Biochemistry Commons^™

Aryl Hydrocarbon Receptor Mediated Restoration Of Cytoglobin As A Treatment For Breast Cancer, Leah Kathleen Rowland

Loma Linda University Electronic Theses, Dissertations & Projects

Nearly 40,000 women die annually from breast cancer in the US. Clinically available targeted breast cancer therapy is ineffective in triple negative breast cancer (TNBC) subtypes, which lack expression of the estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2. TNBC carries a poor prognosis. Previous reports show that aryl hydrocarbon receptor (AhR) agonist 2-(4-amino-3-methylphenyl)- 5-fluorobenzothiazole (5F 203) selectively inhibits the growth of breast cancer cells including those of the TNBC subtype. In the current study, we determined that 5F 203 induces the expression of epigenetically silenced putative tumor suppressor gene cytoglobin (CYGB) and suppresses TNBC cell growth …

The Regulation Of Notch Signaling By Src Kinase And Polyphenolic Compounds, Bryce David Lafoya

Boise State University Theses and Dissertations

Cellular signaling pathways provide cells with the means to sense their environment and communicate with other cells. The Notch signaling pathway is comprised of a set of protein machines which work in unison to coordinate cellular processes in response to stimuli coming from neighboring cells and changing microenvironmental conditions. Notch signaling is an important mode of cellular communication which is crucial to many processes involved in development and disease. During Notch activation, information about the extracellular environment is fed into the cell and relayed to the nucleus through a number of biochemical processes. The information-rich messages carried by Notch signaling …

Characterization Of A Variant Of Tuberous Sclerosis Complex 2 And Its Interaction With Rheb, Sowmya Sivakumar

Graduate Theses and Dissertations

Protein-protein interactions are vital in maintaining proper function and homeostasis in cells. Some signaling pathways are regulated by G-proteins that work like switches to activate and deactivate pathways. Mutations in these proteins, their effectors or the interaction between proteins may cause dysregulation of signals that can lead to many diseases.

Rheb, Ras homology enriched in brain, is a Ras family GTPase that is vital in regulation of the mTOR (mammalian target of rapamycin) pathway that signals cell proliferation and growth. Due to the low intrinsic GTPase activity of Rheb, a GTPase activating protein (GAP), Tuberous Sclerosis Complex 2 (TSC2) down …

Electron Flow And Management In Living Systems: Advancing Understanding Of Electron Transfer To Nitrogenase, Rhesa N. Ledbetter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen is a critical nutrient for growth and reproduction in living organisms. Although the Earth's atmosphere is composed of ~80% nitrogen gas (N₂), it is inaccessible to most living organisms in that form. Biological nitrogen fixation, however, can be performed by microbes that harbor the enzyme nitrogenase. This enzyme converts N₂ into bioavailable ammonia (NH₃) and accounts for at least half of the "fixed" nitrogen on the planet. The other major contributor to ammonia production is the industrial Haber-Bosch process. While the Haber-Bosch process has made significant advances in sustaining the global food supply through …

Egfr Signaling From The Early Endosome., Julie A. Gosney

Electronic Theses and Dissertations

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is an integral component of proliferative signaling. When activated by a ligand at the plasma membrane, EGFR dimerizes with another ErbB family receptor, leading to kinase domain activation and transphosphorylation of C-terminus tyrosine residues. These phosphotyrosines act as crucial regulators of EGFR signaling as effector proteins dock to the receptor at these sites. The receptor undergoes clathrin-mediated endocytosis into early endosomes, where it can then be trafficked to a lysosome for degradation. However, the kinase domain of EGFR retains its activity during trafficking, suggesting that EGFR can continue …

The N-Terminal Methyltransferase Homologs Nrmt1 And Nrmt2 Exhibit Novel Regulation Of Activity Through Heterotrimer Formation., Jon David Faughn

Electronic Theses and Dissertations

Protein, DNA, and RNA methyltransferases have an ever-expanding list of novel substrates and catalytic activities. Even within families and between homologs, it is becoming clear the intricacies of methyltransferase specificity and regulation are far more diverse than originally thought. In addition to specific substrates and distinct methylation levels, methyltransferase activity can be altered through formation of complexes with close homologs. This work involves the N-terminal methyltransferase homologs NRMT1 and NRMT2. NRMT1 is a ubiquitously expressed distributive trimethylase. NRMT2 is a monomethylase expressed at low levels and in a tissue-specific manner. They are both nuclear methyltransferases with overlapping target consensus sequences …

Bayesian Analytical Approaches For Metabolomics : A Novel Method For Molecular Structure-Informed Metabolite Interaction Modeling, A Novel Diagnostic Model For Differentiating Myocardial Infarction Type, And Approaches For Compound Identification Given Mass Spectrometry Data., Patrick J. Trainor

Electronic Theses and Dissertations

Metabolomics, the study of small molecules in biological systems, has enjoyed great success in enabling researchers to examine disease-associated metabolic dysregulation and has been utilized for the discovery biomarkers of disease and phenotypic states. In spite of recent technological advances in the analytical platforms utilized in metabolomics and the proliferation of tools for the analysis of metabolomics data, significant challenges in metabolomics data analyses remain. In this dissertation, we present three of these challenges and Bayesian methodological solutions for each. In the first part we develop a new methodology to serve a basis for making higher order inferences in metabolomics, …

Deciphering The Role Of Human Arylamine N-Acetyltransferase 1 (Nat1) In Breast Cancer Cell Metabolism Using A Systems Biology Approach., Samantha Marie Carlisle

Electronic Theses and Dissertations

Background: Human arylamine N-acetyltransferase 1 (NAT1) is a phase II xenobiotic metabolizing enzyme found in almost all tissues. NAT1 can additionally hydrolyze acetyl-coenzyme A (acetyl-CoA) in the absence of an arylamine substrate. NAT1 expression varies inter-individually and is elevated in several cancers including estrogen receptor positive (ER+) breast cancers. Additionally, multiple studies have shown the knockdown of NAT1, by both small molecule inhibition and siRNA methods, in breast cancer cells leads to decreased invasive ability and proliferation and decreased anchorage-independent colony formation. However, the exact mechanism by which NAT1 expression affects cancer risk and progression remains unclear. Additionally, consequences …

Development Of Rapid, Homogeneous Assay For Investigating Isopeptide Bond Formation Using Fluorescence Polarization/Depolarization Measurements, Samuel Patricc Kasson

Graduate Theses/Dissertations

Autocatalytic intramolecular isopeptide bonds have been found in nature in certain gram-positive bacterial pilus structures. Recently, splitting of these domains that are capable of autocatalytic intramolecular isopeptide bond formation have been applied to create stable, selective, bio-orthogonal Catcher/Tag systems. The CnaB2 domain found in the FbaB pilus structure of Streptococcus pyogenes, has yielded the Catcher/Tag, Protein/Peptide systems termed SpyCatchter and SpyTag. Recent study has focused on tag optimization, stability and bio-orthogonality evaluation, along with applications in bioconjugation. I have recombinantly expressed SpyCatcher and SpyTag-fused proteins in E.coli, and conjugated them to fluorescent probes in order for use in fluorescence polarization/depolarization …

Rna-Seq Reveals Transcriptomic Program Associated With Stemness In Taxane Resistant Prostate Cancer, Christina K. Cajigas-Du Ross

Loma Linda University Electronic Theses, Dissertations & Projects

There is no cure for advanced prostate cancer (PCa), and taxane chemotherapy is the only treatment option once other therapies have failed. However, this is problematic since all patients eventually develop chemoresistance. Emerging treatments for advanced PCa have shown promise at the benchside, but clinical trials have not resulted in newly approved drugs due in part to redundant survival pathways utilized by prostate tumor cells to maintain therapy-resistance. Using RNAsequencing—an innovative approach for quantifying gene expression changes—this dissertation sought to elucidate chemoresistance-associated molecular pathways as a catalyst to develop new therapeutic targets. Results revealed a differential upregulation of stemness-associated genes …

Quantitative Studies Of Amyloidogenic Protein Residue Interaction Networks And Abnormal Ammonia Metabolism In Neurotoxicity And Disease, Jeddidiah Griffin

Electronic Theses and Dissertations

Investigating similarities among neurological diseases can provide insight into disease processes. Two prominent commonalities of neurological diseases are the formation of amyloid deposits and altered ammonia and glutamate metabolism. Computational techniques were used to explore these processes in several neurological diseases. Residue interaction networks (RINs) abstract protein structure into a series of nodes (representing residues) and edges (representing connections between residues likely to interact). Analyzing the RINs of monomeric forms of amyloidogenic proteins for common network features revealed similarities not previously known. First, amyloidogenic variants of lysozyme were used to demonstrate the usefulness of RINs to the study of amyloidogenic …

Metabolic Plasticity In The Cellular Stress Response, Ying Li

Electronic Theses and Dissertations

Changes to the metabolism of the cardiomyocyte are driven by complex signaling pathways in order to adjust to stress. For instance, HIF-1α is classically known to upregulate glycolytic metabolism to compensate for oxygen deficiency. Other important effects upon glucose metabolism, which we investigate here more extensively, were also observed. Hearts derived from mice with the cardiac-restricted expression of a stabilized form of HIF-1α are remarkably ischemia stress-tolerant. Here, stable isotope-resolved metabolomic analyses were utilized to investigate glucose cardiometabolism remodeling by HIF-1αduring ischemia. We found that ¹³C-lactate accumulation was significantly elevated in HIF-1α expressing hearts while paradoxically glycogen was maintained …

In Silico Pharmacokinetic And Molecular Docking Studies Of N-Cinnamoyltetraketide Derivatives As Inhibitors Of Cyclooxygenase-2 Enzyme, Stephen S. Nyandoro, Daniel M. Shadrack, Joan J. E. Munissi, Egid B. Mubofu

Tanzania Journal of Science

Recent phytochemical analysis of Toussaintia orientalis leaves yielded series of novel bioactive N-cinnamoyltetraketide derivatives namely toussaintines A-G (t_1 - t_8) some portraying cytotoxicity against the triple negative aggressive human breast cancer cell line (MDA-MB-231) among other potencies. Despite having broad bioactivity spectrum, their general drug-likeness profiles and mode of action (simulated or actual) targeting any enzyme remains uninvestigated. In silico pharmacokinetic, drug-likeness descriptors and molecular docking of the compounds t_1-t_8 targeting inhibition of cyclooxygenase-2 (COX-2) enzyme were evaluated. The Lipinski Rule of Five heralded the pharmacokinetic properties of the studied metabolites. The studied compounds were docked with COX-2 following already …

In Silico Pharmacokinetic And Molecular Docking Studies Of N-Cinnamoyltetraketide Derivatives As Inhibitors Of Cyclooxygenase-2 Enzyme, Stephen S. Nyandoro, Daniel M. Shadrack, Joan J. E. Munissi, Egid B. Mubofu

Tanzania Journal of Science

Recent phytochemical analysis of Toussaintia orientalis leaves yielded series of novel bioactive N-cinnamoyltetraketide derivatives namely toussaintines A-G (t_1 - t_8) some portraying cytotoxicity against the triple negative aggressive human breast cancer cell line (MDA-MB-231) among other potencies. Despite having broad bioactivity spectrum, their general drug-likeness profiles and mode of action (simulated or actual) targeting any enzyme remains uninvestigated. In silico pharmacokinetic, drug-likeness descriptors and molecular docking of the compounds t_1-t_8 targeting inhibition of cyclooxygenase-2 (COX-2) enzyme were evaluated. The Lipinski Rule of Five heralded the pharmacokinetic properties of the studied metabolites. The studied compounds were docked with COX-2 following already …

Pias-Family Proteins Negatively Regulate Glis3 Transactivation Function Through Sumo Modification In Pancreatic Β Cells, Tyler M. Hoard, Xiaoping Yang, Anton M. Jetten, Gary T. Zeruth Dr.

Faculty & Staff Research and Creative Activity

Gli-similar 3 (Glis3) is Krüppel-like transcription factor associated with the transcriptional regulation of insulin. Mutations within the Glis3 locus have been implicated in a number of pathologies including diabetes mellitus and hypothyroidism. Despite its clinical significance, little is known about the proteins and posttranslational modifications that regulate Glis3 transcriptional activity. In this report, we demonstrate that the SUMO-pathway associated proteins, PIASy and Ubc9 are capable of regulating Glis3 transactivation function through a SUMO-dependent mechanism. We present evidence that SUMOylation of Glis3 by PIAS-family proteins occurs at two conserved lysine residues within the Glis3 N-terminus and modification of Glis3 by SUMO …

Blue Light Induces A Neuroprotective Open Access Gene Expression Program In Drosophila Photoreceptors, Hana Hall, Jingqun Ma, Sudhanshu Shekhar, Walter D. Leon-Salas, Vikki M. Weake

Department of Biochemistry Faculty Publications

Background: Light exposure induces oxidative stress, which contributes to ocular diseases of aging. Blue light provides a model for light‑induced oxidative stress, lipid peroxidation and retinal degeneration in Drosophila melanogaster. In contrast to mature adults, which undergo retinal degeneration when exposed to prolonged blue light, newly‑eclosed fies are resistant to blue light‑induced retinal degeneration. Here, we sought to characterize the gene expression programs induced by blue light in fies of diferent ages to identify neuroprotective pathways utilized by photoreceptors to cope with light‑induced oxidative stress.

Results: To identify gene expression changes induced by blue light exposure, we profled the nuclear …

Conjugation Of Nanomaterials And Nematic Liquid Crystals For Futuristic Applications And Biosensors, Thomas George, Amit Choudhary, Guoqiang Li

Chemistry & Biochemistry Faculty Works

The established role of nematic liquid crystals (NLCs) in the recent rapid development of displays has motivated researchers to modulate the electro-optical properties of LCs. Furthermore, adding nanomaterials into NLCs has led to enhancements of the properties of NLCs, like reduced threshold of the operating voltage, variation in pretilt angle, reduced switching time, etc. These enhanced properties, due to interfacial dynamics, are enabling wider applications of NLCs and nanomaterials. The recent literature of nanomaterial-doped NLCs is rich with various kinds of nanomaterials in a variety of NLCs. The light has been focused on the most widely used and studied gold …

Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

Aerosols of variable composition, size, and shape are associated with public health concerns as well as with light-particle interactions that play a role in the energy balance of the atmosphere. Photochemical reactions of 2-oxocarboxylic acids in the aqueous phase are now known to contribute to the total secondary organic aerosol (SOA) budget. This work explores the cross reaction of glyoxylic acid (GA) and pyruvic acid (PA) in water, the two most abundant 2-oxocarboxylic acids in the atmosphere, under solar irradiation and dark thermal aging steps. During irradiation, PA and GA are excited and initiate proton-coupled electron transfer or hydrogen abstraction …

Proper Splicing Contributes To Visual Function In The Aging Drosophila Eye, Rachel Stegeman, Hana Hall, Spencer E. Escobedo, Henry C. Chang, Vikki M. Weake

Department of Biochemistry Faculty Publications

Changes in splicing patterns are a characteristic of the aging transcriptome; however, it is unclear whether these age‐related changes in splicing facilitate the progressive functional decline that defines aging. In Drosophila, visual behavior declines with age and correlates with altered gene expression in photoreceptors, including downregulation of genes encoding splicing factors. Here, we characterized the significance of these age‐regulated splicing‐associated genes in both splicing and visual function. To do this, we identified differential splicing events in either the entire eye or photoreceptors of young and old flies. Intriguingly, aging photoreceptors show differential splicing of a large number of visual function …

Structural Insights From Hiv-Antibody Co-Evolution And Related Immunization Studies, Jeffrey O. Zhou , '19, Therese Ton , '19, Julia W. Morriss , '19, Diep Nguyen , '19, Daniela Fera

Chemistry & Biochemistry Faculty Works

Human immunodeficiency virus type 1 (HIV-1) is a rapidly evolving pathogen and causes the acquired immunodeficiency syndrome (AIDS) in humans. There are ~30-35 million people infected with HIV around the world, and ~25 million have died since the first reported cases in 1981. Additionally, each year 2-3 million people become newly infected and more than one million die of AIDS. An HIV-1 vaccine would help halt an AIDS pandemic, and efforts to develop a vaccine have focused on targeting the HIV-1 envelope, Env, found on the surface of the virus. A number of chronically infected individuals have been shown to …