Medicine and Health Sciences Commons^™

The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga

Electronic Theses and Dissertations

Dickeya dianthicola (Samson) causing blackleg and soft rot was first detected in potatoes grown in Maine in 2014. Previous work has suggested that insects, particularly aphids, may be able to vector bacteria in this genus between plants, but no conclusive work has been done to confirm this theory. In order to determine whether insect-mediated transmission is likely to occur in potato fields, two model potato pests common in Maine were used: the Colorado potato beetle (Leptinotarsa decimlineata Say) and the green peach aphids (Myzus persicae Sulzer). Olfactometry and recruitment experiments evaluated if either insect discriminates between infected and …

Engineering Hyaluronic Acid For Biomedical Applications, Deep S. Bhattacharya

Theses & Dissertations

This work presents research using the naturally available non- sulfated carbohydrate glycosaminoglycan hyaluronic acid (HA) for the synthesis of different chemical derivatives of HA for evaluation of binding kinetics with CD44 and P- selectin proteins for applications in fluorescence image-guided surgery. Chemical derivatives of HA such as deacetylated HA (deHA), sulfated HA (sHA), and deacetylated and sulfated HA (s-deHA) were synthesized by modulating sulfating and deacetylating reagents to alter binding specificities to CD44. Modified HA derivatives and CD44 biophysical interactions were assessed by fluorescence polarization. In silico techniques were also used to determine binding using molecular docking and MM-PBSA approaches. …

Defining The Role Of Tyrosine Phosphorylation In The Regulation Of Connexin43 In Cardiac Diseases, Li Zheng

Theses & Dissertations

Connexins are integral membrane proteins that oligomerize to form gap junction channels. Ions and small molecules diffuse intercellularly through these channels, allowing individual cellular events to synchronize into the functional response of an entire organ. Gap junction channels composed of Connexin43 (Cx43) mediate electrical coupling and impulse propagation in the normal working myocardium. In the failing heart, Cx43 remodeling (decreased expression, altered phosphorylation state, loss at intercalated discs, and increased presence at lateral membranes) contributes to rhythm disturbances and contractile dysfunction. While there is considerable information regarding key interactions of Cx43 in the regulation of gap junction channels, unfortunately, the …

Delivery Of Small Molecule And Rna Using Synthetic Polymeric Micelles And Multifunctional Exosomes For The Treatment Of Type 1 Diabetes, Yang Peng

Theses & Dissertations

Type 1 diabetes is one of the most challenging chronic autoimmune diseases. The destruction and dysfunction of insulin-secreting β cells are the results of inflammatory infiltration and the synergistic effect of multiple immune cells. The aim of this dissertation is to develop novel and reliable therapeutic approaches to advance the treatment of T1D: including chemical modification of a broad-spectrum immunosuppressant, co-application of small molecule based immune intervention and siRNA based β cell preservative therapy, and administration of a PI3K-δ/γ dual inhibitor to specifically target immune cells, utilizing synthetic polymeric micelles or natural produced multi-functional exosomes derived from human bone marrow …

Alanyl-Trna Synthetase Quality Control Prevents Global Dysregulation Of The Escherichia Coli Proteome, Paul Kelly, Nicholas Backes, Kyle Mohler, Christopher Buser, Arundhati Kavoor, Jesse Rinehart, Gregory Phillips, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Mechanisms have evolved to prevent errors in replication, transcription, and translation of genetic material, with translational errors occurring most frequently. Errors in protein synthesis can occur at two steps, during tRNA aminoacylation and ribosome decoding. Recent advances in protein mass spectrometry have indicated that previous reports of translational errors have potentially underestimated the frequency of these events, but also that the majority of translational errors occur during ribosomal decoding, suggesting that aminoacylation errors are evolutionarily less tolerated. Despite that interpretation, there is evidence that some aminoacylation errors may be regulated, and thus provide a benefit to the cell, while others …

Investigating Biological Mechanisms Of Radiation Resistance In Advanced Stage Cervical Cancer, Fiona Ruiz

Arts & Sciences Electronic Theses and Dissertations

The current standard of care treatment for locally advanced cervical cancer is curative intent pelvic radiation with concurrently administered platinum chemotherapy (CRT). This treatment strategy is effective for many patients, but 33-50% of patients treated with CRT develop disease recurrence. Metastatic and recurrent cervical cancer is an incurable condition, and many of the currently available treatments are associated with significant morbidity and mortality. Identifying these patients upfront is a challenge that clinicians face when developing treatment strategies. Previous studies used to catalog the genomic and transcriptomic landscape of cervical cancer lacked high quality corresponding clinical follow up data for patients, …

Characterization Of The Nuclear Pore Complex In Red Alga, Cyanidioschyzon Merolae, Michelle Veronin

Health and Kinesiology Theses

Cyanidioschyzon merolae (C. merolae) is a primitive, unicellular species of red alga that is considered to be one of the simplest self-sustaining eukaryotes. The highly elementary nature of C. merolae makes it an excellent model organism for studying evolution as well as cell function and organelle communication. In our study, we hypothesize that C. merolae contains the minimal assembly of proteins to make up their Nuclear Pore Complexes (NPCs), and hence are the first ancestral NPCs. NPCs are essential for basic nuclear transport in the cell. They are embedded in the double membrane of the nucleus, the …

Alzheimer's And Amyloid Beta: Amyloidogenicity And Tauopathy Via Dyshomeostatic Interactions Of Amyloid Beta, Jordan Tillinghast

Senior Honors Theses

This paper reviews functions of Amyloid-β (Aβ) in healthy individuals compared to the consequences of aberrant Aβ in Alzheimer’s disease (AD). As extraneuronal Aβ accumulation and plaque formation are characteristics of AD, it is reasonable to infer a pivotal role for Aβ in AD pathogenesis. Establishing progress of the disease as well as the mechanism of neurodegeneration from AD have proven difficult (Selkoe, 1994). This thesis provides evidence suggesting the pathogenesis of AD is due to dysfunctional neuronal processes involving Aβ’s synaptic malfunction, abnormal interaction with tau, and disruption of neuronal homeostasis. Significant evidence demonstrates that AD symptoms are partially …

A Novel Switch-Like Function Of Delta-Catenin In Dendrite Development, Ryan Baumert

Dissertations & Theses (Open Access)

The formation of neuronal networks in the brain is tightly regulated, and dependent on the morphology of dendrites, the branch-like signal-receiving structures extending from neurons. Disruptions in dendrite development, or dendritogenesis, can lead to the atypical neuronal connectivity associated with multiple neurodevelopmental diseases. My research addresses molecular processes that underlie dendritogenesis via analysis of a pair of novel interactions involving the protein delta-catenin.

In neurons, delta-catenin localizes to dendrites and synapses, where it functions in their development and maintenance. Structurally, delta-catenin possesses a central Armadillo domain and a C-terminal PDZ-binding motif. This motif associates with PDZ domain-containing proteins, and is …

Global Acetylation Dynamics In The Heat Shock Response Of Saccharomyces Cerevisiae, Rebecca E. Hardman

Graduate Theses and Dissertations

All organisms face a constant barrage of environmental stresses. Single-cell organisms such as Saccharomyces cerevisiae, or common Baker’s yeast, must rely solely on cellular responses in order to survive. This response must occur in a rapid and highly coordinated manner to quickly inhibit all unnecessary processes and shuttle all available resources to those necessary for survival. One method that cells utilize for rapid protein regulation is the use of post-translational modifications. Enzymes within the cell add or remove a variety of chemical modifications, thus altering the local chemical environment of a protein. This creates a conformational change in the protein …

Mechanisms And Consequences Of Myb Gene Activation In Salivary Gland Tumors, Candace Frerich

Biomedical Sciences ETDs

Salivary gland adenoid cystic carcinoma (ACC) is an aggressive tumor with a tendency to infiltrate surrounding nerves and metastasize to distant sites. The standard treatment often fails to control local tumor recurrence and distant metastases and no approved targeted therapeutic options exist for these tumors. The goal of our studies was to reveal the molecular mechanisms driving ACC tumor development and novel drug targets to improve patient morbidity and mortality.

We first analyzed clinical and RNA-sequencing (RNA-seq) data for 68 formalin-fixed paraffin-embedded (FFPE) ACC tumor samples and described previously unappreciated molecular heterogeneity that predicts patient outcome. The poor outcome subgroup …

Probing Of Carbohydrate-Protein Interactions Using Galactonoamidine Inhibitors, Jessica B. Pickens

Graduate Theses and Dissertations

Glycoside hydrolases are ubiquitous and one of the most catalytically proficient enzymes known, and thus understanding their mechanisms are crucial. Most research has focused on the interaction of the glycon of substrates and their inhibitors within the active site of glycoside hydrolases. The inhibitors employed to probe these interactions generally had small aglycons (i.e. a hydrogen atom, amidines, small aliphatic groups, or benzyl groups). Here, the interactions of the aglycon with glycoside hydrolases are examined by probing the active sites with a library of 25 galactonoamidines. The studies described in this dissertation aim to increase the understanding of stabilization of …

Toward Understanding The Mechanism Of Protein Targeting In The Chloroplast Signal Recognition Particle Pathway, Mercede Furr

Graduate Theses and Dissertations

Protein targeting is a vital cellular function. The signal recognition particle (SRP) pathway is a universally conserved targeting system present in the cytosol and used to co-translationally target many proteins to the inner membrane of prokaryotes and the endoplasmic reticulum of eukaryotes. The chloroplast has a homologous SRP system which post-translationally targets light harvesting chlorophyll binding proteins (LHCPs) to the thylakoid membrane for integration. The chloroplast SRP (cpSRP) is a heterodimer with a 54 kDa subunit equivalent to SRP54 in the canonical pathway. In addition, cpSRP contains a novel 43 kDa subunit which is a unique and irreplaceable component. cpSRP43 …

Production And Purification Of Basic Fibroblast Growth Factor Fused To Two Collagen Binding Domains Expressed In E. Coli Bl21 Using Flask And Fed-Batch, Hazim Aljewari

Graduate Theses and Dissertations

Delivering effective and non-toxic doses of bioactive materials that can aid in activating tissue regeneration to wounded tissue has proven to be an enormous challenge. This study was designed to produce a potential therapeutic recombinant protein by fusing two collagen binding domains to basic fibroblast growth factors (bFGF) through a collagenase cleavage site linker, so it can release the bFGF in a wound site by the action of this enzyme. The novel fusion protein was expressed in Escherichia coli BL-21 (E. coli) using traditional flask shaker and fed-batch cultivation. Cell lysate was purified by FPLC using Immobilized metal affinity chromatography …

The Role Of Membrane Domains In Protein And Lipid Sorting During Endocytic Traffic, Blanca B. Diaz-Rohrer

Dissertations & Theses (Open Access)

The lipid and protein composition of the plasma membrane (PM) must be tightly controlled to maintain cellular functionality, despite constant, rapid endocytosis. Because de novo synthesis of proteins and lipids is energetically costly, the cell depends on active recycling to return endocytosed membrane components back to the PM. For most proteins, the mechanisms and pathways of their PM retention remain unknown. The work presented here shows that association with ordered membrane microdomains is fully sufficient for PM recycling and that abrogation of raft partitioning leads to their degradation in lysosomes. These findings support a model wherein ordered membrane domains mediate …

Influence Of Single And Multiple Histidine Residues And Their Ionization Properties On Transmembrane Helix Dynamics, Orientations And Fraying, Fahmida Afrose

Graduate Theses and Dissertations

Since aromatic and charged residues are often present in various locations of transmembrane helices of integral membrane proteins, their impacts on the molecular properties of transmembrane proteins and their interactions with lipids are of particular interest in many studies. In this work, I used solid-state deuterium NMR spectroscopy in designed model peptide GWALP23 [GGALW(LA)6LWLAGA] with selective deuterium labels to addresses the pH dependence and influence of single and multiple “guest” histidine residues in the orientation and dynamic behaviors of transmembrane proteins. The mutations include Gly to His (G2/22 to H2/22), Trp to His (W5/19 to H5/19) and Leu to His …

Single Molecule Fluorescence Studies Of Protein Structure And Dynamics Underlying The Chloroplast Signal Recognition Particle Targeting Pathway, Dustin R. Baucom

Graduate Theses and Dissertations

The work presented in this dissertation explores the structural dynamics in the chloroplast signal recognition particle pathway. Findings include cpSRP shows scanning functionality similar to that in the cytosolic SRP with the ribosome. The intrinsically disordered C-terminal tail of the Albino3 protein has some transient secondary structure. Upon binding to cpSRP43 in solution, separate secondary structure formation was identified in the C-terminal tail of Albino3. Finally, to increase efficiency of analyzing fluorescence time traces for this work, a modular software was produced.

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

Chancellor’s Honors Program Projects

No abstract provided.

Autophagy Protein Nrbf2 Has Reduced Expression In Alzheimer's Brains And Modulates Memory And Amyloid-Beta Homeostasis In Mice, Veronik Lachance, Qian Wang, Eric Sweet, Insup Choi, Cui-Zan Cai, Xu-Xu Zhuang, Jessica Li Jiang, Robert D. Blitzer, Ozlem Bozdagi-Gunal, Bin Zhang, Jia-Hong Lu, Zhenyu Yue

Biology Faculty Publications

Background Dysfunctional autophagy is implicated in Alzheimer's Disease (AD) pathogenesis. The alterations in the expression of many autophagy related genes (ATGs) have been reported in AD brains; however, the disparity of the changes confounds the role of autophagy in AD. Methods To further understand the autophagy alteration in AD brains, we analyzed transcriptomic (RNAseq) datasets of several brain regions (BA10, BA22, BA36 and BA44 in 223 patients compared to 59 healthy controls) and measured the expression of 130 ATGs. We used autophagy-deficient mouse models to assess the impact of the identified ATGs depletion on memory, autophagic activity and amyloid-beta (A …

The Role Of Atypical Protein Kinase C In Colorectal Cancer Cells Carcinogenesis, S M Anisul Islam

USF Tampa Graduate Theses and Dissertations

Colorectal cancer (CRC) is the third most common malignancy and the fourth most common cause of cancer-related death worldwide. CRC is a life-threatening disease due to therapy-resistant cancerous cells. The exact mechanisms of cell growth, survival, metastasis and inter & intracellular signaling pathways involved in CRC are still a significant challenge. Moreover, the treatment of metastatic CRC considered palliative for many years aimed for an improved life, with little hope of a cure, highlighting the need for developing novel targeted therapy for CRC. Hence, investigating new molecular mechanism(s) that lead to colorectal carcinogenesis may give insight into the therapeutic target. …

The Role Of Inositol Polyphosphate-4-Phosphatase Type Ii B (Inpp4b) In Obese Models And Endocrine Cancers, Manqi Zhang

FIU Electronic Theses and Dissertations

INPP4B is a dual-specificity phosphatase and a tumor suppressor in prostate and breast cancers. Progression of the prostate and breast cancers depends on the androgen receptor (AR) or estrogen receptor alpha (ERα) signaling, respectively. In this work we demonstrated that INPP4B reprograms ERα transcriptional activity in breast cancer. INPP4B maintains expression and protein levels of progesterone receptor (PR), an ERα direct target gene required for mammary gland development. Consistently we demonstrated that Inpp4b knockout severely impairs lateral branching in the mammary gland of maturing virgin females. In advanced prostate cancer, activation and transcriptional reprogramming of AR frequently coincides with the …

Discovery Of Novel Mechanisms Regulating Cancer Extravasation In The Chorioallantoic Membrane Model, Yohan Kim

Electronic Thesis and Dissertation Repository

Cancer metastasis is a multistep process that begins with the invasion of tumour cells into the stroma and migration towards the blood vessels. Tumour cells that have entered the bloodstream must then survive and leave by a process known as extravasation. Finally, extravasated cells proliferate and establish the secondary site in the metastatic cascade. Although extravasation encompasses key events during cancer cell invasion to aid in the development of effective treatments, an in vivo model that rapidly, reproducibly and economically recapitulates cancer cell extravasation is needed. Therefore, the objectives of my research were to 1) establish and validate an in …

Clpc Affects The Intracellular Survival Capacity Of Staphylococcus Aureus In Non-Professional Phagocytic Cells, Gubesh Gunaratnam, Lorena Tuchscherr, Mohamed I. Elhawy, Ralph Bertram, Janina Eisenbeis, Christian Spengler, Thomas Tschernig, Bettina Löffler, Greg A. Somerville, Karin Jacobs, Mathias Herrmann, Markus Bischoff

School of Veterinary and Biomedical Sciences: Faculty Publications

Invasion and persistence of bacteria within host cells requires that they adapt to life in an intracellular environment. This adaptation induces bacterial stress through events such as phagocytosis and enhanced nutrient-restriction. During stress, bacteria synthesize a family of proteins known as heat shock proteins (HSPs) to facilitate adaptation and survival. Previously, we determined the Staphylococcus aureus HSP ClpC temporally alters bacterial metabolism and persistence. This led us to hypothesize that ClpC might alter intracellular survival. Inactivation of clpC in S. aureus strain DSM20231 significantly enhanced long-term intracellular survival in human epithelial (HaCaT) and endothelial (EA.hy926) cell lines, without markedly affecting …

How Oxygen Availability Affects The Antimicrobial Efficacy Of Host Defense Peptides: Lessons Learned From Studying The Copper-Binding Peptides Piscidins 1 And 3, Adenrele Oludiran, David S. Courson, Malia D. Stuart, Anwar R. Radwan, John C. Putsma, Myriam L. Cotten, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating the immune system function and directly killing bacteria through membrane disruption and oxidative damage. The copper-binding HDPs piscidin 1 and piscidin 3 have previously shown potent antimicrobial activity against a number of Gram-negative and Gram-positive bacterial species but have never been investigated in an anaerobic environment. Synergy between piscidins and metal ions increases bacterial killing aerobically. Here, we …

Protein Detection And Structural Characterization By Mass Spectrometry Using Supramolecular Assemblies And Small Molecules, Bo Zhao

Doctoral Dissertations

Mass spectrometry (MS) has played an increasingly prominent role in proteomics and structure biology because it shows superior capabilities in identification, quantification and structural characterization of proteins. To realize its full potential in protein analysis, significant progress has been made in developing innovative techniques and reagents that can couple to MS detection. This dissertation demonstrates the use of polymeric supramolecular assemblies for enhanced protein detection in complex biological mixtures by MS. An amphiphilic random co-polymer scaffold is developed to form functional supramolecular assemblies for protein/ peptide enrichment. The influences of charge density and functional group pK_a on host-guest interactions …

Leaving Ligand Effects On Reactivity And Solubility Of Monofunctional Platinum(Ii) Anticancer Complexes, Heidi Linn Hruska Millay

Masters Theses & Specialist Projects

Monofunctional platinum(II) complexes, such as phenanthriplatin and pyriplatin, have notably different characteristics from the bifunctional anticancer complexes, such as cisplatin and oxaliplatin, which have detrimental toxicities and resistance associated with them. The unique properties of the monofunctional complexes may be exploited to target cancer cells without producing the toxic side effects associated with the current FDA-approved platinum-based anticancer drugs. To advance the understanding of these monofunctional platinum(II) complexes, this study replaced the chloride leaving ligand with an acetate group, which should increase solubility and alter the rate of reactivity with key amino acid and nucleotide targets. Phenanthriplatin and pyriplatin compounds …

The Essential Role Of Carbon Metabolism In The Virulence Of Cryptococcus Neoformans, Mara Weigner

Senior Honors Theses

Cryptococcus neoformans infections are a major cause of meningoencephalitis in immunosuppressed patients worldwide. Inhaled as spores or desiccated yeast cells, C. neoformans can undergo metabolic changes in response to the new host environment that allow it to cross the blood brain barrier and cause deadly central nervous system (CNS) infections. Nutrient acquisition, and specifically carbon metabolism, is critical for survival and proliferation within the host. Notably, efficient carbon metabolism is necessary to produce the polysaccharide capsule, which is arguably C. neoformans’ most important and well-studied virulence factor. As such, a better understanding of carbon acquisition and regulation is essential for …

The Fitness Landscape Of The African Salmonella Typhimurium St313 Strain D23580 Reveals Unique Properties Of The Pbt1 Plasmid, Rocío Canals, Roy R. Chaudhuri, Rebecca E. Steiner, Siân V. Owen, Natalia Quinones-Olvera, Melita A. Gordon, Michael Baym, Michael Ibba, Jay C. D. Hinton

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have used a transposon insertion sequencing (TIS) approach to establish the fitness landscape of the African Salmonella enterica serovar Typhimurium ST313 strain D23580, to complement our previous comparative genomic and functional transcriptomic studies. We used a genome-wide transposon library with insertions every 10 nucleotides to identify genes required for survival and growth in vitro and during infection of murine macrophages. The analysis revealed genomic regions important for fitness under two in vitro growth conditions. Overall, 724 coding genes were required for optimal growth in LB medium, and 851 coding genes were required for growth in SPI-2-inducing minimal medium. These …

Cellular Distribution Of The Prion Protein In Palatine Tonsils Of Mule Deer (Odocoileus Hemionus) And Rocky Mountain Elk (Cervus Elaphus Nelsoni), Matthew M. Hille, Jean E. Jewell, E. Lee Belden

School of Veterinary and Biomedical Sciences: Faculty Publications

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) that affects members of the Cervidae family, including deer (Odocoileus spp.), elk (Cervus Canadensis spp.), and moose (Alces alces spp.). While CWD is a neurodegenerative disease, lymphoid accumulation of the abnormal isoform of the prion protein (PrPSc) is detectable early in the course of infection. It has been shown that a large portion of the PrPSc lymphoid accumulation in infected mule deer takes place on the surface of follicular dendritic cells (FDCs). In mice, FDC expression of PrPC has been shown to be essential for PrPSc accumulation. …

Creating A Molecular Map Of The Pediatric Lung, Quinlen F. Marshall

Forum Lectures

The newborn lung undergoes vast biochemical and physiological changes during adaptation from the intrauterine to the extrauterine environment. Lung morphogenesis continues from birth into early childhood, mediated by dynamic gene expression and a diversity of pulmonary cell types that exhibit remarkable heterogeneity. (Whitsett, JA. et al. Physiol. Rev, 2019). Surprisingly, few studies have solely focused on human lung development during this critical period, and many current studies of lung maturation rely on adult, murine, or diseased samples, limiting their insights and applicability to longitudinal pediatric lung development. Understanding the molecular and physiological nuances of pulmonary development has important clinical relevance, …