Molecular Biology Commons^™

Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, Collin Kessler

Electronic Theses and Dissertations

Microbial communities contain densely packed cells where competition for space and resources are fierce. These communities are generally referred to as biofilms and provide advantages to individual cells against immunological and antimicrobial intervention, dehydration, and predation. High intracellular pools of cyclic diguanylate monophosphate (c-di-GMP) cause cells to aggregate during biofilm formation through the production of diverse extracellular polymers. Genes that encode c-di-GMP catalytic enzymes are commonly mutated during chronic infections where opportunists display enhanced resistance to phagocytosis and antibiotics. Our lab uses an emergent multicellular trait in the model organism Pseudomonas fluorescens Pf0-1 to study the emergence of c-di-GMP mutations …

Identifying A Glucocorticoid-Activated Gpcr That Rapidly And Non-Genomically Increases Camp Levels In Mammalian Cells, Francisco Nunez

Pharmaceutical Sciences (PhD) Dissertations

Glucocorticoids (GCs) are steroid hormones that regulate diverse physiological processes. Synthetic versions of GCs are commonly used to treat inflammatory diseases such as asthma by modulating gene expression to suppressing several inflammatory activities. However, it is estimated that 5-10% of asthmatics are unresponsive to GCs, which may be explained by receptor desensitization and/or the presence of a neutrophilic endotype. One understudied phenomenon of GCs is their ability to induce rapid, non-genomic actions. For example, GCs can acutely modulate calcium concentrations levels, induce smooth muscle relaxation and modulate nitric oxide synthase activity, within minutes and sometimes seconds, which is too rapid …

The Role Of The Hypoxia-Inducible Factor 2 In Pancreatic Cancer: Mechanisms Of Tumor Immunosuppression And Intestinal Radioprotection, Carolina Garcia Garcia

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with dismal prognosis. The only curative option for patients is surgery, but over 80% of patients are not surgical candidates. Unfortunately, PDAC is resistant to the three remaining options. PDAC is characterized by a profoundly hypoxic and immunosuppressive stroma, which contributes to its therapeutic recalcitrance. Alpha-smooth muscle actin+ (αSMA+) cancer-associated fibroblasts (CAFs) are the most abundant stromal component, as well as mediators of stromal deposition. The hypoxia-inducible factors (HIF1 and HIF2) coordinate responses to hypoxia, yet, despite their known association to poor patient outcomes, their functions within the PDAC tumor microenvironment (TME) …

Modeling Electrostatics In Molecular Biology And Its Relevance With Molecular Mechanisms Of Diseases, Mahesh Koirala

All Dissertations

Electrostatics plays an essential role in molecular biology. Modeling electrostatics in molecular biology is complicated due to the water phase, mobile ions, and irregularly shaped inhomogeneous biological macromolecules. This dissertation presents the popular DelPhi package that solves PBE and delivers the electrostatic potential distribution of biomolecules. We used the newly developed DelPhiForce steered Molecular Dynamics (DFMD) approach to model the binding of barstar to barnase and demonstrated that the first-principles method could also model the binding. This dissertation also reflects the use of existing computational approaches to model the effects of Single Amino Acid Variations (SAVs) to reveal molecular mechanisms …

A Review Of Current Methods In Avian Dietary Analysis And Their Integrated Application To Characterize The Trophic Niche Of Louisiana Waterthrush (Parkesia Motacilla)., Brandon Hoenig

Electronic Theses and Dissertations

Characterizing a species’ dietary composition presents an avenue to understand many facets of its ecological niche and can provide essential information for the species’ long-term conservation. To date, the vast majority of diet studies have relied on direct identification of prey during foraging observations or from diet samples to characterize the dietary habits of birds. However, advancements in laboratory-based approaches have revolutionized the field of trophic ecology by allowing researchers to indirectly infer dietary habits with higher resolution across greater time scales. Here, I apply two of these laboratory-based techniques, namely DNA metabarcoding and stable isotope analysis, to characterize the …

Retro-Structural Analysis Of The Four Helix Bundle Motif In Binuclear Proteins, Walker Pedigo, Maggie Smith

Honors Theses

Protein structure is directly related to protein function. There are four levels of protein structure: primary, secondary, tertiary, and quaternary. The interactions amongst the structural components of a protein give rise to its unique characteristics. The four helix bundle motif is a common structural trait in a variety of binuclear proteins. In this study, PyMOL, a molecular visualization system, was used to analyze binuclear proteins that possess a four helix bundle. Images of proteins containing dicopper, diiron, and dimanganese sites were captured. The images were compiled into figures for each individual protein. After creating the figures, each protein was further …

Innate Immunity In The Pathobiology And Treatment Of Infectious And Neurodegenerative Diseases, Mai Mostafa

Theses & Dissertations

Mononuclear phagocytes (MPs; monocytes, macrophages, and dendritic cells) are the governors of innate immunity which is the body’s first line of defense against microbial pathogens. They act beneficial or detrimental. They are crucial for an effective non-specific immune response to invading pathogens by engulfing, destroying, then eliciting an adaptive specific immune response. Given their pivotal functions in the host immune defense, studying MP immune responses in disease is paramount important for understanding disease pathobiology and uncovering therapeutic strategies.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the driver of acute respiratory distress syndrome (ARDS) in coronavirus disease 2019 (COVID-19) amongst …

An Investigation Of Epigenetic Mechanisms Driving The Biology Of Head And Neck Squamous Cell Carcinoma, Scot Carson Callahan

Dissertations and Theses (Open Access)

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide and is associated with significant morbidity and mortality. To date, the majority of work in the field has focused on genomic alterations such as mutations and copy number alterations. However, the clinical success of targeted therapies that exploit known genomic alterations, such as EGFR mutations, has remained mixed. Over the past decade, the importance of epigenetic regulators has come to the forefront, with the realization that many of these genes are mutated in cancer. Despite this realization, the role of epigenetics in regulating tumorigenesis, progression and …

Extracting Dna From Embalmed Tissue To Study Genetic Predisposition To Degenerative Disc Disease, Conner Lynn

Undergraduate Theses

INTRODUCTION. According to a prominent study, 80-90% of people will show some evidence of degenerative disc disease (DDD) by age 50. Researchers have proposed that a Q326W substitution in the COL9A2 gene increases susceptibility to DDD. The role of collagen IX in intervertebral discs is not completely known, but due to its increased flexibility compared to other types of collagens, it is thought to connect collagen II with other components of the cartilage which are important to the integrity of the disc. Collagen II can be found within the nucleus pulposus and the inner portion of the annulus fibrosis. Researchers …

Microbial Diversity And Community Structure In Sediments Associated With The Seagrass (Thallassia Testudinum) In Apalachicola Bay, Florida, Rahma Ahmed, Thomas Mcelroy, Troy Mutchler

Symposium of Student Scholars

Seagrass is an angiosperm which provides many ecosystem services in coastal areas, such as providing food, shelter and nurseries for many species, and decreasing the impact of waves on shorelines. A global assessment reported that 29% of known seagrass meadows are in a state of decline due to the effects of human activity. Seagrass is commonly found in shallow marine waters where they form meadows containing a microbiome that plays an important role in providing nutrients for seagrass growth, though little is known about the microorganisms within the seagrass meadow sediments. Our project collected sediments from seagrass meadows and adjacent …

Improving Photosynthetic Efficiency In Microalgae Through The Genetic Engineering Of Energy Sensors And Photoreceptors, Taylor L. Britton

Biology ETDs

Through photosynthesis microalgae can convert sunlight, water, and CO₂ into chemical energy that can be used to generate carbon neutral biofuels and biomass. With an ever-increasing demand and need for petroleum substitutes it is imperative that we improve the output of industrial-relevant crops such as microalgae. One important way of improving output in algae is by understanding the roles that stress and energy conversion is regulated in these organisms. Photosynthetic organisms fundamentally depend on light- and sugar-driven metabolic and signaling networks, which integrate environmental cues to govern and sustain growth and survival. SnRKs (SNF1-related protein kinases) and the photoreceptor …

Exploring The Functionality Of Putative Bop3 Post-Translational Modifications, Liliya Tkachuk

Honors Scholars Collaborative Projects

All eukaryotic cells require that transcribed mRNAs undergo export form the nucleus to the cytoplasm where they can be translated into proteins. This process requires a host of proteins which are conserved between the unicellular budding yeast, S. cerevisiae, and humans. During this process, Mex67 and other associated proteins facilitate the mRNA to travel across the nuclear pore complex (NPC), doorways embedded in the nuclear envelope. Upon the exit of mRNA, Mex67 is released and recycled back into the nucleus to facilitate the export of more mRNA. This occurs through the action of Dbp5, whose activity is regulated through …

Generating A Colorimetric Ssa4 Transcript Export Reporter For Multicopy Suppression Screen In S. Cerevisiae, Zaid Hatem

[Archive] Belmont University Research Symposium (BURS)

The export of mRNA from the nucleus to the cytoplasm is a regulatory point that is essential to the pathway of gene expression in eukaryotic cells. The export of mRNA transcripts is mediated through selective doorways called the nuclear pore complexes (NPC). Additionally, there are proteins associated with the nuclear pore complex that assist in facilitating the export. This includes association with the export receptor, Mex67, which binds to the transcript and ferries it through NPCs. During cellular stress, such as heat shock, the export of housekeeping mRNA transcripts is halted, forcing these transcripts to remain inside the nucleus and …

Identification And Characterization Of An Ftsq-Null Suppressor Gene In Streptomyces, Alexandra Sherman

Undergraduate Distinction Papers

Streptomyces coelicolor is a filamentous Gram-positive soil bacterium that grows similarly to fungi. The bacteria grow together in a mycelium-like structure that produces aerial hyphae above the media surface for sporulation. Evenly spaced crosswalls develop during cell division of the aerial filaments with the aid of division genes, including ftsZ and ftsQ. These cell division genes are essential for growth in the common bacterium and if silenced will cause the bacterium to die. Streptomyces uniquely retains the ability for growth after a deletion of either the ftsZ or ftsQ gene which causes a loss of septum formation in the …

The Development Of Inhibitors For Sars-Cov-2 Orf8, My Thanh Thao Nguyen

CSB and SJU Distinguished Thesis

An unexpected outbreak of SARS-CoV-2 caused a worldwide pandemic in 2020. Many repurposed drugs were tested, but there are currently only three FDA approved antivirals (Merck’s antiviral Molnupiravir, Pfizer’s antiviral Paxlovid, and Remdisivir).1 Most of the antiviral drugs tested SARS-CoV-2 main protease and RNA-dependent RNA polymerase. However, it is important to explore different drug targets of SARS-CoV-2 to prepare for the virus mutations of the future. This research looks at an alternative approach in which SARSCoV- 2 Open Reading Frame 8 (ORF8), which has been shown to be a rapidly evolving hypervariable gene, was chosen to be the protein of …

Exploring The Functionality Of Putative Bop3 Post-Translational Modifications, Liliya Tkachuk, Rebecca Adams Phd

[Archive] Belmont University Research Symposium (BURS)

All eukaryotic cells require that transcribed mRNAs undergo export form the nucleus to the cytoplasm where they can be translated into proteins. This process requires a host of proteins which are conserved between the unicellular budding yeast, S. cerevisiae, and humans. During this process, Mex67 and other associated proteins facilitate the mRNA to travel across the nuclear pore complex (NPC), doorways embedded in the nuclear envelope. Upon the exit of mRNA, Mex67 is released and recycled back into the nucleus to provide the export of more mRNA. This release occurs through the action of Dbp5, whose activity is regulated …

Purification And Activity Assay Optimization Of Bacterial Catalase From Psychrobacter Koprana, Sydney Willis

Honors Program Theses

To date, catalase protein from bacterial species is not the most widely used commercial catalase. Catalase, the enzyme that breaks down hydrogen peroxide in most living organisms, is an invaluable enzyme in the food, agriculture, and pharmaceutical industries. In 2019, a novel species of a psychrotolerant bacterium was discovered in Cold Harbor, NY. This species, Psychrobacter koprana, exhibits highly active catalase. Preliminary data from activity assays demonstrates that P. koprana catalase has the same activity as commercially available catalase. After purification and activity assay optimization, the activity of this catalase has the potential to be more active than other easily …

An Integrative Investigation Of The Synechococcus A/B Clade During Adaptive Radiation At The Upper Thermal Limit Of Phototrophy, Christopher L. Pierpont

Graduate Student Theses, Dissertations, & Professional Papers

Thermophilic microorganisms have been scientifically observed since the early nineteenth century and have spurred many questions about the limits of life and the capacity of organisms to survive extreme conditions. Decades of research on thermophile proteins and genomes have yielded several proposed correlates of temperature that may contribute to adaptation of bacteria and archaea to high temperature. However, many of the generalizations reported are drawn from analyses of deeply divergent taxa or from individual case studies in isolation from mesophilic relatives. Members of the Synechococcus A/B (SynAB) group are the only cyanobacteria with members able to grow above 65 °C …

Getting To The Root Cause: The Genetic Underpinnings Of Root System Architecture And Rhizodeposition In Sorghum, Farren Smith

Graduate Theses, Dissertations, and Problem Reports (ETD)

Plants are some of the most diverse organisms on earth, consisting of more than 350,000 different species. To understand the underlying processes that contributed to plant diversification, it is fundamental to identify the genetic and genomic components that facilitated various adaptations over evolutionary history. Most studies to date have focused on the underlying controls of above-ground traits such as grain and vegetation; however, little is known about the “hidden half” of plants. Root systems comprise half of the total plant structure and provide vital functions such as anchorage, resource acquisition, and storage of energy reserves. The execution of these key …

Capsaicinoids From Capsicum Annuum As An Alternative Fabh Inhibitor Of Mycobacterium Tuberculosis: In Silico Study, Gabriella Chandrakirana Krisnamurti, Dewi Ratih Tirto Sari, Yohanes Bare

Makara Journal of Science

The number of tuberculosis (TB) cases worldwide reached 1.5 million in 2018; thus, TB is considered a deadly disease. TB is caused by Mycobacterium tuberculosis and involves lipid synthesis. Considering the importance of lipid metabolism in bacteria, FabH may be an essential protein target for repressing lipid synthesis. Capsaicinoids from Capsicum annuum demonstrate potent antibacterial activity. This study predicted the ability of capsaicinoid compounds to inhibit FabH. In silico analysis was performed by retrieving the structure of FabH from PDB and those of selected capsaicinoid derivatives from PubChem. The compounds were docked using AutoDock Vina in PyRx 0.8 software. The …

Intrinsically Disordered Protein Regions In Human Evolution And As Therapeutic Targets, Karen Paco Mendivil

KGI Theses and Dissertations

Intrinsically disordered proteins (IDPs) and IDP regions (IDPRs) fail to form stable structures but have important biological functions via interacting with various molecular partners (proteins, DNA, RNA, glycosaminoglycans). We hypothesized that IDPRs are potential targets for therapeutics development because they are reservoirs of evolutionary innovation, and they play crucial roles in adaptation to pathogens.

We first studied the evolution of IDPRs in the human proteome and compared it with the proteome of non-human primates. We have found that evolutionary young protein-coding genes have included low conserved regions in the N-terminal part of proteins, and such regions are linked to high …

Computational And Biochemical Characterizations Of Anhydrobiosis-Related Intrinsically Disordered Proteins., Brett R. Janis

Electronic Theses and Dissertations

Anhydrobiosis is the remarkable phenomenon of “life without water”. It is a common technique found in plant seeds, and a rare technique utilized by some animals to temporarily stop the clock of life and enter a stasis for up to several millennia by removing all of their cellular water. If this phenomenon can be replicated, then biological and medical materials could be stored at ambient temperatures for centuries, which would address research challenges as well as enhance the availability of medicine in areas of the world where refrigeration, freezing, and cold-chain infrastructure are not developed or infeasible. Furthermore, modifying crop …

Human 5’-Tailed Mirtrons Are Processed By Rnasep, Mohammad Farid Zia

Dissertations

Approximately a thousand microRNAs (miRNAs) are documented from human cells. A third appear to transit non-canonical pathways that typically bypass processing by Drosha, the dedicated nuclear miRNA producing enzyme. The largest class of non-canonical miRNAs are mirtrons which eschew Drosha to mature through spliceosome activity. While mirtrons are found in several configurations, the vast majority of human mirtron species are 5’-tailed. For these mirtrons, a 3’ splice site defines the 3’ end of their hairpin precursor while a “tail” of variable length separates the 5’ base of the hairpin from the nearest splice site. How this tail is removed is …

Covid-19 In Silico Drug With Zingiber Officinale Natural Product Compound Library Targeting The Mpro Protein, Renadya Maulani Wijaya, Muhammad Aldino Hafidzhah, Viol Dhea Kharisma, Arif Nur Muhammad Ansori, Arli Aditya Parikesit

Makara Journal of Science

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a worldwide pandemic. Ginger (Zingiber officinale) is a rhizome, which is commonly used for culinary and medicinal purposes. In Indonesia, ginger is taken as traditional medicine by processing it into a drink known as jamu. The present study aimed to assess and evaluate the bioactive compounds in ginger that can be used in drug design for treating COVID-19. The crystal structure of the SARS-CoV-2 main protease (M^pro) was generated from a protein sequence database, i.e., Protein Data Bank, …

The Structural And Functional Role Of Photosensing In Rgs-Lov Proteins, Zaynab Jaber

Dissertations, Theses, and Capstone Projects

Light provides organisms with energy and spatiotemporal information. To survive and adapt, organisms have developed the ability to sense light to drive biochemical effects that underlie vision, entrainment of circadian rhythm, stress response, virulence, and many other important molecularly driven responses. Blue-light sensing Light-Oxygen-Voltage (LOV) domains are ubiquitous across multiple kingdoms of life and modulate various physiological events via diverse effector domains. Using a small molecule flavin chromophore, the LOV domain undergoes light-dependent structural changes leading to activation or repression of these catalytic and non-catalytic effectors. In silico analyses of high-throughput genomic sequencing data has led to the marked expansion …

Insights Into Halophilic Microbial Adaptation: Analysis Of Integrons And Associated Genomic Structures And Characterization Of A Nitrilase In Hypersaline Environments, Sarah Sonbol

Theses and Dissertations

Hypersaline environments are extreme habitats that can be exploited as biotechnological resources. Here, we characterized a nitrilase (NitraS-ATII) isolated from Atlantis II Deep brine pool. It showed higher thermal stability and heavy metal tolerance compared to a closely related nitrilase.

We also studied integrons in halophiles and hypersaline environments. Integrons are genetic platforms in which an integron integrase (IntI) mediates the excision and integration of gene cassettes at specific recombination sites. In order to search for integrons in halophiles and hypersaline metagenomes, we used a PCR-based approach, in addition to different bioinformatics tools, mainly IntegronFinder.

We found that integrons and …

Polycyclic Aromatic Hydrocarbons And The Microbiomes Of Two Benthic Species, Samantha Ells

Master's Theses

The presence of oil has been shown to affect the microbiomes of the water column, sediments, and organisms, both by altering the diversity and the composition of those microbial communities. If the microbiome is altered it may no longer provide benefits to its host organism, impacting its ability to survive. Thus, it is important to understand the effects of large-scale contamination events including the Deepwater Horizon oil spill. This study set out to examine the effects of oil exposure on the microbiome of two benthic species, southern flounder (Paralichthys lethostigma) and eastern oysters (Crassostrea virginica) to further understand the effects …

Characterization Of Iron-Sulfur Cluster Biogenesis In Methanogenic Archaea, Thomas Modlin Deere

Graduate Theses and Dissertations

Iron-sulfur (Fe-S) clusters are among the oldest cofactors on the planet, used by proteins in almost all forms of life on Earth to carry out processes ranging from energy transfer to DNA replication. Among the organisms believed to use these Fe-S proteins more extensively than almost any others are the methanogens, an ancient lineage of archaeal microbes that produce methane as a required product of their metabolism. Methane, the primary component of commercial natural gas, is both a potent greenhouse gas and an important fossil fuel. It can also be renewably produced as a biofuel. Biogenic methane is almost entirely …

Modeling And Analysis Of Intracellular Signaling Networks And Cellular Decisions, Mustafa Ozen

Dissertations

Developing molecular network analysis methods is important due to their applications on complex biological systems such as target discovery, development of drugs, discovering drug effects, and finding treatments for many complex diseases, e.g., cancer, autoimmune, and mental disorders. An example of analysis techniques is the fault diagnosis analysis, in which the purpose is to quantify how much vulnerable the entire network is to dysfunction of one or multiple molecules. Such analysis can be done after proper network models are implemented, trained, and tested against the experimental data. In this dissertation, a Boolean modeling framework is implemented and methods to train …

Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Phytophthora ramorum is the causal agent of Sudden Oak death (SOD), ramorum dieback and ramorum leaf blight which affect both forest environments and nurseries. This oomycete pathogen has had a huge economic impact on the nursery and lumber industry. Forests in California have experienced substantial mortality of oaks affecting the forest dynamics and diversity. Our research investigates four native species and two ornamental cultivars of plants, which belong to the genus Arctostaphylos (manzanita) and are considered to be new hosts for P. ramorum in the chaparral ecosystem of California. Symptom expression and transmission rates were analyzed on Arctostaphylos glauca, …