Cell Biology Commons^™

Conserved Novel Interactions Between Post-Replicative Repair And Mismatch Repair Proteins Have Differential Effects On Dna Repair Pathways, Anna K. Miller

Theses and Dissertations--Toxicology and Cancer Biology

DNA mismatch repair (MMR) is the DNA repair mechanism that repairs base-base mispairs and small insertions and deletions remaining after replication. MMR is also required for apoptosis after certain types of exogenous DNA damage that result in damage-associated mispairs. The basic MMR mechanism is well understood; however, proteins associated with MMR continue to be identified. The roles of these interacting proteins in MMR are largely unknown. We have identified the yeast protein Rad5 as a novel interactor of the critical MMR proteins Msh2 and Mlh1. Rad5 is a DNA helicase and E3 ubiquitin ligase involved in post-replicative repair. However, to …

Elucidating The Functional Importance Of Peroxiredoxin Iv In Prostate Cancer And Its Secretion Mechanism, Na Ding

Theses and Dissertations--Toxicology and Cancer Biology

Prostate cancer is the most common and second leading cause of cancer death in men. Prevailing theories state that inflammation may drive prostate carcinogenesis via oxidative stress and the generation of reactive oxygen species (ROS) that induce somatic mutagenesis. Since high proliferating cells or cancer cells exhibit aberrant metabolism to satisfy the needs of energy for rapid cell proliferation, they also generate high levels of ROS which stimulates the expression of cellular antioxidants to overcome the dysregulation of redox homeostasis through the regulation of redox-sensitive transcription factors. Among different antioxidants, peroxiredoxin (Prx) family proteins are the highly conserved and mostly …

Sex-Dependent Effects Of Induced Acute Inflammation On Glucose Homeostasis And Rna Editing Enzymes, Christian A. Rivas

Graduate Theses/Dissertations

The first line of defense against bodily insults, like pathogen invasion, is the innate immune system. Innate immunity sets in motion countless cascades that result in inflammation. Inflammation simultaneously affects multiple biological processes like metabolism and gene expression. Males and females react differently to inflammation. To understand both molecular and physiological sex differences in inflammation, we examined how inflammation affects gene expression and glucose metabolism. Adenosine deaminase acting on RNA (ADAR1) is upregulated by inflammation and catalyzes RNA editing, a process where nucleotides encoded by the genome are modified. ADAR1 also controls the innate immune reaction by decreasing activity of …

Cul3 Negatively Regulates Nlrp12-Mediated Inhibition Of The Canonical Nf-Κb Signaling Pathway, Inyeong Lee

Graduate Theses/Dissertations

Nod-like receptor family pyrin domain-containing protein 12 (NLRP12) is mainly known for its inhibitory function on NF-κB signaling in innate immune cells, and more recently, for its ability to regulate chemokine signaling and ubiquitination of the immune receptor RIG-I. Through a yeast 2-hybrid screen, the Lupfer lab previously discovered that NLRP12 interacts with other ubiquitin-associated proteins including Cullin 3 (CUL3) and RING finger protein 2 (RNF2). This research was conducted to mainly investigate the interaction between NLRP12 and CUL3 in human cells and examine the role in regulating NF-κB signaling. Previously, co-immunoprecipitation, followed by western blot analysis, and confocal microscopy …

Identification Of Proteins Involved In Cell Membrane Permeabilization By Nanosecond Electric Pulses (Nsep), Giedre Silkuniene, Uma Mangalanathan, Alessandra Rossi, Peter A. Mollica, Andrei G. Pakhomov, Olga N. Pakhomova

Bioelectrics Publications

The study was aimed at identifying endogenous proteins which assist or impede the permeabilized state in the cell membrane disrupted by nsEP (20 or 40 pulses, 300 ns width, 7 kV/cm). We employed a LentiArray CRISPR library to generate knockouts (KOs) of 316 genes encoding for membrane proteins in U937 human monocytes stably expressing Cas9 nuclease. The extent of membrane permeabilization by nsEP was measured by the uptake of Yo-Pro-1 (YP) dye and compared to sham-exposed KOs and control cells transduced with a non-targeting (scrambled) gRNA. Only two KOs, for SCNN1A and CLCA1 genes, showed a statistically significant reduction in …

Tgif1 Physiological Levels Limit Β-Cell Distress And Neonatal Diabetes, Creighton J. Friend

Theses and Dissertations

TGIF1 belongs to the superfamily of homeodomain proteins, which regulate a wide variety of biological functions, including cell stemness and specification of cell fate during early development. Perhaps surprisingly, we found that enforced expression in pancreatic progenitor cells during embryogenesis resulted in severe diabetes, hinting at the possibility that TGIF1 might regulate pancreas development. Subsequent genetic experiments targeting β-cells showed that TGIF1 affected β-cell function and homeostasis. Transcriptomic analysis revealed that TGIF1 expression inhibits the expression of essential components of UPR signaling, underscoring a potential mechanism in which TGIF1 disrupts protein folding and secretion. Congruently, TGIF1 expression led to a …

Development Of A Chemical Biology Approach To Uncover The Influence Of Sequence Variations On Ces1 Activity In Live Cells, Samuel James Knebel

Masters Theses

Drug metabolism is the biochemical process of modifying drugs to detoxify and remove them through enzymatic transformations. These biotransformation’s occur primarily in the liver and are critical to understanding how pharmaceutical compounds are chemically altered inside the human body. Human carboxylesterases (CESs) catalyze the hydrolysis of esters, amides, thioesters, and carbamates. CES-mediated hydrolysis plays an important role in the metabolism of many drugs including the first FDA approved antiviral treatment for COVID-19, remdesivir (Veklury), the seizure control medication rufinamide (Banzel), and the flu antiviral drug oseltamivir (Tamiflu). CES activity is known to be influenced by a variety of factors including …

Investigating Changes In Er-To-Golgi Protein Transport Following A Short Calcium Pulse: Roles Of Alg-2 And Peflin, Alaa Mohammed Yosri Shaheen

Graduate Student Theses, Dissertations, & Professional Papers

The ER-Golgi interface is a very dynamic environment that involves the movement of protein-loaded vesicles forward and backward. The movement of COPII-coated vesicles from the ER to the Golgi is the initial step in the movement of secreted, organellar, and cell surface proteins toward their final destinations. Many factors can regulate this step, including cytosolic calcium increases. In this study, we examined the effect of a transient calcium pulse on recruitment to ER exit sites of cargo proteins for ER export, the calcium-sensitive regulatory proteins apoptosis-linked gene 2 (ALG-2) and peflin, and the COPII outer coat subunits Sec31A and Sec13. …

How To Build A Cortex: Coordinated Assembly Of Cortical Septins And Actomyosin In The Leader Bleb, Asia Marie Paguntalan

Master's Theses

In confined spaces, migrating cells can undergo mesenchymal-to-amoeboid transitions by altering their cortical dynamics and adhesion with the environment. Septins frequently associate with cortical actin and non-muscle myosin (NMII), but the functional nature of these interactions remains unclear. Upon non-adhesive confinement and NMII enrichment, fibroblasts can switch to a fast, leader bleb-based mode of motility, characterized by the absence of adhesions and stress fibers and formation of a single, elongated leader bleb. During this transition, cortical actin remodeling and polarized NMII contractility drive leader bleb stabilization by generating long-range cortical flows, in coordination with changes in septin localization and assembly …

Measuring How Kinetochore-Microtubule Detachment Contributes To Chromosome Movement And The Correction Of Attachment Errors, Melissa K. Parks

Dartmouth College Ph.D Dissertations

The goal of mitosis is to achieve faithful chromosome segregation; ensuring that the daughter cells inherit equal numbers of chromosomes. This is vital to cell health and viability and if mis-regulated can result in birth defects and disease such as cancer. There are many intricately regulated processes that occur throughout mitosis to achieve proper chromosome segregation, and one such example is the dynamic attachments formed between cytoskeletal structures, known as microtubules, and chromosomes, the carriers of genetic material. These attachments occur at structures called kinetochores, and the microtubules attached here are referred to as kinetochore-microtubules (k-MTs). These k-MTs are inherently …

Identification Of A Dna Polymerase Alpha Gene Sequence In Thermomyces Lanuginosus Fungus, Nathan Williams

Honors Program Theses

With cell growth being the main focus of our research, we chose to study DNA polymerase alpha. DNA polymerase alpha is likely to be involved in cell growth as it is the enzyme that starts DNA replication. Control of this enzyme might lead to decreased cell growth in cancer or increased cell growth in damaged spinal cord tissue. We chose the thermophilic fungus Thermomyces lanuginosus for the study of the enzyme due to the ability to compare the enzyme’s activity during fungal growth at different temperatures. Thermomyces exhibits rapid growth at high temperatures and slow growth at low temperatures. Studying …

Cellular Glycosphingolipid Imbalance Modulates Emt In Cancer Cells, Laura E. Clark, Amanda Dickinson, Santiago Lima

Undergraduate Research Posters

Sphingolipids are key components of the plasma membrane and are regulators of complex biological processes often altered in cancer cells. In human tumors, genes of key enzymes that regulate levels of glucosylceramide and lactosylceramide are often amplified. However, it is unknown why these traits are positively selected in transformed cells. In this work, we used CRISPR-Cas9 to knockout two key enzymes amplified in tumors in HeLa and H1703 tumor-derived cell-lines. As expected, the knockout lines had dramatic accumulation of GlcCer and LacCer. However, unexpectedly, they showed significantly decreased in-vitro wound-healing capacity and an almost complete loss of in-vitro extra-cellular matrix …

Ros And Sfk Signaling Is Required For Development Of Hematopoietic Stem Cells In Zebrafish, Bradley Williams, Erich Damm

Undergraduate Research Posters

ROS and SFK signaling is required for development of hematopoietic stem cells in zebrafish

Bradley Williams and Erich Damm

Background

Hematopoiesis is the process in which the myriad of mature blood cell types, including erythrocytes and leukocytes, develop from hematopoietic stem cells (HSCs) throughout the life of an organism. In vertebrates, HSCs originate from endothelial cells lining the floor of the dorsal aorta. This process is referred to as the endothelial to hematopoietic transition and is likely controlled in part by molecular signals from neighboring cells. Investigation into the molecular signaling mechanisms controlling the development of HSCs is critical to …

Proposing An Rna Interference (Rnai)-Based Treatment For Human Immunodeficiency Virus (Hiv) By Analyzing The Post-Transcriptional Gene Targeting Of Sars-Cov-2, Hepatitis C Virus, And A549 Lung Cancer Cells, Arjun Jagdeesh

Undergraduate Research Posters

Human Immunodeficiency Virus (HIV) is a retrovirus that infects CD4+ T cell lymphocytes in humans, leading to the development of Acquired Immunodeficiency Syndrome (AIDS) if left untreated. While current treatment methods, including antiretroviral combination treatments, effectively limit HIV replication, HIV can evade these treatments due to its high mutation rate. Long-term antiretroviral treatment can also be toxic to patients, meaning patients would benefit from a new mechanism of HIV treatment. RNA interference (RNAi) is an antiviral pathway found in mammals, plants, and insects that involves a small-interfering RNA that is incorporated into a protein complex called the RNA-induced Silencing Complex …

Therapies For Mitochondrial Disorders, Kayli Sousa Smyth, Anne Mulvihill

SURE Journal: Science Undergraduate Research Experience Journal

Mitochondria are cytoplasmic, double-membrane organelles that synthesise adenosine triphosphate (ATP). Mitochondria contain their own genome, mitochondrial DNA (mtDNA), which is maternally inherited from the oocyte. Mitochondrial proteins are encoded by either nuclear DNA (nDNA) or mtDNA, and both code for proteins forming the mitochondrial oxidative phosphorylation (OXPHOS) complexes of the respiratory chain. These complexes form a chain that allows the passage of electrons down the electron transport chain (ETC) through a proton motive force, creating ATP from adenosine diphosphate (ADP). This study aims to explore current and prospective therapies for mitochondrial disorders (MTDS). MTDS are clinical syndromes coupled with abnormalities …

Characterization Of Ape1 And Dna G-Quadruplex Interaction In Transcription Regulation And Dna Damage Repair, Suravi Pramanik

Theses & Dissertations

Human AP Endonuclease 1 (APE1) is the primary enzyme in the base excision repair (BER) pathway that repairs apurinic/apyrimidinic (AP) sites, the most frequently formed DNA lesions in the genome. Recently, through genome-wide mapping analysis, we have shown that APE1, as well as its post-translationally modified form, acetylated APE1 (AcAPE1), is enriched in the gene regulatory regions. The APE1/AcAPE1-enriched regions also harbor Guanine (G)-rich sequences that fold into DNA secondary structures called G-quadruplexes (G4s). Our lab has demonstrated a strong genome-wide correlation between the occurrence of G4 structures and the binding of APE1 and AcAPE1. However, it is unknown whether …

The Role Of Ubiquitin E3 Ligase Fbxo21 In Steady-State, Stressed, And Malignant Hematopoiesis, Karli J. Wittorf

Theses & Dissertations

Hematopoietic stem cells (HSCs) allow for the formation of all cell types in the blood and maintain these populations throughout a person’s life. The process of hematopoiesis is regulated through a variety of molecular mechanisms that are either signaled from the cell’s environment (extrinsic) or from within the cell itself (intrinsic). One intrinsic mechanism that regulates hematopoietic cell fate decisions is the ubiquitin proteasome system (UPS). The UPS controls protein levels by tagging them with polyubiquitin chains and promoting their degradation through the proteasome. The key component of the UPS is the ubiquitin E3 ligase as this protein is the …

Novel Mechanisms Of Protein Kinase C Α Regulation And Function, Xinyue Li

Theses & Dissertations

Protein kinase Cα (PKCα) is a member of the PKC family of serine/threonine kinases, which have been implicated in regulation of many cellular processes, including cell proliferation, differentiation, survival, and transformation. A large body of evidence from the Black laboratory and others support an anti-proliferative function of PKCα in normal epithelial tissues, including the intestinal mucosa and endometrial epithelium. PKCα is also tumor suppressive in epithelial cancers, such as colorectal cancer (CRC) and endometrial cancer (EC). However, a major obstacle to harnessing the tumor suppressive functions of PKCα to benefit patients is the widespread loss of PKCα expression in tumors. …

Underlying Mechanism Of Ovarian Reserve Preservation From Gonadotoxicity, Yi Luan

Theses & Dissertations

Cancer therapies often lead to premature ovarian insufficiency by ovarian damage and follicle depletion. However, the oocyte death pathway induced by chemotherapies has been debated. Here we clarified the precise mechanism of ovarian depletion induced by cyclophosphamide and doxorubicin. Cyclophosphamide induced direct apoptosis in oocytes rather than overactivation of primordial follicles. Dormant oocytes instead of activated oocytes with high PI3K activity were more sensitive to cyclophosphamide. Although the ABL inhibitor, GNF2, has been proposed to ameliorate the apoptosis of primordial follicles against cyclophosphamide, GNF2 did not prevent the loss of primordial follicles induced by cyclophosphamide in the systems tested. Oocyte-specific …

Bis-Indolyl Compounds And The Induction Of Apoptosis In T98g Glioblastoma Multiforme Cells, Margot C. Brown

Seton Hall University Dissertations and Theses (ETDs)

1,1-bis(3’idolyl)-1(aryl)methane compounds (BIM compounds) have been shown to have anti-cancer properties in colon cancer, bladder cancer, and leukemia cells. The purpose of this work was to determine if BIM compounds could be an effective treatment of glioblastoma multiforme. Sulforhodamine B (SRB) assays showed that 20µM of the BIM compounds could inhibit cellular proliferation of the T98G glioblastoma multiforme cell line over 72 hours. Then immunoblotting was used to analyze the molecular pathway induced by BIM compounds. An increase in the expression of both BAX and cleaved caspase 3 suggest BIM compounds activate programmed cell death, or apoptosis in glioblastoma cells. …