Molecular Biology Commons^™

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 …

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 …

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 …

The Role Of E. Coli Transcript-Cleavage Factors Gre In Transcriptional Regulation Under Hyperosmotic Stress, Kseniya Obraztsova

Graduate School of Biomedical Sciences Theses and Dissertations

Escherichia coli adapts to changes in the osmotic environment through the process of osmotic response which entails synthesis of specific enzymes and transporters to accumulate essential osmoprotectants. This process is highly regulated at the level of transcription. Upon cell exposure to high salt, RNA polymerase (RNAP} rapidly dissociates from genomic DNA, while the nucleoid becomes hyper condensed. During the subsequent osmoadaptation phase RNAP reassociates with the DNA and resumes transcription. The mechanisms of transcription initiation, promoter escape and its regulation during osmoadaptation are poorly understood. Here we demonstrate that a highly conserved bacterial regulator, transcript cleavage factor GreA, is essential …

The Genetic Hierarchy Of The Heterochronic Pathway In C. Elegans, Jennifer Tsialikas

Graduate School of Biomedical Sciences Theses and Dissertations

The correct timing of developmental events is fundamental to the growth of every animal. The pathways that control developmental timing and cell-fate succession are complex and robust in a way that underscores this importance. In this work, I have shown how an early developmental regulator, LIN-14, acts to integrate the earliest aspects of development with the events that take place afterward. I have uncovered how microRNAs from two different families fit into the cascade of proteins and micro RNA regulation that defines the developmental timing pathway. Finally, my work has helped to uncover the dual-acting nature of two proteins in …

Intestinal Cytoplasmic Lipid Droplets, Associated Proteins, And The Regulation Of Dietary Fat Absorption, Theresa M. D'Aquila

Open Access Dissertations

Dietary fat provides essential nutrients, contributes to energy balance, and regulates blood lipid concentrations. These functions are important to health, but can also become dysregulated and contribute to diseases such as obesity, diabetes, and cardiovascular disease. The small intestine absorbs dietary fat through an efficient multi step process of digestion, uptake, metabolism, and secretion or storage. When dietary fat is taken up by the absorptive cells of the small intestine, enterocytes, it can be secreted into circulation where it contributes to blood lipid levels or temporarily stored in cytoplasmic lipid droplets (CLDs). The objective of this dissertation is to investigate …

Blood-Tissue Barriers And Autoantibodies In Neurodegenerative Disease Pathogenesis: An Approach To Diagnostics And Disease Mechanism, Eric Luria Goldwaser

Graduate School of Biomedical Sciences Theses and Dissertations

Brain homeostasis can be affected in a number of ways that lead to gross anatomical, cellular, and molecular disturbances giving rise to diseases like Alzheimer’s disease (AD) and related dementias. Unfortunately, the mechanistic pathoetiology of AD’s hallmark features of cerebral amyloid plaque buildup and neuronal death are still disputed. Using human brain AD sections, immunohistochemistry experiments revealed internalized surface proteins, co-localized to an expanded lysosomal compartment. Other stains for amyloid-β1-42 (Aβ42) and various immunoglobulin (Ig) species displayed them leaking out of the cerebrovasculature through a dysfunctional blood-brain barrier (BBB), binding to neurons in the vicinity, and localizing to intracellular vesicles …

Define The Epigenetic Profiles And Subtype-Specific Genes Of Breast Cancer, Wenqian Li

Dissertations and Theses (Open Access)

Molecular profiling has identified 5 distinct subtypes of breast cancer, luminal A, luminal B, HER2-enriched, basal-like, and claudin-low breast cancer. These 5 subtypes correlate with hormone response, patient prognosis, and response to therapy. Although steady state gene expression patterns have been explored using expression microarrays, very little is known about the initial, disease-driving transcriptional changes in these cancers or epigenetic changes associated with the differential gene expression signatures. Defining these changes may provide new insights into the mechanisms by which these subtypes arise, as well as new avenues for breast cancer prevention, diagnosis, and treatment. Using Chromatin Immunoprecipitation sequencing and …

Defining The Functions Of Usp22 And Usp44 In Regulation Of H2bub1 Levels, Xianjiang Lan

Dissertations and Theses (Open Access)

Aberrant levels of histone ubiquitination are involved in various human diseases including neurodegenerative disorders and cancers. Particularly, Histone H2B monoubiquitination (H2Bub1) is highly associated with gene regulation in both normal cells and diseases. Many deubiquitinases (mainly USPs) are defined to regulate global H2Bub1 levels. However, how these USPs are regulated and how they contribute to diseases are not well understood.

USP22, part of the deubiquitination module (DUBm) in the SAGA complex, is a well-defined regulator of H2Bub1 levels. ATXN7, another crucial subunit of the SAGA DUBm, is involved in a neurodegenerative disease, spinocerebellar ataxia type 7 (SCA7), due to a …

Cell Cycle Arrest By Tgfß1 Is Dependent On The Inhibition Of Cmg Helicase Assembly And Activation, Brook Samuel Nepon-Sixt

USF Tampa Graduate Theses and Dissertations

Tumorigenesis is a multifaceted set of events consisting of the deregulation of several cell-autonomous and tissue microenvironmental processes that ultimately leads to the acquisition of malignant disease. Transforming growth factor beta (TGFß) and its family members are regulatory cytokines that function to ensure proper organismal development and the maintenance of homeostasis by controlling cellular differentiation, proliferation, adhesion, and survival, as well as by modulating components of the cellular microenvironment and immune system. The pleiotropic control by TGFß of these cell intrinsic and extrinsic factors is intimately linked to the prevention of tumor formation, the specifics of which are dependent on …

Anticancer Activities Of Resveratrol In Colorectal Cancer, Evelien Schaafsma, Tze-Chen Hsieh, Barbara B. Doonan, John T. Pinto, Joseph M. Wu

NYMC Faculty Publications

Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a dietary polyphenolic phytochemical that has demonstrated health benefits such as cardioprotection, the prevention of neurodegeneration and chemoprevention. Resveratrol has shown great potential in the prevention and treatment of carcinomas and clinical trials support resveratrol as anticancer compound in colorectal carcinoma. Colorectal cancer remains a major cause of cancer-related deaths for both men and women in industrialized countries. Because of this widespread prevalence, identifying major risk factors and initiating colorectal screening procedures provide the distinct advantage for recognizing early disease and addressing treatable forms of CRC. Epidemiological studies of fruit and vegetable consumption in relationship to developing …

Cmg Helicase Assembly And Activation: Regulation By C-Myc Through Chromatin Decondensation And Novel Therapeutic Avenues For Cancer Treatment, Victoria Bryant

USF Tampa Graduate Theses and Dissertations

The CMG (Cdc45, MCM, GINS) helicase is required for cellular proliferation and functions to unwind double-stranded DNA to allow the replication machinery to duplicate the genome. Cancer cells mismanage helicase activation through a variety of mechanisms, leading to the potential for the development of novel anti-cancer treatments. Mammalian cells load an excess of MCM complexes that act as reserves for new replication origins to be created when replication forks stall due to stress conditions, such as drug treatment. Targeting the helicase through inhibition of the MCM complex has sensitized cancer cells to drugs that inhibit DNA replication, such as aphidicolin …

Influencing Pathways That Cause Metastasis And Stemness In Epithelial Ovarian Cancer, Alyse Lynn Huisken-Hill

Electronic Theses, Projects, and Dissertations

Ovarian cancer is the fifth leading cause of cancer death in women between the ages of 35 and 74. With 22 thousand new cases and 15 thousand deaths annually ovarian cancer is among the most deadly cancers with a death to incidence ratio of 68%. With 70% of cases High Grade Serous Ovarian Carcinoma (HGSOC) is the most common type of ovarian cancer and causes 90% of ovarian cancer deaths. 80% of patients have reoccurrence within five years and only 15-30% of patients with recurrent metastatic ovarian cancer respond to current therapies, chemotherapy and surgery. One reason for the high …

The Effects Of Chronic Partial Sleep Deprivation And Chronic Voluntary Alcohol Consumption On Δfos B Accumulation, Kristian Ponder

Masters Theses, 2010-2019

The present study explores the relation between sleep restriction and alcohol use and the neural substrates that result from chronic behaviors. Accumulation of the transcription factors ΔFosB is suggested as a possible outcome of chronic behaviors, such as addiction. Sleep is discussed as possible mediating factor in the relationship between ΔFosB and chronic alcohol consumption. There were four experimental groups in this study: Control (C), Sleep Deprivation only (SD), Alcohol Exposure only (AO), and both sleep deprivation and alcohol exposure (B). Levels of ΔFosB accumulation in the Nucleus Accumbens (NAc) revealed a significant main effect of sleep deprivation, but no …

Purification Of A Bacteriophage Protein Involved In Host Range Specificity, Alec Brown

Honors Projects

The Escherichia coli ferric hydroxamate uptake receptor FhuA serves as the receptor for ferrichrome-Fe(III) complexes, with TonB protein energizing the active transport of the complex. The FhuA receptor is exploited by a variety of bacteriophages as a conduit into the cell. Interestingly, certain of these phages carry a gene called “Cor”, the product of which, when cloned and expressed from a plasmid, blocks transport by FhuA. In the present study, components of the cor gene from the bacteriophage ϕ80 were used to construct an IPTG-inducible MalE-Cor-His6 fusion protein, which allowed for affinity purification of the Cor protein. At 61 residues …

Epigenetic Regulation Of Gene Expression During Spermatogenesis, Karishma Nayak

Senior Honors Projects

In the US livestock production industry, improving reproductive efficiency will improve animal welfare and maintain reasonable costs of meat and milk for consumers. In recent research, abnormalities in epigenetic markers in sperm during spermatogenesis, has been linked to male subfertility in many species. Epigenetics is the study of changes in organisms caused by modifications of gene expression, including DNA methylation, rather than alteration of the genetic code itself. When this process is disturbed, it can negatively impact semen therefore decreasing its fertility. Through further research on how DNA methylation influences gene expression during spermatogenesis and its impact on sperm quality, …

Engineering A Mutation In The Heparin Binding Pocket Of The Human Fibroblast Growth Factor, Roshni Patel

Chemistry & Biochemistry Undergraduate Honors Theses

Fibroblast growth factors (FGFs) are family of proteins that belong to a group of growth factors that are found in mammals and play an important role in angiogenesis, differentiation, organogenesis, and tissue repair. In summary, their main functionality is involved in cell division and proliferation. Because FGFs plays such a vital role in cell proliferation, they are mainly involved in the process of wound healing and injuries. FGF binds to its ligand, heparin—a heavily sulfated glycosaminoglycan. The binding of heparin to FGF occurs through electrostatic interactions, specifically between the negatively charged sulfate groups on heparin and positively charged residues such …

The Effects Of Pulmonary Hypertension In Diabetic Zucker Rats On Pulmonary Vascular Contraction And Right Ventricular Size, Michael Franzetti

Biological Sciences Undergraduate Honors Theses

Pulmonary hypertension is a life-threatening disease that is identified by a resting mean pulmonary arterial pressure over 25 mmHg and established by right heart catheterization (Saglam et al., 2015). The symptoms commonly associated with pulmonary hypertension include fatigue, dyspnea, syncope, and chest pain, which severely limit quality of life in diagnosed patients (Saglam et al., 2015). According to recent studies in patients with pulmonary hypertension, the one, three and five year mortality rates are 8%, 25%, and 34%, respectively (Burudpakdee, Shah, Joish, Divers, & Yaldo, 2014). Although some advances have been made in therapies for pulmonary hypertension, the prognosis is …

In Vitro Investigation Of The Effect Of Exogenous Ubiquitin On Processes Associated With Atherosclerosis, Chase W. Mussard

Undergraduate Honors Theses

Atherosclerosis, characterized by the build-up of cholesterol, immune cells and cellular debris within arterial walls, is accelerated following myocardial infarction by poorly understood mechanisms. Ubiquitin, a small, well-studied intracellular protein involved in protein turnover via the proteasome pathway, has recently been shown to exert extracellular effects on cardiac myocytes, in vitro, and in mice undergoing myocardial remodeling. This study investigates the potential role of extracellular ubiquitin in atherosclerosis by determining its effects on two critical atherosclerotic processes: the migration of vascular smooth muscles cells and the uptake of modified LDL by monocyte/macrophages in foam cell formation. In the presence …

Investigation Of Novel Functions For Dna Damage Response And Repair Proteins In Escherichia Coli And Humans, Benjamin A. Hilton

Electronic Theses and Dissertations

Endogenous and exogenous agents that can damage DNA are a constant threat to genome stability in all living cells. In response, cells have evolved an array of mechanisms to repair DNA damage or to eliminate the cells damaged beyond repair. One of these mechanisms is nucleotide excision repair (NER) which is the major repair pathway responsible for removing a wide variety of bulky DNA lesions. Deficiency, or mutation, in one or several of the NER repair proteins is responsible for many diseases, including cancer. Prokaryotic NER involves only three proteins to recognize and incise a damaged site, while eukaryotic NER …

Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely

Electronic Theses and Dissertations

Pseudomonas aeruginosa produces N-(3-oxododecanoyl)-homoserine lactone (C12) as a quorum-sensing molecule that functions to facilitate bacteria-bacteria communication. C12 has also been reported to affect many aspects of human host cell physiology, including evoking cell death in various types of cells. However, the signaling pathway(s) leading to C12-triggerred cell death remains unclear. To clarify cell death signaling induced by C12, we examined mouse embryonic fibroblasts (MEFs) deficient in one or more caspases. Our data indicate that, unlike most apoptotic inducers, C12 evokes a novel form of apoptosis in cells, probably through the direct induction of mitochondrial membrane permeabilization. Previous studies indicate that …

Developing And Using Methyl-Specific Antibodies To Study The Biological Roles Of Arginine Methylation, Vidyasiri Vemulapalli

Dissertations and Theses (Open Access)

Arginine residues can be modified in three different ways to produce asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and monomethylarginine (MMA). These modifications are catalyzed by a family of nine protein arginine methyltransferases (PRMT1-9), which are of three types (I, II, and III). The majority of Type I enzymes asymmetrically dimethylate Glycine- and Arginine-rich (GAR) motifs, except for PRMT4, which methylates Proline-, Glycine-, and Methionine-rich (PGM) motifs. The same substrates (GAR or PGM motifs) can also be dimethylated by PRMT5 in a symmetric fashion. However, it is not clear whether there are dedicated residues within these motifs for ADMA and SDMA, …

The Roles Of Malt1 In Nf-Κb Activation And Solid Tumor Progression, Deng Pan

Dissertations and Theses (Open Access)

The transcription factor NF-κB plays a central role in many aspects of biological processes and diseases, such as inflammation and cancer. Although it has been suggested thatNF-κB is critical in tumorigenesis and tumor progression, the molecular mechanism by which NF-κB is activated in solid tumor remains largely unknown. In the current work, we focus on growth factor receptor-induced NF-κB activation and tumor progression, including epidermal growth factor receptor (EGFR)-induced NF-κB in lung cancer and heregulin receptor (HER2)-induced NF-κB in breast cancer. We found that Mucosa-associated lymphoma translocation protein 1 (MALT1), also known as paracaspase, is required for EGFR-induced NF-κB activation …

The Ccaat-Binding Factor Dependent Regulation Of The Oxidative Stress Response In Candida Albicans, Ananya Chakravarti

Graduate Theses and Dissertations

The success of Candida albicans as an opportunistic human pathogen has been attributed to several factors, including the ability to survive in limiting iron environments and the ability to evade the respiratory burst of human macrophages and neutrophils. The goal of this research is to elucidate the role of the CCAAT-binding factor in the oxidative stress response of Candida albicans. Prior whole genome microarray studies performed in our lab compared the gene expression of a wild type Candida albicans strain versus a hap5Δ strain under iron-limiting growth conditions. Among the differentially regulated genes, CTA1, encoding catalase, had a four-fold higher …

Nonreplicative Dna Helicases Involved In Maintaining Genome Stability, Salahuddin Syed

USF Tampa Graduate Theses and Dissertations

Double-strand breaks and stalled forks arise when the replication machinery encounters damage from exogenous sources like DNA damaging agents or ionizing radiation, and require specific DNA helicases to resolve these structures. Sgs1 of Saccharomyces cerevisiae is a member of the RecQ family of DNA helicases and has a role in DNA repair and recombination. The RecQ family includes human genes BLM, WRN, RECQL4, RECQL1, and RECQL5. Mutations in BLM, WRN, and RECQL4 result in genetic disorders characterized by developmental abnormalities and a predisposition to cancer. All RecQ helicases have common features including a …

Axonal Transport And Life Cycle Of Mitochondria In Parkinson's Disease Model, Hyun Sung

Open Access Dissertations

In neurons, normal distribution and selective removal of mitochondria are essential for preserving compartmentalized cellular function. Parkin, an E3 ubiquitin ligase associated with familial Parkinson’s disease, has been implicated in mitochondrial dynamics and removal. However, it is not clear how Parkin plays a role in mitochondrial turnover in vivo, and whether the mature neurons possess a compartmentalized Parkin-dependent mitochondrial life cycle. Using the live Drosophila nervous system, here, I investigate the involvement of Parkin in mitochondrial dynamics; organelle distribution, morphology and removal. Parkin deficient animals displayed less number of axonal mitochondria without disturbing organelle motility behaviors, morphology and metabolic state. …

Fipronil Promotes Adipogenesis Via Ampkα-Mediated Pathway In 3t3-L1 Adipocytes, Quancai Sun, Jeremy Yang, Kyong-Sup Yoon, John M. Clark, Yeonhwa Park

SIUE Faculty Research, Scholarship, and Creative Activity

Emerging evidence suggests that organochlorine, organophosphorus and neonicotinoid insecticide exposure may be linked to the development of obesity and type 2 diabetes. However, there is no knowledge of the potential influence of fipronil, which belongs to the phenylpyrazole chemical family, on obesity. Thus, the goal of this study was to determine the role of fipronil in adipogenesis using 3T3-L1 adipocytes. Fipronil treatment, at 10 mM, increased fat accumulation in 3T3-L1 adipocytes as well as promoted key regulators of adipocyte differentiation (CCAAT/enhancer-binding protein α and peroxisome proliferator-activated receptor gamma-γ), and key regulators of lipogenesis (acetyl-CoA carboxylase and fatty acid synthase). The …

The Glucose Metabolite Methylglyoxal Inhibits Expression Of The Glucose Transport Genes By Inactivating The Cell Surface Glucose Sensors Rgt2 And Snf3 In Yeast, Adhiraj Roy, Salman Hashmi, Zerui Li, Angela Dement, Kyu Hong Cho, Jeong-Ho Kim

Biochemistry and Molecular Medicine Faculty Publications

Methylglyoxal (MG) is a cytotoxic by-product of glycolysis. MG has inhibitory effect on the growth of cells ranging from microorganisms to higher eukaryotes, but its molecular targets are largely unknown. The yeast cell-surface glucose sensors Rgt2 and Snf3 function as glucose receptors that sense extracellular glucose and generate a signal for induction of expression of genes encoding glucose transporters (HXTs). Here we provide evidence that these glucose sensors are primary targets of MG in yeast. MG inhibits the growth of glucose-fermenting yeast cells by inducing endocytosis and degradation of the glucose sensors. However, the glucose sensors with mutations …

Global Regulator Of Virulence A (Grva) Coordinates Expression Of Discrete Pathogenic Mechanisms In Enterohemorrhagic Escherichia Coli Through Interactions With Gadw-Gade, Jason K. Morgan, Ronan K. Carroll, Carly M. Harro, Khoury W Vendura, Lindsey N. Shaw, James T. Riordan

Molecular Biosciences Faculty Publications

UNLABELLED: Global regulator of virulence A (GrvA) is a ToxR-family transcriptional regulator that activates locus of enterocyte effacement (LEE)-dependent adherence in enterohemorrhagic Escherichia coli (EHEC). LEE activation by GrvA requires the Rcs phosphorelay response regulator RcsB and is sensitive to physiologically relevant concentrations of bicarbonate, a known stimulant of virulence systems in intestinal pathogens. This study determines the genomic scale of GrvA-dependent regulation and uncovers details of the molecular mechanism underlying GrvA-dependent regulation of pathogenic mechanisms in EHEC. In a grvA-null background of EHEC strain TW14359, RNA sequencing analysis revealed the altered expression of over 700 genes, including the downregulation …

Decorin As A Multivalent Therapeutic Agent Against Cancer., Thomas Neill, Liliana Schaefer, Renato V. Iozzo

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Decorin is a prototypical small leucine-rich proteoglycan that epitomizes the multifunctional nature of this critical gene family. Soluble decorin engages multiple receptor tyrosine kinases within the target-rich environment of the tumor stroma and tumor parenchyma. Upon receptor binding, decorin initiates signaling pathways within endothelial cells downstream of VEGFR2 that ultimately culminate in a Peg3/Beclin 1/LC3-dependent autophagic program. Concomitant with autophagic induction, decorin blunts capillary morphogenesis and endothelial cell migration, thereby significantly compromising tumor angiogenesis. In parallel within the tumor proper, decorin binds multiple RTKs with high affinity, including Met, for a multitude of oncosuppressive functions including growth inhibition, tumor cell …