Biochemistry, Biophysics, and Structural Biology Commons^™

Cell Cycle Regulator Delays Pilus Production In Caulobacter Crescentus, Eli Johnson

Honors Theses

Caulobacter crescentus is a model bacterium for its unusual life cycle. This cycle features three distinct phases- the stalked stage, pre-divisional or actively dividing stage, and the swarmer stage, characterized by the production of a flagellum and multiple pili. Pili are necessary for cell attachment to surfaces and their reuptake into the cell can help drive the cell cycle forward. The gene that encodes the pilus subunit, pilA, is regulated by four binding sites for the cell cycle regulator CtrA. Previous research has determined that one site induces expression while two of the four sites inhibit expression. It is unknown …

Omani Camels From A Cultural And Genomics Perspective, Al Muatasim Al Zadjali

Electronic Theses and Dissertations

The Dromedarian camel, Camelus dromedarius, is native to the Arabian Peninsula, including the Sultanate of Oman. These camels are used for food, milk, as well as show and racing competitions. Despite their economic and cultural importance research on camels in Oman is limited. The goal of this study was to examine their genomic variation, relationship with camels in other parts of the Arabian Peninsula, and to determine if selective breeding has led to the establishment of distinct breeds in Oman. Information was compiled from multiple sources to produce a comprehensive review on the breeding, management, economic and cultural use, …

Impact Of Glycerophosphocholine Metabolism On Phenotypes In Saccharomyces Cerevisiae And Schizosaccharomyces Pombe, Victoria Hrach

Electronic Theses and Dissertations

Glycerophosphocholine (GPC) is an abundant metabolite in eukaryotes. In baker’s yeast, Saccharomyces cerevisiae, GPC can be produced via deacylation of the major membrane glycerophospholipid phosphatidylcholine (PC). My lab has identified a novel pathway to re-synthesize PC from GPC by acylating it at the sn-1 and sn-2 positions; this pathway has been termed the PC Deacylation-Reacylation Pathway (PC-DRP). We previously characterized the acyltransferase Gpc1 and its ability to synthesize one-tailed lyso-PC from GPC, as well as that noting that GPC1 is upregulated in inositol-free conditions and results in more saturated PC. Here, I add to this basic characterization by establishing …

Protein Oxidation In Aging And Alzheimer’S Disease Brain, Rukhsana Sultana, D. Allan Butterfield

Markey Cancer Center Faculty Publications

Proteins are essential molecules that play crucial roles in maintaining cellular homeostasis and carrying out biological functions such as catalyzing biochemical reactions, structural proteins, immune response, etc. However, proteins also are highly susceptible to damage by reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this review, we summarize the role of protein oxidation in normal aging and Alzheimer’s disease (AD). The major emphasis of this review article is on the carbonylation and nitration of proteins in AD and mild cognitive impairment (MCI). The oxidatively modified proteins showed a strong correlation with the reported changes in brain structure, carbohydrate …

Predicting The Pathway Involvement Of Metabolites Based On Combined Metabolite And Pathway Features, Erik D. Huckvale, Hunter N. B. Moseley

Markey Cancer Center Faculty Publications

A major limitation of most metabolomics datasets is the sparsity of pathway annotations for detected metabolites. It is common for less than half of the identified metabolites in these datasets to have a known metabolic pathway involvement. Trying to address this limitation, machine learning models have been developed to predict the association of a metabolite with a “pathway category”, as defined by a metabolic knowledge base like KEGG. Past models were implemented as a single binary classifier specific to a single pathway category, requiring a set of binary classifiers for generating the predictions for multiple pathway categories. This past approach …

The Interactions Of Centromeric Nucleosomes Elucidated By Atomic Force Microscopy, Shaun Filliaux

Theses & Dissertations

Nucleosomes are the fundamental unit of compaction for DNA in the genome. These positively charged proteins have two main types of nucleosomes: canonical (H3 containing) and centromere (CENP-A containing). The compacting of DNA allows for DNA to fit into the nucleus of cells, but creates a barrier for DNA accessibility for operations such as replication or transcription. Centromeric chromatin is a subset of chromatin structure and governs chromosome segregation. Compared to the bulk chromosome, centromeres are composed of H3 and CENP-A nucleosomes in which H3 histones is replaced by its homolog CENP-A histone. This results in nucleosomes with different structures, …

Homeobox A10: Regulator Of Pancreatic Cancer Progression And Survival, Sophia G. Kisling

Theses & Dissertations

Pancreatic ductal adenocarcinoma (PDAC) has one of the lowest incidence rates among all major cancers, yet it is disproportionally responsible for 8% of all cancer deaths. This high death rate is primarily attributed to the immunosuppressive tumor microenvironment and a lack of clinically relevant molecular targets. However, the underlying biology responsible for these poor outcomes remains obscure. To facilitate improved management of PDAC, an in-depth understanding of the molecular player(s) involved in PDAC aggressiveness is needed. Therefore, we analyzed the transcriptomic profiles of PDAC patients with long- and short-term survival and performed gene set enrichment analysis (GSEA), identifying a novel …

Cis-Regulatory Mechanisms Through Stages Of Erythroid Regenration, Yichao Zhou

Theses & Dissertations

Produced by steady state erythropoiesis, erythrocytes serve as vital regulators of metabolism and life by delivering oxygen to all the cells and tissues. Under acute anemia, steady state erythropoiesis is not sufficient to produce enough erythrocytes, leading to distinct mechanisms needed to regenerate large numbers of mature erythrocytes rapidly. Erythroid regeneration occurs in four stages: activation, expansion and differentiation, resolution, and post-resolution, according to the dynamics of erythrocyte numbers and progenitor activity. Erythroid regeneration throughout this timeline requires some critical extracellular cues, but the intrinsic molecular mechanisms needed to accelerate and decelerate the activity of erythroid progenitors in anemia and …

Novel Spirocyclic Dimer (Spid3) Displays Potent Preclinical Effects In Hematological Malignancies, Alexandria Eiken

Theses & Dissertations

Chronic lymphocytic leukemia (CLL) is a heterogeneous disease characterized by the accumulation of mature CD5⁺ B-cells in the peripheral blood, bone marrow, and secondary lymphoid tissues (e.g., spleen and lymph nodes).Despite the efficacy of front-line therapies, CLL is still an incurable disease, highlighting the need for development of novel therapeutics and further study of resistance mechanisms. Within the lymph node CLL tumor microenvironment (TME), there is an upregulation of gene signatures associated with B-cell receptor (BCR) and downstream nuclear factor kappa B (NF-κB) signaling compared to CLL cells found within the blood or bone marrow niches. Additionally, BCR signaling …

Mucin 5ac Modulates Cancer-Associated Fibroblast Heterogeneity Through Epigenetic Regulation, Rachel J. Kehrberg

Theses & Dissertations

Pancreatic cancer is characterized by a stroma component that comprises up to 90% of the tumor. Cancer-associated fibroblasts (CAFs) are a significant component of the stroma and contribute to cancer pathobiology through the secretion of extracellular matrix, growth factors, metabolites, and cytokines. CAFs are a highly heterogeneous population derived from various precursors, including adipose-derived and bone marrow- derived mesenchymal stem cells (AD-MSCs, BM-MSCs) and pancreatic stellate cells (PSCs). In this dissertation, we examine how mucin 5ac (Muc5ac) mediates the maturation of AD-MSCs, BM-MSCs, and PSCs into CAFs and the heterogeneity between CAFs derived from these various precursors. Muc5ac promotes the …

Targeting Lifr/C-Myc/Ddx21 Axis To Overcome Docetaxel Resistance In Prostate Cancer, Sushanta Halder

Theses & Dissertations

Resistance to chemotherapy poses a significant challenge in the treatment of advanced-stage prostate cancer (PCa), specifically with chemotherapy drugs like docetaxel (Doce), which is often employed after the failure of hormone therapy. However, 50-90% of PCa patients develop resistance to docetaxel within three years of post-chemo treatment, compounded by serious adverse side effects necessitating dose reductions. Various strategies are being investigated to address this issue, including identifying new therapeutic targets or mechanisms, developing novel combination therapies, and optimizing dosing regimens. In particular, our research is focused on uncovering the underlying mechanisms of resistance to docetaxel, such as the activation of …

Mucins: Drivers Of Cancer Cell And Microenvironment Crosstalk In Pancreatic Cancer, Xiaoqi Li

Theses & Dissertations

Mucins facilitate the pancreatic cancer (PC) initiation, progression, and metastasis. Among mucins, MUC4 has been reported to inhibit lymphokine-activated cell killing and induce the apoptosis of cytotoxic T-cells. Counterintuitively, MUC4 expression is upregulated by multiple T-cell-secreted cytokines, such as IFN-γ, IL-17, and stroma-secreted factors like retinoic acid. Previously, we have identified that nuclear receptor coactivator 3 (NCOA3) regulates the MUC1 and MUC4 expression by increasing chromatin accessibility and maintaining protein stability. However, the comprehensive crosstalk mediated by MUC4 in cancer cells and T-cells and how its upstream regulator, NCOA3, modifies the cancer cell-intrinsic behavior is still elusive. Here, we show …

Identifying The Molecular Determinants Of Lung Metastatic Adaptation In Prostate Cancer, Grace M. Waldron

Theses & Dissertations

Prostate cancer (PC) stands as the primary diagnosed cancer in men in the US at approximately 299,010 cases in 2024 and ranks second globally, posing a significant public health challenge. Clinical presentations vary widely, from indolent to aggressive forms, necessitating stage-specific treatment regimens. Understanding its metastatic nature is critical due to the impact of cancer cell dissemination on disease morbidity, with bone and visceral organs serving as key sites of metastasis. Despite bone metastasis being the most common site for metastasis, visceral metastases at sites such as the liver and lungs correlate with poorer survival, emphasizing the role of microenvironmental …

A Study Of The Effects Of An Amino Acid Residue On The Thermal Stability Of A Collagen Triple Helix In Varied Sequence Context, Ph, And Ionic Strength Of The Buffer, Zhenxun Xu

Theses and Dissertations

Collagen mimetic peptides are used broadly for collagen research and biomedical applications. Unlike the synthetic peptides obtained by solid phase chemical synthesis, recombinant peptides have more than 100 amino acid residues in length and are expressed in E. coli using designed genes. These longer peptides can offer improved, more native-like functions of native collagen for biomedical applications. One major challenge is the intrinsically low stability of native collagen, which has a melting temperature just above the physiological temperature of the organism. To understand how to enhance the thermostability of the peptides, I investigated the effects of amino acid sequences on …

Understanding The Non-Canonical Regulation Of Srebp In Aspergillus Fumigatus, Muhammad Abubakar Khan

Dartmouth College Ph.D Dissertations

Aspergillus fumigatus is an opportunistic fungal pathogen causing invasive pulmonary aspergillosis (IPA), with high mortality rates in immunocompromised individuals. Adaptation to the hypoxic microenvironment of IPA is crucial for fungal virulence. The transcription factor SrbA, a Sterol Regulatory Element-Binding Protein (SREBP) homolog, plays a key role in this hypoxic response and regulates genes involved in hypoxic growth, sterol biosynthesis, and azole resistance, making it an attractive therapeutic target.

However, SrbA activation in A. fumigatus lacks critical components of the canonical SREBP pathway, such as SCAP, Site-1 protease (S1P), and Site-2 protease (S2P). Instead, the rhomboid protease RbdB, signal peptide peptidase …

Incorporating Solvent Effects In Dft: Insights From Cation Exchange In Faujasites, An T. Ta, Ayoub Daouli, R. Seaton Ullberg, Eric Fonseca, Vanessa Proust, Agnès Grandjean, Richard G. Hennig, Hans Conrad Zur Loye, Michael Badawi, Simon R. Phillpot

Faculty Publications

Zeolites are versatile materials renowned for their extra-framework cation exchange capabilities, with applications spanning diverse fields, including nuclear waste treatment. While detailed experimental characterization offers valuable insight, density functional theory (DFT) proves particularly adept at investigating ion exchange in zeolites, owing to its atomic and electronic resolution. However, the prevalent occurrence of zeolitic ion exchange in aqueous environments poses a challenge to conventional DFT modeling, traditionally conducted in a vacuum. This study seeks to enhance zeolite modeling by systematically evaluating predictive differences across varying degrees of aqueous solvent inclusion. Specifically focusing on monovalent cation exchange in Na-X zeolites, we explore …

The Role Of Med13 In Proteaphagy, John Sauer, Brittany Friedson, Katrina Cooper

Rowan-Virtua Research Day

Regulation of proteasomes is important for adaptation to cellular stress. Previous studies have shown that following starvation stress, proteasomes are targeted for destruction by autophagy. However, how cells control proteasomes in response to nitrogen starvation remains unclear. This study delves into the intricate interplay between Med13, proteaphagy, and stress response regulation, aiming to elucidate their roles in cellular survival mechanisms. It focused on the highly conserved Cdk8 kinase module (CKM) of the Mediator complex a that plays a pivotal involvement in cellular signaling and gene regulation under stress conditions. During the investigation, we asked if the degradation of specific proteasome …

Fiddler Crab Gut Microbiomes As An Indicator For Eutrophication Due To Waste-Water Contamination In Estuaries, Madison L. Geraci

Honors Theses

Estuaries are unique biogeochemical zones in coastal systems that provide a myriad of ecological functions: providing habitat for critically important fishery species, diverse species of plants and animals, and contributing to nutrient cycling. Estuaries are vulnerable to anthropogenic stressors as they are intersections between marine and terrestrial communities and are often the hotspot of coastal development and activity. Estuarine sediments act as repositories for anthropogenic contaminants, including excess nutrient runoffs and waste-water pollution that can cause states of eutrophication. Microorganisms are sensitive to these environmental changes, presenting a unique opportunity of being useful bioindicators of environmental stress. Isolating microorganisms from …

Evaluation Of The Efficiency Of Muscle-Specific Promoters To Express Non-Endogenous Proteins In Skeletal Muscle, Gabrielle Bulliard, Made Harumi Padmaswari, Christopher E. Nelson

Biomedical Engineering Undergraduate Honors Theses

Gene therapies are emerging as powerful tools for treating genetic diseases and cancers, offering the potential for a permanent cure. Hemophilia B, affecting approximately 6,000 men in the U.S., results from a deficiency in coagulation factor IX protein (FIX), which is crucial for blood clotting. A substantial portion of patients, over 40%, suffer from severe hemophilia B, experiencing spontaneous, prolonged bleeding. Current prophylactic treatments involve frequent coagulation factor infusions, yet a curative approach would alleviate this burden. Gene editing technologies like CRISPR-Cas systems show promise for correcting genetic mutations, but the diverse nature of factor IX gene (F9) …

An Investigation Of Protein Arginine Methyltransferase 1 Substrate Recognition Through Ribonucleoprotein Modifications, Isabella Beverly Lonardo

Undergraduate Honors Capstone Projects

Just as humans need to communicate with each other, our cells have a series of processes that allows them to communicate from one to another. Protein Arginine Methyltransferase I is an enzyme that helps mediate cellular communication by selectively binding to target proteins and performing chemistry that has broad-reaching downstream effects. However, the mechanisms that underly PRMT1 selectivity have yet to be elucidated. This study uses alterations to a series of known targets, called ribonucleoproteins, to identify some of the characteristics that govern recognition by the PRMT1 enzyme. I have made significant progress in the creation, expression, and purification of …

Testing Resilience Of Microalgae Biofilms When Exposed To Hydrothermal Liquefaction Aqueous Phase, Davis Riley Haag

Undergraduate Honors Capstone Projects

There are a multitude of experimental and processing techniques in the bioenergy field that produce sustainable and carbon negative to carbon neutral methods of converting renewable resources into biologically based hydrocarbons. One example of a process is hydrothermal liquefaction (HTL) which specializes in converting wet biomass into biocrude oil. One reason that these processes are not used outside experimental testing is due to the high cost of performing these processes. There is potential to move these processes to larger scale testing and eventually industrial adaptation if breakthroughs are made to offset the process expenses. There is a waste product produced …

Intrinsically Disordered Proteins And Their Role In Biomolecular Condensates, Danielle Latham

All Dissertations

Proteins are biomacromolecules responsible for the functions of life. While classically proteins are thought to be well structured in order to perform a specific function, 50% of proteins within Eukaryotic cells contain intrinsically disordered regions (IDRs), regions with no well-defined structure. IDRs are often used for cell signaling, responding to external factors such as temperature changes or the presence of small molecules. To understand how IDRs can function without structure, it is important to understand the dynamics of such systems. Understanding IDR intramolecular and intermolecular interactions will shed light on IDR dynamics. Intramolecular interactions are first explored using fluorescence spectroscopy …

Establishing An Objective, Quantifiable Method For Detecting Erosive Tooth Wear, Camille Kita

Biological Sciences Undergraduate Honors Theses

This study aims to monitor and evaluate erosive tooth wear (ETW) by measurement of enamel surface thickness and texture in a clinical setting. The objective approach is fundamentally different from the standard subjective visual assessment that professionals in the dental field using the Basic Erosive Wear Evaluation (BEWE) method.

Twenty-nine hyposalivation and three control subjects were used in this longitudinal study, for a total of 597 samples (only 577 teeth were eligible for surface texture analysis) evaluated in a longitudinal study including both baseline and 12 month follow up surfaces. Each participant’s buccal surface of the tooth was first analyzed …

Assessment Of Culture Media Conditions For Bacteria/Macrophages Co-Cultures, Sage M. Luebbert

Chemistry & Biochemistry Undergraduate Honors Theses

Co-cultures are utilized as a tool in biology to measure immune responses to pathogens. This method involves a coordinated reaction between two populations, a bacterial biofilm of S.aureus and macrophages derived from THP-1 cells. The current state of the art prevents the continuous supply of nutrients and removal of waste products which causes macrophage death. This limits the time to collect samples and therefore the ability to measure proteins within the innate immune response. The time constraint is a major issue for long term co-culturing. This thesis aims to optimize the co-culturing process by developing a two-pump system to …

Tpm^Ph Derivative Of Tungsten; Hydrogen-Bonding In 7-Coordinate Cation Complex, Olivia Ryon Simcox

Undergraduate Honors Thesis Collection

Tpm^Ph, or tris(3-phenylpyrazolyl)methane reacts with tungsten hexacarbonyl to form the ligand-metal complex tris(3-phenylpyrazolyl)methane tungsten tricarbonyl, or Tpm^PhW(CO)3. The further complexes of Tpm^PhW(CO)3 and Tpm^PhMo(CO)3 are not known. This project aims to explore how the addition of a phenyl substituent to the pyrazole ring on Tpm impacts the synthesis of [Tpm^PhW(CO)3I]+X– and [Tpm^PhW(CO)3H]+X–. The inclusion of this phenyl substituent may impact the possible hydrogen bonding of then hydrogen contained in the carbon-hydrogen bond. This work aims to explore the extent of hydrogen-bonding of the carbon-hydrogen bond of the Tpm^Ph ligand in cationic metal complexes.

Investigating The Modulation Of Metastasis By Dax-1 In Adrenal Carcinoma Cells, Aarya Mishra

Undergraduate Honors Theses

The nuclear hormone receptor (NHR), DAX-1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1), is important in adrenal and gonadal development as well as steroidogenesis. It is encoded by the NR0B1 gene and functions mainly as a transcriptional repressor. Classified as an orphan receptor within the NHR superfamily, DAX-1 has been shown to inhibit other NHRs including estrogen receptor, androgen receptor and steroidogenic factor 1. DAX-1 is found to be underexpressed in breast and prostate cancers and, specifically in prostate cancer, is believed to be a transcriptional repressor of genes that are involved in epithelial-mesenchymal transition …

Development Of Selective Rna Aptamers For Kainate Receptors, Samantha Ingenito

Legacy Theses & Dissertations (2009 - 2024)

Ionotropic glutamate receptors (iGluRs) play a major role in mediating the excitatoryfunctions in the central nervous system (CNS). iGluRs are ligand-gated ion channels that are activated when glutamate binds to the extracellular ligand binding domain, thereby leading to the opening of the ion channels. Three subtypes of iGluRs include kainate receptors, α-amino-3- hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors, and N-methyl-D-aspartate (NMDA) receptors. Abnormal and dysregulation of these receptors have cytotoxic effects for neurons and have been implicated in various neurological diseases. For instance, elevated expression of a key AMPA receptor subunit has been linked to conditions such as ALS, where cytotoxic levels …

Identifying Novel Therapeutics And Modifiers Of Myotonic Dystrophy Type 1, Jesus Alberto Frias

Legacy Theses & Dissertations (2009 - 2024)

The expansion of microsatellite repeats within the human genome has been identified as the cause of numerous hereditary diseases, including myotonic dystrophy (DM). DM is an autosomal dominant disease with a worldwide prevalence of ~1:8000 individuals. DM presents multisystemic symptoms such as myotonia, cardiac conduction defects, muscle wasting and weakness, insulin resistance, and cataracts. There are two genetically distinct, yet clinically similar types of DM: DM type 1 (DM1), caused by CTG repeat expansions in the 3’ UTR of the dystrophia myotonica protein kinase (DMPK) gene and DM type 2 (DM2), resulting from CCTG repeat expansions in the first intron …

A Phylogenetic Analysis Of The Population Dynamics Of A Captive Colony Of Diploptera Punctata., Nick Peterson

Theses/Capstones/Creative Projects

The unique milk production of Diploptera punctata makes this species a promising model species in entomology for studying the evolution of milk production and for insect endocrinology. Despite this, the genetic diversity of captive populations of the species is not well studied. To better evaluate the captive diversity and population dynamics of Diploptera punctata at UNO we extracted the DNA of 20 random individuals and amplified their DNA using 4 different primers before cleaning the amplified products and sequencing the genes of the samples for use in both individual and concatenated phylogenetic trees. Our results indicate the UNO colony of …

Exploring The Effects Of N,N-Dimethylbiguanide And Ω-3 Pufas On Muscle Stem Cell Differentiation, Enayah Alhshim

Graduate Theses and Dissertations

The impacts of omega-3 (ω-3) fatty acid and metformin hydrochloride (Met-HCl) on muscle stem cells differentiation, mimicking the fetal muscle development under gestational diabetes mellitus (GDM), were investigated. ω-3 fatty acids have been known for their ability to regulate adipogenic transcription factors such as Sterol Regulatory Element-Binding Protien (SREBPs) and Peroxisome Proliferator-Activated Receptors (PPARs). This regulation resulted in gene expression modification for lipid metabolism and adipocyte differentiation, thus preventing excessive fat accumulation. Additionally, emerging evidence suggested that ω-3 fatty acids may also exert direct effects on myogenic processes that influence muscle stem cells proliferation, differentiation, and maturation. Meanwhile, Met-HCl, an …