Cell Biology Commons^™

Sequence Properties Of An Intramolecular Interaction That Inhibits P53 Dna Binding, Emily Gregory, Gary W. Daughdrill

Molecular Biosciences Faculty Publications

An intramolecular interaction between the p53 transactivation and DNA binding domains inhibits DNA binding. To study this autoinhibition, we used a fragment of p53, referred to as ND WT, containing the N-terminal transactivation domains (TAD1 and TAD2), a proline rich region (PRR), and the DNA binding domain (DBD). We mutated acidic, nonpolar, and aromatic amino acids in TAD2 to disrupt the interaction with DBD and measured the effects on DNA binding affinity at different ionic strengths using fluorescence anisotropy. We observed a large increase in DNA binding affinity for the mutants consistent with reduced autoinhibition. The ΔΔG between DBD and …

Identifying Adaptor Proteins For Selective Mrna Export In S. Cerevisiae, Chloe Baker, Rebecca Adams

Science University Research Symposium (SURS)

The export of mature mRNA from the nucleus of the cell to the cytoplasm is crucial for a cell’s survival, as this process is necessary to produce proteins encoded by these transcripts. In S. cerevisiae (yeast) cells, a protein known as Mex67 must bind to the mRNA while it’s in the nucleus so it can cross through the nuclear pore complex (NPC). Mex67 cannot bind to the mRNA directly, instead it needs to be accompanied by adaptor proteins to aid it in getting across the NPC. Stress conditions such as heat shock interferes with the function of these adaptor …

Functionalization Of Chitosan Based Microparticles For In Vitro 3d Culture Of Human Liver Cells, William Imes

Williams Honors College, Honors Research Projects

Previous work involving 3D culture of human liver cells with fluorinated chitosan based microparticles has shown that their incorporation provides needed structural cues that the culture of cells alone does not provide, such as increased gas transport. However, using bare microparticles to grow large 3D cellular structures is not practical as they tend to collapse before any meaningful research can be done on them. It is proposed that this is because of the lack of extracellular matrix (ECM)components within pure cell culture in vitro, which in their absence cannot adequately facilitate biochemical communication and adhesion between cells. It is …

Salivary Gland Stromal Heterogeneity And Epithelial Controls, Nicholas L. Moskwa

Legacy Theses & Dissertations (2009 - 2024)

Organogenesis is the process organs go through where cellular communications coordinate all a developing organ needs. What organs need are more cells, in the right place, doing the right job. In the salivary gland, we know that stromal cells are important for organogenesis and that they coordinate the epithelium’s form and functions. However, specific stromal contributions have focused on epithelial quantity and placement. There is less information about how the stroma directs the epithelium towards certain functions. Here we used organoids as a model for understanding what stromal signaling directs epithelial cell fate. We found that stromal cell state is …

Genetic Regulation Within Cellular Stress Response Pathways, Jhos M. Dufflart

Legacy Theses & Dissertations (2009 - 2024)

Cellular stress is something that a cell deals with on a regular basis. Fortunately, there are several different mechanisms that are set in place in order to deal with them. Depending on the stress present in the cell there will be different stress response pathways that are activated in order to mitigate the stress or initiate cellular death mechanisms. Transcription factors (TFs) are key components within these pathways, and this will be the focus of this thesis. TFs within mammalian stress response pathways are tasked with the essential regulation of multiple genes within these pathways and are oftentimes linked with …

Exploring The Roles Of Stress, Codon Usage, And Rna Modifications In Myotonic Dystrophy Type 1, Afrooz Golestanian

Legacy Theses & Dissertations (2009 - 2024)

Myotonic dystrophy (DM), the most common form of muscular dystrophy, is a neuromuscular disease caused by microsatellite repeat expansions. It can represent a multi-systemic autosomal dominant disease with DM1 and DM2 subtypes. A cytosine-thymine-guanine (CTG) triplet repeat in the 3’ untranslated region (3’UTR) of myotonic dystrophy protein kinase (DMPK) gene causes DM1 disease, which leads to the production of a longer, abnormal and toxic mRNA. The toxic DMPK mRNA sequester the splicing proteins such as Muscle blind-like (MBNL) and rbFOX which leads to gene expression alteration. Repeat associated non-AUG (RAN) translation also occurs in DM1. Mitochondrial dysregulation has also been …

Elucidating The Role Of Polycomb Repressive Complex 2 In Lung Stem Cell Fate And Lung Disease, Aria Byrd

Theses and Dissertations--Toxicology and Cancer Biology

The average human lungs take ~22,000 breaths and inhale ~2,000 gallons of air each day. This organ is the primary conduit for the transfer of oxygen to the internal organs, making it crucial for the sustainment of life. Consequently, mechanical malfunction of the lungs and/or pollution of inhaled air negatively impact internal organ function and ultimately put survival in jeopardy. Epigenetics, by nature, is a plastic phenomenon in which environmental stimuli influence short term, long term, and generational gene expression patterns. Chronic exposure of harmful stimuli to the lung epithelium has also been shown to alter epigenetic pathways, engender aberrant …

Sex Dimorphism In Hematopoiesis And Bone Marrow Niche, Xiaojing Cui

Theses and Dissertations--Toxicology and Cancer Biology

Hematopoietic stem cells (HSC), which are a rare population of cells existing in human circulating blood and bone marrow, can form the whole-blood system by their self-renewal capacity and differentiation ability. Sex dimorphism can be found in hematopoietic stem and progenitor cells, and in the development of hematopoietic lineages. Also, males are at higher risk and have a worse prognosis for most hematologic malignancies than females. Under normal conditions, the number of circulating progenitor cells in women is lower than in men. Furthermore, female mice have a higher rate of HSC division than male mice. A dramatic gender difference exists …

Metabolic Diversity Among Fibroblasts From Regenerating And Non-Regenerating Mammals, Ebenezer Aryee

Theses and Dissertations--Biology

Regeneration is a wound repair process that terminates in the restoration of tissue function and structure. Fibroblasts play pivotal roles in regenerative and fibrotic wound repair. Reports of extensive regenerative ability in mammals have been historically rare, but more recently spiny mice (Acomys) have emerged as a bona fide model of complex tissue regeneration. Recent work has indicated that fibroblasts from regenerators (Acomys and Oryctolagus) are more resistant to reactive oxygen species (ROS)-induced senescence compared to non-regenerating species, suggesting the influence of intrinsic cellular states on the fate of wound repair. Determining the basal metabolic signature …

Intracellular Trafficking And Distribution Of Cd And Inp Quantum Dots In Hela And Ml-1 Thyroid Cancer Cells, Min Zhang

Graduate Theses/Dissertations

The study of the interaction of engineered nanoparticles, including quantum dots (QDs), with cellular constituents and the kinetics of their localization and transport, has provided new insights into their biological consequences in cancers and for the development of effective cancer therapies. The present study aims to elucidate the toxicity and intracellular transport kinetics of CdSe/ZnS and InP/ZnS QDs in late-stage ML-1 thyroid cancer using well-tested HeLa cells as a control. The XTT viability assay showed that ML-1 cells, and non-cancerous mouse fibroblast cells, exhibit no viability defect in response to these QDs, whereas HeLa cell viability decreases. These results suggest …

A Study Of Cobalt (Iii) Oxide Nanoparticle Delivery Of Sirna Molecules Directed Against Signaling Intermediates Of The P2y2 Receptor, Rachel Blair Stroud

Graduate Theses/Dissertations

G protein-coupled receptors are evolutionarily ubiquitous sensors of extracellular signals, propagating intracellular signal cascades through heterotrimeric G proteins. P2Y₂ receptors are GPCRs which are activated by extracellular nucleotides to mediate signaling cascades via Gαq coupling. Many GPCRs are subject to a common mechanism for signal termination involving phosphorylation of the C-terminal tail followed by β-arrestin binding and subsequent endocytic internalization of the complex. This effect has been described for the P2Y₂ R in the 1321N1 astrocytoma cell line, and UTP-induced activation and desensitization profiles have been previously defined. There is need to develop molecular vehicles for safe and …

Further Investigation Of The Initiating Mechanism Of The Type I Collagen Glomerulopathy, Matthew James Freese

Graduate Theses/Dissertations

The progressive accumulation of collagen and other extracellular matrix proteins in the renal mesangium results in fibrosis, glomerulosclerosis, and eventual renal failure. Mice deficient in integrating α2(I) collagen into the type I collagen structure, termed Col1a2-deficient mice, model kidney fibrosis through the condition Type I Collagen Glomerulopathy, because homotrimeric type I collagen accumulates extracellularly in the mesangium of renal glomeruli. Accumulation of homotrimeric type I collagen compresses blood vessels in glomeruli, which reduces filtration, increases pressure, and results in fibrosis. Picrosirius red (PSR) staining was used on Col1a2 deficient and wildtype mice to evaluate collagen deposition. Histological evaluation and …

Bone Morphogenetic Proteins Shape TReg Cells, Piotr Kraj

Biological Sciences Faculty Publications

The transforming growth factor-β (TGF-β) family includes cytokines controlling cell behavior, differentiation and homeostasis of various tissues including components of the immune system. Despite well recognized importance of TGF-β in controlling T cell functions, the immunomodulatory roles of many other members of the TGF-β cytokine family, especially bone morphogenetic proteins (BMPs), start to emerge. Bone Morphogenic Protein Receptor 1α (BMPR1α) is upregulated by activated effector and Foxp3+ regulatory CD4+ T cells (Treg cells) and modulates functions of both of these cell types. BMPR1α inhibits generation of proinflammatory Th17 cells and sustains peripheral Treg cells. This finding underscores the importance of …

Deconstructing Brown Adipocyte Neogenesis In Brown And White Adipose Tissue, Rayanne Burl

Wayne State University Dissertations

Global incidence of Type 2 Diabetes (T2D) has reached epidemic proportions, and increasing evidence indicates that dysfunctional adipose tissue is an important contributor to the pathogenesis of T2D. Expanding brown adipocyte (BA) populations within adipose tissues through adrenergic activation improves energy balance and insulin sensitivity. In order to exploit this remodeling of adipose tissue for therapeutic benefit, we need to understand the mechanisms by which adrenergic signaling expand populations of BAs in vivo. These studies utilized single-cell RNA-sequencing and transgenic mouse models, in combination with single-molecule fluorescence in situ hybridization (smFISH) and immunoistochemical analysis, to study BA neogenesis in vivo. …

Understanding The Effects Of Embryonic Hyperglycemia On Retinal Development And Maintenance, Kayla Titialii-Torres

Theses and Dissertations--Biology

Hundreds of millions of people are affected by diabetes worldwide. Whether they are diagnosed with prediabetes or Type I or II diabetes, there are a variety of mechanisms in the pathogenesis of diabetes. Diabetes is a disease which consists of recurring states of hyperglycemia that can be difficult to manage due to either lack of insulin production or improper utilization of insulin. While these mechanisms of action differ, complications induced by diabetes occur in both poorly regulated Type I and II. Common complications of diabetes include nerve damage, kidney damage, and eye damage. Eye damage specifically is called diabetic retinopathy …

The Role Of Protein Tyrosine Phosphatase Receptor Type F In Intestinal Homeostasis And Colorectal Cancer, Ashley T. Skaggs

Theses and Dissertations--Molecular and Cellular Biochemistry

Protein phosphorylation defines one of the most important regulatory mechanisms in cell signaling. PTPRF, protein tyrosine phosphatase receptor type F, belongs to the class I R2A subfamily of protein tyrosine phosphatases (PTP). The overall objective of this dissertation is to investigate the molecular mechanisms by which PTPRF regulates normal and cancer stem cells by controlling Wnt signaling.

Dysregulation of Wnt signaling promotes the initiation and progression of colorectal cancer (CRC). We first determined the functional important of PTPRF in regulating Wnt signaling in CRC. Combining cell culture, 3D tumor organoid and xenograft models, results from our study establish PTPRF as …

A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy

Theses and Dissertations--Molecular and Cellular Biochemistry

Toxoplasma gondii is an opportunistic, protozoan parasite of all warm-blooded animals, infecting roughly one-third of humans worldwide. Humans acquire infections by consuming T. gondii tissue cysts in undercooked meat or from oocysts shed in cat feces. Encysted parasites convert into rapidly growing tachyzoites that disseminate throughout the body, defining the acute phase of infection. Under host immune pressure, tachyzoites convert into bradyzoites that populate tissue cysts found in CNS or muscle tissue and persist for the lifetime of the host, defining the chronic phase of infection. Tissue cysts are responsible for transmission via carnivory, but also possess the ability to …

Development Of Novel Pyridazine Derivatives And Drug Delivery Systems Against Dengue, Janae A. Culmer

College of Graduate Studies: Theses & Dissertations

The lack of approved vaccines, medications and treatment regimens has significantly contributed to the rapid spread of mosquito-borne viruses such as Dengue and Zika virus. The complex immunopathology of these viruses presents limitations for the development and implementation of a definitive, safe and effective approach to combat infections.Previous research has demonstrated that vector control strategies such as the elimination of larval habitats, larviciding with insecticides, the use of biological agents and the application of adulticides have been unsuccessful in the reduction of viral transmission leading to the need for the continued development of antivirals. This research proposes an approach for …

Tissue And Sex-Specific Rna Editing During Induced Acute Inflammation, Claire E. Nichols

Graduate Theses/Dissertations

A-to-I RNA editing is a process where select adenosine (A) nucleotides are deaminated by an editing enzyme, ADAR, to become inosines (I) in RNA transcripts. RNA editing can affect the sequence of the encoded protein and the regulation of the RNA. ADAR1 also plays a role in regulating innate immunity and its expression is upregulated during inflammation. Current data on the effects of increasing ADAR1 on RNA editing is limited, and most studies are completed only in male animals. We are interested in expanding RNA editing data to include female animals. Lipopolysaccharide (LPS) was used to induce acute inflammation and …

Nutrient Scarcity And Cellular Cooperation In A Clonal Hydroid, Weam S. El Rahmany

Graduate Research Theses & Dissertations

Biological complexity forms when lower-level units (e.g., genes, cells, organisms) cooperatively band together. This complexity may be exemplified by multicellularity, the cooperation between the cells of the same species, or symbiosis, cooperation between the cells of different species. This cooperation is under continual threat, as defection, the opposite of cooperation, is favored by default by lower-level units (i.e., cells). Animal cancers may be the most well-known phenomena that exemplify the concept of cellular defection. Cancer cells have been shown to feature morphological and metabolic traits, developed through differential gene expression or mutations, that favor their growth at the cost of …