Cell Biology Commons^™

Bax Activation Through The N-Terminal Bh3-Like Domains Of Vdac1 And Vdac2, Autumn A. Peters

Honors Theses

Voltage-dependent anion channels (VDACs) are central to mitochondrial function by mediating metabolite diffusion across the mitochondrial outer membrane (MOM). Two isoforms­­­­­­­­­­­,­­­­­­­­­­­­­­­­­­­­­­­­­­­­ VDACs 1 and 2, are also implicated in apoptosis based on interactions with Bcl-2 family proteins that control this process, including Bax and Bcl-xL. Activation of the pro-apoptotic protein Bax by interaction with ‘BH3-only’ proteins, such as Bim or Bid, induces MOM permeabilization to signal apoptosis, yet accumulating evidence indicates VDACs 1 and 2 may also affect Bax. We discovered that the VDAC N-terminal domains contain high sequence similarity to the conserved BH3 domains within Bcl-2 family members that …

Cell Cycle Regulator Delays Pilus Production In Caulobacter Crescentus, Eli Johnson

Honors Theses

Caulobacter crescentus is a model bacterium for its unusual life cycle. This cycle features three distinct phases- the stalked stage, pre-divisional or actively dividing stage, and the swarmer stage, characterized by the production of a flagellum and multiple pili. Pili are necessary for cell attachment to surfaces and their reuptake into the cell can help drive the cell cycle forward. The gene that encodes the pilus subunit, pilA, is regulated by four binding sites for the cell cycle regulator CtrA. Previous research has determined that one site induces expression while two of the four sites inhibit expression. It is unknown …

Fiddler Crab Gut Microbiomes As An Indicator For Eutrophication Due To Waste-Water Contamination In Estuaries, Madison L. Geraci

Honors Theses

Estuaries are unique biogeochemical zones in coastal systems that provide a myriad of ecological functions: providing habitat for critically important fishery species, diverse species of plants and animals, and contributing to nutrient cycling. Estuaries are vulnerable to anthropogenic stressors as they are intersections between marine and terrestrial communities and are often the hotspot of coastal development and activity. Estuarine sediments act as repositories for anthropogenic contaminants, including excess nutrient runoffs and waste-water pollution that can cause states of eutrophication. Microorganisms are sensitive to these environmental changes, presenting a unique opportunity of being useful bioindicators of environmental stress. Isolating microorganisms from …

Understanding The Functional Role Of Lone Star Tick (Amblyomma Americanum) Threonyl-Trna Synthetase In Reproductive Fitness, Anza Ali

Honors Theses

Introduction: Transfer RNA synthetases are a family of enzymes that catalyze the addition of amino acids to their corresponding transfer RNAs (tRNAs) and play an essential role in protein synthesis. Ticks are obligate hematophagous ectoparasites that rely on prolonged feeding periods to complete their life cycle on a vertebrate host. Tick tRNA synthetases help the tick in continuous protein synthesis for efficient blood feeding and reproductive fitness, thus presenting a potential target for developing new tick control strategies. Studies have been conducted assessing the functionality of different tRNA synthetases such as Valine-tRNA synthetase, Asparagine-tRNA synthetase, Lysine-tRNA synthetase, and Leucine-tRNA synthetase …

Does Vdac2 Have A Bh3 Domain?, Lillian Ferkany

Honors Theses

Mitochondrial outer membrane permeabilization (MOMP) by Bax oligomerization triggers apoptosis. BCl-2 family proteins, classified as BH3 only proteins, pro-survival proteins, or pro-apoptotic proteins, control apoptosis partly through their agonist or antagonistic effects on Bax, which are mediated by their conserved BH3 domains. All BH3 domains form an alpha helix containing 5-7 conserved hydrophobic residues, designated H0-H5, and one conserved aspartic acid that drive interaction with Bax and other ‘multi-domain’ BCl-2 members. BH3 agonists induce Bax oligomerization, while BH3 antagonists sequester Bax to prevent MOMP. We discovered that voltage dependent anion channels (VDACs) in the MOM contain a putative BH3-like domain …

Generation Of Baiap3 Expression Construct For Subcellular Localization And Phenotypic Rescue, Ireland Ann Little

Honors Theses

Mast cells secrete a variety of biological mediators crucial for innate and adaptive immunity. One such mediator is Tumor Necrosis Factor (TNF). TNF released from mast cells and other immune cells has been shown to elicit complex signaling pathways in target cells, resulting in the production of pro-inflammatory cytokines and/or immune cell recruitment. At the molecular level, TNF secretion/exocytosis is mediated by soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and other regulatory proteins that work together to promote the fusion between secretory granules and the plasma membrane. One regulatory protein, Munc13-4, which facilitates the priming of secretory granules, was recently …

Microglia Polarize In Response To Transactive Response Dna-Binding Protein-43 (Tdp-43) And Display Partial Recovery After Removal Of The Stimulus, Alicen Wilcox

Honors Theses

The proper response to protein signals is necessary for a healthy central nervous system (CNS), and protein dysregulation is a feature of neurodegenerative diseases. Transactive response DNA-binding protein-43 (TDP-43) is an intranuclear protein, but mislocalization is associated with amyotrophic lateral sclerosis (ALS). TDP-43 is released into the extracellular space where it is sensed by microglia, the CNS-resident immune cells. Our data and the literature suggest that microglia respond to TDP-43 dysregulation by increasing CNS inflammation. The goal of this study was to determine the impact of TDP-43 on microglial function and the extent to which microglia recovery. To study the …

Purification Of Pcbp2 And Its Effect On The Formation Of Dna I-Motifs And Secondary Structures, Nathan Redden

Honors Theses

Several secondary, non-B forms of DNA are associated with the promoter regions of many oncogenes, including the intensely studied c-MYC gene that codes for a transcription factor. Two such secondary structures, G-quadruplexes, and i-motifs, have become topics of interest due to their prevalence within oncogenic promoters, as well as their potential accessibility for drug targeting. B-form DNA can adopt alternative structures under certain conditions. These alternative structures are favored when there is an asymmetric distribution of guanosine and cytosine on complimentary DNA strands. The strand rich in guanosine is able to form a quadruple stranded DNA complex termed a G-quadruplex. …

Molecular Characterization Of Galectin From Amblyomma Americanum In Context Of Α-Gal Syndrome, Sumar Beauti

Honors Theses

The lone star tick Amblyomma americanum is a vector of various disease-causing pathogens and tick-borne alpha-gal syndrome (AGS) with rapidly expanding populations in the south- and northeast regions of the United States. This study aimed to molecularly characterize galectin and determine its involvement in galactose-α-1,3-galactose (α-gal) synthesis, transport, reproductive fitness, and microbial homeostasis in this tick. The lone star tick galectin possesses two conserved carbohydrate recognition domains and shares homology with other Ixodid tick galectins. Time and tissue-dependent expression data shows that galectin is constantly expressed in salivary glands, midgut, and ovary tissues. An RNA interference approach was used to …

The Impact Of Age/Rage Signaling On Oxidative Stress Under Diabetic Conditions In Cardiac Fibroblasts, Christopher Dorroh

Honors Theses

Diabetes is a major health concern in the United States, with 1.5 million new cases diagnosed each year. Patients who suffer from diabetes have an increased risk of developing heart failure, a form of cardiovascular disease. Heart failure has been shown to result from increased left ventricular stiffness, which in turn is caused by increased remodeling of the extracellular matrix (ECM). This increase in ECM remodeling is a result of AGE/RAGE signaling, which occurs at a heightened level in the cardiac fibroblast cells of diabetics. Studies have shown that diabetics have elevated levels of AGEs (Advanced Glycation End-Products), which bind …

Multi-Generational Effects Of ∆9-Tetrahydrocannabinol Exposure On Gene Expression In Liver Tissue, Kayla Lovitt

Honors Theses

Cannabis is the most commonly used, cultivated, and trafficked illicit drug worldwide. Increased availability and acceptance of cannabis and cannabinoid-containing products provide the necessity for understanding how these substances influence aging. In this study, zebrafish (Danio rerio) were exposed to concentrations of Δ⁹-tetrahydrocannabinol (THC) (0.08, 0.4, 2 µM) during embryonic-larval development, the effects on aging were measured 30 months later and in the offspring of the exposed fish (F1 generation. We observed results indicating a biphasic and hormetic effect. Treatment with the lowest concentration of THC significantly increased egg production, while higher concentrations resulted in impaired …

Development Of An Auto-Bioluminescent Lung Cell Line For Evaluation Of In Vitro Effects Of E-Cigarette Compounds On Normal Cell Proliferation, Olivia Morrison

Honors Theses

The effects of smoking have long been studied; however, with the rise of electronic cigarettes there is a growing interest in the effects of this smoking substitute. Marketed as a safer alternative to tobacco cigarettes, the popularity of electronic cigarette (e-cigarette) use has dramatically increased. This has demanded regulatory methods to be put into effect, however, scientific study is only beginning on the new fad to determine the impacts of its use on the human body. The present study aims to examine the biological effects of lung cell exposure to tobacco alkaloids found in electronic cigarette filling solutions. We hypothesize …

Development And Validation Of Gene Delivery Methods For ​Crassostrea Virginica, Adrienne N. Tracy

Honors Theses

The Eastern oyster (Crassostrea virginica) is an important part of the East Coastal USA economy because aquaculture creates jobs. Sadly, the oysters are under constant threat due to increasing pollution, red tides, and diseases. Bivalves, and oysters in particular, are also becoming potential model organisms in medical research. With the sequencing of the oyster genome, scientists are focusing on deciphering the function of the predicted genes. However, the limited number of molecular and cellular tools available makes functional annotation of the genome challenging. A consistent, replicable gene delivery system needs to be developed to assess gene function and understand the …

Structure-Activity Relationship Of Novel Rgd-Containing Cyclic Peptides Against Αvβ3 Integrin, Aaron Silva

Honors Theses

The αvβ3 integrin, a receptor for many extracellular matrix proteins with the RGD sequence motif, is involved in multiple physiological processes. The integrin is highly expressed on tumor cells, therefore making it a target for cancer therapy and imaging. Efforts have been made to develop an RGD-containing ligand against the αvβ3 integrin.

A series of RGD-containing cyclic octapeptides (LXW analogs) were previously synthesized, tested in vitro, and screened as integrin antagonists with a different binding affinity (Xiao et al., 2010; Wang et al., 2015), but the structure-activity relationship remains to be elucidated. In the current study, the structures of three …

The Subcloning And Expression Of Munc18a In Escherichia Coli For Antibody Production And Analysis In Mast Cell Degranulation Reactions, Brandi Goble

Honors Theses

Mast cells are secretory cells responsible for fighting off infection through the early recognition of pathogens. This process is completed through the secretion of proinflammatory mediators that are stored in secretory granules within the cytoplasm of the cell. The degranulation secretion process relies on regulated fusion of secretory granules to the cell membrane via membrane-bound SNARE proteins that bridges the two opposed membranes. The intricate regulation of SNARE-mediated mast cell degranulation is not well understood. However, Sec1/Munc18 (SM) proteins, specifically the Munc18 isoforms, are known to play a critical role in the process (Brochetta, et. al., 2014). The Xu lab …

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Drosophila Models To Investigate The Role Of Regulation Of Cell Death In Development And Cancer, Anam Hussain

Honors Theses

Cell death is of key importance in maintaining health and normal development. In cancer, cell death is improperly controlled provoking uncontrolled proliferation of cells, which results in severe harm to the body. The Hippo pathway is an identified pathway in Drosophila melanogaster that is involved with regulating the different mechanisms of survival and proliferation within the cells. It is known to interact with a gene known as Dronc that is a key participant in the cell death pathway of apoptosis. Previous work has shown how the loss of certain caspases, which are cysteine proteases, is linked with cell survival. My …

Is The Zebrafish Zombie Mutant Caused By A Mutation In Cdc20?, Peyton Johnston

Honors Theses

The zombie mutant was identified as an early arrest mutant, stopping in development around the 10-somite stage (14 hours of development). Further inspection revealed that this mutant was a cell cycle mutant and cells in the mutant arrest during metaphase as early as the 5-somite stage (11.6 hours of development). A similar phenotype is seen in the Drosophila melanogaster cell cycle gene fizzy, known to be to be a homolog of the Saccharomyces cerevisiae gene, cell division cycle 20 (cdc20). CDC20 is an activator protein of the anaphase promoting complex/cyclosome (APC/C), an ubiquitin E3 ligase that is …

Characterization Of Embryonic Stem Cell-Differentiated Cells As Mesenchymal Stem Cells, Rachael N. Kuehn

Honors Theses

Embryonic stem cells (ESCs), due to their ability to differentiate into different cell types while still maintaining a high proliferation capacity, have been considered as a potential cell source in regenerative medicine. However, current ESC differentiation methods are low yielding and create heterogeneous cell populations. If transplanted in the human body, differentiated ESCs could be rejected by the immune system, form tumors, or may not function normally within the human body. On the other hand, mesenchymal stem cells (MSCs), a type of adult stem cell typically derived from bone marrow, have proved to be excellent candidates in clinical applications due …

Activation Of Nf-Κb Transcription Factor During In Vitro Differentiation Of Mouse Embryonic Stem Cells, Natalya A. Ortolano

Honors Theses

Embryonic stem cells (ESCs) are a promising cell source for regenerative medicine. However, recent studies indicated that ESCs and ESC-derived cells (ESC-DCs) lack functional innate immunity against various pathogens and inflammatory cytokines. This presents a barrier to clinical application, as ESC-DCs would be placed in a wound site and exposed to pathogens and inflammatory cytokines. Using mouse ESCs (mESCs) as a model, we recently demonstrated that they are deficient in expressing type I interferons (IFN) and inflammatory cytokines. To determine the molecular basis for this finding, this study examined the activation state of nuclear factor-κB (NF-κB), a transcription factor that …

Alteration In 5ht1a Receptor Activity From A Prenatal Exposure To Dexamethasone In A Stressed And Non-Stressed Adult Male Rat, Darshan S. Shah

Honors Theses

Synthetic glucocorticoids (GC) are used as a clinical therapeutic to stimulate lung development in fetuses that present the risk of preterm delivery. Previous studies have shown that a prenatal exposure to Dexamethasone (DEX) causes a disturbance in normal GC mediation of neuritic outgrowth, cell signaling, and serotonergic systems. Our hypothesis is that a prenatal exposure to DEX during the third trimester of pregnancy alters 5HT1A receptor function. Pregnant dams were injected daily with 150μg/ml/kg of DEX from gestation day 14 through 19. Control dams were treated with and equal volume of saline. Swim stress followed by elevated plus maze testing …

A Review Of Literature For Osteology: Cell Biology, Tissue Biology, And The Application Of Synthetic Compounds For The Facilitation Of Bone Tissue Repair, Ryan T. Jones

Honors Theses

Bone is a dynamic matter that provides support, structure, mineral reserves, and stem cell reserves for the body. Important functions range from structural support for the body to roles in maintaining homeostasis. Structure and support for the body is the most obvious role, with the skeletal system as a whole providing a normal force for other tissues and organs to resist gravity. Protection is also inferred for tissues and organs from impacting forces, especially with axial bones covering vital organs in the thoracic cavity. Another function of bone includes the ability to store and release minerals when needed to maintain …

The Wheat Bzip Factor, Taabf1, Mediates Aba-Induced Gene Expression In Bombarded Barley Aleurone Layers, Benjamin R. Keyser

Honors Theses

The plant hormone Abscisic acid (ABA) plays a central role in maturation and germination in seeds, as well as mediating adaptive responses to abiotic environmental stresses. ABA induces the expression of many genes, including late-embryogenesis-abundant genes such as HVA1. To elucidate the ABA signaling pathway leading to HVA1 expression, we focus on the bZIP factor TaABF1. Analysis of the interplay between ABA and TaABF1 in the aleurone cells of imbibing cereal grains indicated that the two are not additive in their induction of the HVA1 promoter. A synthetic ABA analog, PBI-51, did not specifically inhibit the effect of exogenous ABA …

Stability Of Eukaryotic Elongation Factor One Alpha Protein In The Cell, Jennifer Watry

Honors Theses

Eukaryotic Elongation Factor One Alpha (eEF1A) is an abundant protein found in every cell of every organism and is involved in functions concerning protein synthesis and degradation, the cytoskeleton, and signaling. How these functions are regulated is not yet understood for this protein. Regulation of the protein may be controlled by transcription of the genes encoding the protein or the stability and modification of the protein. The goal of this project was to determine the stability of eEf1A proteins in Arabidopsis thaliana. Protein stability was determined by treating tissues with cycloheximide, an inhibitor of protein synthesis. Gel electrophoresis and …

A Quantitative Study Of The Distinctive Proteins Of The Eosinophil: A Comparison Of Normals And Eosinophilic Patients, James M. Olson

Honors Theses

Eosinophils have long been associated with parasitic and allergic diseases. Methods of procurement and purification of eosinophils in the last ten years have allowed intensive investigation into their components, properties, functions, and mechanisms (Gleich et al, 1982). The goals of this project are to separate eosinophils in blood samples taken from patients with eosinophilia and from normals based on density over distontinuous Metrizamide gradients; to determine quantitatively the levels of the three distinctive proteins of the eosinophil, specifically MBP, EDN, and ECP; and to compare the levels of these proteins found in eosinophils of patients with eosinophilia to the amounts …

A Comparative Consideration Of Lipoprotein Distribution And Stress Response In The Mallard Duck And Man, Janice Mackay

Honors Theses

Lipid is associated with all of the major serum protein fractions of both the mallard duck and man. however, whereas the ρ lipoproteins predominate in man with little lipo-albumin evident, according to available literature, in ducks the lipo-albumin constitutes more than half of the serum lipoproteins, and a substantial lipo-prealbumin fraction is evident. Most studies of lipo-proteins are carried out on human serum primarily for the purpose of diagnosis of abnormalities. The stress response in many animals includes a rise in serum α-globulin levels, but its physiological basis is still speculative. While a consideration of the changes in lipoprotein distribution …

The Role Of D-Gluconic Acid In The Regulation Of The Synthesis Of The Enzymes Of The Entner-Doudoroff Pathway In Pseudomonas Fluorescens, Steven C. Quay

Honors Theses

Induction of Entner-Duodoroff pathway enzymes in Pseudomonas fluorescens was investigated to study the role of gluconate as a possible inducer. Glucose oxidase-deficient mutants were isolated and characterized. One of these mutants, gox-7, was deficient in particulate glucose oxidase; another mutant, gox-17, was deficient in particulate glucose and gluconate oxidase activities. Gluconate, but not glucose, induced synthesis of gluconokinase and 6-phosphogluconate dehydratase in both mutants. High constitute levels of 2-keto-3-deoxy-6-phosphogluconate aldolase were found when both mutants were grown on glucose. Growth of parent and both mutant strains on glycerol also resulted in high levels of Entner-Doudoroff pathway enzymes. It was concluded …