Molecular Biology Commons^™

Human 5’-Tailed Mirtrons Are Processed By Rnasep, Mohammad Farid Zia

Dissertations

Approximately a thousand microRNAs (miRNAs) are documented from human cells. A third appear to transit non-canonical pathways that typically bypass processing by Drosha, the dedicated nuclear miRNA producing enzyme. The largest class of non-canonical miRNAs are mirtrons which eschew Drosha to mature through spliceosome activity. While mirtrons are found in several configurations, the vast majority of human mirtron species are 5’-tailed. For these mirtrons, a 3’ splice site defines the 3’ end of their hairpin precursor while a “tail” of variable length separates the 5’ base of the hairpin from the nearest splice site. How this tail is removed is …

Salicylic Acid: A Key Regulator Of Redox Signalling 1 And Plant Immunity, Mohd Saleem, Qazi Fariddudin, Christian Castroverde

Biology Faculty Publications

In plants, the reactive oxygen species (ROS) formed during normal conditions are essential in regulating several processes, like stomatal physiology, pathogen immunity and developmental signaling. However, biotic and abiotic stresses can cause ROS over-accumulation leading to oxidative stress. Therefore, a suitable equilibrium is vital for redox homeostasis in plants, and there have been major advances in this research arena. Salicylic acid (SA) is known as a chief regulator of ROS; however, the underlying mechanisms remain largely unexplored. SA plays an important role in establishing the hypersensitive response (HR) and systemic acquired resistance (SAR). This is underpinned by a robust and …

A Conserved Structural Role For The Walker-A Lysine In P-Loop Containing Kinases, Fatlum Hajredini, Ranajeet Ghose

Publications and Research

Bacterial tyrosine kinases (BY-kinases) and shikimate kinases (SKs) comprise two structurally divergent P-loop containing enzyme families that share similar catalytic site geometries, most notably with respect to their Walker-A, Walker-B, and DxD motifs. We had previously demonstrated that in BY-kinases, a specific interaction between the Walker-A and Walker-B motifs, driven by the conserved “catalytic” lysine housed on the former, leads to a conformation that is unable to efficiently coordinate Mg²⁺•ATP and is therefore incapable of chemistry. Here, using enhanced sampling molecular dynamics simulations, we demonstrate that structurally similar interactions between the Walker-A and Walker-B motifs, also mediated by …

Neuron-Specific Mitochondrial Oxidative Stress Results In Epilepsy, Glucose Dysregulation And A Striking Astrocyte Response, Ruth E Fulton, Jennifer N Pearson-Smith, Christopher Q Huynh, Timothy Fabisiak, Li-Ping Liang, Stefanos Aivazidis, Brigit A High, Georgia Buscaglia, Timothy Corrigan, Robert Valdez, Takahiko Shimizu, Manisha N Patel

Faculty, Staff and Students Publications

Mitochondrial superoxide (O2.−) production is implicated in aging, neurodegenerative disease, and most recently epilepsy. Yet the specific contribution of neuronal O2.− to these phenomena is unclear. Here, we selectively deleted superoxide dismutase-2 (SOD2) in neuronal basic helix-loop-helix transcription factor (NEX)-expressing cells restricting deletion to a subset of excitatory principle neurons primarily in the forebrain (cortex and hippocampus). This resulted in nSOD2 KO mice that lived into adulthood (2-3 months) with epilepsy, selective loss of neurons, metabolic rewiring and a marked mitohormetic gene response. Surprisingly, expression of an astrocytic gene, glial fibrillary acidic protein (GFAP) was significantly increased relative …

Covid-19 In Silico Drug With Zingiber Officinale Natural Product Compound Library Targeting The Mpro Protein, Renadya Maulani Wijaya, Muhammad Aldino Hafidzhah, Viol Dhea Kharisma, Arif Nur Muhammad Ansori, Arli Aditya Parikesit

Makara Journal of Science

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a worldwide pandemic. Ginger (Zingiber officinale) is a rhizome, which is commonly used for culinary and medicinal purposes. In Indonesia, ginger is taken as traditional medicine by processing it into a drink known as jamu. The present study aimed to assess and evaluate the bioactive compounds in ginger that can be used in drug design for treating COVID-19. The crystal structure of the SARS-CoV-2 main protease (M^pro) was generated from a protein sequence database, i.e., Protein Data Bank, …

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 …

Mutations In Several Auxin Biosynthesis Genes And Their Effects On Plant Phenotypes In Arabidopsis, Gabriela Hernandez, Lauren Huebner, Bethany Karlin Zolman

Undergraduate Research Symposium

Auxins are important hormones in plants that regulate growth and development. Disruptions in the auxin biosynthesis pathway result in morphological changes in phenotypes in the model plant Arabidopsis thaliana, including differences in root and leaf formation. Mutations in the Tryptophan Aminotransferase of Arabidopsis (TAA1) and YUCCA (YUC4) genes interfere with the plant's ability to synthesize Indole-3-acetic acid (IAA), the primary auxin involved in plant development. IBR1 and IBR3 act in the multistep conversion of indole-3-butyric acid (IBA) to IAA. ILL2, IAR3, and ILR1 hydrolyze IAA-amino acid conjugates into free IAA. The goal of …

Mechanisms Of Substrate Recognition By The Cul3-Based E3 Ligase, Katia Graziella De Oliveira Rebola

Dissertations and Theses

Cul3-based E3 ligase is responsible for regulating a variety of cellular pathways, many of which are known to have profound effects on the proper function of multicellular organisms. Although progress over the past years has been truly impressive, our understanding of the mechanisms of E2 recruitment and selection by the BCR complex and all the roles that Cul3 plays on kidneys remains in its infancy. To explore these aspects, this dissertation aims to analyze the Cul3 complex using two different approaches: (1) We used the powerful tool of chimeric analysis to map the essential domain binding characteristics of Cul3 taking …

Aurora Kinase A Inhibition Reverses The Warburg Effect And Elicits Unique Metabolic Vulnerabilities In Glioblastoma, Trang T. T. Nguyen, Enyuan Shang, Chang Shu, Sungsoo Kim, Angeliki Mela, Nelson Humala, Aayushi Mahajan, Hee Won Yang, Hasan Orhan Akman, Catarina M. Quinzii, Guoan Zhang, Mike-Andrew Westhoff, Georg Karpel-Massler, Jeffrey N. Bruce, Peter Canoll, Markus D. Siegelin

Publications and Research

Aurora kinase A (AURKA) has emerged as a drug target for glioblastoma (GBM). However, resistance to therapy remains a critical issue. By integration of transcriptome, chromatin immunoprecipitation sequencing (CHIP-seq), Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), proteomic and metabolite screening followed by carbon tracing and extracellular flux analyses we show that genetic and pharmacological AURKA inhibition elicits metabolic reprogramming mediated by inhibition of MYC targets and concomitant activation of Peroxisome Proliferator Activated Receptor Alpha (PPARA) signaling. While glycolysis is suppressed by AURKA inhibition, we note an increase in the oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO), which was …

Complete Mitochondrial Genome Sequence Of The Gulf Coast Tick (Amblyomma Maculatum), Amanda E. Brenner, Rahul Raghavan

Biology Faculty Publications and Presentations

The complete circularized mitochondrial genome sequence of Amblyomma maculatum is 14,803 bp long. It encodes 13 protein coding genes, 2 rRNA genes, 22 tRNA genes, 2 tick box motifs, and 2 control regions. The gene arrangement and content are consistent with those of previously reported Metastriata tick mitochondrial genomes.

Study Of The Gain-Of-Function Mutant P53 And Parp1 In Triple-Negative Breast Cancer, Devon Lundine

Dissertations, Theses, and Capstone Projects

Cancer cells often lose expression of the p53 protein or express mutant forms of p53. Some of these mutant p53 proteins, called gain-of-function mutant p53, have gained oncogenic functions. Previously, our group observed mutant p53 R273H interacts with replicating DNA and upregulates the chromatin localization of several DNA replication factors including PCNA, MCM2-7, and PARP1 (termed the mtp53-PARP-MCM axis). In this thesis, we explore the contribution of mutant p53 and PARP1 in castration-resistant prostate cancer (mutant p53 P223L and V274F) and triple-negative breast cancer (mutant p53 R273H). In the castration-resistant prostate cancer cell line DU145, we examine two mutant p53 …

Understanding The Influence Of Zinc On Grain Cadmium Accumulation And Bioaccessibility In Rice, Michael A. Tavarez

Dissertations, Theses, and Capstone Projects

The effect of cadmium and zinc on mineral concentrations in three cultivars of rice

Interactions between the essential mineral zinc (Zn) and the toxic heavy metal cadmium (Cd) play an important role in regulating transport of both minerals to rice grains. Understanding these interactions is crucial for limiting cadmium and increasing zinc transfer to the food chain. Previous studies on the matter have had conflicting results suggesting synergistic and antagonistic relationships between the minerals. The goal of this work was to identify the effect of external cadmium and zinc on the uptake and translocation of both minerals from roots to …

The Structural And Functional Role Of Photosensing In Rgs-Lov Proteins, Zaynab Jaber

Dissertations, Theses, and Capstone Projects

Light provides organisms with energy and spatiotemporal information. To survive and adapt, organisms have developed the ability to sense light to drive biochemical effects that underlie vision, entrainment of circadian rhythm, stress response, virulence, and many other important molecularly driven responses. Blue-light sensing Light-Oxygen-Voltage (LOV) domains are ubiquitous across multiple kingdoms of life and modulate various physiological events via diverse effector domains. Using a small molecule flavin chromophore, the LOV domain undergoes light-dependent structural changes leading to activation or repression of these catalytic and non-catalytic effectors. In silico analyses of high-throughput genomic sequencing data has led to the marked expansion …

The Role Of Estrogen Receptor Alpha In Regulating Messenger Rna 3’ End Processing And Controlling Gene Expression In Breast Cancer Cells, Sophia Varriano

Dissertations, Theses, and Capstone Projects

Estrogen signaling regulates various physiological processes within the female reproductive, cardiovascular, immune, and central nervous systems and is predominantly mediated by estrogen receptors (ER), ERα and ERβ. Transcriptional regulation by ERs has been widely studied, where activated ERs bind either directly to target genes through binding to estrogen response elements or indirectly through interacting with other proteins, resulting in changes in gene expression. However, the potential role of factors involved in the estrogen signaling pathway in posttranscriptional regulation has not been extensively documented. As 70-80% of breast cancers (BCs) are identified as ER(+), studying how these factors, particularly ERα, regulates …

Dual Control Of One Component Signaling: Mechanistic And Structural Insights Into El222 Active States, Uthama Phani R. Edupuganti

Dissertations, Theses, and Capstone Projects

Photoreceptors play a crucial role in signal transduction as specialized proteins which sense light as environmental stimuli and transduce the signal to control of downstream functions. Here we focus our attention on one class of these proteins, the Light-Oxygen-Voltage (LOV) domain, which is sensitive to blue light via an internally-bound flavin chromophore. Since their initial discovery in plant phototropins, many details of their photochemistry, chromophore interactions, and use with a diverse set of functional effectors have been described. However, several key details, especially a comprehensive understanding of signaling mechanism and its regulation, still remain elusive due in part to the …

Oxydifficidin-Producing Bacillus Presents Novel Antimicrobial Activity Against Neisseria Gonorrhoeae Involving The Deda Protein, Jingbo Kan

Dissertations, Theses, and Capstone Projects

Bacterial human pathogens cause severe infectious diseases which are the second most common cause of death next to cancer and cardiovascular diseases in the world, especially in developing countries. Gonorrhea particularly, is the second most common sexually transmitted infection (STI) which is caused by the microorganism Neisseria gonorrhoeae (GC). Centers for Disease Control and Prevention (CDC) estimates that more than 1.6 million new gonorrhea cases emerged in USA in 2018 (“Detailed STD Facts - Gonorrhea” n.d.). Also, the WHO (World Health Organization) shows that gonorrhea is the most antibiotic resistant STI (“PAHO/WHO | Gonorrhea” n.d.), highlighting the shortage of efficient …

Conserved Regions Mediate Interactions Between Canonical Nox Domains, Akua Acheampong

Symposium of Student Scholars

NAPDH oxidase (NOXes) are membrane-bound enzymes that generate reactive oxygen species (ROS) that play a role in immune response and signaling. Misregulation of NOXes is implicated in various human pathologies. NOXes contain a catalytic core comprised of a heme-containing transmembrane (TM) domain and a cytoplasmic dehydrogenase (DH) domain that binds FAD and NADPH. Several conserved regions at the interface of the TM and DH domains in eukaryotic NOXes have been suggested to mediate enzyme function and activity. In 2017, researchers successfully purified SpNox, a bona fide NOX homolog from Streptococcus pneumoniae and verified its NOX properties. SpNox’s robust activity in …

High-Throughput Phenotyping Of Rice Grains Subjected To High Nighttime Temperature Stress, Shannon Shareice Cunningham

Student Theses and Dissertations

Rice grain size is affected by high nighttime temperature stress (HNT). Although studied in small subsets, the Rice Diversity Panel 1 has not been extensively studied to determine HNT effects on grain size. Accessions have been identified as tolerant and sensitive to HNT under greenhouse conditions (Dhatt et al., 2020). A high throughput phenotyping (HTPP) method and a PlantCV2 workflow were implemented in this work to determine grain dimensions. Seed area was found to be a good indicator of HNT tolerance with a coefficient of variation being 15%. Among tolerant accessions, seed area increased by an average of 1.57 mm2 …

Insights Into Halophilic Microbial Adaptation: Analysis Of Integrons And Associated Genomic Structures And Characterization Of A Nitrilase In Hypersaline Environments, Sarah Sonbol

Theses and Dissertations

Hypersaline environments are extreme habitats that can be exploited as biotechnological resources. Here, we characterized a nitrilase (NitraS-ATII) isolated from Atlantis II Deep brine pool. It showed higher thermal stability and heavy metal tolerance compared to a closely related nitrilase.

We also studied integrons in halophiles and hypersaline environments. Integrons are genetic platforms in which an integron integrase (IntI) mediates the excision and integration of gene cassettes at specific recombination sites. In order to search for integrons in halophiles and hypersaline metagenomes, we used a PCR-based approach, in addition to different bioinformatics tools, mainly IntegronFinder.

We found that integrons and …

Fgfr4 Glycosylation And Processing In Cholangiocarcinoma Promote Cancer Signaling, Andrew J. Phillips

Theses & Dissertations

Cholangiocarcinoma is a cancer of cholangiocytes, or epithelial cells lining the biliary tract. It is associated with a poor prognosis and additional therapeutic treatments are needed to help patients affected by this disease. Fibroblast growth factor receptor 4 (FGFR4) is receptor tyrosine kinase that is involved in various physiologic and pathologic processes. TCGA analysis of thirty different tumor types showed the highest FGFR4 mRNA levels in cholangiocarcinoma. At the protein level, FGFR4 was observed in the majority of cholangiocarcinomas screened and, higher levels were associated with a poorer prognosis. FGFR4 is an N-linked glycosylated receptor tyrosine kinase that we show …