Life Sciences Commons^™

The Fate Of Icd-1 During Misfolded Protein Induced Apoptosis In Caenorhabditis Elegans, Kyle H. Perez

Senior Honors Projects, 2010-2019

Severe misfolded protein stress initiates cellular responses that often result in the death of the affected cell, typically by apoptosis. An essential aspect of apoptosis is caspase-mediated cleavage of proteins that, once cleaved, further propagate death. One heterodimeric structure putatively targeted in this process in the nascent polypeptide-associated complex (NAC), a translational chaperone thought to help prevent misfolded protein stress in the ER. The purpose of this investigation was to determine whether the beta subunit of the NAC in C. elegans (ICD-1) is cleaved during the induction of apoptosis, with the hypothesis that ICD-1 is cleaved during stressed-induced apoptosis to …

Evidence Of A Role For G Protein Signaling Modulator 3 In Cell Division, Drew C. Wallace

Electronic Thesis and Dissertation Repository

Components of G protein-mediated signaling are associated with positioning and orienting the mitotic spindle in the process of cell division. However, a functional role for G protein signaling modulator 3 (GPSM3) in cell division has yet to be defined. The purpose of this study was to investigate a potential role for GPSM3 in cell division. Vascular smooth muscle cells (VSMCs) from Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats, that are known to express GPSM3, were used as a model system. Here I report that GPSM3 mRNA and protein levels varied during different stages of the cell cycle in SHR VSMCs. …

Mitogen And Morphogen Signaling Dysregulation: Pathophysiological Influence In Pancreatic Cancer And Alzheimer’S Disease, Eric Cruz

Theses & Dissertations

Although the etiology of a particular disease will vary, there are genetic and epigenetic bottlenecks that frequently converge resulting in dysregulation of mitogenic and morphogenetic signaling. This propensity is acutely experienced in malignancy and neurodegenerative disease.

Here, we have first investigated the role of dysregulated signaling in the context of pancreatic cancer (PC). Morphogenetic signaling has been regarded as a pleiotropic pathway with the potential to promote and inhibit metastatic features. Our investigation of bone morphogenetic protein 2 (BMP-2), an archetypical member of the BMP superfamily, has revealed the presence of extracellular, intracellular, and long non-coding RNA products. Our findings …

The Association Between Oxidative Stress, Cellular Differentiation And Galectins In Human Promyelocytic Leukemia Cells (Hl-60), James R. Vinnai

Electronic Thesis and Dissertation Repository

Galectins are a group of β-galactoside-binding proteins involved in different cellular processes including stress responses and differentiation. The role and expression of galectins under oxidative stress and during neutrophilic differentiation was examined in HL-60 cells. Galectin gene (LGALS), and galectin protein expression were determined using RT-qPCR and immunoblotting, respectively. Neutrophilic differentiation was measured via a spectrofluorometric assay. DNA methylation and JNK signaling were investigated as galectin regulatory mechanisms. Menadione-induced oxidative stress, DMSO-induced differentiation, DNA hypomethylation and JNK signaling all promoted similar galectin expression profiles. Antioxidant N-acetylcysteine attenuated the menadione-induced galectin expression but only partially attenuated DMSO-induced galectin expression. …

Regulation Of Alteration/Deficiency In Activation 3 (Ada3) By Acetylation And Its Role In Cell Cycle Regulation And Oncogenesis, Shashank Srivastava

Theses & Dissertations

The ADA3 (Alteration/Deficiency in Activation 3) protein is a transcriptional adaptor protein that was initially discovered as a component of several HAT (Histone Acetyltransferase) complexes, the enzyme complex responsible for histone acetylation, which is a prerequisite for transcription. Earlier the studies from Dr. Band’s laboratory and that of others’ have deciphered a crucial role of ADA3 in cell cycle regulation (both through G₁/S and G₂/M phase transitions) and in maintaining the genomic stability.

While our laboratory investigated the mechanism behind the role of ADA3 in G₁/S transition, the same remained unknown for G_{2 …}

Defining The Role Of Phosphorylation And Dephosphorylation In The Regulation Of Gap Junction Proteins, Hanjun Li

Theses & Dissertations

Gap junctions are intercellular channels that permit the free passage of ions, small metabolites, and signaling molecules between neighboring cells. In the diseased human heart, altered ventricular gap junction organization and connexin expression (i.e., remodeling) are key contributors to rhythm disturbances and contractile dysfunction. Connexin43 (Cx43) is the dominant gap junction protein isoform in the ventricle which is under tight regulation by serine/tyrosine phosphorylation. Phosphorylation and dephosphorylation regulate many aspects of Cx43 function including trafficking, assembly and disassembly, electrical and metabolic coupling at the plaque, as well as to modulate the interaction with other proteins.

Serine phosphorylation has long been …

Insights Into The Role Of Connexin26 And Connexin30 In Skin Health, Syndromic Disease, And Cutaneous Wound Healing, Eric R. Press

Electronic Thesis and Dissertation Repository

Connexin26 (Cx26) and Cx30 facilitate gap junctional intercellular communication (GJIC) in the epidermis and are linked to several syndromic skin diseases. We investigated 5 disease- linked Cx26 mutants and demonstrated that the severity and extent of disease can be predicted from the gain- or loss-of function properties of each mutant, as well as the ability to induce cell death. We also used transgenic mice expressing S17F Cx26 (linked to keratitis-ichthyosis- deafness syndrome) or A88V Cx30 (linked to Clouston Syndrome) to investigate the pathophysiology these skin diseases. We demonstrated that S17F Cx26, but not A88V Cx30, promotes palmoplantar keratoderma by disrupting …

Ros Regulation Of Axonal Mitochondrial Transport, Pin-Chao Liao

Open Access Dissertations

Mitochondria perform critical functions including aerobic ATP production and calcium (Ca2+) homeostasis, but are also a major source of reactive oxygen species (ROS) production. To maintain cellular function and survival in neurons, mitochondria are transported along axons, and accumulate in regions with high demand for their functions. Oxidative stress and abnormal mitochondrial axonal transport are associated with neurodegenerative disorders. However, we know little about the connection between these two. Using primaryDrosophila neuronal cell culture and the third instar larval nervous system as in vitro and in vivo models, respectively, we studied mitochondrial transport under oxidative stress conditions. In vitro …

Investigating The Effects Of Ph On Alphaviral E3-E2 Glycoprotein Association, Organization, And Cellular Tropism, Jason Michael Sequra

Open Access Dissertations

In alphaviruses the role of E3 is required in protecting the fusion peptide region of E1 during intracellular transport. Throughout viral processing, the association of E2 and E3 is required for the successful trafficking and incorporation of E1 into the mature virion. This E3-E2 association has been observed to extend to mature virions in the solved structure for the envelope of Semliki Forest virus (SFV) and supported by the solved structure for the entire Venezuelan equine encephalitis virion (VEEV) with exclusive contacts being made between E3-E2. Immunization with monoclonal antibodies against VEEV E3 provided protection for mice challenged by lethal …

Characterization Of Vesicular Monoamine Transporter 2 And Its Role In Parkinson's Disease Pathogenesis Using Drosophila, Antonio Joel Tito Jr., Sheng Zhang

Dissertations & Theses (Open Access)

Parkinson’s disease (PD) is a progressive neurodegenerative disorder caused by the selective loss of the dopaminergic neurons in the Substantia nigra pars compacta region of the brain. PD is also the most common neurodegenerative disorder and the second most common movement disorder. PD patients exhibit the cardinal symptoms, including tremor of the extremities, rigidity, slowness of movement, and postural instability, after 70-80% of DA neurons degenerate. It is, therefore, imperative to elucidate the underlying mechanisms involved in the selective degeneration of DA neurons. Although increasing numbers of PD genes have been identified, why these largely widely expressed genes induce …

Punctuated Evolution Within A Eurythermic Genus (Mesenchytraeus) Of Segmented Worms: Genetic Modification Of The Glacier Ice Worm F1f0 Atp Synthase, Shirley A. Lang

Graduate School of Biomedical Sciences Theses and Dissertations

Segmented worms (Annelida) are among the most successful animal inhabitants of extreme environments worldwide. An unusual group of Mesenchytraeus worms endemic to the Pacific Northwest of North America occupy geographically proximal ecozones ranging from low elevation temperate rainforests to high altitude glaciers. Along this altitudinal transect, Mesenchytraeus representatives from disparate habitat types were collected and subjected to deep mitochondrial and nuclear phylogenetic analyses. Evidence presented here employing modern bioinformatic analyses (i.e., maximum likelihood, Bayesian inference, multi-species coalescent) supports a Mesenchytraeus “explosion” in the upper Miocene (5-10 million years ago) that gave rise to ice, snow and terrestrial worms, derived from …

Microenvironment-Induced Pten Loss By Exosomal Microrna Primes Brain Metastasis Outgrowth, Lin Zhang

Dissertations & Theses (Open Access)

Development of life-threatening cancer metastases at distant organs requires disseminated tumor cells’ adaptation to and co-evolution with the drastically different microenvironments of metastatic sites. Cancer cells of common origin manifest distinct gene expression patterns after metastasizing to different organs. Clearly, the dynamic interplay between metastatic tumor cells and extrinsic signals at individual metastatic organ sites critically impacts the subsequent metastatic outgrowth. Yet, it is unclear when and how disseminated tumor cells acquire the essential traits from the microenvironment of metastatic organs that prime their subsequent outgrowth. Here we show that primary tumor cells with normal expression of PTEN, an important …

Molecular And Functional Analysis Of The Pixb Gene In Xenorhabdus Nematophila, John Lucas

Theses and Dissertations

Xenorhabdus nematophila and the entomopathogenic nematode Steinernema carpocapsae form a mutualistic relationship facilitating the infection, death and consumption of an insect host. The infective juvenile (IJ) form of S. carpocapsae invades the insect host through natural openings and proceeds to the hemocoel where exposure to hemolymph stimulates the release of X. nematophila from the anterior vesicle. Excreted X. nematophila releases immunosuppressive compounds and insect toxins into the insect hemolymph that facilitates death of the host. As X. nematophila reaches high cell density it secretes exoenzymes that degrade insect tissues and produces antibiotics that reduce microbial competition. S. carpocapsae utilizes the …

Engineered Human Acidic Fibroblast Growth Factor (Fgf1) With An Enhanced Thermal And Proteolytic Stability, Duaa Abdullah Almansaf

Graduate Theses and Dissertations

Fibroblast growth factor receptor (FGFR) is made up of three significant domains. The most important domain is the intracellular domain where the dimerization and autophosphorylation occur. Fibroblast growth factor (FGF) interacts with specific FGFR to regulate many cellular processes during the embryonic stage. Furthermore, FGF is significant for adults because FGF plays an important role in regulating cellular differentiation as well as wound healing. The cellular regulating processes are initiated through binding FGF to heparin followed by binding FGF/heparin to FGFR to form FGF/heparin/FGFR complex. Thus, FGFR is dimerized and autophosphorylated. The phosphorylation of FGFR triggers downstream signaling pathways, which …

Influence Of Ph And Acidic Side Chain Charges On The Behavior Of Designed Model Peptides In Lipid Bilayer Membranes, Venkatesan Rajagopalan

Graduate Theses and Dissertations

The molecular properties of transmembrane proteins and their interactions with lipids regulate biological function. Of particular interest are interfacial aromatic residues and charged residues in the core helix whose functions range from stabilizing the native structure to regulating ion channels. This dissertation addresses the pH dependence and influence of potentially negatively charged tyrosine, glutamic acid or aspartic acid side chains. We have employed GWALP23 (acetyl-GGALW5LALALALALALALW19LAGA-amide) as favorable host peptide framework. We have substituted W5 with Tyr (Y5GWALP23) and Leu residues with Glu (L12E, L14E or L16E) or Asp (L14D or L16D), and have incorporated specific 2H-labeled alanine residues within the …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

Using Mouse Models To Define How The P53 R72p Polymorphism Impacts The Adverse Effects Of Doxorubicin And Ionizing Radiation, Emily Dominguez

Dissertations & Theses (Open Access)

The single nucleotide polymorphism (SNP) at codon 72 of the tumor suppressor gene p53 codes for either an arginine (R) or proline (P) (p53 R72P). This SNP may impact how cells respond to genotoxic insult. Studies in cell culture and in tissues from mouse models of the SNP indicate that, in response to gentoxic treatment, the two variants may differentially induce apoptosis and expression of p53 target genes. In epidemiological studies, the P variant is associated with decreased cancer survival and increased risk of side-effects from genotoxic cancer treatment. Genotoxic therapy is still the mainstay of cancer treatment, and doxorubicin …

Ultrastructural Changes During Pollen Wall Development And Germination In Arabidopsis Thalaiana, Katrina Olsen

Theses and Dissertations

The Arabidopsis thaliana meiotic mutant 6491 has been identified as displaying temperature sensitive male reduced- fertility. It has been determined that callose wall formation is defective, both in temporal and structural areas. There is irregular rippling in the plasma membrane and aberrant formation of the exine portion of the pollen wall. A developmental study using brightfield, epifluorescence, and transmission electron microscopy of the early stages of wall formation in 6491 has been completed, along with a similar study of Arabidopsis thaliana (L.) heynh, ecotype Wassilewskija (WS). Due to the temperature-sensitive nature of the mutant line, a further study of both …

Exploring The Production Of Extracellular Matrix By Astrocytes In Response To Mimetic Traumatic Brain Injury, Addison Walker

Graduate Theses and Dissertations

Following injury to the central nervous system, extracellular modulations are apparent at

the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of …

Dopamine Effects Of Stimulant And Non-Stimulant Drugs Used In The Treatment Of Attention Deficit Hyperactivity Disorder, Preeti Chalwadi

Theses and Dissertations

Attention deficit hyperactivity disorder (ADHD) is thought to be associated with dysfunction of ascending catecholamine neuronal systems, particularly dopamine (DA) and norepinephrine (NE). Dysfunction of these catecholamine neurons innervating the prefrontal cortex is hypothesized to underlie impaired executive functions. Dysfunction of the DA neurons innervating the striatum is additionally hypothesized to underlie deficits in motivation and reinforcement learning. However, mechanisms of action of therapeutic drugs used for treating ADHD have mainly focused on catecholamines in the prefrontal cortex and have not adequately addressed the role played by DA signaling in the striatum. Stimulants such as Adderall® and Ritalin® are chemically …

Vdr-Ripk1 Interaction And Its Implications In Cell Death And Cancer Intervention, Waise Quarni

USF Tampa Graduate Theses and Dissertations

Receptor interacting protein kinase 1 (RIPK1) is an enzyme acting downstream of tumor necrosis factor alpha to control cell survival and death. RIPK1 expression has been reported to cause drug resistance in cancer cells; but so far, no published studies have investigated the role of RIPK1 in vitamin D action. In the present study, we investigated whether RIPK1 played any role in 1,25-dihydroxyvitamin D3 (1,25D3)-induced growth suppression. In our studies, RIPK1 decreased the transcriptional activity of vitamin D receptor (VDR) in luciferase reporter assays independently of its kinase activity, suggesting a negative role of RIPK1 in 1,25D3 action. RIPK1 also …

The Cellular Context Of Estradiol Regulation In The Zebra Finch Auditory Forebrain, Maaya Ikeda

Doctoral Dissertations

Estradiol, traditionally known as a hormone that communicates with distant cells in the body, is also synthesized locally in the brain to act as a neuromodulator. Neuromodulators differ from neurotransmitters in that they simultaneously affect a population of neurons and their actions are not limited to the synapse. One of the many effects of estradiol signaling is rapid modulation of auditory processing in response to external stimuli. The enzyme required for estradiol synthesis, aromatase, is highly expressed in the regions that are involved in higher-order processing of sounds in humans and songbirds. Since zebra finches, a type of songbird, are …

Understanding The Differences Between Neuronal Calcium Sensor Proteins: A Comparison Of Neurocalcin Delta And Hippocalcin, Jeffrey M. Viviano

Graduate School of Biomedical Sciences Theses and Dissertations

Many neuronal functions, including learning and memory are driven by changes in intracellular Ca2+concentrations. The Neuronal Calcium Sensor (NCS) family of proteins is responsible for mediating the response to calcium. They are typically comprised of 4 EF hands; of which EF 2, 3, and 4 bind calcium.

Hypothesis: NCS proteins carry out unique, non-overlapping functions, and that specific characteristics of the family can be mapped to precise regions of the proteins.

Results: The effect on the following properties were investigated primarily on two highly similar NCS proteins, Neurocalcin Delta (NCALD) and Hippocalcin (HPCA): (1) Response to calcium was determined through …

Replication-Transciption Switch In Human Mitochondria, Karen Agaronyan

Graduate School of Biomedical Sciences Theses and Dissertations

Coordinated replication and expression of mitochondrial genome is critical for metabolically active cells during various stages of development. However, it is not known whether replication and transcription can occur simultaneously without interfering with each other and whether mtDNA copy number can be regulated by the transcription machinery. Human mitochondrial RNA polymerase (mtRNAP) is a central enzyme involved in gene expression in mitochondria. It generates genome-size polycistronic transcripts and also makes replication primers at two origins of replication. MtRNAP is distantly related to phage T7 RNAP. While T7 RNAP is optimized to produce large amounts of transcripts to overcompete the bacterial …

Depletion Of The Rna Helicase Skiv2l2 Impedes Mitotic Progression And Histone Mrna Turnover In Murine Cell Lines, Alexis Marie Onderak

Dissertations (1934 -)

RNA surveillance via the nuclear exosome requires cofactors such as the helicase SKIV2L2 to process and degrade certain noncoding RNAs. This dissertation aimed to characterize the phenotype associated with RNAi knockdown of SKIV2L2 in two murine cancer cell lines: Neuro2A and P19. Skiv2l2 knockdown in Neuro2A and P19 cells induced changes in gene expression indicative of cell differentiation and reduced cellular proliferation. Analysis of the cell cycle revealed defective progression through mitosis following SKIV2L2 depletion. These results indicate that SKIV2L2 enhances mitotic progression, thereby maintaining cancer cell proliferation and preventing differentiation. Indeed, SKIV2L2 levels were found to be downregulated during …

Molecular Analysis Of Ftsz-Ring Assembly In E. Coli Cytokinesis, Kuo-Hsiang Huang

Dissertations, Theses, and Capstone Projects

An essential first step in bacterial division is the assembly of a cytokinetic ring (Z-ring) formed by the tubulin-like FtsZ at midcell. The highly conserved core domain of FtsZ has been reported to mediate assembly of FtsZ polymers in vivo and in vitro. Species-specific differences in the FtsZ C-terminal domain such as the FtsZ CTV region and interactions with several modulatory proteins such as ZapC and ZapD, restricted to certain bacterial classes, also serve as key determinants of FtsZ protofilament bundling. Here, we characterize (i) the roles of the FtsZ CTV region in mediating both longitudinal and lateral interactions …

Characterization Of The Catalytic Ck2 Subunits With Substitutions At Residues Involved In Inhibitor Binding, Paul Desormeaux

Electronic Thesis and Dissertation Repository

CK2 is a constitutively active, ubiquitously expressed and pleiotropic serine/threonine protein kinase that is implicated in many cellular functions including tumorigenesis. CK2 has two catalytic subunits, CK2a and CK2a’, that carry out its function in the cell. Previous studies have indicated that inhibitor-refractory mutants have been effective in recovering residual CK2 activity, in the presence of inhibitors, when compared to wild type CK2. Based on these observations, inhibitor-refractory mutants were created for both CK2a and CK2a’ and tested with various concentrations with two CK2-specific inhibitors, CX-4945 and inhibitor VIII. The CK2a triple mutant (V66A/I174A/H160D) was tested in inducible U2OS Flp-In …

Regulation Of Nachrs And Stemness By Nicotine And E-Cigarettes In Nsclc, Courtney Schaal

USF Tampa Graduate Theses and Dissertations

Lung cancer is the leading cause of cancer-related death in both men and women, nationally and internationally and kills more people each year than breast, prostate, and colon cancers combined. Non-small cell lung carcinoma (NSCLC) is the most common histological subtype of lung cancer, and accounts for 85% of all cases. Cigarette smoking is the single greatest risk factor for lung cancer, and is correlated with 80-90% of all lung cancer deaths. Nicotine, the addictive component of tobacco smoke, is not a carcinogen and cannot initiate tumors itself; however, it is known to act as a tumor promoter, by enhancing …

The Mechanism Of Tubular Recycling Endosome Biogenesis, Shuwei Xie

Theses & Dissertations

Endocytic trafficking is a critical process for cellular homeostasis, and multiple ailments that include cardiovascular disease and cancer are related to the dysregulation of endocytic transport. As vesicles and target membranes are key to endocytic transport, lipids are essential for the regulation of endocytic trafficking pathways. We have shown that the tubular recycling endosomes (TRE) are essential for the regulation of endocytic recycling pathways. However, the mechanisms by which TRE are biosynthesized and carry out their functions remain unsolved. Studies from our lab have shown that phosphatidic acid (PA) recruits Molecule Interacting with Casl-Like protein 1 (MICAL-L1) as well as …

Role Of Ddr1 In Pancreatic Cancer, Huocong Huang

Theses & Dissertations

Pancreatic ductal adenocarcinomas are highly malignant cancers, characterized by extensive invasion into surrounding tissues, metastasis to distant organs at a very early stage, and a limited response to therapy. One of the main features of pancreatic ductal adenocarcinomas is desmoplasia, which leads to extensive deposition of collagen I. We have demonstrated that collagen I can induce epithelial-mesenchymal transition (EMT) in pancreatic cancer cells. A hallmark of EMT is an increase in the expression of a mesenchymal cadherin, N-cadherin. Our previous studies have shown that up-regulation of N-cadherin can promote tumor cell invasion and that collagen I-induced EMT is through two …