Molecular Biology Commons^™

Epitranscriptomic Regulation In Breast Cancer And Pcb-Induced Liver Disease., Belinda Petri

Electronic Theses and Dissertations

Post-transcriptional RNA modifications including N6-methyladenosine (m6A) regulate mRNA stability, splicing, and translation. My research examined m6A in two disease models: breast cancer (BCa) and non-alcoholic fatty liver disease (NAFLD). Acquired resistance to endocrine therapies (ET) develops in approximately 20% of BCa patients with estrogen receptor α positive (ER+) tumors following treatment. The mechanisms by which tumor cells evade ET are not completely understood. Using a cell line model, we investigated the role of an m6A reader protein, HNRNPA2B1 (A2B1) that is upregulated in ET-resistant ER+ BCa cells. Stable overexpression of A2B1 in ET-sensitive MCF-7 cells (MCF-7-A2B1), results in ET resistance, …

Utilizing Crispr Cas9 To Visualize Dopamine Receptors In Caenorhabditis Elegans, Lauren Michelle Velasquez

Electronic Theses, Projects, and Dissertations

Dopamine (DA) is a neurotransmitter with imperative implications in many functions including movement, reward, and cognition. Studying the pathways of dopaminergic neurons at multiple levels allows us to understand the ways in which these systems can go wrong. We study dopamine in a model system such as the worm Caenorhabditis elegans because of its relatively simple and well-characterized nervous system. DA is involved in regulating chemosensory behaviors in worms. The purpose of this research project is to definitively answer the following question: Are the dopamine receptors DOP-1 and DOP-4 expressed in chemosensory neurons? Previous reporter assays show that neither of …

Role Of Short Interspersed Nuclear Elements (Sines) Of Maternally Imprinted Microrna Clusters In Hemochorial Placental Antiviral Immunity, Ishani Wickramage

USF Tampa Graduate Theses and Dissertations

The evolution of hemochorial placentas in which the fetal trophoblast is bathed in maternal blood has vastly improved fetal development and survival in primates and rodents, due to the enhanced efficiency of nutrient, gas and waste exchange between the mother and the fetus. However, the extensive contact between the fetal tissues and maternal blood in these placentas also poses an increased risk of vertical transmission of pathogens such as viruses from the mother to the fetus. In response to this selection pressure, hemochorial placentas have evolved robust defense mechanisms to protect the immunologically naive fetus. Unlike somatic cells that require …

Study Of Polytopic Membrane Protein Topological Organization As A Function Of Membrane Lipid Composition, Takefumi Morizumi, Kyumhyuk Kim, Hai Li, Elena G Govorunova, Oleg A Sineshchekov, Yumei Wang, Lei Zheng, Éva Bertalan, Ana-Nicoleta Bondar, Azam Askari, Leonid S Brown, John L Spudich, Oliver P Ernst

Faculty, Staff and Student Publications

Kalium channelrhodopsin 1 from Hyphochytrium catenoides (HcKCR1) is a light-gated channel used for optogenetic silencing of mammalian neurons. It selects K+ over Na+ in the absence of the canonical tetrameric K+ selectivity filter found universally in voltage- and ligand-gated channels. The genome of H. catenoides also encodes a highly homologous cation channelrhodopsin (HcCCR), a Na+ channel with >100-fold larger Na+ to K+ permeability ratio. Here, we use cryo-electron microscopy to determine atomic structures of these two channels embedded in peptidiscs to elucidate structural foundations of their dramatically different cation selectivity. Together with structure-guided mutagenesis, we show that K+ versus Na+ …

Proteomic Approaches To Identify Unique And Shared Substrates Among Kinase Family Members, Charles Lincoln Howarth

Dartmouth College Ph.D Dissertations

Protein phosphorylation is a reversible post-translational modification that is a critical component of almost all signaling pathways. Kinases regulate substrate proteins through phosphorylation, and nearly all proteins are phosphorylated to some extent. Crucially, breakdown in phosphorylation signaling is an underlying factor in many diseases, including cancer. Understanding how phosphorylation signaling mediates cellular pathways is crucial for understanding cell biology and human disease.

Targeted protein degradation (TPD) is a strategy to rapidly deplete a protein of interest (POI) and is applicable to any gene that is amenable to CRISPR-Cas9 editing. One TPD approach is the auxin-inducible degron (AID) system, which relies …

Loss Of Pml Nuclear Bodies In Familial Amyotrophic Lateral Sclerosis-Frontotemporal Dementia, Francesco Antoniani, Marco Cimino, Laura Mediani, Jonathan Vinet, Enza M. Verde, Valentina Secco, Alfred Yamoah, Priyanka Tripathi, Eleonora Aronica, Maria Elena Cicardi, Davide Trotti, Jared Sterneckert, Anand Goswami, Serena Carra

Farber Institute for Neuroscience Faculty Papers

Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD) are two neurodegenerative disorders that share genetic causes and pathogenic mechanisms. The critical genetic players of ALS and FTD are the TARDBP, FUS and C9orf72 genes, whose protein products, TDP-43, FUS and the C9orf72-dipeptide repeat proteins, accumulate in form of cytoplasmic inclusions. The majority of the studies focus on the understanding of how cells control TDP-43 and FUS aggregation in the cytoplasm, overlooking how dysfunctions occurring at the nuclear level may influence the maintenance of protein solubility outside of the nucleus. However, protein quality control (PQC) systems that maintain protein homeostasis comprise …

Structural Diversity And Stress Regulation Of The Plant Immunity-Associated Calmodulin-Binding Protein 60 (Cbp60) Family Of Transcription Factors In Solanum Lycopersicum (Tomato), Vanessa Shivnauth, Sonya Pretheepkumar, Eric J. R. Marchetta, Christina A. M. Rossi, Keaun Amani, Christian Castroverde

Biology Faculty Publications

Cellular signaling generates calcium (Ca2+) ions, which are ubiquitous secondary messengers decoded by calcium-dependent protein kinases, calcineurins, calreticulin, calmodulins (CAMs), and CAM-binding proteins. Previous studies in the model plant Arabidopsis thaliana have shown the critical roles of the CAM-BINDING PROTEIN 60 (CBP60) protein family in plant growth, stress responses, and immunity. Certain CBP60 factors can regulate plant immune responses, like pattern-triggered immunity, effector-triggered immunity, and synthesis of major plant immune-activating metabolites salicylic acid (SA) and N-hydroxypipecolic acid (NHP). Although homologous CBP60 sequences have been identified in the plant kingdom, their function and regulation in most species remain unclear. In …

High-Resolution Cryo-Em Structure Of The Pseudomonas Bacteriophage E217, Fenglin Li, Chun-Feng Hou, Ravi K. Lokareddy, Ruoyu Yang, Francesca Forti, Federica Briani, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

E217 is a Pseudomonas phage used in an experimental cocktail to eradicate cystic fibrosis-associated Pseudomonas aeruginosa. Here, we describe the structure of the whole E217 virion before and after DNA ejection at 3.1 Å and 4.5 Å resolution, respectively, determined using cryogenic electron microscopy (cryo-EM). We identify and build de novo structures for 19 unique E217 gene products, resolve the tail genome-ejection machine in both extended and contracted states, and decipher the complete architecture of the baseplate formed by 66 polypeptide chains. We also determine that E217 recognizes the host O-antigen as a receptor, and we resolve the N-terminal portion …

Defining A Factor-Induced Signaling Signature For Endothelial Tubulogenesis, Sprouting, And Pericyte Recruitment, Prisca Kuanting Lin

USF Tampa Graduate Theses and Dissertations

Endothelial cells (ECs) form the inner lining of blood capillary walls. Our laboratory has developed a serum-free, defined Factor system that allows for human ECs to sprout, form lumens and tube networks, recruit pericytes, and induce capillary basement membrane deposition in 3D extracellular matrices. We have shown that the Factor system drives morphogenesis through the activation of multiple signaling pathways; however, we do not know if all factors in the Factor system are needed to induce maximal EC morphogenesis. If so, we have yet to identify why the Factors are critical to the model other than that they induce activation …

Fibrosis-The Tale Of H3k27 Histone Methyltransferases And Demethylases, Morgan D. Basta, Svetlana Petruk, Alexander Mazo, Janice L. Walker

Department of Biochemistry and Molecular Biology Faculty Papers

Fibrosis, or excessive scarring, is characterized by the emergence of alpha-smooth muscle actin (αSMA)-expressing myofibroblasts and the excessive accumulation of fibrotic extracellular matrix (ECM). Currently, there is a lack of effective treatment options for fibrosis, highlighting an unmet need to identify new therapeutic targets. The acquisition of a fibrotic phenotype is associated with changes in chromatin structure, a key determinant of gene transcription activation and repression. The major repressive histone mark, H3K27me3, has been linked to dynamic changes in gene expression in fibrosis through alterations in chromatin structure. H3K27-specific homologous histone methylase (HMT) enzymes, Enhancer of zeste 1 and 2 …

Enhanced Bypass Of Pd-L1 Translation Reduces The Therapeutic Response To Mtor Kinase Inhibitors, Yanan Cao, Qing Ye, Murong Ma, Qing-Bai She

Markey Cancer Center Faculty Publications

Increased PD-L1 expression in cancer cells is known to enhance immunosuppression, but the mechanism underlying PD-L1 upregulation is incompletely characterized. We show that PD-L1 expression is upregulated through internal ribosomal entry site (IRES)-mediated translation upon mTORC1 inhibition. We identify an IRES element in the PD-L1 50-UTR that permits cap-independent translation and promotes continuous production of PD-L1 protein despite effective inhibition of mTORC1. eIF4A is found to be a key PD-L1 IRES-binding protein that enhances PD-L1 IRES activity and protein production in tumor cells treated with mTOR kinase inhibitors (mTORkis). Notably, treatment with mTORkis in vivo elevates PD-L1 levels and reduces …

Messes: Software For Transforming Messy Research Datasets Into Clean Submissions To Metabolomics Workbench For Public Sharing, P. Travis Thompson, Hunter N. B. Moseley

Markey Cancer Center Faculty Publications

In recent years, the FAIR guiding principles and the broader concept of open science has grown in importance in academic research, especially as funding entities have aggressively promoted public sharing of research products. Key to public research sharing is deposition of datasets into online data repositories, but it can be a chore to transform messy unstructured data into the forms required by these repositories. To help generate Metabolomics Workbench depositions, we have developed the MESSES (Metadata from Experimental SpreadSheets Extraction System) software package, implemented in the Python 3 programming language and supported on Linux, Windows, and Mac operating systems. MESSES …

The Metabolomics Workbench File Status Website: A Metadata Repository Promoting Fair Principles Of Metabolomics Data, Christian D. Powell, Hunter N. B. Moseley

Markey Cancer Center Faculty Publications

Background: An updated version of the mwtab Python package for programmatic access to the Metabolomics Workbench (MetabolomicsWB) data repository was released at the beginning of 2021. Along with updating the package to match the changes to MetabolomicsWB’s ‘mwTab’ file format specification and enhancing the package’s functionality, the included validation facilities were used to detect and catalog file inconsistencies and errors across all publicly available datasets in MetabolomicsWB.

Results: The MetabolomicsWB File Status website was developed to provide continuous validation of MetabolomicsWB data files and a useful interface to all found inconsistencies and errors. This list of detectable issues/errors include format …

Exploring The Interactions Between Sars-Cov-2 And Host Proteins, Sojan Shrestha

School of Biological Sciences: Dissertations, Theses, and Student Research

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the current pandemic, Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 is considered to be of zoonotic origin; it originated in non-human animals and was transmitted to humans. Since the early stage of the pandemic, however, the evidence of transmissions from humans to animals (reverse zoonoses) has been found in multiple animal species including mink, white-tailed deer, and pet and zoo animals. Furthermore, secondary zoonotic events of SARS-CoV-2, transmissions from animals to humans, have been also reported. It is suggested that non-human hosts can act as SARS-CoV-2 reservoirs where accumulated …

Functional Analysis Of The Gamma-Aminobutyric Acid Type A Receptor Subunit Alpha-1 (Gabra1) Gene During Zebrafish Development., Nayeli Gabriela Reyes-Nava

Open Access Theses & Dissertations

The GABRA1 gene encodes for the alpha-1 (α1) subunit of the Gamma-Aminobutyric acid type A receptor (GABAAR), which are the primary modulators of synaptic inhibition in the central nervous system (CNS). Alpha-1 subunits are essential for maintaining the normal function of native receptors and contribute to over 60% of all GABAARs in the CNS. Remarkably, a broad spectrum of neurodevelopmental and epilepsy-associated disorders have been linked with mutations in the GABRA1 gene. However, the developmental, behavioral, and molecular mechanisms underlying GABRA1-associated epileptic disorders remain to be fully understood. Hence, the overarching goal of this dissertation is to investigate the behavioral …

Novel Roles Of The Blm Syndrome Dna Helicase In Genome Maintenance And Mitochondrial Regulation, Brian B. Rodemoyer

USF Tampa Graduate Theses and Dissertations

Bloom syndrome (BS) is an extremely rare autosomal recessive genetic disorder caused by defects in the BLM gene. Patients with BS display a broad phenotypic spectrum including abnormally short stature, microcephaly, sun sensitivity, insulin resistance, perpetual oxidative stress, and a ~300-fold greater propensity for developing cancer than the general population. As such, BS patients typically do not live past their 20’s. The BLM gene encodes the BLM helicase, a member of the highly conserved RecQ family of 3’ to 5’ DNA helicases. Most of our cellular understanding of BLM is through its role in DNA damage repair through the homologous …

Withaferin A And Immune Checkpoint Blocker Therapy For The Treatment Of Non-Small Cell Lung Cancer, Roukiah Khalil

USF Tampa Graduate Theses and Dissertations

Lung cancer is the first cause of cancer-related deaths in both men and women with an overall five-year survival rate of 28%. Although immune checkpoint blockers (ICBs) are currently FDA-approved for the treatment of non-small cell lung cancer (NSCLC), only 17-20% of patients achieve durable responses by the induction of immunologic memory. The lack of response in most patients can be attributed to the tumor-intrinsic or tumor-extrinsic immune resistance mechanisms. A biomarker of importance is the Programmed Death Ligand-1 (PD-L1), as higher PD-L1 expression is usually associated with a better response to ICBs. Although studies have attempted to combine ICBs …

Regulation Of The Wnt/Wingless Receptor Lrp6/Arrow By The Deubiquitylating Complex Usp46, Zachary T. Spencer

Dartmouth College Ph.D Dissertations

The evolutionarily conserved Wnt/Wingless signal transduction pathway is critical for the proper development of all animals and implicated in numerous diseases in adulthood. Upon binding of the Wnt/Wingless ligand, a cascade of events culminates in inactivation of the destruction complex, a negative regulator of the pathway, and the subsequent formation of singalosomes which mediate pathway activation. A critical component of signalosome formation is the Wnt/Wingless receptor LRP6/Arrow. Upon canonical pathway activation, LRP6/Arrow undergoes activation via phosphorylation by several kinases and complexes with another Wnt/Wingless receptor Frizzled, along with several cytoplasmic components. While many studies have investigated the regulatory mechanisms of …

Exploring Strain Variation And Bacteriophage Predation In The Gut Microbiome Of Ciona Robusta, Celine Grace F. Atkinson

USF Tampa Graduate Theses and Dissertations

Current microbiome studies have shown that the maintenance of homeostasis betweenmicrobial populations (e.g. bacteria, viruses) and the host immune system (e.g. innate immune molecules) is necessary for balancing health and disease outcomes within the host. These studies most often utilize vertebrate models; however, research in this field can benefit from diverse model systems that facilitate our ability to conduct experiments to identify phylogenically conserved rules influencing homeostasis in the gut of animals. The Dishaw has developed the use of a filter-feeding marine invertebrate chordate, Ciona robusta, to model such fundamental interactions[1]–[6]. While most biological diversity and functional contribution within microbiomes …

Examining Parent-Of-Origin Effects On Transcription And Rna Methylation In Mediating Aggressive Behavior In Honey Bees (Apis Mellifera), Sean T. Bresnahan, Ellen Lee, Lindsay Clark, Rong Ma, Michael P. Markey, Juliana Rangel, Christina M. Grozinger, Hongmei Li-Byarlay

Biochemistry and Molecular Biology Faculty Publications

Conflict between genes inherited from the mother (matrigenes) and the father (patrigenes) is predicted to arise during social interactions among offspring if these genes are not evenly distributed among offspring genotypes. This intragenomic conflict drives parent-specific transcription patterns in offspring resulting from parent-specific epigenetic modifications. Previous tests of the kinship theory of intragenomic conflict in honey bees (Apis mellifera) provided evidence in support of theoretical predictions for variation in worker reproduction, which is associated with extreme variation in morphology and behavior. However, more subtle behaviors – such as aggression – have not been extensively studied. Additionally, the canonical epigenetic mark …