Life Sciences Commons^™

Disease-Associated Mutation A554v Disrupts Normal Autoinhibition Of Dnmt1, Rebecca L. Switzer, Zach J. Hartman, Geoffrey R. Hewett, Clara F. Carroll

Faculty Journal Articles

DNA methyltransferase 1 (DNMT1) is the enzyme primarily responsible for propagation of the methylation pattern in cells. Mutations in DNMT1 have been linked to the development of adult-onset neurodegenerative disorders; these disease-associated mutations occur in the regulatory replication foci-targeting sequence (RFTS) domain of the protein. The RFTS domain is an endogenous inhibitor of DNMT1 activity that binds to the active site and prevents DNA binding. Here, we examine the impact of the disease-associated mutation A554V on normal RFTS-mediated inhibition of DNMT1. Wild-type and mutant proteins were expressed and purified to homogeneity for biochemical characterization. The mutation increased DNA binding affinity …

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 …

Migratory Material: Epigenetics & Weaving At The Us-Mexico Border, Valerie Navarrete

Masters Theses

Discourse often sutures the body shut, disallowing representations of identity to outgrow sociopolitical interests. This issue may originate from borders, but also from the unnamable pathology that generational colonial trauma transmits to the mind, body, and environment. Without a direct form of translatability, this thesis proposes a new materialism that deviates from any object-oriented ontology. Untethered and intra-active, epigenetics and weaving represent objects that transform typical ways of knowing and seeing. Their sensitivity to the environment, in addition to their mobility across generations of time, broaden the spatiotemporal loci of the body and its embodiment. Proposing new materials that expand …

New Dna Repair And Demethylation Functions In Uracil Dna Glycosylase Superfamily, Chenyan Chang

All Dissertations

Uracil-DNA glycosylase (UDG) superfamily, which consists of several groups of enzymes that recognize the damaged DNA bases and initiate the base excision repair (BER) pathway, is most important in dealing with DNA deamination and other base modifications. Thymine DNA glycosylase (TDG), which belongs to family 2 in the UDG superfamily, is able to specifically recognize and cleave the 5-methylcytosine (mC) oxidative derivatives including 5-formylcytosine (fC), 5-carboxylcytosine (caC), 5-hydromethyluracil (hmU) caused by active demethylation or DNA damage. My dissertation work is mainly focused on the fC and caC glycosylase activity within UDG superfamily. Chapter 1 is a general introduction to the …

Characterizing The Dynamic Localization Of Cmi In Early Drosophila Development, Asra Habibullah

Master's Theses

The COMPASS-like family of lysine methyltransferases, MLR/MLX complexes, are epigenetic regulators that are essential for normal development through the methylation of the fourth lysine residue on histone 3 (H3K4), a universal epigenetic mark associated with active transcription. This family of complexes is highly conserved from yeast to mammals and the genes encoding the human MLR complexes have been associated with various developmental diseases and cancers (Dingwall and Fagan, 2019). In D. melanogaster, the enzymatic methyltransferase core of this complex is composed of two proteins: Cara Mitad (Cmi, also known as Lpt) and Trithorax-related (Trr). Although these proteins have been shown …

Dna Methylation And The Response To Infection In Introduced House Sparrows, Melanie Gibson

Electronic Theses and Dissertations

Epigenetics is the study of molecular modification of a genome without changing its base pairs. The most studied type of epigenetic mechanism is DNA methylation, which is capable of turning a gene “on” or “off.” Epigenetic potential is the capacity to which an individual can have methylation on its genome. The more CpGs available, the greater the epigenetic potential. In invasive species, genetic variation has been observed to be paradoxical: not much of it exists on a genomic level, but epigenetically, phenotypic variation can occur. The focus on shift in gene expression in this study is on Toll-Like Receptor 4 …

Prenatal Choline Supplementation During Maternal Obesity Alters Offspring Response To Western Diets, Hunter W. Korsmo

Dissertations, Theses, and Capstone Projects

Maternal obesity has led to an increase in adverse offspring developmental outcomes and a greater risk for long-term metabolic diseases. Choline, a semi-essential nutrient, can be incorporated into phosphatidylcholine (PC) as well as sphingomyelin (SM) and donate its labile methyl group for the remethylation of homocysteine after choline is oxidized to betaine. Prenatal choline insufficiency has been related to maternal obesity and metabolic diseases, such as metabolic associated fatty liver disease (MAFLD). Choline may interact with maternal obesity to influence the programming offspring.

Chapter 1 presents an introduction of choline and the various clinical outcomes associated with choline supplementation during …

An Investigation Of Epigenetic Mechanisms Driving The Biology Of Head And Neck Squamous Cell Carcinoma, Scot Carson Callahan

Dissertations & Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide and is associated with significant morbidity and mortality. To date, the majority of work in the field has focused on genomic alterations such as mutations and copy number alterations. However, the clinical success of targeted therapies that exploit known genomic alterations, such as EGFR mutations, has remained mixed. Over the past decade, the importance of epigenetic regulators has come to the forefront, with the realization that many of these genes are mutated in cancer. Despite this realization, the role of epigenetics in regulating tumorigenesis, progression and …

Plant Homeodomain Finger Protein 20 (Phf20) And Its Homolog Phf20 Like 1 (Phf20l1) Define Two Distinct Non-Specific Lethal (Nsl) Complexes, Hieu Van, Hieu T. Van

Dissertations & Theses (Open Access)

Plant Homeodomain Finger Protein 20 (PHF20) and its homolog PHF20 Like 1 (PHF20L1) are known subunits of the Non-Specific Lethal (NSL) complex, which acetylates lysine residues on histone H4 and regulates gene expression. The current model assumes that PHF20 and PHF20L1 are present together in the NSL complex, although it has never been tested. Performing extensive biochemical analysis, we observed that PHF20 and PHF20L1 were exclusively and independently associated with the NSL complex. Our protein domain analysis showed that the C-termini of PHF20 and PHF20L1 are crucial for their interactions with the respective complexes. Furthermore, enrichment sites of PHF20 and …

Histone Post-Translational Modification Dysregulation Contributes To Toxicity In Amyotrophic Lateral Sclerosis Proteinopathy Models, Seth A. Bennett

Dissertations, Theses, and Capstone Projects

Amyotrophic Lateral Sclerosis (ALS) is the third most common adult onset neurodegenerative disorder worldwide. It is generally characterized by progressive paralysis starting at the limbs ultimately leading to death caused by respiratory failure. There is no cure and current treatments fail to slow the progression of the disease. As such, new treatment options are desperately needed. Epigenetic targets are an attractive possibility because they are reversible. Epigenetics refers to heritable changes in gene expression unrelated to changes in DNA sequence. Histone modifications, a main epigenetic mechanism, occur in many amino acid residues and include phosphorylation, acetylation, methylation as well as …

Enhancing Therapeutic Approaches For Melanoma Patients Targeting Epigenetic Modifiers., Maria Gracia-Hernandez, Zuleima Munoz, Alejandro Villagra

Biochemistry and Molecular Medicine Faculty Publications

Melanoma is the least common but deadliest type of skin cancer. Melanomagenesis is driven by a series of mutations and epigenetic alterations in oncogenes and tumor suppressor genes that allow melanomas to grow, evolve, and metastasize. Epigenetic alterations can also lead to immune evasion and development of resistance to therapies. Although the standard of care for melanoma patients includes surgery, targeted therapies, and immune checkpoint blockade, other therapeutic approaches like radiation therapy, chemotherapy, and immune cell-based therapies are used for patients with advanced disease or unresponsive to the conventional first-line therapies. Targeted therapies such as the use of BRAF and …

Unveiling Global Roles Of G-Quadruplexes And G4-22 In Human Genetics, Ruth Barros De Paula

Dissertations & Theses (Open Access)

G-quadruplexes are non-B DNA structures formed by four or more runs of repeated guanines that confer unique features to living organism’s genomes. These sequences are enriched in regulatory regions, such as promoters and 5’ UTRs, and have distinct regulatory roles in both health and disease states. Even though previous studies showed the impact of G4 in gene expression, none of them summarized the location-specific effect of G4. Also, there is no broad understanding about the most common G4 repeat in the human genome, named here as G4-22, and how it links to the evolution of mammals and their biology. In …

Discovery Of Novel Ubiquitin- And Methylation-Dependent Interactions Using Protein Domain Microarrays, Jianji Chen

Dissertations & Theses (Open Access)

Post-translational modifications (PTMs) drive signal transduction by interacting with "reader" proteins. Protein domain microarray is a high throughput platform to identify novel readers for PTMs. In this dissertation, I applied two protein domain microarrays identifying novel readers for histone H2Aub1 and H2Bub1, and H3TM K4me3. Ubiquitinations of histone H2A at K119 (H2Aub1) and histone H2B at K120 (H2Bub1) function in distinct transcription regulation and DNA damage repair pathways, likely mediated by specific "reader" proteins. There are only two H2Aub1-specific readers identified and no known H2Bub1-specific readers. Using a ubiquitin-binding domain microarray, I discovered the phospholipase A2-activating protein (PLAA) PFU domain …

Initial And Advanced Stages Of Microbiota Establishment Within The Tsetse Fly, Miguel Eduardo Medina Munoz

Graduate Theses, Dissertations, and Problem Reports

Symbiosis is a long-term physical association between two or more species, although little is known regarding its evolutionary origins, particularly at the genetic level. Tsetse flies are the vector of African trypanosomes, causative agents of Human and Animal African Trypanosomiases. Tsetse provide an ideal model for studying initial and advanced stages of symbiosis. Tsetse have a simple digestive tract microbiota primarily consisting of two bacteria; the ancient mutualist Wigglesworthia glossinidia and the recently acquired Sodalis glossinidius. This work presents a chronological study in evolutionary terms of the history of a microbial-insect association. First, I present concepts on symbiosis and …

Discrimination Of Monozygotic Twins Using Dna Methylation Levels Of One Cpg Site At Chromosome 3, Dino O. Robinson

Student Theses

Conventional STR typing, commonly used in forensics for human identification, poses a problem in criminal cases and paternity disputes involving monozygotic (MZ) twins because they share identical DNA sequences. To date, no routine method is available in forensics to differentiate between individuals of MZ pairs. Recently, epigenetic methods measuring differential DNA methylation patterns have been applied to MZ twin differentiation. In this study, we investigated the potential to identify MZ twins using a previously identified DNA methylation site in chromosome 3, cg18562578, in a sample of 129 MZ and 37 dizygotic (DZ) twin pairs. We used bisulfite converted saliva DNA …

10th Annual Postdoctoral Science Symposium, University Of Texas Md Anderson Cancer Center Postdoctoral Association

Annual Postdoctoral Science Symposium Abstracts

The Annual Postdoctoral Science Symposium (APSS) was initiated on August 4, 2011, by the MD Anderson Postdoctoral Association to provide a platform for talented postdoctoral fellows throughout the Texas Medical Center to present their work to a wider audience.

APSS is a scientific symposium organized by postdoctoral fellows from The University of Texas MD Anderson Cancer Center that welcomes submissions and presentations from postdoctoral fellows from all Texas Medical Center affiliated institutions and other Houston area institutions. The APSS provides a professional venue for postdoctoral scientists to develop, clarify and refine their research as result of formal reviews and critiques …

9th Annual Postdoctoral Science Symposium, University Of Texas Md Anderson Cancer Center Postdoctoral Association

Annual Postdoctoral Science Symposium Abstracts

The mission of the Annual Postdoctoral Science Symposium (APSS) is to provide a platform for talented postdoctoral fellows throughout the Texas Medical Center to present their work to a wider audience. The MD Anderson Postdoctoral Association convened its inaugural Annual Postdoctoral Science Symposium (APSS) on August 4, 2011.

The APSS provides a professional venue for postdoctoral scientists to develop, clarify, and refine their research as a result of formal reviews and critiques of faculty and other postdoctoral scientists. Additionally, attendees discuss current research on a broad range of subjects while promoting academic interactions and enrichment and developing new collaborations.

Understanding The Molecular And Cellular Functions Of Odd-Skipped Related 1 In Outflow Tract Development, Menglan Xiang

Theses and Dissertations

The cardiac outflow tract (OFT) is a transient conduit that connects the embryonic heart chambers to the vascular network. Transcription factor Osr1 promotes the proliferation and cell cycle progression of second heart field (SHF), an essential cell population that contribute to the developing OFT. In this study, we investigated the role of Osr1 in OFT development on cellular and molecular levels using a systems biology approach. We observed OFT rotation and elongation defects, as well as double-outlet right ventricle and overriding aorta as a result of SHF-specific deletion of Osr1. Using genetic inducible fate mapping, we showed that Osr1-expressing SHF …

Substituted Anthraquinones Represent A Potential Scaffold For Dna Methyltransferase 1-Specific Inhibitors, Rebecca L. Switzer, Jessica Medrano, David A. Reedel, Jill Weiss

Faculty Journal Articles

In humans, the most common epigenetic DNA modification is methylation of the 5-carbon of cytosines, predominantly in CpG dinucleotides. DNA methylation is an important epigenetic mark associated with gene repression. Disruption of the normal DNA methylation pattern is known to play a role in the initiation and progression of many cancers. DNA methyltransferase 1 (DNMT1), the most abundant DNA methyltransferase in humans, is primarily responsible for maintenance of the DNA methylation pattern and is considered an important cancer drug target. Recently, laccaic acid A (LCA), a highly substituted anthraquinone natural product, was identified as a direct, DNA-competitive inhibitor of DNMT1. …

Divergent Transcriptional Regulation Of Suppressors Of Cytokine Signaling Genes In Adipocytes, Paula Mota De Sa

LSU Doctoral Dissertations

The Janus Kinase - Signal Transducer and Activator of Transcription (JAK-STAT) signaling pathway transduces several signals crucial for development and homeostasis. Suppressors of cytokine signaling (SOCS) proteins control JAK-STAT signaling via a negative feedback loop. The transcription factor STAT5 is known to play a significant role in fat cell development and function, and several studies suggest that acetylation may affect STAT5 transcriptional activity. To test this hypothesis, we treated 3T3-L1 adipocytes with growth hormone (GH) to activate STAT5 in the presence or absence of histone deacetylase (HDAC) inhibitors. STAT5 acetylation levels were low in adipocytes and mostly unchanged by the …

Advanced Proteomic And Epigenetic Characterization Of Ethanol-Induced Microglial Activation, Jennifer Guergues Guergues

USF Tampa Graduate Theses and Dissertations

Microglia, the resident immune cells of the brain, can exhibit a broad range of activation phenotypes and have been implicated in several diseases and disorders of the central nervous system. Here, we described a method optimized for sensitive and rapid quantitative proteomic analysis of microglia that involves suspension trapping (S-Trap) for efficient and reproducible protein extraction from a microglial cell count expected from an individual mouse brain (~300K) while also simultaneously providing the first comprehensive proteomic characterization of a novel adult-derived mouse microglial cell line. This enhanced method was used throughout all subsequent works and was especially necessary when we …

Investigating The Role Of The Chromosome 19 Microrna Cluster In Human Trophoblast Differentiation And Infantile Hemangioma, Ezinne Francess Mong

USF Tampa Graduate Theses and Dissertations

Trophoblast differentiation and invasion is essential for normal implantation and establishment of the maternal-fetal interface, which allows for proper nutrient exchange and support of the fetus. For this to occur, cytotrophoblasts must undergo an epithelial to mesenchymal transition and differentiate into migratory and invasive extravillous trophoblasts (EVTs) that invade the maternal decidua and myometrium. Trophoblast differentiation, migration and invasion is highly regulated by a complex network of signaling pathways, adhesion molecules and transcription factors and is important for the remodeling of maternal spiral arteries from low flow, high resistance to high flow, low resistance vessels to allow optimal perfusion of …

Parp1 Is A Versatile Factor In The Regulation Of Mrna Stability And Decay, Elena A. Matveeva, Lein F. Mathbout, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

PARP1 is an abundant nuclear protein with many pleiotropic functions involved in epigenetic and transcriptional controls. Abundance of mRNA depends on the balance between synthesis and decay of a particular transcript. PARP1 binds RNA and its depletion results in increased expression of genes involved in nonsense-mediated decay, suggesting that PARP1 might be involved in mRNA stability. This is of interest considering RNA binding proteins play key roles in post-transcriptional processes in all eukaryotes. We tested the direct impact of PARP1 and PARylation on mRNA stability and decay. By measuring the half-lives of two PARP1-mRNA targets we found that the half-lives …

Coupling Of Parp1-Mediated Chromatin Structural Changes To Transcriptional Rna Polymerase Ii Elongation And Cotranscriptional Splicing, Elena A. Matveeva, Qamar M. H. Al-Tinawi, Eric C. Rouchka, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Background: Recently, we showed that PARP1 is involved in cotranscriptional splicing, possibly by bridging chromatin to RNA and recruiting splicing factors. It also can influence alternative splicing decisions through the regulation of RNAPII elongation. In this study, we investigated the effect of PARP1-mediated chromatin changes on RNAPII movement, during transcription and alternative splicing.

Results: We show that RNAPII pauses at PARP1–chromatin structures within the gene body. Knockdown of PARP1 abolishes this RNAPII pausing, suggesting that PARP1 may regulate RNAPII elongation. Additionally, PARP1 alters nucleosome deposition and histone post-translational modifications at specific exon–intron boundaries, thereby affecting RNAPII movement. Lastly, genome-wide analyses …

Bisthioether Stapled Peptides Targeting Polycomb Repressive Complex 2 Gene Repression, Gan Zhang

Dissertations, Theses, and Capstone Projects

Interactions between proteins play a key role in nearly all cellular process, and therefore, disruption of such interactions may lead to many different types of cellular dysfunctions. Hence, pathologic protein-protein interactions (PPIs) constitute highly attractive drug targets and hold great potential for developing novel therapeutic agents for the treatment of incurable human diseases. Unfortunately, the identification of PPI inhibitors is an extremely challenging task, since traditionally used small molecule ligands are mostly unable to cover and anchor on the extensive flat surfaces that define those binary protein complexes. In contrast, large biomolecules such as proteins or peptides are ideal fits …

The Role Of H3k4 Methyltransferases In Drosophila Memory, Nicholas Raun

Electronic Thesis and Dissertation Repository

Gene transcription required for long-term memory requires the modification of histones. However, there are still many uncertainties about the identity and spatial expression of genes regulated by histone modifications during memory related processes. In this project I examined the role of Drosophila melanogaster methyltransferases Set1 and trx in courtship memory. Genetic knockdown of Set1 and trx in the mushroom body (MB) revealed that Set1 was necessary for short- and long-term memory, while trx was only required for long-term memory. Transcriptional profiling of MBs following trx-knockdown revealed expression changes in MB-enriched genes and genes involved in RNA processing. Among the …

Role Of P300 Zz Domain In Chromatin Association And Histone Acetylation, Yongming Xue

Dissertations & Theses (Open Access)

Transcription is strictly regulated by numerous factors including transcription coactivators. The p300 protein and its close paralogue CREB-binding protein (CREBBP, aka CBP) are well-known transcriptional coactivators that have intrinsic lysine acetyltransferase activity. The functions of p300/CBP largely rely on their capabilities to bind to chromatin and to acetylate the histone substrates. However, the molecular mechanisms underlying the regulation of these processes are not fully understood.

Through combination of various biochemical, biophysical and molecular approaches, we show that the ZZ-type zinc finger (ZZ) domain of p300 functions as a histone reader that specifically binds the N-terminal tail of histone H3. Crystal …

Genetic And Epigenetic Investigations On Pulmonary Hypertension Syndrome In Meat Type- Chickens, Khaloud Alzahrani

Graduate Theses and Dissertations

This dissertation presents a collection of studies that investigate the genetic and epigenetic associations to ascites phenotype in broiler chickens. Ascites is a significant metabolic disease associated with fast-growing meat-type chickens (broilers) and is a terminal result of pulmonary hypertension syndrome PHS. It is a multi-factorial syndrome caused by interactions between genetic, physiological, environmental, and managemental factors. It was estimated that ascites accounts for losses of about US$1 billion annually worldwide and for over 25% of broilers mortality. Although traditional and molecular genetic methods in the selection and in performance improvements, has greatly reduced ascites frequency, yet it has not …

The Regulation Of Dna Methylation In Mammalian Development And Cancer, Nicolas Veland

Dissertations & Theses (Open Access)

DNA methylation is an essential epigenetic modification in mammals, as it plays important regulatory roles in multiple biological processes, such as gene transcription, maintenance of chromosomal structure and genomic stability, genomic imprinting, retrotransposon silencing, and X-chromosome inactivation. Dysregulation of DNA methylation is associated with various human diseases. For example, cancer cells usually show global hypomethylation and regional hypermenthylation, which have been implicated in genomic instability and tumor suppressor silencing, respectively. Although great progress has been made in elucidating the biological functions of DNA methylation over the last several decades, how DNA methylation patterns and levels are regulated and dysregulated is …

Investigation Of Alcohol-Induced Changes In Hepatic Histone Modifications Using Mass Spectrometry Based Proteomics, Crystina Leah Kriss

USF Tampa Graduate Theses and Dissertations

Alcohol liver disease (ALD) is a major health concern throughout the world. Currently, in the United States, 17 million people suffer from alcoholism, of which 1.4 million people are receiving treatment [1, 2]. The link between ethanol metabolism, reactive oxygen species (ROS) and liver injury in ALD has been well characterized over the last couple decades [3-10]. Ethanol metabolism relies on the availability of the cofactor NAD+ for the oxidation of ethanol into acetate, consequently causing alterations in redox potential. Redox dysfunction within the mitochondria can affect multiple pathways important in maintaining cellular homeostasis. Chapter 1 provides an introduction to …