Cell Biology Commons^™

Plasmodium Falciparum 26s Proteasome Network: A Mystery Solved, Christina Grogan

D.U.Quark

One ofthe most devastating diseases thatthreatens the world population is malaria. The 26S proteasome complex of the malaria parasite Plasmodium falciparum, which was previously unknown, was characterized by the authors through an affinity purification protocol that isolated functional 26S proteasome complexes. This allowed for the identification of subunit composition and PfUSP14, a proteasomeassociated deubiquitinase. This new understanding presents a potential target to disrupt protein regulation in thequest for effective antimalarial strategies.

Autophagy Inhibition In Pain: Role Of A Microrna, Andrea Stevens

D.U.Quark

Neuropathic pain caused by peripheral nerve injury (PNI) leads to the activation and infiltration of microglial cells and to a neuroinflammatory-induced pain state. miRNAs and autophagy are two main factors and/or mechanisms which have the ability to alter the pain state. In this study, miR-195 was shown to be markedly increased after PNI and associated with the pain phenotype. In addition, inhibition of autophagy in vivo led to p62 accumulation, decreased production of LC3, and inhibition of ATG14.

Compartmentalized Camp Responses To Prostaglandin Ep2 Receptor Activation In Human Airway Smooth Muscle Cells, Shailesh R. Agarwal, Kathryn Miyashiro, Htun Latt, Rennolds S. Ostrom, Robert D. Harvey

Pharmacy Faculty Articles and Research

Background and Purpose

Previous studies indicate that prostaglandin EP2 receptors (EP2Rs) selectively couple to adenylyl cyclase type 2 (AC2) in non-lipid raft domains of airway smooth muscle (ASM) cells, where they regulate specific cAMP-dependent responses. The goal of the present study was to identify the cellular microdomains where EP2Rs stimulate cAMP production.

Experimental Approach

FRET-based cAMP biosensors were targeted to different subcellular locations of primary human ASM cells. The Epac2-camps biosensor, which expresses throughout the cell, was used to measure bulk cytoplasmic responses. Epac2-MyrPalm and Epac2-CAAX were used to measure responses associated with lipid raft and non-raft regions of the …

The Recycling Gtpase, Rab-10, Regulates Autophagy Flux In Caenorhabditis Elegans, Nicholas J. Palmisano

Dissertations, Theses, and Capstone Projects

Autophagy and endocytosis are two cellular pathways that are vital to cell growth and homeostasis. Autophagy is a dynamic and catabolic process involving the formation of a double-membrane vesicle called the autophagosome, which engulfs long-lived proteins and damaged organelles. Endocytosis involves the uptake of extracellular material into the cell through the formation of intracellular vesicles termed endosomes. Although both endocytosis and autophagy are interconnected processes, the extent to which endocytic proteins and/or compartments contribute to autophagy, and how these endocytic components do so, is still unknown. To improve our understanding of the connections that exist between autophagy and endocytosis, we …

A Lipid Binding Structure And Functional Analysis Of Human Arv1, Jessie Lee Cunningham

Graduate School of Biomedical Sciences Theses and Dissertations

Metabolic Syndrome (MetS) is a combination of risk factors that can over time increase the probability of developing diseases, including cardiovascular disease, type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), and non-alcoholic steatohepatitis (NASH). Acyl-coenzyme-A: cholesterol O-acyl transferase related enzyme required for viability-1, abbreviated as Arv1, is an evolutionarily conserved putative lipid binding protein. Several studies have implicated hArv1 as a critical regulator of lipid transport and trafficking.

Recent work using an Arv1 knock out (KO) mouse model have established a clear link between Arv1 function and the progression of MetS and NAFLD/NASH [unpublished data] [1]. Overall, studies show that …

The 'Pseudomonas Aeruginosa' Psl Polysaccharide Is A Social But Noncheatable Trait In Biofilms, Yasuhiko Irie, Aled E. Roberts, Kasper N. Kragh, Vernita D. Gordon, Jaime B. Hutchison, Rosalind J. Allen, Gavin Melaugh, Thomas Bjarnsholt, Stuart A. West, Stephen P. Diggle

Biology Faculty Publications

Extracellular polysaccharides are compounds secreted by microorganisms into the surrounding environment, and they are important for surface attachment and maintaining structural integrity within biofilms. The social nature of many extracellular polysaccharides remains unclear, and it has been suggested that they could function as either cooperative public goods or as traits that provide a competitive advantage. Here, we empirically tested the cooperative nature of the PSL polysaccharide, which is crucial for the formation of biofilms in Pseudomonas aeruginosa. We show that (i) PSL is not metabolically costly to produce; (ii) PSL provides populationlevel benefits in biofilms, for both growth and antibiotic …

Functional Roles Of Matrix Metalloproteinases In Bone Metastatic Prostate Cancer, Jeremy S. Frieling

USF Tampa Graduate Theses and Dissertations

Skeletal metastasis is a lethal component of many advanced cancers including prostate, the second most common cancer among men. Patients whose prostate cancer is localized and detected early benefit from multiple treatment options ranging from active surveillance to radiation and surgery, resulting in a 5-year survival rate of nearly 100%. Unfortunately, the prognosis and survival for patients with advanced metastatic disease is much worse due to the highly aggressive nature of the disease and a paucity of treatment options. Understanding the mechanisms and interactions that occur between metastatic cancer cells and the bone will enable the future treatment landscape for …

Applied Drug Development And Combinatorial Strategies For Antimicrobial Treatment, Steven K. Lai Hing

Andrews Research Conference

Streptococcus mutans JH1140 is a strain of bacteria which produces a lantibiotic product, named mutacin 1140. Mutacin 1140 has been shown to be effective at inhibiting Gram-positive bacterial infections caused by Staphylococcus aureus and Streptococcus pneumoniae. Mutacin 1140 is a ribosomally synthesized peptide antibiotic that undergoes extensive posttranslational modifications (PTM). We have found that Mutacin 1140 and an aminoglycoside, Kanamycin, when combined together, act synergistically against Staphylococcus aureus. This was determined by performing serial kill curve dilution overlays on solid media, followed up with kill curve by microdilution plate, and most recently confirmed with kill curve CFU count plates …

Macrophages Are Necessary For Epimorphic Regeneration In African Spiny Mice, Jennifer Simkin, Thomas R. Gawriluk, John C. Gensel, Ashley W. Seifert

Biology Faculty Publications

How the immune system affects tissue regeneration is not well understood. In this study, we used an emerging mammalian model of epimorphic regeneration, the African spiny mouse, to examine cell-based inflammation and tested the hypothesis that macrophages are necessary for regeneration. By directly comparing inflammatory cell activation in a 4 mm ear injury during regeneration (Acomys cahirinus) and scarring (Mus musculus), we found that both species exhibited an acute inflammatory response, with scarring characterized by stronger myeloperoxidase activity. In contrast, ROS production was stronger and more persistent during regeneration. By depleting macrophages during injury, we demonstrate …

Platelets Prime Hematopoietic-Vascular Niche To Drive Angiocrine-Mediated Liver Regeneration, Koji Shido

Seton Hall University Dissertations and Theses (ETDs)

A critical function for blood vessels is that they secrete paracrine factors necessary for development, homeostasis and repair of the rest of all organs. Among them, the liver is a highly vascular organ, and can undergo regeneration after injury. This liver regeneration process is governed by dynamic interplay between hepatocytes and non-parenchymal cells, liver sinusoidal endothelial cells (LSECs). However, how factors produced from LSECs triggered by injury remains to be defined. Following mouse in vivo liver injury model, activated platelets deploy stromal cell-derived factor 1 and vascular endothelial growth factor A to stimulate CXCR7+ LSECs, orchestrating hepatic regeneration. Upon injection …

The Regulation Of Rotavirus–Infected Ht29.F8 And Ma104 Cells Treated With Arachidin 1 Or Arachidin 3, Caleb M. Witcher

Electronic Theses and Dissertations

Rotavirus (RV) infections cause severe life threatening diarrhea in young children and immunocompromised individuals. Several effective vaccines have been developed for young children but are not protective against all strains of RV, and there are no anti-RV therapeutics. Our laboratory has discovered a decrease in the number of infectious simian RV particles (SA114f) in human intestinal cell line, HT29.f8 cells with the addition of either of two stilbenoids, arachidin-1 (A1) or arachidin-3 (A3). This suggests effects on the host cell and RV replication. We examined the cellular effects of human RV strain (Wa) on a human intestinal cell line (HT29.f8) …

Cd82 Membrane Scaffolding Regulates Hematopoietic Cell Functions, Christina Marie Termini

Biomedical Sciences ETDs

Through their ability to self-renew and differentiate, hematopoietic stem/progenitor cells (HSPCs) maintain the adult blood and immune systems. The microenvironment, or niche, in which HSPCs reside, serves as a critical regulator of HSPC functions. As previous work has identified the tetraspanin CD82 as a mediator of HSPC-niche interactions, we aimed to determine the mechanism by which this occurs. Our data demonstrate that CD82 expression and scaffolding regulate HSPC interactions with niche components by organizing the α4 integrin subunit into tightly packed nanoclusters. The HSPC niche can also protect acute myeloid leukemia (AML) cells from therapeutics. Therefore, we next examined how …

Characterization Of Neuronal Specific Responses To Induced Misfolded Protein Stress In Caenorhabditis Elegans, Claire Gormley

Senior Honors Projects, 2010-2019

Abstract

Misfolded protein stress has been associated with many types of disease,

including neurodegenerative disorders like Alzheimer’s, Parkinson’s and Huntington’s

disease. When a cell accumulates misfolded proteins in the endoplasmic reticulum,

misfolded protein stress occurs and the unfolded protein response (UPR) is triggered to

induce mechanisms that will allow the cell to either survive or undergo cell death. The

nascent polypeptide associated complex (NAC) is a co-translational chaperone and α/β

heterodimer that manages protein folding and localization, and protects against misfolded

protein stress; changes in NAC function have been linked to both neurodegeneration and

cancer. In these studies, I depleted …

The Role Of Ehd2 In Triple-Negative Breast Cancer Tumorigenesis And Progression, Timothy A. Bielecki

Theses & Dissertations

Triple-negative breast cancer (TNBC) comprises 10%-15% of all breast cancer cases, yet is clinically challenging due to lack of targeted therapies which leads to higher mortality. Molecular subtyping has identified the most aggressive subclasses of breast cancer to be enriched in components of caveolae. While caveolae have been linked to many biological processes, their precise role in TNBC is still poorly understood. EHD2, a member of the C-terminal EPS15-Homology Domain-containing (EHD) protein family, has emerged as a new regulator of caveolae dynamics and is essential to maintain a stable membrane pool of caveolae. Studies in model cells demonstrate that caveolae …

Mapping The Interaction Between Lrrc59 And Cip2a Oncoprotein, Tamika C. Reed

Graduate School of Biomedical Sciences Theses and Dissertations

The oncogene cancerous inhibitor of protein phosphatase 2A (CIP2A) has been shown to promote oncogenesis through numerous protein-protein interactions. CIP2A was initially found to be a direct inhibitor of the PP2A tumor suppressor protein; however, new research has demonstrated that CIP2A can act independently of PP2A through protein-protein interactions resulting in deregulation of the cell cycle and the development of therapeutic drug resistance, tumorigenesis, and cell proliferation. It has been shown that leucine rich repeat containing 59 protein (LRRC59) binds to and is required for the nuclear translocation of CIP2A, thereby making this interaction a target for drug therapy. Thus, …

Characterization Of E-Cadherin Regulation In Response To Zeb1 Inhibition In Endometrial Cancer Cell Lines, Chidozie Paul Chukwu

Graduate School of Biomedical Sciences Theses and Dissertations

Epithelial to mesenchymal transition (EMT) is the process in which cells lose their epithelial structure during gastrulation. This process also affects the migration and movement of tumor cells and promotes invasion and metastases of endometrial carcinomas. Down-regulation of E-cadherin (CDH1) by transcription factors is the key target of EMT modulators and is achieved mainly by ZEB1 (zinc finger E-box binding homeobox 1). Current research looking at restoration of E-cadherin expression in vitro involves the use of small molecules such as histone deacetylase (HDAC) inhibitors and DNA methyltransferase inhibitors. Trichostatin A (TSA) and small interfering ribonucleic acid (siRNA) are tools that …

The Role Of The Expansion Segment 7 Of 25s Rrna During Oxidative Stress In Saccharomyces Cerevisiae, Ethan Gardner

Graduate School of Biomedical Sciences Theses and Dissertations

Translation is an essential process for protein expression in both eukaryotes and prokaryotes. Like any cellular process, translational factors are prone to damage when the cell is under stress. One common stressor that nearly all cells may experience is abnormal levels of reactive oxygen species (ROS). Damage caused by ROS has been associated with disease ranging from neurodegenerative impairments, to the aging process of cells. These oxygen radicals are capable of damaging a litany of molecules including nucleic acids, and molecular factors involved in translation. It has been shown that tRNA can be cleaved upon ROS-induced stress and these fragments …

Lymphoid Hematopoiesis And The Role Of B-Cells In Transgenic Mouse Model Of Sickle Cell Disease, Christina Cotte

University Scholar Projects

Sickle cell disease (SCD) has been shown to be associated with decreased baseline immunity and thus increased susceptibility to infection. I sought to discern possible causes of this by looking into the correlations between SCD and hematopoiesis, the immune system and the neuroendocrine system, and ultimately by conducting experiments surrounding the impaired immune system of SCD. These experiments focused on the potential causes and effects of the diminution of B-1a cells in the SCD spleen. Adoptive transfers, infections with Streptococcus pneumoniae, and histologic imaging were conducted to establish if the diminution of the B-1a cells in the SCD spleen …

Detection Of Leukocytes Stained With Acridine Orange Using Unique Spectral Features Acquired From An Image-Based Spectrometer, Courtney J. Hunter

Biomedical Engineering Undergraduate Honors Theses

A leukocyte differential count can be used to diagnosis a myriad blood disorders, such as infections, allergies, and efficacy of disease treatments. In recent years, attention has been focused on developing point-of-care (POC) systems to provide this test in global health settings. Acridine orange (AO) is an amphipathic, vital dye that intercalates leukocyte nucleic acids and acidic vesicles. It has been utilized by POC systems to identify the three main leukocyte subtypes: granulocytes, monocytes, and lymphocytes. Subtypes of leukocytes can be characterized using a fluorescence microscope, where the AO has a 450 nm excitation wavelength and has two peak emission …

Investigating Localization And Activity-Dependent Translation Of Astrocyte Mrna, Rohan Khazanchi

Senior Honors Papers / Undergraduate Theses

Over the past two and a half years, I have studied fundamental aspects of astrocyte biology by investigating the existence and mechanism of astrocyte local translation peripherally around tripartite synapses consisting of pre- and post-synaptic neuron terminals and an associated astrocyte. Astrocytes are critical components of central nervous system synapses (which are predominately tripartite in nature); thus, it is important to consider how astrocyte dysregulation and dysfunction could contribute to the pathogenesis of diseases of synaptic connectivity such as autism spectrum disorders, Alzheimer’s disease, seizure disorders, and more. Overall, my projects involved the development of novel methods to identify astrocyte-specific …

Uncovering The Identity And Metabolism Of Bacterial Coa-Rna, Joseph R. Spangler

Dissertations

Coenzyme A is an indispensable molecule in all known life with roles in metabolism, gene regulation, and macromolecule synthesis. As CoA is derived from RNA itself, it’s incorporation into RNA by in vitro methods has proven useful in research probing the origin of life based on the RNA World theory. The discovery in contemporary bacteria of RNA modified with CoA, however, provided an unexpected twist to previously well-characterized bacterial systems. The identity of sequences associated with CoA-RNA has been elusive since their discovery in 2009 based on the difficulties in isolation while maintaining RNA quality. The aim of this study …

Identifying The Signaling Mechanisms Of Egfr-Mediated Apoptosis., Nicole Marion Jackson

Electronic Theses and Dissertations

The Epidermal Growth Factor Receptor (EGFR) is a 170-kilodalton transmembrane protein that belongs to the ErbB family of receptor tyrosine kinases. Upon ligand-mediated activation, the EGFR is responsible for cell growth, proliferation, and tissue homeostasis; however, the EGFR is overexpressed in many human malignancies, including MDA-MB-468 cells, a metastatic breast epithelial cell line. Studies within this cell line, and other cell lines characterized with high EGFR levels, have shown that EGF stimulation results in the induction of apoptosis. However, the mechanisms and signaling effectors implicated in this process have yet to be elucidated. The overarching research goal of this dissertation …

Phopsphorylation And Ubiquitin Modification At Dna Damage Sites In Response To Double-Strand Breaks, Atanu Paul

Dissertations and Theses (Open Access)

Genomes of all organisms are continuously damaged by numerous exogenous and endogenous sources leading to different kinds of DNA lesions, which if not repaired efficiently may trigger wide-scale genomic instability, a hallmark of cancer development. To overcome this, cells have evolved a sophisticated sensory network called the DNA damage response (DDR) comprised of a large number of distinct protein complexes categorized as sensor, mediator, transducer and effector proteins that amplify the DNA damage signal and activate cell cycle checkpoint to initiate DNA repair or trigger apoptosis where the defect is beyond repair. This intricate signaling pathway is tightly regulated by …

Paracrine Regulation Of Melanocyte Genomic Stability: A Focus On Nucleotide Excision Repair, Stuart Gordon Jarrett, Katharine Marie Carter, John August D'Orazio

Markey Cancer Center Faculty Publications

UV radiation is a major environmental risk factor for the development of melanoma by causing DNA damage and mutations. Resistance to UV damage is largely determined by the capacity of melanocytes to respond to UV injury by repairing mutagenic photolesions. The nucleotide excision repair (NER) pathway is the major mechanism by which cells correct UV photodamage. This multistep process involves the basic steps of damage recognition, isolation, localized strand unwinding, assembly of a repair complex, excision of the damage‐containing strand 3′ and 5′ to the photolesion, synthesis of a sequence‐appropriate replacement strand, and finally ligation to restore continuity of genomic …

Molecular Mechanisms Of Inward And Outward Budding From Multivesicular Endosomes, Monica Gireud Goss

Dissertations and Theses (Open Access)

Regulating the residence time of membrane proteins (e.g. transporters, ion channels, receptors) on the cell surface can modify their response to extracellular cues and allow for cellular adaptation to environmental conditions. The fate of membrane proteins that are internalized from the plasma membrane and arrive at the limiting membrane of the late endosome/multivesicular body (MVB) is dictated by whether they remain on the limiting membrane, bud into internal MVB vesicles, or bud outwardly from the membrane. The molecular details underlying the disposition of membrane proteins that transit this pathway and the mechanisms regulating these trafficking events are unclear. We established …

The Role Of The Diras Family Members In Regulating Ras Function, Cancer Growth And Autophagy, Margie Nicole Sutton

Dissertations and Theses (Open Access)

DIRAS3 is a maternally imprinted tumor suppressor gene that is downregulated by multiple mechanisms across several tumor types. When re-expressed, DIRAS3 decreases proliferation, inhibits motility, and induces autophagy and tumor dormancy. DIRAS3 encodes a 26 kDa small GTPase with 60% homology to Ras and Rap, differing from oncogenic Ras family members by a 34-amino acid N-terminal extension that is required for its tumor suppressive function in ovarian cancer. By assessing the structure-function relationship, I found that DIRAS3 inhibits Ras-induced transformation and is a natural antagonist of Ras/MAPK signaling. DIRAS3 binds directly to Ras and disrupts cluster formation inhibiting the activation …

Proteomic Identification Of Histone Post-Translational Modifications Induced By Dna Double-Strand Breaks And Novel Proteins Involved In The Dna Damage Response, Pingping Wang

Dissertations and Theses (Open Access)

Inaccurate repair of DNA double-strand breaks (DSBs) can lead to DNA mutation and chromosome rearrangements, causing human diseases such as cancer. Although we know the basic mechanisms of DSB repair, the added complexities in the chromatin context are unclear. This is partially due to the lack of unbiased systems for identifying proteins and post-translational modifications (PTMs) involved in DSB repair. In this work, we established a novel method, termed DSB-ChAP-MS (Double Strand Break-Chromatin Affinity Purification with Mass Spectrometry), for the affinity purification of a sequence-specific single copy endogenous chromosomal locus containing a DSB, followed by the proteomic identification of enriched …

Investigation Of The Roles Of Asf1 And Caf-1-Mediated Chromatin Assembly In The Human Dna Damage Response, Ting-Hsiang Huang

Dissertations and Theses (Open Access)

The access-repair-restore model for the role of chromatin in DNA repair infers that chromatin is a mere obstacle to DNA repair. However, here we show that blocking chromatin assembly of newly-synthesized histones, via knockdown of the histone chaperones ASF1A, CAF-1 or a mutation that specifically prevents ASF1 binding to histones, hinders loading of Rad51 onto ssDNA during homologous recombination, as a consequence of reduced recruitment of the Rad51 loader MMS22L/TONSL to ssDNA, resulting in persistent RPA foci, extensive DNA end-resection, and persistent activation of the ATR-Chk1 pathway. By contrast, ASF1 and CAF-1 render the rapid inactivation of ATM Chk2 pathway …

Characterization Of The Ubiquitin Ligase, Ube4b, In Endocytic Trafficking, Natalie Sirisaengtaksin, Natalie Sirisaengtaksin

Dissertations and Theses (Open Access)

Endocytosis is a process by which cells internalize membrane proteins to remove them from the plasma membrane, allowing cells to regulate the cell surface expression of transmembrane proteins. In this manner, cellular responses to extracellular cues may be tuned by limiting the number of proteins available at the cell surface. One particular class of proteins, receptor tyrosine kinases (RTK), is internalized upon binding to extracellular ligands during their residence at the cell surface. The epidermal growth factor receptor (EGFR) is an RTK whose trafficking through the endocytic pathway through the cell is well-documented. Stimulation of EGFR with its cognate ligand, …

The Role Of Adenosine Signaling In Mature Erythrocytes And Erythroid Progenitors, Hong Liu

Dissertations and Theses (Open Access)

Adenosine is a ubiquitous nucleoside in almost all the cells throughout our bodies. It is highly induced particularly under hypoxia or energy depletion conditions. Adenosine functions as a critical ligand, after binding to membrane-associated adenosine receptors, adenosine initiates a downstream signaling cascade and subsequently contributes to functions of nervous system, immune response, vascular function and even metabolism.

Hypoxia is a condition with limited O₂ availability in the whole body or a region of the body. It is a major consequence of many respiratory and cardiovascular diseases, as well as for people living and working at high altitudes or other …