Biochemistry, Biophysics, and Structural Biology Commons^™

Tdp43 Autoregulation Gives Rise To Dominant Negative Isoforms That Are Tightly Controlled By Transcriptional And Post-Translational Mechanisms, Megan M. Dykstra, Kaitlin Weskamp, Nicolás B. Gómez, Jacob Waksmacki, Elizabeth Tank, M. Rebecca Glineburg, Allison Snyder, Emile Pinarbasi, Michael Bekier, Xingli Li, Morgan R. Miller, Jen Bai, Shameena Shahzad, Neha Nedumaran, Clare Wieland, Corey Stewart, Sydney Willey, Nikolas Grotewold, Jonathon Mcbride, John J. Moran, Aditya V. Suryakumar, Michael Lucas, Peter M. Tessier, Michael Ward, Peter K. Todd, Sami J. Barmada

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The nuclear RNA-binding protein TDP43 is integrally involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Previous studies uncovered N-terminal TDP43 isoforms that are predominantly cytosolic in localization, prone to aggregation, and enriched in susceptible spinal motor neurons. In healthy cells, however, these shortened (s)TDP43 isoforms are difficult to detect in comparison to full-length (fl)TDP43, raising questions regarding their origin and selective regulation. Here, we show that sTDP43 is created as a by-product of TDP43 autoregulation and cleared by nonsense-mediated RNA decay (NMD). sTDP43-encoding transcripts that escape NMD are rapidly degraded post-translationally via the proteasome …

Sialylation Of Tnfr1 By St6gal1 Modulates Receptor Dynamics And Determines Cell Fate, Jihye Hwang

All ETDs from UAB

Abnormal glycosylation has long been identified as a key feature of cancer. Aberrant glycan structures on tumor cells arise from the dysregulation of select glycosyltransferases. For example, sialyltransferase ST6GAL1 is notable for its high expression in various cancers, including breast, colon, ovarian, and pancreatic. ST6GAL1 introduces α2-6-linkage sialylation to N-glycans on proteins, endowing cancer cells with stem cell-like properties. This modification contributes to resistance to apoptosis mediated by death receptors like TNFR1. Despite its significance in cancer, the regulatory mechanisms controlling ST6GAL1 expression remain largely unexplored. Additionally, it is unclear whether the apoptosis-resistant effect of sialylation is caused by an …

Mechanistic Insights Of Translational Readthrough To Suppress Nonsense Mutations, Kari Thrasher

All ETDs from UAB

A nonsense mutation is a point mutation in DNA that gives rise to a premature termination codon (PTC) in the open reading frame of the transcribed mRNA. Translation of this PTC-containing transcript terminates prematurely, leading to the creation of truncated non-functional protein. Translational readthrough is one therapeutic option being explored to suppress nonsense mutations that cause disease. Here, we further elucidate amino acid incorporation and the functional consequences of readthrough of nonsense mutations that cause cystic fibrosis. Additionally, we reveal the molecular mechanisms activated by a recently described small molecule readthrough agent, SRI- 41315. Finally, we discuss the various therapeutic …

Nls-Binding Deficient Kapβ2 Reduces Neurotoxicity Via Selective Interaction With C9orf72-Als/Ftd Dipeptide Repeats, Kevin Kim, Amandeep Girdhar, Maria Elena Cicardi, V. Kankate, Miyuki Hayashi, Ruoyu Yang, Jenny Carey, Charlotte M Fare, James Shorter, Gino Cingolani, Davide Trotti, Lin Guo

Department of Biochemistry and Molecular Biology Faculty Papers

Arginine-rich dipeptide repeat proteins (R-DPRs) are highly toxic proteins found in patients with C9orf72-linked amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). R-DPRs can cause toxicity by disrupting the natural phase behavior of RNA-binding proteins (RBPs). Mitigating this abnormal phase behavior is, therefore, crucial to reduce R-DPR-induced toxicity. Here, we use FUS as a model RBP to investigate the mechanism of R-DPR-induced aberrant RBP phase transition. We find that this phase transition can be mitigated by Kapβ2. However, as a nuclear import receptor and phase modifier for PY-NLS-containing RBPs, the function of WT Kapβ2 could lead to undesired interaction with its …

Investigating The Interactions Between Elm1 And Hsl7 In The Morphogenesis Checkpoint Of Saccharomyces Cerevisiae, Rachel Foster

Masters Theses & Specialist Projects

Cell shape is essential to understanding the normal regulatory processes that occur within the cell and can indicate there are abnormalities present when there is dysfunction in the cell's development, which can have broader implications regarding human disease. The morphogenesis pathway couples cell division to the timely formation of a daughter bud in Saccharomyces cerevisiae and consists of Elm1, Hsl1, Hsl7, and Swe1 proteins which interact with septins at the bud neck to provide stability for the bud and to facilitate cell division. Elm1 is needed for the recruitment of Hsl1 and subsequently Hsl7. Hsl7 will then tether Swe1 to …

Characterization Of Legionella Pneumophila Effector Protein Ceg10, Emmanuella Ofoka

Masters Theses & Specialist Projects

Legionella pneumophila, the causative agent of Legionnaires' disease, utilizes a Type IV secretion system (T4SS) to transport effector proteins into host cells. This bacterium is said to have over 300 effector proteins. Among these, the Ceg10 effector protein had remained uncharacterized, despite evidence suggesting the importance of bacterial effector proteins in the host-pathogen interaction. This study aimed to perform a structural and functional characterization of Ceg10 through transcriptomic, bioinformatics, and molecular analyses. Transcriptomic profiling of HEK 293T cells expressing Ceg10 revealed significant differential gene expression, with approximately 20 upregulated genes, including leucine-rich repeat, as well as other downregulated genes. …

Expression And Function Of Floral Symmetry Genes In The Regulation Of Flower Shape In Fedia Graciliflora, Theresa A. Mustacchio

Theses and Dissertations

Shifts between radial symmetry (actinomorphy) and bilateral symmetry (zygomorphy) in flowers have occurred multiple times independently within angiosperms (flowering plants). Evidence across angiosperms indicate the transcription factors RADIALIS (RAD), DIVARICATA (DIV), and CYCLOIDEA (CYC) play a major role in regulating floral symmetry and morphology. The CYC-like genes have been shown to shift their expression dorsally independently in nearly all shifts to bilaterally symmetrical flowers examined. Three core eudicot clades of CYC-like genes have been identified: CYC1, CYC2 and CYC3, with only CYC2 genes being shown to have a role in floral symmetry. We use the non-model plant, Fedia graciliflora (Caprifoliaceae) …

Analysis Of The Influence Of Telomere Length Variation On Flowering Time And Plant Fitness In Arabidopsis, Brianna Spadavecchia

Theses, Dissertations and Capstones

Telomeres are conserved structures at the ends of eukaryotic chromosomes that promote genome stability. In most eukaryotes, the DNA found within these protective end caps consists of short, G-rich nucleotide repeats. Cells with critically short telomeres face a variety of potential adverse outcomes such as end-to-end chromosome fusion, apoptosis, etc. The length of telomeric DNA varies substantially between different plant species and even between genotypes of the same species. A previous study using T-DNA mutants of the model plant Arabidopsis thaliana with long or short telomeres suggested that telomere length may be an adaptive trait. Specifically, for reproductive fitness, the …

Ashwagandha And Sexual Health In Women With Hypoactive Sexual Desire Disorder: Exploring Extent Of Adaptogenic Properties, Rhea Chatterjee

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

Hypoactive Sexual Desire Disorder (HSDD) affects 40% of women and potentially decreases their quality of life. Currently, the primary treatment for HSDD is Flibanserin, which is a serotonergic agonist and an antidepressant. However, the limited efficacy of Flibanserin encourages the exploration of the utilization of traditional drugs such as Withania somnifera, otherwise known as Ashwagandha, as an alternative treatment for HSDD. Minimal studies examine ayurvedic medications or the symptoms of illnesses that traditional Western medicines are unable to treat. This comprehensive literature review investigated the efficacy of Ashwagandha in improving sexual function in women with HSDD. The paper evaluated …

Cdh-3/Cadherin, Yap-1/Yap And Egl-44/Tead Promote Syx-2/Syntaxin And Eff-1 Fusogen-Mediated Phagosome Closure, Alec Whited, Aladin Elkhalil, Ginger Clark, Piya Ghose

Biology Theses - Archive

Physical interactions between cells, such as cell-cell junctions, can profoundly impact cell fate. A vital cell fate for normal development and homeostasis is programmed cell death. Cells fated to die must be efficiently cleared away via phagocytosis, and defects are associated with a variety of diseased states. Whether cell-cell physical associations affect programmed cell elimination has not been well-explored. Here we describe, in vivo, a cell-cell adhesion-driven signaling pathway that ensures compartment-specific cell clearance during development. We previously described the specialized cell death program “Compartmentalized Cell Elimination” (CCE) in the C. elegans embryo. During CCE, the tail-spike cell (TSC), a …

Resveratrol Exerts Anti-Inflammatory Effects On Human Thp-1 Macrophages, Valeria B. Martinez

Chemistry & Biochemistry Theses - Archive

Inflammation is a natural biological response to harmful stimuli. It initiates a series of reactions that prompt defensive and curative mechanisms, ridding the body of offending agents and healing remaining injuries. Inflammation involves the intricate communication between cells, requiring complex signaling that mediates various pathways. This acute form of inflammation is vital for our survival, promoting a myriad of mechanisms that function to defend and heal. However, if this inflammatory response is not resolved, it results in a prolonged condition referred to as chronic inflammation. This persistent inflammatory state is incredibly harmful, damaging the host's healthy cells, tissues, and organs. …

The Role Of Sodium Butyrate As An Inflammatory Regulator And Its Effect On Long Noncoding Rnas In Neuroinflammation, Angel Covarrubias

Chemistry & Biochemistry Theses - Archive

Inflammation is a crucial homeostatic process that contributes to both the elimination of foreign invaders and tissue repair. Inflammation at sites of tissue injury or infection is initiated by the detection of a harmful stimulus, triggering vital inflammatory immune signaling pathways and a cascade of cytokines and inflammatory mediators. The dysregulation of this process, however, can result in inappropriate inflammatory responses manifesting in tissue damage and compromised cell function. Dysregulation of the inflammatory response is seen frequently in many human diseases such as Diabetes, Cancer, cardiovascular disease, and neurodegenerative diseases.

In the context of the Central Nervous system, inflammation is …

Characterizing And Targeting The Non-Catalytic Functions Of Phosphatase Of Regenerating Liver 3 (Prl-3) In Oncogenesis And Cancer Progression, Jeffery T. Jolly

Theses and Dissertations--Molecular and Cellular Biochemistry

Phosphatase of Regenerating Liver 3 (PRL-3) is frequently upregulated in various cancers and is associated with poor patient prognosis. Although traditionally studied for its phosphatase activity, PRL-3 also interacts with the CNNM family of magnesium transporters through its catalytic site, and these two functions are mutually exclusive at any given time. Most previous studies relied on a commonly used PRL-3 mutation that disrupts both phosphatase activity and CNNM binding, making it challenging to determine which function drives its oncogenic effects. To address this gap in the field, I utilized a panel of PRL-3 mutants that selectively disrupt either phosphatase activity …

Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers

Theses and Dissertations

Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.

To …

Using Rna Sequencing To Examine Encephalic Gene Expression In Cactus Mice, Sarah A. Nicholls

Honors Theses and Capstones

Many of the exact mechanisms by which desert-adapted animals avoid dehydration-induced complications are unknown, though there are likely ties to the general mammalian dehydration response, a multisystem process spearheaded by the brain. Peromyscus eremicus, the cactus mouse, can survive its whole life without intaking water and is commonly used as a model to study desert adaptations. In this study, we have used bulk transcriptomics to characterize the differential gene expression across hydrated and dehydrated P. eremicus in five major regions of the brain: the cerebral cortex (referred to throughout much of this paper as the cortex), hippocampus, thalamus, midbrain, …

Epigenetic Potential Remains Stable Over 100 Years After Introduction, Danielle Dawkins

College of Graduate Studies: Theses & Dissertations

Introduced species provide important insights into organismal behavioral responses. Epigenetic mechanisms are one of the various ways in which behaviors can be modified, particularly through DNA methylation. Through such mechanisms, phenotypic changes can occur in response to environmental changes, allowing an organism to be more plastic. Epigenetic potential (EP) represents the capacity for an organism to be epigenetically modified, and can be measured by counting CpG motifs; cytosine adjacent to guanine within a DNA sequence. Phenotypic plasticity as it relates to EP has been studied extensively in the house sparrow (Passer domesticus), a globally introduced songbird. It is …

Systematic Review Of Immunohistochemistry Protocols, Arpitha Parthasarathy

Pitzer Senior Theses

Immunohistochemistry (IHC) is an essential technique in biological research that allows for the visualization and localization of proteins within tissue samples. This systematic review analyzes the most effective, efficient and reproducible protocols for IHC. It focuses on three critical steps: freezing, cryosectioning, and staining of skeletal muscle tissues in mice models. A total of 41, 44, and 48 articles on freezing, cryosectioning, and staining techniques, respectively, were analyzed, from reputable sources in biology like PubMed and Web of Science. Results showed the following. For freezing, the use of isopentane combined with liquid nitrogen appeared to be the best method, minimizing …

Creation Of A Dual-Fluorescence Reporter System To Assay Mirna Regulation Of Apobec3a, Tolulope D. Ajayi

All Graduate Theses, Dissertations, and Other Capstone Projects

MicroRNAs have an important role in regulating gene expression, including regulating the transcripts of the APOBEC3 family of cytidine deaminases. The APOBEC3 family is part of the immune defense against viral infection but has also been implicated in cancer progression. The hypothesis for this thesis is that specific miRNAs could be identified that regulate APOBEC3A (A3A) expression. I used molecular cloning and confocal microscopy to evaluate the miRNA-mediated silencing of A3A. A commercially available vector, psiCHECK-2, can be used to assay microRNA (miRNA) activity on specific targets. Molecular cloning was performed to modify the psiCHECK-2 Dual luciferase system (Renilla and …

Investigating The Role Of Fnci-1 In The Development And Function Of The C. Elegans Nervous System, Meagan Collins

Open Access Master's Theses

Fanconi Anemia (FA) is a rare human genetic disease caused by mutation of any of twenty-three genes on the FA pathway, which functions in the repair of DNA damage and the maintenance of genome stability. FA is clinically characterized by congenital abnormalities and a predisposition to aplastic anemia and malignancies. Recently, progressive neurological symptoms and abnormal neurological findings on imaging have been noted in FA patients, including cerebral and cerebellar lesions, calcification, necrosis, gliosis, and associated acute and chronic neurological symptoms; this constellation of symptoms has been termed Fanconi Anemia-Associated Neurological Syndrome (FANS).

To elucidate the molecular etiology of FANS, …

Investigating Regulation And The Regulome Of The Nucleic Acid Binding Protein Spovg Within Borrelia Burgdorferi, Timothy C. Saylor

Theses and Dissertations--Medical Sciences

Prior studies indicated Borrelia burgdorferi SpoVG protein was regulated, SpoVG binds specifically to a number of nucleic acids, and SpoVG binds to the non-variable section of the major virulence factor vlsE. Although a direct transcriptional activator or inhibitor was not elucidated, it is shown that SpoVG is regulated based on cell culture density independent of the growth rate of B. burgdorferi, indicating that SpoVG regulation is outside the scope of the alternative sigma factor RpoS. Using a dCas9 CRISPRi construct to target SpoVG resulted in protein expression trending towards upregulation of the BosR-RpoS regulon, and a marked decrease …

Discovery Of Photosynthetic Oxic N2-Fixation In Cyanobacteria Using Wet Lab And Machine Learning Approaches, James A. Young Iii

Electronic Theses and Dissertations

No abstract provided.

Characterization Of The Erv41-Erv46 Complex As A Retrograde Receptor For Misfolded Secretory Proteins, John Andrew Fuesler

Dartmouth College Ph.D Dissertations

The Endoplasmic Reticulum (ER), the site of secretory protein biosynthesis

provides a favorable environment to promote polypeptide folding, protein

oligomerization and export. Although the ER contains many chaperones and other

factors that assist in protein folding, this process is error prone. Eukaryotes have

evolved protein quality control checkpoints to maintain homeostasis in the secretory

pathway, however these processes are imperfect and may result in proteotoxicity

when toxic levels or aggregates of proteins arise. Mutations in proteins involved in

trafficking in the early secretory pathway are closely associated with disease states.

Therefore, it is of great interest to further understand how …

Molecular Interactions Between The Shellfish Pathogen Vibrio Coralliilyticus Re22 And The Probiont Phaeobacter Inhibens S4sm, Jessica Coppersmith

Open Access Dissertations

Oyster larvae aquaculture is an important industry, both economically and environmentally, helping to create sustainable food systems by supplying seed oysters to farms, and also to restoration projects aimed at building coastal resilience and improving water quality by rejuvenating wild populations. However, oyster larvae are highly susceptible to rapid mortality events, crashes, which can seriously impact the industry. One source of these crashes in hatchery systems is vibriosis, caused by pathogenic species of Vibrio bacteria that are ubiquitous in temperate coastal waters, and with rising surface water temperatures their prevalence and virulence are increasing. To prevent these larval crashes from …

Microbial And Plant Biodiversity In Appalachian Agroecosystems And Their Implications For Soil Health, Kinsey Reed Close

Graduate Theses, Dissertations, and Problem Reports (ETD)

The sustainability of agricultural landscapes depends on understanding the complex interactions between plants, soil, and microbes. In Appalachia, a region shaped by complex terrain and long histories of human and ecological interaction, small family farms produce hay, livestock, and row crops. These agroecosystems, though often treated as “artificial” by many ecologists, have the potential to support both food production and biodiversity conservation if managed with an understanding of ecological complexity. This dissertation examines how plant and microbial diversity interact with soil and management to influence nutrient cycling, soil health, and long-term resilience in Appalachian agricultural systems. A literature review revealed …

Using Lateral Flow Assay To Assess The Prevalence Of Trachemys Hybridization, Lillian Groves

Honors Program Theses

The current study focuses on Trachemys species, which is a group of freshwater turtles found throughout the Greater Antilles. The role of studying an isolated island, such as the Dominican Republic, is significant because it serves as a way to better understand how the combined effects of species migration, mass tourism, and climate change can greatly impact isolated species. Of particular significance is how these forces interact in complex ways to reshape habitats and threaten biodiversity. Additionally, the introduction of a highly invasive species, Trachemys scripta elegans (T. scripta), in this environment pressures native species by acting as a source …

Probing The 10-23 Dnazyme Catalytic Core: Insights From Structural And Mechanistic Studies, Evan Rhyse Cramer

Graduate Theses, Dissertations, and Problem Reports (ETD)

The 10-23 DNAzyme is a catalytically active DNA oligonucleotide capable of cleaving RNA at purine-pyrimidine junctions in the presence of divalent metal ions, most notably magnesium. Despite its promise as a programmable RNA knockdown tool, its clinical and biotechnical utility has been hampered by limited structural characterization, low catalytic efficiency under physiological conditions, and poor understanding of its in-cell activity. This dissertation presents a comprehensive framework for the structural and functional analysis of DNAzymes using the 10-23 DNAzyme as a model system. In the absence of high-resolution structures, we first employed detailed in vitro biochemical assays to map essential residues …

Caspases Protect Against Hyperglycemia Induced Necroptosis-Like Cell Death In Brain Endothelial Cells, Aleena S. Mathew

Theses and Dissertations

Acute diabetes characterized by high spikes in blood glucose levels in association with severe hyperglycemia can lead to an increased risk of ischemic stroke in the brain. To better understand high blood glucose levels, hyperglycemia, in the brain we explored its effects on endothelial cells. Endothelial cells line the inner walls of blood vessels and are directly impacted in hyperglycemia. Brain endothelial cells are a major component of the blood brain barrier (BBB) which tightly regulates the brain’s microenvironment. The type of cell death such as apoptosis, caspase dependent, or necroptosis, caspase independent, can exacerbate diabetes associated complications. There is …

Characterization Of Dietary And Hormonal Influences On Renal Sodium Transporters And Channels In Rodent Models, Evelyn Chan

Scripps Senior Theses

Within kidneys, a diverse array of renal epithelial cells works to maintain electrolyte and water balance to regulate blood pressure and pH. These cells contain varying types of sodium transporters that adjust sodium reabsorption according to the body’s needs. Previous studies have observed sex-specific differences in renal sodium transporter regulation, which are thought to optimize reproduction in females. In this study, we performed high resolution microscopy and detailed characterization of cell type-specific expression and localization of major sodium transporters and channels in rodents in response to dietary and hormonal influences. Specifically, we examined the impact of dietary salt intake and …

The Role Of Fruiting Bodies In Protecting A Community Of Myxococcus Xanthus Spores From The Environment, Dave Lall

Wayne State University Dissertations

Environmental microorganisms have evolved a variety of strategies to survive fluctuations in environmental conditions, including the production of biofilms and differentiation into spores. Myxococcus xanthus are ubiquitous soil bacteria that produce starvation-induced multicellular fruiting bodies filled with environmentally resistant spores (a specialized biofilm). Isolated spores have been shown to be more resistant than vegetative cells to heat, ultraviolet radiation, and desiccation. The evolutionary advantage of producing spores inside of fruiting bodies is not clear. Here, we examine a hypothesis that the fruiting body provides additional protection from environmental insults. We developed a high-throughput method to compare the recovery (outgrowth) of …

Examining The Biotic And Abiotic Degradation Of Simple Phenols, Madeline Gruenberg

Browse all Theses and Dissertations

Plant secondary metabolites are a diverse class of compounds that encompass small phenols to large polymeric structures such as tannins. Smaller compounds such as phenolic acids can serve as substrates for soil microbes and enzymes. We monitored the degradation of three small phenols pyrogallol, gallic acid, and benzoic acid in biotic and abiotic conditions. They were chosen to observe the impacts of specific functional groups on both degradation processes and act as model compounds to mimic larger tannin reactivity. Both abiotic and biotic degradation of pyrogallol resulted in the formation of a stable quinone, while abiotic degradation of gallic acid …