Biochemistry, Biophysics, and Structural Biology Commons^™

Mitochondrial Heteroplasmy Contributes To The Dynamic Atovaquone Resistance Response In Plasmodium Falciparum, Sasha Victoria Siegel

USF Tampa Graduate Theses and Dissertations

Of the considerable challenges researchers face in the control and elimination of malaria, the development of antimalarial drug resistance in parasite populations remains a significant hurdle to progress worldwide. Atovaquone is used in combination with proguanil (Malarone) as an antimalarial treatment in uncomplicated malaria, but is rendered ineffective by the rapid development of atovaquone resistance during treatment. Previous studies have established that de novo mutant parasites confer resistance to atovaquone with a substitution in amino acid 268 in the cytochrome b gene encoded by the parasite mitochondrial genome, yet much is still unknown about how this resistance develops, and whether …

The Effects Of Phytohormones And Isoprenoids In Dihydroartemisinin-Induced Dormancy In The Erythrocytic Stages Of Plasmodium Falciparum, Marvin Duvalsaint Duvalsaint

USF Tampa Graduate Theses and Dissertations

Our ability to control malaria has been challenged by increasing antimalarial resistance. Plasmodium falciparum undergoes dormancy in the blood stages which is hypothesized to be a means by which they are able to survive under drug pressure. This helps select for resistant parasites which grow following removal of drug. The mechanisms behind dormancy and the subsequent recrudescence are not fully understood but translating knowledge from related organisms which undergo a similar phenomenon might shed some light. Higher plants utilize dormancy during the early development stages to survive under unfavorable conditions, increasing fitness of the seedling and ensuring viability when this …

Conditional Loss Of Pten In Myogenic Progenitors Leads To Postnatal Skeletal Muscle Hypertrophy But Age-Dependent Exhaustion Of Satellite Cells, Feng Yue, Pengpeng Bi, Chao Wang, Jie Li, Xiaoqi Liu, Shihuan Kuang

Department of Animal Sciences Faculty Publications

Skeletal muscle stem cells (satellite cells [SCs]) are normally maintained in a quiescent (G0) state. Muscle injury not only activates SCs locally, but also alerts SCs in distant uninjured muscles via circulating fac- tors. The resulting GAlert SCs are adapted to regener- ative cues and regenerate injured muscles more effi- ciently, but whether they provide any long-term benefits to SCs is unknown. Here, we report that em- bryonic myogenic progenitors lacking the phospha- tase and tensin homolog (Pten) exhibit enhanced proliferation and differentiation, resulting in muscle hypertrophy but fewer SCs in adult muscles. Interest- ingly, Pten null SCs are predominantly …

Hiv Glycoprotein Gp120 Impairs Fast Axonal Transport By Activating Tak1 Signaling Pathways, Sarah H. Berth, Nichole Mesnard-Hoaglin, Bin Wang, Hajwa Kim, Yuyu Song, Maria Sapar, Gerardo Morfini, Scott T. Brady

Publications and Research

Sensory neuropathies are the most common neurological complication of HIV. Of these, distal sensory polyneuropathy (DSP) is directly caused by HIV infection and characterized by length-dependent axonal degeneration of dorsal root ganglion (DRG) neurons. Mechanisms for axonal degeneration in DSP remain unclear, but recent experiments revealed that the HIV glycoprotein gp120 is internalized and localized within axons of DRG neurons. Based on these findings, we investigated whether intra-axonal gp120 might impair fast axonal transport (FAT), a cellular process critical for appropriate maintenance of the axonal compartment. Significantly, we found that gp120 severely impaired both anterograde and retrograde FAT. Providing a …

Phytochrome B Integrates Light And Temperature Signals In Arabidopsis, Martina Legris, Cornelia Klose, E Sethe Burgie, Cecilia Costigliolo Rojas Rojas, Maximiliano Neme, Andreas Hiltbrunner, Philip A. Wigge, Eberhard Schäfer, Richard D. Vierstra, Jorge J. Casal

Biology Faculty Research

Ambient temperature regulates many aspects of plant growth and development, but its sensors are unknown. Here, we demonstrate that the phytochrome B (phyB) photoreceptor participates in temperature perception through its temperature-dependent reversion from the active Pfr state to the inactive Pr state. Increased rates of thermal reversion upon exposing Arabidopsis seedlings to warm environments reduce both the abundance of the biologically active Pfr-Pfr dimer pool of phyB and the size of the associated nuclear bodies, even in daylight. Mathematical analysis of stem growth for seedlings expressing wild-type phyB or thermally stable variants under various combinations of light and temperature revealed …

Gene Expression Profiling And The Role Of Hsf1 In Ovarian Cancer In 3d Spheroid Models, Trillitye Paullin

USF Tampa Graduate Theses and Dissertations

Ovarian cancer is the most lethal gynecological cancer, with over 200,000 women diagnosed each year and over half of those cases leading to death. These poor statistics are related to a lack of early symptoms and inadequate screening techniques. This results in the cancer going undetected until later stages when the tumor has metastasized through a process that requires the epithelial to mesenchymal transition (EMT). In lieu of traditional monolayer cell culture, EMT and cancer progression in general is best characterized through the use of 3D spheroid models. In this study, we examine gene expression changes through microarray analysis in …

Quantitative Proteomic Investigation Of Disease Models Of Type 2 Diabetes, Mark Gabriel Athanason

USF Tampa Graduate Theses and Dissertations

PANcreatic DERived factor (PANDER, FAM3B) is a member of a superfamily of FAM3 proteins that are uniquely structured and strongly expressed from the endocrine pancreas and co-secreted with insulin. Unique animal models available to our lab have indicated that PANDER can induce a selective hepatic insulin resistant (SHIR) phenotype whereby insulin signaling is blunted yet lipogenesis is increased. The complexity of the biological networks involved with this process warranted the logical approach of employing quantitative mass spectrometry based proteomic analysis using stable isotope labeling of amino acids in cell culture (SILAC) to identify the global proteome differences between the PANDER …

Pld-Specific Small-Molecule Inhibitors Decrease Tumor-Associated Macrophages And Neutrophils Infiltration In Breast Tumors And Lung And Liver Metastases, Karen M. Henkels, Naveen Reddy Muppani, Julian Gomez-Cambronero

Biochemistry and Molecular Biology Faculty Publications

Phospholipase D-2 (PLD2) has a key role in breast cancer formation and metastasis formation with PLD small inhibitors reducing primary tumor growth. This study aimed to evaluate the importance of targeting PLD on the tumor microenvironment. We provide evidence about the beneficial effect of PLD inhibitors [FIPI (dual PLD1/PLD2) or VU0155072-2 (PLD2 inhibitor)] on avoiding infiltration of tumor-helping macrophages and neutrophils. Tumor growth and metastasis within the primary tumors had low (<20% over controls) PLD enzyme activity. Unexpectedly, we found that the inhibitors also affected PLD2 gene expression and protein albeit at a lesser extent. The later could indicate that targeting both the actual PLD enzyme and its activity could be beneficial for potential cancer treatments in vivo. F4/80 and Ly6G staining of macrophages and neutrophils, respectively, and Arg1 staining data were consistent with M2 and N2 polarization. NOS2 staining increased in xenotransplants …

The Nuts And Bolts Of The Platelet Release Reaction, Smita Joshi, Sidney W. Whiteheart

Molecular and Cellular Biochemistry Faculty Publications

Secretion is essential to many of the roles that platelets play in the vasculature, e.g., thrombosis, angiogenesis, and inflammation, enabling platelets to modulate the microenvironment at sites of vascular lesions with a myriad of bioactive molecules stored in their granules. Past studies demonstrate that granule cargo release is mediated by Soluble NSF Attachment Protein Receptor (SNARE) proteins, which are required for granule-plasma membrane fusion. Several SNARE regulators, which control when, where, and how the SNAREs interact, have been identified in platelets. Additionally, platelet SNAREs are controlled by post-translational modifications, e.g., phosphorylation and acylation. Although there have been many …

Significance Of Pten Phosphorylation And Its Nuclear Function In Lung Cancer, Prerna Malaney

USF Tampa Graduate Theses and Dissertations

Phosphorylation mediated inactivation of PTEN leads to multiple malignancies with increased severity. However, the consequence of such inactivation on downstream functions of PTEN are poorly understood. Therefore, the objective of my thesis is to ascertain the molecular mechanisms by which PTEN phosphorylation drives lung cancer. PTEN phosphorylation at the C-terminal serine/threonine cluster abrogates its tumor suppressor function. Despite the critical role of the PTEN C-tail in regulating its function, the crystal structure of the C-tail remains unknown. Using bioinformatics and structural analysis, I determined that the PTEN C-tail is an intrinsically disordered region and is a hot spot for post-translational …

Co2-Fixing One-Carbon Metabolism In A Cellulose-Degrading Bacterium Clostridium Thermocellum, Wei Xiong, Paul P. Lin, Lisa Warner, James C. Liao, Pin-Ching Maness, Katherine J. Chou

Biomedical Research Institute Publications and Presentations

Clostridium thermocellum can ferment cellulosic biomass to formate and other end products, including CO₂. This organism lacks formate dehydrogenase (Fdh), which catalyzes the reduction of CO₂ to formate. However, feeding the bacterium ¹³C-bicarbonate and cellobiose followed by NMR analysis showed the production of ¹³C-formate in C. thermocellum culture, indicating the presence of an uncharacterized pathway capable of converting CO₂ to formate. Combining genomic and experimental data, we demonstrated that the conversion of CO₂ to formate serves as a CO₂ entry point into the reductive one-carbon (C1) metabolism, and internalizes CO_{2 …}

An Iron Detection System Determines Bacterial Swarming Initiation And Biofilm Formation, Chuan-Sheng Lin, Yu-Huan Tsai, Chih-Jung Chang, Shun-Fu Tseng, Tseng-Ru Wu, Chia-Chen Lu, Ting-Shu Wu, Jang-Jih Lu, Jim-Tong Horng, Jan Martel, David M. Ojcius, Hsin-Chih Lai, John Ding-E. Young

All Dugoni School of Dentistry Faculty Articles

Iron availability affects swarming and biofilm formation in various bacterial species. However, how bacteria sense iron and coordinate swarming and biofilm formation remains unclear. Using Serratia marcescens as a model organism, we identify here a stage-specific iron-regulatory machinery comprising a two-component system (TCS) and the TCS-regulated iron chelator 2-isocyano-6,7-dihydroxycoumarin (ICDH-Coumarin) that directly senses and modulates environmental ferric iron (Fe3+) availability to determine swarming initiation and biofilm formation. We demonstrate that the two-component system RssA-RssB (RssAB) directly senses environmental ferric iron (Fe³⁺) and transcriptionally modulates biosynthesis of flagella and the iron chelator ICDH-Coumarin whose production requires the pvc cluster. …

Development Of In Vivo Systems For Detecting And Studying Ribosome Inhibition By Small Molecules, Shijie Huang

Chemistry and Chemical Biology ETDs

The ribosome is the quintessential antibacterial drug target, with many structurally and mechanistically distinct classes of antibacterial agents acting by inhibiting ribosome function. Detecting and quantifying ribosome inhibition by small molecules and investigating their binding modes and mechanisms of action are critical to antibacterial drug discovery and development efforts. To develop a ribosome inhibition assay that is operationally simple, yet provides direct information on the drug target and the mechanism of action, we have developed engineered E. coli strains harboring an orthogonal ribosome controlled green fluorescent protein reporter that produce fluorescent signal when the O-ribosome is inhibited. As a proof …

Regulation Of Palmitoylation Enzymes And Substrates By Intrinsically Disordered Regions, Krishna D. Reddy

USF Tampa Graduate Theses and Dissertations

Protein palmitoylation refers to the process of adding a 16-carbon saturated fatty acid to the cysteine of a substrate protein, and this can in turn affect the substrate’s localization, stability, folding, and several other processes. This process is catalyzed by a family of 23 mammalian protein acyltransferases (PATs), a family of transmembrane enzymes that modify an estimated 10% of the proteome. At this point in time, no structure of a protein in this family has been solved, and therefore there is poor understanding about the regulation of the enzymes and their substrates. Most proteins, including palmitoylation enzymes and substrates, have …

Engineering Small Molecule Based Dimerization To Induce Translation And Provide Optogenetic Control, Catherine Wright

Chemistry and Chemical Biology ETDs

We wanted to develop a system that combines the spatial control of photoactivation and control of translation to build a tool to spatially control translation in neurons. This kind of tool could be used to investigate the role of spatially controlled translation of any protein in neural behavior. In this way the development and growth of neural processes could be studied to elucidate the mechanisms for spatially sensitive events such as pathfinding, repair, or long-term potentiation.

Chemically induced dimerization was used to install a switch into the activation of translation for specific genes. An abscisic acid (ABA) dependent dimerization of …

Pt-Mal-Lhrh Mediates Breast Cancer Cell Cytotoxicity Through Increased Apoptosis, Kendall E. Collins

Posters-at-the-Capitol

In the United States one in eight women will be afflicted with breast cancer. It is estimated that in 2016 there will be approximately 246,600 new invasive breast cancer cases and 61,000 new non-invasive cases. Triple negative breast cancers account for 15% of all breast cancers and are significantly more aggressive than other subtypes. Treatment options for triple negative breast cancer are limited due to the cancers not expressing the estrogen, progestogen, or herceptin receptors making them unresponsive to hormonal therapy. Our recent work centers around developing a novel chemotherapeutic agent that will direct therapy selectively to triple negative (4T1) …

Swimming Mechanisms Of Temperate Forest Ants, Noah D. Gripshover, Evan M. Gora, Stephen P. Yanoviak

Posters-at-the-Capitol

Swimming Mechanisms of Temperate Forest Ants (Camponotus pennsylvanicus and Formica subsericea)

Noah D. Gripshover, Evan M. Gora, and Stephen P. Yanoviak

University of Louisville

Abstract

Environmental challenges shape the evolution of animal behavior and morphology. For wingless terrestrial invertebrates like ants, pools of water on the forest floor are particularly dangerous. Here we show that ants can overcome this obstacle using a modified gait to transverse the water surface. We compared the locomotor morphology and swimming performance of two arboreal ant species that are common in Kentucky (Camponotus pennsylvanicus and Formica subsericea). We defined performance as speed …

Tertiary Alphabet For The Observable Protein Structural Universe, Craig\ O. Mackenzie, Jianfu Zhou, Gevorg Grigoryan

Dartmouth Scholarship

Here, we systematically decompose the known protein structural universe into its basic elements, which we dub tertiary structural motifs (TERMs). A TERM is a compact backbone fragment that captures the secondary, tertiary, and quaternary environments around a given residue, comprising one or more disjoint segments (three on average). We seek the set of universal TERMs that capture all structure in the Protein Data Bank (PDB), finding remarkable degeneracy. Only ∼600 TERMs are sufficient to describe 50% of the PDB at sub-Angstrom resolution. However, more rare geometries also exist, and the overall structural coverage grows logarithmically with the number of TERMs. …

Design Of Novel Ion Channel Modulators, Vladimir Yarov-Yarovoy

Science Seminar Series

Function and modulation of neuronal sodium channels are critical for the neuromodulation of electrical excitability and synaptic transmission in neurons - the basis for many aspects of signal transduction, learning, memory and physiological regulation. Mutations in neuronal voltage-gated sodium channel genes are responsible for various human neurological disorders. Furthermore, human neuronal voltage-gated sodium channels are primary targets of therapeutic drugs used as local anesthetics and for treatment of neurological and cardiac disorders. Yarov-Yarovoy's lab is working on rational design of novel therapeutically useful blockers of voltage-gated sodium channels for treatment of pain and epilepsy. Serious, chronic pain affects at least …

A Pipette-Based Calibration System For Fast-Scan Cyclic Voltammetry With Fast Response Times, Eric S. Ramsson

Peer Reviewed Articles

Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique that utilizes the oxidation and/or reduction of an analyte of interest to infer rapid changes in concentrations. In order to calibrate the resulting oxidative or reductive current, known concentrations of an analyte must be introduced under controlled settings. Here, I describe a simple and cost-effective method, using a Petri dish and pipettes, for the calibration of carbon fiber microelectrodes (CFMs) using FSCV.

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 …

The Rodent Parvovirus H-1 And Its Potential In Combination With Tien Hsien Liquid As A Treatment For Breast Cancer, Hayley I. Spires

Selected Honors Theses

Breast cancer is responsible for 12% of cancer diagnoses each year, and it is the leading cause of cancer-related mortality in women worldwide. Current treatments have provided some success in combatting the disease but are not considered a final solution. The framework for how researchers approach cancer has continued to change, and this includes the introduction of oncolytic viruses as novel therapeutics for cancer. The rodent parvovirus H-1 has shown strong potential in clinical and subclinical trials, but its S phase dependency limits its usefulness against cancer stem cell populations. Tien Hsien Liquid is commerically available, nontoxic, and has shown …

Polymorphisms In Mthfr, Ms And Cbs Genes And Premature Acute Myocardial Infarction In A Pakistani Population, Mohammad Perwaiz Iqbal, Khalida Iqbal, Asal Khan Tareen, Siddiqa Parveen, Naseema Mehboobali, Ghulam Haider, Saleem Perwaiz Iqbal

Department of Biological & Biomedical Sciences

High prevalence of premature coronary heart disease in Pakistanis compared to other populations points towards the genetic predisposition of this population to develop this disease. Since no investigations have been carried out in Pakistan to study the relationship of polymorphisms in genes involved in homocysteine cycle, the objective of the present study was to find out if there is any association of methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C; methionine synthase (MS) A2756G; cystathionine-beta-synthase (CBS) 844ins68, G919A polymorphisms with premature acute myocardial infarction (AMI) in a population of Pakistani patients with this disease. In a cross-sectional study, DNA samples of 143 AMI …

Methods To Assess The Direct Interaction Of C. Jejuni With Mucins, Julie Ann Naughton, Marguerite Clyne, Gina Duggan, Billy Bourke

Books/Book chapters

Studies of the interaction of bacteria with mucus secreting cells can be complemented at a more mechanistic level by exploring the interaction of bacteria with purified mucins. Here we describe a far western blotting approach to show how C. jejuni proteins separated by SDS PAGE and transferred to a membrane or slot blotted directly onto a membrane can be probed biotinylated mucin. In addition we describe the use of novel mucin microarrays to assess bacterial interactions with mucins in a high throughput manner.

A Polyaniline-Based Sensor Of Nucleic Acids, Partha Sengupta, Jared Gloria, Marcus K. Parker, Alex S. Flynt

Faculty Publications

Detection of nucleic acids is at the center of diagnostic technologies used in research and the clinic. Standard approaches used in these technologies rely on enzymatic modification that can introduce bias and artifacts. A critical element of next generation detection platforms will be direct molecular sensing, thereby avoiding a need for amplification or labels. Advanced nanomaterials may provide the suitable chemical modalities to realize label-free sensors. Conjugated polymers are ideal for biological sensing, possessing properties compatible with biomolecules and exhibit high sensitivity to localized environmental changes. In this article, a method is presented for detecting nucleic acids using the electroconductive …

Assessing The Risk Of Resistance Evolution, Adult And Larval Susceptibility, And Sublethal Effects After Exposure Of Corn Rootworms To Vacuolar Atpase-A And Snf7 Dsrnas, Adriano Elias Pereira

Department of Entomology: Dissertations, Theses, and Student Research

Corn rootworms are Diabroticite beetles from the genus Diabrotica and include the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, and the northern corn rootworm, D. barberi Smith & Lawrence, as the most important pests in the U.S. Corn Belt. The southern corn rootworm (SCR), D. undecimpunctata howardi Barber, is considered a polyphagous plant pest and feeds in a wide variety of plants including peanuts, cucurbits, soybeans, and especially corn. Resistance to control methods including behavioral resistance to crop rotation and to corn hybrids expressing Bacillus thuringiensis Berliner toxins in WCR has frequently been reported. SCR has been considered a …

The Biological Function Of Hammerhead Rana Ribozyme In Human Genome, Ibtehal M. A. Awad

Theses

Hammerhead RNA [HHR] sequence originally found in viroids is also detected in many species. HHR are often found in introns of different genes ranging from prokaryotes to

eukaryotes. HHR can form specific tertiary structure that make specific region susceptible to cleavage. However, the role of the HHR is not clear in other life forms. This study aims to

Investigate the role of HHR in the intron 6 of (RECK) gene. Our study shows that when blocking the HHR sequence in the intron6, the production of RECK protein declines which may be due to the effect of HHR in splicing and …

Expression, Purification, And Crystallization Of An Endoxylanase From Bacteroides Vulgatus, Jesslyn Park, Jason Hurlbert

The Winthrop McNair Research Bulletin

Sustainable sources of energy are growing in demand as fossil fuels are rapidly expended. One such energy source is fuel ethanol generated from the fermentation of plant biomass by engineered bacterial biocatalysts. The creation of a biocatalyst capable of converting nearly any plant matter to fuel ethanol requires the identification of novel enzymes capable of degrading specific carbohydrate polymers and cloning these enzymes into a bacterial host. This study seeks to structurally characterize a novel xylanase of glycosyl hydrolase family 30 (GH30) from Bacteroides vulgatus, a bacterium found in the human gut microbiome, via x-ray crystallography. The gene for …

Pyk2 Activates The Nlrp3 Inflammasome By Directly Phosphorylating Asc And Contributes To Inflammasome-Dependent Peritonitis, I-Che Chung, Chun-Nan Ouyang, Sheng-Ning Yuan, Hsin-Pai P. Li, Jeng-Ting Chen, Hui-Ru Shieh, Yu-Jen Chen, David M. Ojcius, Ching-Liang Chu, Jau-Song Yu, Yu-Sun Chang, Lih-Chyang Chen

All Dugoni School of Dentistry Faculty Articles

The inflammasome adaptor protein, ASC, contributes to both innate immune responses and inflammatory diseases via self-oligomerization, which leads to the activation of the protease, caspase-1. Here, we report that the cytosolic tyrosine kinases, FAK and Pyk2, are differentially involved in NLRP3 and AIM2 inflammasome activation. The inhibition of FAK and Pyk2 with RNA interference or chemical inhibitors dramatically abolished ASC oligomerization, caspase-1 activation, and IL-1β secretion in response to NLRP3 or AIM2 stimulation. Pyk2 is phosphorylated by the kinase Syk and relocalizes to the ASC specks upon NLRP3 inflammasome activation. Pyk2, but not FAK, could directly phosphorylate ASC at Tyr146, …

Contribution Of Epithelial Hypoxia Signaling To Pulmonary Fibrosis: Role Of Fak1 And Galectin-1 As Driver Molecules, Jaymin J. Kathiriya

USF Tampa Graduate Theses and Dissertations

Idiopathic Pulmonary Fibrosis (IPF) is a deadly disease of unknown origin, which causes 80,000 deaths every year in the US and Europe combined. Unknown etiology and late diagnosis, combined with limited treatment options, contribute to a dismal survival rate of 3-5 years post diagnosis. Although molecular mechanisms underlying IPF pathogenesis and progression have been studied for over two decades, lack of in vivo models that recapitulate chronic, progressive, and irreversible nature of IPF have contributed to limited therapeutic success in clinical trials. Currently, only two drugs, Pirfenidone and Nintedanib, are approved for IPF treatment in the US, with their efficacy …