Cell Biology Commons^™

Inhibition Of Post-Transcriptional Steps In Ribosome Biogenesis Confers Cytoprotection Against Chemotherapeutic Agents In A P53-Dependent Manner, Russell T Sapio, Anastasiya N Nezdyur, Matthew Krevetski, Leonid Anikin, Vincent J Manna, Natalie Minkovsky, Dimitri G Pestov

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The p53-mediated nucleolar stress response associated with inhibition of ribosomal RNA transcription was previously shown to potentiate killing of tumor cells. Here, we asked whether targeting of ribosome biogenesis can be used as the basis for selective p53-dependent cytoprotection of nonmalignant cells. Temporary functional inactivation of the 60S ribosome assembly factor Bop1 in a 3T3 cell model markedly increased cell recovery after exposure to camptothecin or methotrexate. This was due, at least in part, to reversible pausing of the cell cycle preventing S phase associated DNA damage. Similar cytoprotective effects were observed after transient shRNA-mediated silencing of Rps19, but not …

Molecular Mechanisms Of Dna Replication Initiation In Hpvs With Genetic Variations Leading To Cellular Carcinogenesis, Gulden Yilmaz

Graduate School of Biomedical Sciences Theses and Dissertations

Human papillomaviruses are a vast family of double-stranded DNA viruses containing non-carcinogenic and carcinogenic types, whose crucial differences remain unknown, except for the difference in the frequency of DNA replication. The human papillomavirus (HPV) E2 protein regulates the initiation of viral DNA replication and transcription. Its recognition and binding to four 12 bp palindromic sequences in the viral origin is essential for its function. Little is known about the DNA binding mechanism of the E2 protein found in HPV types that have low risk for oncogenicity (low-risk) as well as the roles of various elements of the individual binding sites. …

Chaperoning Ef Hands That Shape Calcium Response: Ncald, Hpca And S100b, Jingyi Zhang

Graduate School of Biomedical Sciences Theses and Dissertations

All organisms have an internal clock with a defined period between repetitions of activities. The period for circadian clock in human is 24.5 hours, while in mouse and rat, it is 23.5 hours. However, all organisms are forced to be in synchronization with their environment. A major environmental force that resets the internal clock to 24 hours is light. This phenomenon is defined as “light entrainment” or “phase-setting”. It is unclear how this entrainment process occurs. Studies from this laboratory indicate a role for two neuronal calcium sensor proteins: Neurocalcin  (NCALD) and S100B. For these two genes, mRNA as …

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 …

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 …

Development Of Cellular Assays To Monitor Enzymatic And Biological Activity Of Cd73: A Key Modulator Of Anti-Tumor Immune Response, Alexandra Fanuka

Graduate School of Biomedical Sciences Theses and Dissertations

Ecto-5’-nucleotidase, known as CD73, is an extracellular enzyme that converts adenosine monophosphate (AMP) to adenosine and has recently been identified as a potential drug target for cancer immunotherapy. Its immunosuppressive effects, mediated by the activity of adenosine, are associated with higher rates of tumor invasion and metastasis, as well as poorer prognoses overall in many cancer types. CD73 is often co-expressed with ectonucleoside triphosphate diphosphohydrolase-1 (CD39), which catalyzes the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP), and ADP to AMP on the surface of tumor cells. Dual expression further propagates immunosuppressive effects of adenosine in the tumor microenvironment. …

Punctuated Evolution Within A Eurythermic Genus (Mesenchytraeus) Of Segmented Worms: Genetic Modification Of The Glacier Ice Worm F1f0 Atp Synthase, Shirley A. Lang

Graduate School of Biomedical Sciences Theses and Dissertations

Segmented worms (Annelida) are among the most successful animal inhabitants of extreme environments worldwide. An unusual group of Mesenchytraeus worms endemic to the Pacific Northwest of North America occupy geographically proximal ecozones ranging from low elevation temperate rainforests to high altitude glaciers. Along this altitudinal transect, Mesenchytraeus representatives from disparate habitat types were collected and subjected to deep mitochondrial and nuclear phylogenetic analyses. Evidence presented here employing modern bioinformatic analyses (i.e., maximum likelihood, Bayesian inference, multi-species coalescent) supports a Mesenchytraeus “explosion” in the upper Miocene (5-10 million years ago) that gave rise to ice, snow and terrestrial worms, derived from …

Understanding The Differences Between Neuronal Calcium Sensor Proteins: A Comparison Of Neurocalcin Delta And Hippocalcin, Jeffrey M. Viviano

Graduate School of Biomedical Sciences Theses and Dissertations

Many neuronal functions, including learning and memory are driven by changes in intracellular Ca2+concentrations. The Neuronal Calcium Sensor (NCS) family of proteins is responsible for mediating the response to calcium. They are typically comprised of 4 EF hands; of which EF 2, 3, and 4 bind calcium.

Hypothesis: NCS proteins carry out unique, non-overlapping functions, and that specific characteristics of the family can be mapped to precise regions of the proteins.

Results: The effect on the following properties were investigated primarily on two highly similar NCS proteins, Neurocalcin Delta (NCALD) and Hippocalcin (HPCA): (1) Response to calcium was determined through …

Replication-Transciption Switch In Human Mitochondria, Karen Agaronyan

Graduate School of Biomedical Sciences Theses and Dissertations

Coordinated replication and expression of mitochondrial genome is critical for metabolically active cells during various stages of development. However, it is not known whether replication and transcription can occur simultaneously without interfering with each other and whether mtDNA copy number can be regulated by the transcription machinery. Human mitochondrial RNA polymerase (mtRNAP) is a central enzyme involved in gene expression in mitochondria. It generates genome-size polycistronic transcripts and also makes replication primers at two origins of replication. MtRNAP is distantly related to phage T7 RNAP. While T7 RNAP is optimized to produce large amounts of transcripts to overcompete the bacterial …

The Role Of E. Coli Transcript-Cleavage Factors Gre In Transcriptional Regulation Under Hyperosmotic Stress, Kseniya Obraztsova

Graduate School of Biomedical Sciences Theses and Dissertations

Escherichia coli adapts to changes in the osmotic environment through the process of osmotic response which entails synthesis of specific enzymes and transporters to accumulate essential osmoprotectants. This process is highly regulated at the level of transcription. Upon cell exposure to high salt, RNA polymerase (RNAP} rapidly dissociates from genomic DNA, while the nucleoid becomes hyper condensed. During the subsequent osmoadaptation phase RNAP reassociates with the DNA and resumes transcription. The mechanisms of transcription initiation, promoter escape and its regulation during osmoadaptation are poorly understood. Here we demonstrate that a highly conserved bacterial regulator, transcript cleavage factor GreA, is essential …

The Genetic Hierarchy Of The Heterochronic Pathway In C. Elegans, Jennifer Tsialikas

Graduate School of Biomedical Sciences Theses and Dissertations

The correct timing of developmental events is fundamental to the growth of every animal. The pathways that control developmental timing and cell-fate succession are complex and robust in a way that underscores this importance. In this work, I have shown how an early developmental regulator, LIN-14, acts to integrate the earliest aspects of development with the events that take place afterward. I have uncovered how microRNAs from two different families fit into the cascade of proteins and micro RNA regulation that defines the developmental timing pathway. Finally, my work has helped to uncover the dual-acting nature of two proteins in …

The Role Of Neurovascular Compromise, Autoimmune Antibodies And Neuronal Calcium Sensor Proteins During The Onset And Progression Of Alzheimer's Disease - Linking The Retina With The Brain, Hao Wu

Graduate School of Biomedical Sciences Theses and Dissertations

Alzheimer's disease (AD), the main cause of dementia, is a progressive and irreversible neurodegenerative disease. The pathological hallmarks of the disease include bloodbrain barrier (BBB) breach, neurofibrillary tang les and amyloid plaques. Also, emerging evidence has raised the possibility that instead of a secondary consequence, the neuroinflammation contributes to the development and early progression of AD. However, the mechanism underlying the blood-neural barrier (BNB), chronic inflammation and neuronal degenerative diseases (NDDs) remain to be elucidated.

To explore the role of the chronic inflammation in NDDs and delineate the early steps of these diseases, in vivo drug-induced and transgenic mouse models …

Blood-Tissue Barriers And Autoantibodies In Neurodegenerative Disease Pathogenesis: An Approach To Diagnostics And Disease Mechanism, Eric Luria Goldwaser

Graduate School of Biomedical Sciences Theses and Dissertations

Brain homeostasis can be affected in a number of ways that lead to gross anatomical, cellular, and molecular disturbances giving rise to diseases like Alzheimer’s disease (AD) and related dementias. Unfortunately, the mechanistic pathoetiology of AD’s hallmark features of cerebral amyloid plaque buildup and neuronal death are still disputed. Using human brain AD sections, immunohistochemistry experiments revealed internalized surface proteins, co-localized to an expanded lysosomal compartment. Other stains for amyloid-β1-42 (Aβ42) and various immunoglobulin (Ig) species displayed them leaking out of the cerebrovasculature through a dysfunctional blood-brain barrier (BBB), binding to neurons in the vicinity, and localizing to intracellular vesicles …

Microrna-Target Interactions In Embryonic Stem Cells, Shuang Wu

Graduate School of Biomedical Sciences Theses and Dissertations

Animal embryogenesis is a highly orchestrated process involving many geneexpression programs that determine specific fates of individual cells during development. Gene expression can be regulated at different stages such as at transcription initiation or mRNA stability, and microRNA-mediated gene regulation is a crucial pathway on the regulation of mRNA stability. microRNAs, or miRNAs, are small, conserved non-coding RNAs that negatively regulate gene expression post-transcriptionally. The mouse miR-290-295 cluster and its human homolog miR-371-373 are stem cell-specific miRNA clusters, and their expression can only be observed in early embryos, primordial germ cells, germ cell compartments of adult testis and embryonic stem …

Neurocalcin ẟ Response To Calcium: Which Ef Hand Matters The Most?, Trokon Fiawoo

Graduate School of Biomedical Sciences Theses and Dissertations

Changes in intracellular calcium levels play a very important role in cell signaling, in turn, affecting neuronal functions such as memory, learning and cell death. A class of proteins called Neuronal Calcium Sensor (NCS) proteins serves to modulate the functioning of the neuronal cells in response to changes in calcium levels. Structurally, all NCS proteins have 4 calcium-binding EF hand motifs, although EF I does not bind to calcium in many members. All NCS proteins are myristoylated at the N-terminus. Neurocalcin delta (NCALD) is an NCS protein, and shares 95% similarity in primary amino acid sequence with another major NCS …

Assembly And Structure Of Human Mitochondrial Transcription Initiation Complex, Yaroslav Morozov

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondria play a key role in energy metabolism in nearly all eukaryotic cells. Apart from that, they participate in many other biochemical pathways, such as amino acid and nucleotide metabolism, and biosynthesis of cholesterol, heme, and iron-sulfur clusters. Mitochondria are also involved in cell signaling, apoptosis and regulation of cell cycle. Abnormalities of mitochondrial morphology and function are often associated with tumor progression, neurodegeneration and aging.

Mitochondria are unique organelles in mammalian cells because they have their own genomic DNA, transcription and translation systems. Various mutations and defects in mitochondrial gene expression lead to severe diseases that include various mitochondrial …

Hexokinase Ii Localization Is Independent Of Ampk Activation In Hela Cells, Alyssa Brown

Graduate School of Biomedical Sciences Theses and Dissertations

In order for a cancer cell to thrive, it must alter its metabolism to produce the energy needed for rapid growth. Cells accomplish this by the Warburg Effect, or switching metabolism to aerobic glycolysis, where a cell can rapidly break down sugar into ATP, lactic acid and additional byproducts. Hexokinase 2, the enzyme that catalyzes the first committed step of glycolysis, may also be upregulated in cancer cells to increase glucose breakdown. Similar proteins for metabolism are found in both S. cerevisiae and mammalian cells. S. cerevisiae regulates metabolism through glucose repression, by Snf1 (mammalian homolog: AMPK) activation, which aids …

Utility And Origin Of Blood-Based Autoantibodies For Early Detection And Diagnosis Of Neurodegenerative Diseases, Cassandra Demarshall

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies are self-reactive antibodies that have been widely implicated as causal agents of autoimmune diseases. They are found in the blood of all human sera, regardless of age, gender, or the presence or absence of disease. While the underlying reason for their ubiquity remains unknown, it has been hypothesized that they participate in the clearance of blood-borne cell and tissue debris generated in both healthy and diseased individuals on a daily basis. Although much evidence supports this debris clearance role, recent studies also suggest a causal role for autoantibodies in disease. My thesis work has focused on this "cause and/or …

Functional Analysis Of Rpl22: Coordinating Differentiation Signals And Developmental Gene Translation To Promote Cell Fate Decisions, Stephen Kim

Graduate School of Biomedical Sciences Theses and Dissertations

The execution of meiosis and spore formation in S. cerevisiae requires a transient transcription program that is initiated by Ime I-dependent destruction of the repressor Ume6. IMEJ transcription is tightly contro1led by both cell type and nutritional cues but how its translation is regulated has been unknown. This study demonstrates that Rpl22A and Rpl22B, eukaryotic-specific ribosomal protein paralogs of the 60S large subunit, are required for efficient Ime I translation. While IME1 mRNA is induced normally in the absence of both para logs following transfer to sporulation medium, Ume6 remains stabilized, downstream early meiotic gene remain repressed, and development is …

The Development Of A Platform For Expression And Purification Of The Mammalian Transmembrane Transporter Abca4, Amaryllis Ortiz

Graduate School of Biomedical Sciences Theses and Dissertations

Purpose- ABCA4 is an ATP Binding Cassette (ABC) protein localized at cone and rod photoreceptor outer segments of the retina. Though mutations in ABCA4 have been found to cause a broad spectrum of disorders, ABCA4's high molecular weight (~210 kDa) and biochemical transmembrane properties have made ABCA4 functional studies unsuccessful. Identifying how ABCA4 functions might have significant clinical impact and open unanticipated avenues for therapeutic interventions. Thus, the objective of this study was to develop a new expression system able to produce the full-length, correctly folded and fully functional ABCA4 protein.

Methods- the ABCA4 gene was amplified from the PCMV6-ABCA4 …

Hippocalcin Response To Calcium: Do Conserved Tryptophans – W30 Or W103 – Matter?, Sunkesula K. Sagar

Graduate School of Biomedical Sciences Theses and Dissertations

Changes in intracellular calcium levels play a very important role in cell signaling, in turn, affecting neuronal functions such as memory, learning and cell death. A class of proteins called Neuronal Calcium Sensor (NCS) proteins serves to modulate the functioning of the neuronal cells in response to changes in calcium levels, and prevent neuronal apoptosis. Structurally, all NCS proteins have 4 calcium-binding EF hand motifs, although EF1 does not bind to calcium in many members. All NCS proteins have an acyl modification at the N- terminus – where a myristoyl group is added post-translationally. Hippocalcin (HPCA) is an NCS protein, …

Structural And Functional Interactions Between Bro1 Domain Of Human Alix Protein And Nucleocapsid Packaging Rna Complex From Hiv, Scott Gross

Graduate School of Biomedical Sciences Theses and Dissertations

A virus is only as powerful as its ability to spread. Enveloped retroviruses, namely HIV-1, use exocytosis pathways that normal host cells use to release particles from the plasma membrane. The main pathways of interest in this study are the Endosomal Sorting Complex Required for Transport (ESCRT) and adjacent ALIX pathways. The ESCRT pathway is especially important for degradation of receptor/cargo complexes that form Multi-Vesicular Bodies (MVBs). Currently, there is no known therapy that targets this endosomal pathway, which would prevent the spread of the virus to other cells. The virus has adapted to jump from pathway to pathway when …

Age-Dependent Breakdown Of The Blood Brain Barrier And Associated Changes In S100b Ko Mice, Eric V. Brown

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies play an important role in many autoimmune diseases. Recent research has shown that breakdown of the blood brain barrier (BBB) occurs concomitant to generation of brain reactive autoantibodies in many neurodegenerative diseases, which serve as biomarkers and drivers of pathology. SI00B, a calcium binding protein found most highly expressed in astrocytes which ensheathe the BBB, has many functions in neural development and signaling. Currently literature indicates that S100B KO mice develop normally, with no phenotypic abnormalities. Here, it is demonstrated that S100B KO mice seem to develop a chronic BBB breakdown similar to that seen in human neurodegenerative diseases. …

Meiotic Checkpoint Activation Promotes Anaphase Promoting Complex/Cyclosome Substrate Specificity And Ume6/Sin3/Rpd3-Independent Reduction In Emg Expression, Rebecca Lewandowski

Graduate School of Biomedical Sciences Theses and Dissertations

Complex differentiation pathways, such as yeast meiosis and sporulation, are initiated in response to cell type and external stimuli and are driven by changes in tightly regulated and temporally expressed transcriptional programs. These programs are monitored by checkpoint mechanisms that couple meiotic progression to transcriptional activity to ensure each stage is successfully completed prior to progression into the next phase. This work investigated transcriptional regulation controlling meiotic progression when cells sense an insult to genetic integrity. These studies revealed that the early meiotic gene (EMG) repressor Ume6p is degraded during meiotic checkpoint activation triggered by the deoxyribonucleotide reductase inhibitor and …

Novel Biomarkers Can Be Used As Targets To Combat Cancer, Harini Krishnan

Graduate School of Biomedical Sciences Theses and Dissertations

Cancer kills almost 8 million people per year worldwide. Therefore, about 13 people die from cancer every minute. Clearly, current cancer treatments are not completely effective. Moreover, many chemotherapeutic reagents are not very specific for cancer cells.

These agents attack rapidly dividing cells, including a wide array of normal cells, in addition to cancer cells, in the body. This lack of specificity can cause collateral damage and significant side effects in patients. More targeted therapies are needed to successfully combat cancer. Specific cancer biomarkers need to identified and characterized in order to develop better targeted anti-cancer drugs.

Tumor cells can …

Regulation Of Strand-Specific Processing In Human Pre-Mir-371 And Its Mouse Homologs, Jianting Shi

Graduate School of Biomedical Sciences Theses and Dissertations

MicroRNAs (miRNAs) are small noncoding RNAs, known to regulate genes by inducing target mRNA degradation or translational repression. This regulatory function has been shown to assist developmental timing control and increasingly more evidence reveals some of the miRNAs may have tissue/cell type-specific function, showing the potential to assist cell differentiation. Mouse miR-290-295 cluster is embryonic stem cell (ESCs)-specific miRNA cluster and human miR-371-373 cluster has been verified to be its functional homolog. We have previously demonstrated that human pre-miR-371 is processed into multiple miRNA species, which represent the seeds of the mouse of miR-290-5p, miR-292-5p, miR-292-3p-iso2 and miR-293-3p. Deep sequencing …

The Development Of A Comprehensive Antifungal Susceptibility Testing Assay For Vulvovaginal Candidiasis Therapy, David Hardaker

Graduate School of Biomedical Sciences Theses and Dissertations

Vulvovaginal candidiasis is the most common fungal infection of the female urogenital tract, commonly caused by Candida albicans and C. glabrata. However, treatment can be difficult when caused by non-albicans strains due to resistance to the oral antifungal drug fluconazole. The mechanism through which strains of Candida, particularly C. glabrata, develop resistance to different antifungal classes has not been completely characterized. The ergosterol biosynthesis pathway, an important component of the cell membrane, is the major target of antifungals such as fluconazole, an inhibitor of the ERG 11 gene. Current research shows that an upregulation of specific genes in C. glabrata …

Analysis Of The Regulation And Function Of Cip2a To Identify Candidate Biomarkers For Prostate Cancer, Diana Savoly

Graduate School of Biomedical Sciences Theses and Dissertations

Protein Phosphatase 2A (PP2A) is a tumor suppressor involved in the regulation of several signaling pathways and the cell cycle. PP2A becomes inactivated by several inhibitors, including Cancerous Inhibitor of PP2A (CIP2A). CIP2A has been identified as an oncogene, which is over-expressed in cancers and inhibits PP2A through direct interaction. CIP2A is recognized as a biomarker for cancer; however, it is not cancer-specific. Therefore, we identified and examined the use of CIP2A-regulated proteins as potential biomarkers in prostate cancer to better diagnose prostate cancer in patients. Currently, Prostate Specific Antigen (PSA) is widely used to detect prostate cancer; however, it …