Cell Biology Commons^™

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 …

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. …

Overexpression Of Sox18 Increased Cell Proliferation, Migration And Colony Formation In Pediatric Sarcomas, Jack E. Ojile

Honors Program Theses and Research Projects

Cancer has become one of the leading causes for premature deaths and continues to increase in rank across the world. An estimated 19.3 million new cases of cancer were reported in 2020 and 10 million cancer related deaths occurred worldwide. Ewing sarcoma and Rhabdomyosarcoma are two pediatric cancers that have not made significant improvements to patient survival for a metastatic diagnosis and the current chemotherapy regiment can cause several undesirable side effects immediately after treatment or later in life. SOX18 has been observed to play some role in various tumorigenic properties like proliferation, invasion, and resisting cell death signals in …

The Role Of Long Non-Coding Rna (Lncrna) In The Organization Of Nuclear Bodies, Soobin An

Symposium of Student Scholars

Nuclear bodies (NBs) (e.g., the nucleolus, nuclear speckles, and others) are membraneless compartments within the eukaryotic cell nucleus that selectively accumulate and retain specific nuclear proteins. NBs have become a new interest in recent discoveries because of their potential involvement in cancer and neurological disorders. However, the regulation and function of NBs are still enigmatic. Our laboratory studies a specific type of NBs, called B-bodies, to understand how NBs are formed and regulated in the nucleus. We hypothesized that long non-coding RNA (lncRNA) functions as a structural scaffold of NBs.

The B-body is a recently discovered NB expressed in the …

Investigations Into Prg-2 And Its Involvement In Developing Gallus Gallus Retinal Neurons, Jeffrey Parham

Graduate Theses

I am interested in the development of the nervous system, especially since during development nerves grow and extend, but in adults, they do not regenerate if damaged. We are specifically interested in the molecules that guide nerves to the correct target during their development. Lysophosphatidic acid (LPA) is a bioactive molecule that has been shown to play a role in neural development. LPA, through repeated studies, has been shown to stop neurons from growing by causing a physical change in a neuron’s growth cone (a structure used for navigation and growth). Recently, a novel set of genes, called PRGs, have …

Dpc29 Promotes Mitochondrial Translation Post-Initation In Saccharomyces Cerevisiae, Kyle Andrew Hubble

Graduate School of Biomedical Sciences Theses and Dissertations

Although the cytosolic and bacterial translation systems are well studied, much less is known about translation in mitochondria. In the yeast Saccharomyces cerevisiae, mitochondrial gene expression is predominately regulated by translational activators. These regulators are thought to promote translation by binding the elongated 5’-UTRs on their target mRNAs. Since mammalian mitochondrial mRNAs generally lack 5’-UTRs, they must regulate translation by other mechanisms. As expected, most yeast translational activators lack orthologues in mammals. Recently, a mitochondrial gene-specific translational activator, TACO1, was reported in mice and humans. To better define its role in mitochondrial translation I examined the yeast TACO1 orthologue, DPC29. …

Assessing Selective Export Of Fluorescent Ssa4 Reporters, Caroline Firmin, Rebecca Adams

Science University Research Symposium (SURS)

The process of creating proteins from mRNA is necessary for cell viability. Importantly, the proteins that are generated are differentially regulated so that the cell makes specific proteins in response to its environment. For example, mRNA is selectively exported during stress conditions to allow response to this stress. During heat shock at 42°C, in which proteins are denatured, the gene SSA4 encodes a selectively transported protein chaperone that allows refolding of denatured proteins. This study sought to explore the mechanisms of this selective export. To do this, I analyzed the expression of a fluorescent reporter wherein GFP is expressed with …

Cell Division Dynamics Of Escherichia Coli In Extreme Environments, Steven P. Murray

Graduate Theses and Dissertations

Life is remarkable in how resilient it can be. Many organism, classified as ex- tremophiles, can not only survive in extreme environments, but they can thrive in them. In the search for extraterrestrial life, the best candidates to harbor life exist with some kind of extreme condition. Europa, for example, is a favorite for the possibility of accommodating life as we know it within our solar system. Thought there is believed to be a liquid ocean under its icy surface, this habitat would be under immense pressures and high salinity. To best know where to look for extraterrestrial life, it …

Understanding SjöGren's Syndrome As A Systemic Autoimmune Disorder, Gaietchyne Chery

Legacy Theses & Dissertations (2009 - 2024)

Sjögren’s syndrome is an autoimmune condition characterized by a dysfunction in the lachrymal and salivary glands which results in dry eyes and dry mouth. Since its first description in 1892, the disease is one of the most common autoimmune diseases after lupus erythematosus and rheumatoid arthritis in the United States. Despite its high prevalence in the general population, Sjögren’s syndrome remains hard to diagnose due to the wide range of symptoms associated with the disease that is also shared by other conditions. Furthermore, the mechanisms behind the pathogenesis are not properly understood even though multiple factors have been proposed to …

Exploring The Anticancer Mechanism Of Thienopyrazole Derivative Tpz-1 In Acute Myeloid Leukemia, Jessica Dyanne Hess

Open Access Theses & Dissertations

Anticancer drug discovery is a time and resource-consuming process for which exceedingly reliable and efficient modern approaches are needed. Phenotypic drug screenings can generate highly potent and innovative drug candidates; however, deconvolution of the drugâ??s target often presents significant barriers to drug development. To overcome this hurdle, we have originally combined in vitro and in silico analyses to uncover the molecular mechanism(s) driving the anticancer activity of the uniquely structured small molecule drug candidate, Tpz-1. Our study revealed that Tpz-1 is a multitargeted agent which induces the programmed death of HL-60 acute myeloid leukemia cells primarily through disruption of microtubule …

Ankyrin Dependent Mitochondrial Function And Bioenergetics In The Heart, Janani Subramaniam, Janani Subramaniam

Dissertations and Theses (Open Access)

ANK2 mutations in patients are associated with numerous arrhythmias, cardiomyopathies, and other heart defects. In the heart, AnkB, the protein encoded by ANK2, clusters relevant ion channels and cell adhesion molecules in several important domains; however, its role at Mitochondria Associated ER/SR Membranes (MAMs) has yet to be investigated. MAMs are crucial to mitochondrial function and metabolism and are signaling hubs implicated in various cardiac pathologies. Among several functions, these sites mediate the direct transfer of calcium from the ER/SR to the mitochondria to modulate ATP synthesis. Given that mitochondrial function and energy production are paramount to cardiovascular heath, …

The Role Of Fatty Acid Metabolism In The Pathogenesis Of Trypanosoma Brucei, Nava Poudyal

All Dissertations

Trypanosoma brucei is the protozoan parasite that causes African Sleeping Sickness in humans and nagana, a wasting disease in cattle. T. brucei completes its life cycle in two hosts, mammals and the tsetse fly insect vector. Due to the geographical restriction of the tsetse fly, the disease is endemic in sub-Saharan Africa. Both the insect and mammalian forms of the parasite need fatty acids to anchor their surface proteins. We worked on three projects on fatty acid metabolism and its role in immune evasion strategies of T. brucei. First, we assessed the role of T. brucei surface proteins in …

Differential Impacts Of Hhv-6a Versus Hhv-6b Infection In Differentiated Human Neural Stem Cells, Elham Bahramian

Graduate Theses and Dissertations

Within the family Herpesviridae, sub-family β-herpesvirinae, and genus Roseolovirus, there areonly three human herpesviruses that have been described: HHV-6A, HHV-6B, and HHV-7. Initially, HHV-6A and HHV-6B were considered as two variants of the same virus (i.e., HHV6). Despite high overall genetic sequence identity (~90%), HHV-6A and HHV-6B are now recognized as two distinct viruses. Sequence divergence (e.g., >30%) in key coding regions and significant differences in physiological and biochemical profiles (e.g., use of different receptors for viral entry) underscores the conclusion that HHV-6A and HHV-6B are distinct viruses of the β-herpesvirinae. Despite these viruses being implicated as causative agents in …

A Study On Interactions Between Metal-Organic Frameworks And Biological Materials, Josh Phipps

Graduate Theses and Dissertations

Metal-organic frameworks or MOFs are an extremely useful tool in many areas of applications. Their popularity in recent years has arisen from their high efficiency in catalytic chemical reactions. This is made possible due to their porous interior and the ability of the MOFs components to be functionalized. These same traits make MOFs excellent for use in protein encapsulation or immobilization and have the potential to become excellent drug carriers. Their development in this utilization has been limited dramatically compared to MOFs chemical applications. This is due in part to the nature of biological processes taking longer to study, but …

The Effects Of Deleting Lrb E3 Ligase Region 2 On Red Light Responses In Arabidopsis Thaliana, Sabina Liskey

Masters Theses

The ability of plants to absorb light through photoreceptors is essential for successful plant development. Phytochromes are important plant photoreceptors that detect and absorb red and far-red light and must function properly for plant survival. The Light Response BTB proteins (LRB) play an important role in a plant’s response to red light by degrading phytochrome B (PhyB) via the ubiquitin proteasome system (UPS). Although there has been a successful investigation into understanding the function of the LRBs, the function of a few regions within LRB proteins remains unknown, including a portion located on the N-terminal end of the protein, termed …

Regulation Of Parkinson’S Disease-Associated Genes By Pumilio Proteins And Micrornas In The Human Neuroblastoma Cell Line Sh-Sy5y, Lisa J. Snoderly-Foster

Dissertations

Parkinson’s disease (PD) is the second most common age-related, neurodegenerative disease. A small collection of genes has been linked to PD, including SNCA encoding the protein alpha-synuclein that aggregates in Lewy bodies, a hallmark of PD. Overexpression of these genes can lead to pathogenesis, yet the regulatory mechanisms that control protein production of the genes are not fully understood. The SH-SY5Y neuronal cell line is a common model for the study of neurodegenerative diseases, including PD. However, SH-SY5Y cells are difficult to transfect, a process necessary for genetic manipulations and downstream analysis of RNA and protein. Herein, I describe the …

A Pooling Strategy For Detecting Carbapenem Resistance Genes By The Xpert Carba-R Test In Rectal Swab Specimens, Fred C. Tenover, Peng Zhang, Qi Wang, Chaoe Zhou, Feifei Zhang, Xinghui Gao, Yi-Wei Tang, Hui Wang

Biology Faculty Publications

Rapid and accurate detection of carriers of carbapenemase-producing organisms (CPO) in hospitalized patients is critical for infection control and prevention. This study aimed to evaluate a pooling strategy for the detection of carbapenem resistance genes (CRG) in multiple specimens using the Xpert Carba-R test. Two rectal swabs each were collected from 415 unique patients. One swab was tested by Carba-R on the five specimen-pooled strategy. The other swab was tested individually by culture followed by DNA sequence analysis for CRG as the reference. At the first 5:1 pooling testing, 22 of 83 pools were positive, which yielded 34 positives from …

Canalization And Other Design Principles Of Gene Regulatory Networks, Claus Kadelka

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Ferrocenium Salt Aided Substitution Reactions And Synthesis Of Glycosylated Curcumin Derivatives, Deva Saroja Talasila

Dissertations

Organic synthesis has been significantly advanced with the employment of transition metal complexes. The discovery of transition metal catalysts provided the synthetic community with powerful tools for accelerating reactions and making them more selective and efficient. Many chemical reactions do not happen without a catalyst.

Iron-based catalysts have several advantages for the chemical industry because it is a non-toxic and ecologically friendly metal. Our group previously found that ferrocenium cations with a 3+ oxidation state of iron-catalyzed propargylic substitution reactions at low temperatures. The sandwich structure of ferrocenes allows substituents to be introduced on the cyclopentadienyl rings, which allows for …

Cell Size Control Mechanisms In The Multiple Fission Cell Cycle Of Chlamydomonas, Dianyi Liu

Dissertations

Size homeostasis is achieved by a balance between cell growth and cell division, but the underlying mechanisms are yet fully understood. Green alga Chlamydomonas reinhardtii (Chlamydomonas) is a unique model for size control. Instead of the canonical binary fission cell cycle, Chlamydomonas uses a multiple fission cell cycle where a prolonged G1 phase is followed by rapid alternative n rounds of S/M (DNA synthesis and mitosis) cycles to produce 2ⁿ daughter cells. Two size checkpoints show size-dependence: the Commitment checkpoint governs a minimum size for a cell to divide at least once, and the S/M checkpoint governs the division …

Regulation Of Tissue Mechanics And Adherens Junctions By Small Gtpase Rhoa During Drosophila Embryogenesis, Hanqing Guo

Dartmouth College Ph.D Dissertations

Actomyosin contractility plays an important role at both the cell and tissue level during developments. In this study, we developed an optogenetic tool that can acutely inhibit actomyosin contractility by targeting its main activator Rho1. This optogenetic tool can achieve myosin inhibition within one minute and thus enable further dissection of actomyosin function in development. In my first two projects, I used Drosophila mesoderm invagination (also known as ventral furrow formation) as a model to study epithelial folding, a fundamental mechanism for constructing complex 3D tissues. Apical constriction mediated by actomyosin contractility is a common mechanism for epithelial folding. However, …

Impacts Of Intermediate And Long-Term Vitamin D Deficiency On The Murine Gastric Epithelial Cells And Acid Secretion, Shaima Raji Sirajudeen

Dissertations

The biological functions of vitamin D (VD) are diverse. It influences immunological response, cell proliferation and differentiation, and calcium homeostasis. However, over one billion people globally are VD deficient. The VD receptors, VDR and PDIA3, mediate the biological activities of VD. Studies on the biological roles of VD are numerous but very little on the stomach. The stomach is divided into three main parts – forestomach, corpus and antrum. Gastric glands, which make up the functional units of the stomach, are made up of numerous cell lineages and are located in the corpus and antrum, which are the glandular parts …

Leaf Phenology And Freeze Tolerance Of The Invasive Tree Pyrus Calleryana (Roseaceae) And Potential Native Competitors, Margaret E. Maloney, Abby Hay, Eric B. Borth, Ryan W. Mcewan

Biology Faculty Publications

Pyrus calleryana is one of the most problematic invasive species in the eastern United States. The mechanisms that enable Py. calleryana to establish and outcompete native plants are not fully understood but likely include a profile of advantageous traits. Extended leaf phenology is a characteristic noted in many woody invasive plants. Leaf phenology of Py. calleryana and two native woody species, Populus deltoides and Platanus occidentalis, was observed in natural areas near Dayton, OH from December 2019 to November 2020. A frost event in May also gave us the serendipitous opportunity to assess frost tolerance of these species. We …

Data Supporting A Saturation Mutagenesis Assay For Tat-Driven Transcription With The Gigaassay, Ronald Benjamin, Christopher J. Giacoletto, Zachary T. Fitzhugh, Danielle Eames, Lindsay Buczek, Xiaogang Wu, Jacklyn Newsome, Mira V. Han, Tony Pearson, Zhi Wei, Atoshi Banerjee, Lancer Brown, Liz J. Valente, Shirley Shen, Hong-Wen Deng, Martin R. Schiller

Life Sciences Faculty Research

The data in this article are associated with the research paper “GigaAssay – an adaptable high-throughput saturation mutagenesis assay". The raw data are sequence reads of HIV-1 Tat cDNA amplified from cellular genomic DNA in a new single-pot saturation mutagenesis assay designated the “GigaAssay”. A bioinformatic pipeline and parameters used to analyze the data. Raw, processed, analyzed, and filtered data are reported. The data is processed to calculate the Tat-driven transcription activity for cells with each possible single amino acid substitution in Tat. This data can be reused to interpret Tat intermolecular interactions and HIV latency. This is one of …