating Neuronal Activity: Copper, Isoproterenol, And Beta-Blockers On The Brain, Veronica Go

Chancellor’s Honors Program Projects

No abstract provided.

Calmodulin-Like Protein 38: A Component Of Ribonucleoprotein Particles During Hypoxic Stress Responses In Arabidopsis, Ansul Lokdarshi

Doctoral Dissertations

Waterlogging stress leads to a crisis in energy metabolism and the accumulation of toxic metabolites due to the hypoxic and/or anoxic environment associated with this condition. To respond and adapt to this situation, higher plants employ an integrated genetic program that leads to the induction of anaerobic response polypeptide genes that encode metabolic and signaling proteins involved in altering metabolic flow and other adaptive responses. The study presented here shows that the Arabidopsis thaliana calmodulin-like protein CML38 is calcium sensor protein that serves as a member of the core anaerobic response gene family and is involved in modulating the survival …

Cellular Localization And Metabolomic Analysis Of The Arabidopsis Thaliana Major Intrinsic Protein Nip2;1: A Root-Specific Lactic Acid Transporter Induced In Response To Hypoxic Stress, Taylor K. Fuller

Chancellor’s Honors Program Projects

No abstract provided.

Manipulating Adipose Tissue Fatty Acid Oxidation To Reduce Fatness In Broiler Chickens, Tania Emmanuelle Torchon

Masters Theses

Compared to rodents, broiler chickens, those reared for meat, are an attractive model for studies of adipose biology, and obesity development in children. The broiler chicken lacks the gene for uncoupling protein 1, the hallmark for brown adipose tissue making them a useful model to study lipid metabolism in white adipocytes. Two studies were performed to investigate if white adipose tissue had the metabolic ability for fatty acid oxidation (FAO), and to investigate the effects of dietary fatty acids on abdominal fat development of young broiler chickens as a model for childhood obesity. In study one, chickens were fasted for …

Characterization Of The Role Of Alpha-Arylphorin In The Heliothis Virescens Midgut Response To Cry1ac Toxin From Bacillus Thuringiensis, Jerreme Jamael Jackson

Doctoral Dissertations

Homeostasis of the intestinal epithelium in Heliothis virescens is mediated by the proliferation and differentiation of multipotent intestinal stem cells (ISCs) that lie adjacent to the basal lamina. In response to extrinsic and intrinsic signals, ISC proliferation and differentiation promotes epithelial growth and regeneration following the loss of integrity. We tested the in vivo effects of the ISC mitogen, a [alpha]-arylphorin, on ISC proliferation and the morphological changes of the midgut during larval development. Additionally, we examined how these changes affected the intestinal epithelium response to Cry1Ac toxin from Bacillus thuringiensis. Histological and in vitro evidence supported two distinct …

Pore Selectivity And Gating Of Arabidopsis Nodulin 26 Intrinsic Proteins And Roles In Boric Acid Transport In Reproductive Growth, Tian Li

Doctoral Dissertations

Plant nodulin-26 intrinsic proteins (NIPs) are members of the aquaporin superfamily that serve as multifunctional channels of uncharged metabolites and water. They share the same canonical hourglass fold as the aquaporin family. The aromatic arginine (ar/R) selectivity filter controls transport selectivity based on size, hydrophobicity, and hydrogen bonding with substrates. In Arabidopsis thaliana, NIP II subclass proteins contain a conserved ar/R “pore signature” that is composed of Alanine at the helix 2 position (H2), Valine/Isoleucine at the helix 5 position (H5), and an Alanine (LE1) and an invariant Arginine (LE2) at the two loop E positions. In this study, …

Comparative Genomics Of Microbial Chemoreceptor Sequence, Structure, And Function, Aaron Daniel Fleetwood

Doctoral Dissertations

Microbial chemotaxis receptors (chemoreceptors) are complex proteins that sense the external environment and signal for flagella-mediated motility, serving as the GPS of the cell. In order to sense a myriad of physicochemical signals and adapt to diverse environmental niches, sensory regions of chemoreceptors are frenetically duplicated, mutated, or lost. Conversely, the chemoreceptor signaling region is a highly conserved protein domain. Extreme conservation of this domain is necessary because it determines very specific helical secondary, tertiary, and quaternary structures of the protein while simultaneously choreographing a network of interactions with the adaptor protein CheW and the histidine kinase CheA. This dichotomous …

Localization Of Chemoreceptors In Azospirillum Brasilense., Anastasia Aksenova

Masters Theses

In order to ensure their survival, bacteria must sense and adapt to a variety of environmental signals. Motile bacteria are able to orient their movement in a chemical gradient by chemotaxis. During chemotaxis, environmental signals are detected by chemotaxis receptors and are propagated via a signal transduction cascade to affect bacterial motility. In a model organism Escherichia coli, chemotaxis receptors, also called MCPs (for methyl-accepting chemotaxis proteins) sense changes in concentration gradients by making temporal comparisons about the chemical composition of their surroundings. Decreased attractant concentration or increased repellant concentration results in conformational changes in the MCPs that culminate …

Applications And Improvements In The Molecular Modeling Of Protein And Ligand Interactions, Jason Bret Harris

Doctoral Dissertations

Understanding protein and ligand interactions is fundamental to treat disease and avoid toxicity in biological organisms. Molecular modeling is a helpful but imperfect tool used in computer-aided toxicology and drug discovery. In this work, molecular docking and structural informatics have been integrated with other modeling methods and physical experiments to better understand and improve predictions for protein and ligand interactions. Results presented as part of this research include:

1.) an application of single-protein docking for an intermediate state structure, specifically, modeling an intermediate state structure of alpha-1-antitrypsin and using the resulting model to virtually screen for chemical inhibitors that can …

Characterization Of Bacterial Chemotaxis Receptors Sensing And Signaling, Molly Elizabeth Payne

Chancellor’s Honors Program Projects

No abstract provided.

The Drosophila Gypsy Insulator Supports Transvection In The Presence Of The Vestigial Enhancer, Todd Schoborg, Srilalitha Kuruganti, Ryan Rickels, Mariano Labrador

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

Though operationally defined as cis-regulatory elements, enhancers can also communicate with promoters on a separate homolog in trans, a mechanism that has been suggested to account for the ability of certain alleles of the same gene to complement one another in a process otherwise known as transvection. This homolog-pairing dependent process is facilitated in Drosophila by chromatin-associated pairing proteins, many of which remain unknown and their mechanism of action uncharacterized. Here we have tested the role of the gypsy chromatin insulator in facilitating pairing and communication between enhancers and promoters in trans using a transgenic eGFP reporter system …