Molecular Biology Commons^™

Unraveling The Role Of Novel G5 Peptidase Family Proteins In Virulence And Cell Envelope Biogenesis Of Staphylococcus Aureus, Stephanie M. Marroquin

USF Tampa Graduate Theses and Dissertations

Virulence factors and the bacterial cell envelope are two important components in S. aureus pathogenesis and survival. More importantly, understanding the regulation of these cellular processes is crucial to further understanding and combating this successful pathogen. To date, numerous factors have been identified as playing a role in the regulation of Agr activity in S. aureus, including transcription factors, antisense RNAs, and host elements. Herein we investigate the product of SAUSA300_1984 (termed MroQ), a transmembrane G5 peptidase family protein, as a novel effector of this system. Using a USA300 mroQ mutant we observed a drastic reduction in proteolysis, hemolysis, and …

The Role Of Cpeb2 Alternative Splicing In Tnbc Metastasis, Shaun C. Stevens

USF Tampa Graduate Theses and Dissertations

Breast cancer is the second leading cause of cancer-related deaths for women in the U.S. Although the overall 5-year survival rate for breast cancer is 90%, this rate drops substantially for triple-negative breast cancer (TNBC) due to its high metastatic potential. Furthermore, there is a lack of targeted therapeutics for TNBC, and clinical trials have been largely unsuccessful. These characteristics validate the need for identifying novel therapeutic targets for the treatment of TNBC. The study of alternative splicing (AS) has emerged as a powerful tool to elucidate the molecular underpinnings driving cancer.

Our lab has identified cytoplasmic polyadenylation element-binding protein …

Investigation Of An Alternative Protocol For The Production Of Sars-Cov-2 Antigenic Proteins, Nichole Ninaltowski

USF Tampa Graduate Theses and Dissertations

With the COVID-19 pandemic showing no signs of slowing down, large-scale antigenic protein production is still needed for surveillance using serologic assays. From screening to vaccines to biotherapeutics, being able to produce the proteins for these assays is essential; however, the current gold standard method for producing SARS-CoV-2 spike proteins is prohibitively expensive for most research groups.

Alternative methods of transfecting mammalian cells to produce recombinant proteins that are relatively inexpensive have been used for years. Unlike the expensive, commercially available lipid-based methods, other established methods such as polyethyleneimine (PEI), are considerably easier, and cheaper to meet the needs of …

Cellular And Molecular Alterations Associated With Ovarian And Renal Cancer Pathophysiology, Ravneet Kaur Chhabra

USF Tampa Graduate Theses and Dissertations

Elucidating molecular alterations underlying tumor development and chemoresistance are critical to expand our understanding of the disease pathophysiology. This dissertation is focused on analyzing the cellular and molecular alterations associated with LPA-induced chemoresistance in clear cell renal cell carcinoma (ccRCC) cells and chronic iron-induced deregulation of miRNA expression in fallopian tube secretory epithelial cells (FTSECs).

Kidney cancer is one of the ten most common cancers worldwide with <15% survival rate at advanced stage (American Cancer Society). ccRCC is the most common type of kidney cancer and is described as a metabolic disease characterized by deregulated lipid metabolism leading to increased intracellular lipid droplets [9, 10]. The current molecular-targeted treatment strategies involve VEGF/VEGFR and mTOR inhibition [9, 12]. However, there are limitations to these approaches leading to the reduced efficacy and/or increased resistance in ccRCC cells [13, 14]. Therefore, it is important to decipher the factors involved in compromising the chemosensitivity in these cells.

Lysophosphatidic acid (LPA), a bioactive phospholipid, was previously reported to increase resistance against Sunitinib (VEGFR/PDGFR inhibitor) in ccRCC cells and to increase migration and invasion in various tumors [15-17]. In Chapter 3 of …

Screening Next-Generation Fluorine-19 Probe And Preparation Of Yeast-Derived G Proteins For Gpcr Conformation And Dynamics Study, Wenjie Zhao

USF Tampa Graduate Theses and Dissertations

GPCR regulates numerous diverse physiological processes relevant to diabetes, obesity, Alzheimer's diseases, and several central nervous system disorders and targets proteins in signaling pathways. It has created nearly 200 billion profits from its derivative drugs in 2018. There are near 400 structures of over 70 GPCRs have been resolved by X-ray crystallography, cryo-electron microscopy, and NMR spectroscopy. One of the current challenges that remain in the conformational transition and dynamics study using NMR spectroscopy is to obtain sufficient quantities of the G proteins and GPCRs. Pichia pastoris has shown its tremendous promise in expressing the GPCRs in a high yield, …

Evolution Of Targeted Therapy Resistance In Eml4-Alk Positive Non-Small Cell Lung Cancer, Robert Vander Velde

USF Tampa Graduate Theses and Dissertations

Targeted therapies have emerged as potent treatments that lead to the remission of many tumors. However, they rarely cure cancers in advanced, metastatic settings. This is due to the evolution of resistance, which in turn can be ascribed to the survival of small subpopulations of tolerant and/or resistant cells. Here we investigated the evolution of resistance to EML4-ALK inhibitors in non-small cell lung cancer (NSCLC) and demonstrated that resistance evolves gradually, from unique pre-treatment sub-populations, as multiple resistance mechanisms accumulate in a Darwinian fashion. Despite accumulating multiple changes, cells evolved, in parallel, toward similar inhibitor specific phenotypes. Evolving cells have …

Transcriptomic And Functional Investigation Of Bacterial Biofilm Formation, Brooke R. Nemec

USF Tampa Graduate Theses and Dissertations

Staphylococcus aureus and Acinetobacter baumannii are two highly successful human pathogens, which have adopted very different, but effective survival strategies. The success of S. aureus is attributed to the tight regulation of an arsenal of virulence factors. Conversely, A. baumannii lacks what would be considered traditional virulence factors and, instead, has developed a high tolerance for environmental stress, which allows it to persist in unforgiving environments, including nosocomial settings and the human body. One common characteristic of these two organisms is their proclivity for biofilm formation. Herein, we discuss the diverse mechanisms governing biofilm formation for A. baumannii and S. …

Cytoplasmic Polyadenylation Element Binding Protein 2 Alternative Splicing Regulates Hif1Α During Chronic Hypoxia, Emily M. Mayo

USF Tampa Graduate Theses and Dissertations

Chronic pulmonary hypoxia commonly results in the sustained expression of HIF1 (hypoxia inducible factor 1), a heterodimeric transcription factor, that, if unrestrained, can result in dramatic vasculature remodeling, pulmonary arterial hypertension, and right-sided heart failure. Together, these pulmonary disorders cost approximately $100 billion annually to treat due to the limited therapeutic targets designed to inhibit HIF1 expression. In this study, we introduce a translational regulator of HIF1 expression, known as Cytosolic polyadenylation element binding proteins 2 (CPEB2). Our lab has previously demonstrated in cancer cells that alternatively spliced isoforms of CPEB2 regulate the translation of the HIF1 oxygen-dependent subunit, HIF1α, …

Circrev1 Expression In Triple-Negative Breast Cancer, Meagan P. Horton

USF Tampa Graduate Theses and Dissertations

Triple-negative breast cancer (TNBC) comprises only 24% of breast cancer cases, yet is the second leading cause of cancer mortality in women due to its aggressive nature (1). This increase in mortality is due to the lack of receptors for three targetable growth factors (HER2, progesterone, and estrogen receptors). Our previous studies have indicated that these cancers are highly dysregulated in respect to alternative splicing. Hence, we undertook a study aimed at identifying circular RNAs (circRNAs) generated from back-splicing events which were dysregulated in TNBC. We have identified a novel circRNA transcript, circular REV1 (circREV1), which is upregulated in our …

Bone Microenvironmental Control Of Skeletal Malignancy, Chen Hao Lo

USF Tampa Graduate Theses and Dissertations

Bone is a common site of metastasis for many solid malignancies. Bone-metastatic cancers pose a significant clinical problem worldwide and is among the main causes for cancer patient morbidity and mortality. Patients with advanced bone-metastatic diseases often present with either osteolytic or osteogenic bone diseases as their cancers progress. These bone pathologies are products of the cancer co-opting the local bone remodeling stroma to yield important growth nutrients and factors. Unfortunately, skeletal metastases remain incurable and are fatal. Identifying and understanding the causal multicellular and molecular interactions underlying skeletal malignancies can yield crucial ideas for targeting and inhibiting disease progression. …