Biochemistry, Biophysics, and Structural Biology Commons^™

Global Coordination Between Gene Expression Processes In C. Crescentus, James Raymond Aretakis

Wayne State University Dissertations

Gene expression is an essential process of all organisms which occurs in two steps, mRNA transcription, and translation and which is shut off by mRNA decay. For a bacterium to grow and divide, these steps need to be tuned to optimize the synthesis rates of thousands of proteins from their genes. Genome-wide experiments were used to determine the absolute transcription rates, mRNA degradation rates, and translation rates on a gene by gene basis in the model bacterium Caulobacter crescentus. This not only provides a system biology view of the organism’s gene expression resource allocation, but also provides a chance to …

Factor Fiction? Identifying A Putative Toxoplasma Gondii Transcriptional Complex, Julia M. Paquette

Honors Theses and Capstones

Toxoplasma gondii is a highly prevalent protozoan parasite that is estimated to infect 30-50% of the global population, though there is no treatment for chronic infection and current treatments for acute infection may have serious side effects. Transcription is a tightly regulated process in T. gondii, allowing the parasite to successfully invade and replicate within host cells, and it is thus a promising avenue to study gene regulation and to investigate possible novel therapeutics. In our lab’s previous research, a TFIID-like complex was identified in T. gondii and found to be associated with the parasite specific bromodomain protein BDP3. …

Arabinoxylan Structural Profiling Of Cool-Season Pasture Grasses Via High-Performance Anion-Exchange Chromatography With Pulsed Amperometric Detection (Hpaec-Pad) Analysis Of Endoxylanase Digests, Glenna Erin Joyce

Theses and Dissertations--Animal and Food Sciences

Arabinoxylan (AX) is a major structural polysaccharide found in the cell walls of monocots such as cereal grains and pasture grasses. The variety of AX structural components and substitution patterns contribute to AX structural diversity between different monocot species as well as plant tissues.

The rumen is the first digestion site of masticated food material in cattle and provides 70% of energy to host through fermentation of forage. There are many species of pasture grasses that act as a forage source. Differences in AX structure found in these pasture grasses may impact rumen microbial fermentation. Understanding the AX structure of …

Exploring The Connection Between The Spontaneous Regression Seen In Neuroblastomas, Hypertumors, And Reactive Oxygen Species, Shahad Musa, Manitha Mulpuru

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

Peto’s Paradox is defined as the lack of correlation between larger animals and cancer risk. Under the assumption that all cells have equal risk of becoming cancerous, larger animals should have greater rates of cancer. However, the inverse is true. Determining the cause of this variation may allow a supplemental approach to cancer treatment. A combination of two reasons may account for this correlation including hypertumors and metabolism. Hypertumors, or cheater cells, are hypothesized to suppress cancer growth through spontaneous autophagic degradation and overexpression of the RAS g-protein. Both of these characteristics are exhibited in Neuroblastomas. An anticancer drug used …

Development And Clinical Validation Of Knowledge-Based Planning Models For Stereotactic Body Radiotherapy Of Early-Stage Non-Small-Cell Lung Cancer Patients, Justin David Visak

Theses and Dissertations--Radiation Medicine

Lung stereotactic body radiotherapy (SBRT) is a viable alternative to surgical intervention for the treatment of early-stage non-small-cell lung cancer (NSCLC) patients. This therapy achieves strong local control rates by delivering ultra-high, conformal radioablative doses in typically one to five fractions. Historically, lung SBRT plans are manually generated using 3D conformal radiation therapy, dynamic conformal arcs (DCA), intensity-modulated radiation therapy, and more recently via volumetric modulated arc therapy (VMAT) on a C-arm linear accelerator (linac). Manually planned VMAT is an advanced technique to deliver high-quality lung SBRT due to its dosimetric capabilities and utilization of flattening-filter free beams to improve …

Host Factors Affecting Group Ii Intron Retrotransposition, Justin Michael Waldern

Legacy Theses & Dissertations (2009 - 2024)

Group II introns are self-splicing mobile elements that are thought to be the evolutionary ancestors of eukaryotic retrotransposons, the spliceosome, and spliceosomal introns. Yet, little is known about how group II introns have coevolved within their native hosts or about the corresponding host biology.Using the Ll.LtrB intron in its native host, Lactococcus lactis, I first sought to identify host factors that influence retrotransposition. Since retrotransposition can be costly to the host organism, group II introns must achieve a delicate balance between self-proliferation and host preservation. By utilizing the native host organism, my goal was to unearth retrotransposition-related mechanisms that have …

Pre-Steady-State Kinetic Characterization Of An Antibiotic-Resistant Mutation Of Staphylococcus Aureus Polc, Rachel Alice Nelson

Legacy Theses & Dissertations (2009 - 2024)

In this dissertation I provide a pre-steady-state kinetic characterization of an antibiotic-resistant mutant of a Staphylococcus aureus DNA polymerase. Staphylococcus aureus is one of the most common causes of infections in humans, and is widely known for its ability to acquire resistance to most antibiotics. Staphylococci infections pose a significant burden to the healthcare system and increase mortality, as more than 95% of Methicillin-Resistant S. aureus (MRSA) infections do not respond to first-line antibiotics. The limited treatment options for Staphylococci infections underscores the need for novel, alternative strategies. In this thesis, I discuss 6-anilinouracils (6-AU), a family of potent dGTP …

Development Of Chemical Methods For Oligonucleotide Purification, Paramagnetic Labeling And Synthesis Of Dna-Based Advanced Materials, Muhan He

Legacy Theses & Dissertations (2009 - 2024)

This thesis describes a chemical method for alternative oligonucleotide purification that is non-chromatographic and gel-free and allows to routinely synthesize and purify long functional RNA strands. The purification of long RNAs is based on the bio-orthogonal inverse electron demand Diels-Alder (IEDDA) chemistry between trans-cyclooctene (TCO) and tetrazine (Tz). Target oligonucleotide strands are selectively tagged with Tz and can be captured and purified from the failure sequences with immobilized TCO. RNA strands are synthesized on solid support through a photolabile linker to avoid the loss of Tz tag. Purity of the isolated oligonucleotides was evaluated using gel electrophoresis, HPLC and mass …

Retrotransposon-Mediated Transduction Of An Environmental Cue To Regulate Centrosome Fate, Shawn Patrick Murphy

Legacy Theses & Dissertations (2009 - 2024)

In 1969, the enrichment of mobile element repeat sequences led Britton and Davidson to propose the hypothesis that gene expression in higher eukaryotes is regulated through the exaptation of mobile elements. In this work, I have explored the hypothesis that mobile elements can also be harnessed by the host to regulate asymmetric cell division, thereby determining cell fate. Retrotransposons are ubiquitous eukaryotic mobile elements that transpose through an RNA intermediate. They are often active in cell types that divide asymmetrically to yield daughter cells with different fates, such as embryonic stem cells, germline stem cells, neuronal stem cells and the …

The Phosphodiesterase, Rv0805, Is An Unheralded Component Of Tb Complex Mycobacterial Physiology In And Beyond Camp Homeostasis, James R. Mcdowell

Legacy Theses & Dissertations (2009 - 2024)

Phosphodiesterases (PDEs) are integral components of 3’,5’-cyclic adenosine monophosphate (cAMP) signaling pathways by degrading cAMP to modulate the concentration, duration, and localization of the cAMP signal which maintains the specificity of cAMP pathways. The human pathogen, Mycobacterium tuberculosis (Mtb) has a unique cAMP network architecture with at least 15 adenylyl cyclases (ACs) that generate cAMP, but only one characterized PDE, Rv0805, which is found exclusively in pathogenic mycobacteria. Rv0805 can influence Mtb cAMP levels but the absence of Rv0805 orthologs in non-pathogenic mycobacteria and apparent separation of Rv0805 from cAMP directed roles led to numerous questions surrounding PDE function in …

Identification Of Ires Activity In Cellular Mrnas And Viral Rna Using A Circular Rna Construct, Priyanka Sehta

Legacy Theses & Dissertations (2009 - 2024)

Translation initiation is a critical step in the process of protein synthesis. The canonical way of translation initiation involves ribosomes being recruited to the 7-methyl guanosine cap present at the 5’end of the untranslated region (5’ UTR) of the RNAs. However, viral RNAs and some cellular mRNAs lack this 5’ cap structure and thus deploy an alternate non-canonical translation initiation mechanism. In non-canonical translation initiation, ribosome recruitment is facilitated by the RNA secondary structures called Internal Ribosome Entry Site (IRES) present most often in the 5’ UTR. To measure IRES-mediated translation, the dual luciferase assay has been the gold standard. …

Role Of Rna Helicases In The Drosophila Germline, Patrick Blatt

Legacy Theses & Dissertations (2009 - 2024)

Gametogenesis, the process of creating egg or sperm, is required for launching successive generations of sexually reproducing organisms. The developmental milestones that occur during gamete production have been studied for decades and are of critical interest to gain insight to conserved features of human fertility. Drosophila has been used for over a century as an efficient research model and remains pivotal in uncovering fundamental biological paradigms. During Drosophila egg production, or oogenesis, several developmental transitions must be traversed to ensure completion of oogenesis including: Germline Stem Cell (GSC) maintenance and differentiation, mitotic and meiotic cell divisions, and production of maternally …

Missense Mutations In The Gamma Crystallins And Mechanisms Of Lens Opacity, Wenjuan Hou

Legacy Theses & Dissertations (2009 - 2024)

Cataract, or clouding of the ocular lens, among the most common types of eye diseases, is the leading cause of blindness worldwide. With the opacity or clouding of the lens, light incident on the lens is scattered rather than being transmitted and is thus prevented from focusing on the retina. The lens becomes cataractous due to a large number of reasons, among which aging and genetic mutations are two of the most common factors. Clouding of the center of the lens or nuclear opacity, is the most frequently observed type of age-onset cataract, as well as inherited, congenital cataract [1, …

Study Of Primary Cilium Structure And Intraflagellar Transport, Shufeng Sun

Legacy Theses & Dissertations (2009 - 2024)

Primary cilia are hair-like protrusions that stem from the basal bodies in the cytoplasm and extend into the extracellular space to sense signals. Intraflagellar transport (IFT) functions to transport cargo molecules into and out of the ciliary compartment to assemble, maintain, and disassemble the cilia. Accurate knowledge of the three-dimensional (3D) structure of primary cilia and precise details of the IFT profile is the foundation for understanding the sensory functions of primary cilia. This work covers three aspects of primary cilia. Firstly, we obtained and analyzed the overall 3D architecture of the complete primary cilia axoneme region using serial section …

Kinetic Characterization Of Two C-Family Polymerases From The Gram-Positive Bacterium Staphylococcus Aureus, Sean P. Fagan

Legacy Theses & Dissertations (2009 - 2024)

In this dissertation, I review the fundamental processes and mechanisms for bacterial DNA replication, especially the mechanisms employed by high-fidelity DNA polymerases to replicate the genome. Unlike the prototypical bacterial system from Escherichia coli which uses a single C-family polymerase, DNA polymerase IIIα (Pol IIIα), to replicate the genome, low-GC content Gram-positive bacteria utilize two essential C-family polymerases, PolC and DnaE. PolC and DnaE work cooperatively to replicate the genome, with DnaE initiating synthesis from RNA-primers and PolC performing the bulk synthesis. Although atomic structures of both PolC and Pol IIIα are available, detailed pre-steady state kinetic analysis of the …

Female And Male-Controlled Livestock Holdings Impact Pastoralist Food Security And Women’S Dietary Diversity, Henriette Gitungwa, Christopher Gustafson, E.Y. Jimenez, E. Wesley F. Peterson, M. Mwanzalila, Asha Makweta, E. Komba, R.R. Kazwala, J.A.K. Mazet, Elizabeth Vanwormer

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Food insecurity is a global problem that requires a One Health approach. As many households in low- and middle-income nations rely on crops and livestock that they produce to meet their household’s needs, food security and nutrition are closely linked to the health of animals and the environment. Resources controlled by women are more often allocated to uses that benefit the entire household, such as food, health, and educating children, than men’s resources. However, studies of gender control of resources among pastoralist societies are scant. We examined the effect of female and male control of livestock resources on food …

Sars-Cov-2: An Investigation On Mutagenicity And Its Effects On Infectivity And Mortality, Tyler Elliott Silverwood

Honors Theses and Capstones

SARS-CoV-2, the etiological agent of the COVID-19 pandemic, has rapidly become a worldwide public health concern. Classified as a betacoronavirus, it is the third human coronavirus (HCoV) to emerge in the 21st century that causes severe disease, alongside SARS-CoV and MERS-CoV. The genome consists of open reading frames encoding accessory proteins and four structural proteins, including the spike protein which is a key determinant of host cell tropism. Mutations within the genome, particularly the spike gene, have been linked in-vitro to increased binding affinity to the human receptor angiotensin-converting enzyme 2 (hACE2), increased fitness in human hosts, and immune evasion. …

High Throughput Analysis To Study Emerging Pollutants And Nanoparticle Fate In Biological Systems, Xiaolong He

Doctoral Dissertations

”The increasing applications of emerging and fugitive contaminants (EFCs) and engineered nanoparticles (ENPs) attract significant research interest for their potential risks to human health and the environment. In order to assess the health risks of these emerging contaminants, rapid and reliable analytical methods to measure the concentrations and fates of these contaminants are imperative. This dissertation focuses on the developments of advanced analytical methods and their applications to study those emerging contaminants in crop plant and simulated gastric fluid (SGF). Three types of mass spectrometry based methodologies have been developed, one is freeze-thaw/centrifugation extraction followed by high performance liquid chromatography …

Functional Characterization Of Threonine 49 Phosphorylation Of Cytochrome C, Antoine Khobeir

Wayne State University Theses

Cytochrome c (Cytc) is a pivotal multifunctional mitochondrial protein that serves as a single electron carrier between complexes III and IV of the electron transport chain. It has important roles in both cellular respiration and apoptosis. The novel Thr49 (T49) phosphorylation of Cytc likely affects mitochondrial respiration, membrane potential, ROS production, ATP production, and apoptosis. Based on the functional characterization of previously mapped phosphorylation sites (Tyr97, Tyr48, Thr28, Ser47, Thr58) of the lab, we hypothesize that T49 phosphorylation will lead to controlled respiration, optimal intermediate mitochondrial membrane potential, lower ROS production, and inhibition of apoptosis compared to unphosphorylated Cytc. Here …

Novel Role Of Endoplasmic Reticulum-Associated Degradation In The Regulation Of Ceruloplasmin, Stephen William Hippleheuser

Wayne State University Theses

Ceruloplasmin (Cp) is a secreted ferroxidase produced by the hepatocytes that assists in the transport of iron throughout the human body. In human aceruloplasminemia patients, due to Cp deficiency excess intracellular iron buildup leads to ailments like liver cirrhosis, neurodegeneration, and blindness. We recently found that the biogenesis of Cp in the endoplasmic reticulum (ER) is regulated by a principal ER quality-control process, ER-associated degradation (ERAD). ERAD clears misfolded ER proteins for cytosolic proteasomal degradation, with the Sel-1 suppressor of lin-12-like (Sel1L)-HMG-CoA reductase degradation 1 (Hrd1) protein complex representing the most conserved branch in mammals. Interestingly, we found that Sel1L-Hrd1 …