Molecular Biology Commons^™

Binding Of Maize Necrotic Streak Virus (Mnesv) 3’ I-Shaped Structure (3’ Iss) To Eukaryotic Translation Factors (Eifs) And Implication In Eif4f Mediated Translation Initiation, Qiao Liu

Dissertations, Theses, and Capstone Projects

5' m⁷GpppN cap and the 3' poly adenosine (A) tail of eukaryotic mRNAs are key elements for recruiting translation initiation machinery in canonical translation initiation. Unlike host mRNAs, many viruses lack these elements and yet they are translated efficiently. Plant viruses, in particular, have complex structures within their untranslated regions (UTR) that allow them to bypass some cellular translation control steps. In Maize necrotic streak virus (MNeSV) 3' UTR, an I-Shaped RNA Structure (ISS) has been reported to mediate the virus translation initiation progress. 3’ ISS binding with eIF4F has been shown to facilitate translation. 5’ -3’ kissing …

Investigation Of The Homologs Rad51 And Dmc1 Role In Cell Division And Homologous Recombination, Amaal Abulibdeh

Graduate Theses/Dissertations

RecA-like proteins homologs Rad51 and Dmc1 (disruption of meiotic control) promote recombination between homologous chromosomes by repairing programmed DNA Double-Strand Breaks (DSBs). Dmc1 is a Recombinase involved in meiosis-specific repair of DSBs, whereas Rad51 has been found to be involved in meiotic and non-meiotic DSBs repair. Previous studies showed that when RAD51 is overexpressed, interhomologous recombination still occurs even when DMC1 is knocked out. Dmc1 and Rad51 have not been fully characterized in the ciliate Tetrahymena thermophila. In order to more fully investigate the role of Rad51 and Dmc1 in Homologous Recombination Repair (HHR), this work focuses on using …

Development Of Endogenous Tagging Plasmids For Characterization Of Protein Interactions, Localization, And Post-Translational Modifications Of Tetrahymena Thermophila Rad23, Evan Andrew Wilson

Graduate Theses/Dissertations

Rad23 is a protein involved in both nucleotide excision repair (NER) and proteasome-mediated degradation, and has been suggested to facilitate interactions between these two pathways. The model organism Tetrahymena thermophila, which has a transcriptionally silent micronucleus, provides a useful platform for studying the role of Rad23 in global genome NER (GG-NER). However, the ectopic expression systems used thus far in T. thermophila to study Rad23 are repressed by UV light and do not account for the background expression of endogenous RAD23; these phenomena prevent insightful gains to the true dynamics of Rad23. In this thesis, endogenous tagging …

Roles Of Phospholipases And Ribosomal S6 Kinase In Lipid Remodeling And Growth In Arabidopsis Response To Phosphate Deprivation, Yuan Su

Dissertations

Phosphate (Pi) is one of three macronutrients for plants, which is vital for plant growth and development. Understanding the mechanism by which plants respond and adapt to Pi deficiency not only unveils functions of genes and pathways involved, but also provides potential tools to manipulate crops to better stand Pi stress in low Pi-containing lands. One of the significant metabolic changes in plants under Pi starvation is the membrane lipid remodeling that converts Pi-containing lipids such as phospholipids to Pi-free lipids, such as glycolipids. To elucidate the metabolism and regulation of lipid remodeling, this dissertation characterizes the role of two …

Reconstitution Of Gabaergic Postsynapses In Host Cells, Karthik Kanamalla

Honors Scholar Theses

Type A GABA receptors (GABAARs) can be found embedded in postsynaptic membranes or in a variety of extrasynaptic locations. Receptors with synaptic function are recruited to the postsynapse by submembranous scaffolds composed of gephyrin and collybistin (CB). This study was aimed at assessing whether the ability to interact with the scaffold differentiates synaptic from non-synaptic receptors. Using HEK293 cells as an expression system, and indirect immunofluorescence (IF), co-localization of extrasynaptic receptors α1β3δ and α4β3δ with the CB-gephyrin scaffold was assessed and compared with that of the synaptic receptor α1β3γ2. Results indicated that both extrasynaptic receptors were able to colocalize with …

Role Of Protein Charge Density On Hepatitis B Virus Capsid Formation, Xinyu Sun, Dong Li, Zhaoshuai Wang, Panchao Yin, Rundong Hu, Rundong Hu, Hui Li, Qiao Liu, Yunyi Gao, Baiping Ren, Jie Zheng, Yinan Wei, Tianbo Liu

Chemistry Faculty Publications

The role of electrostatic interactions in the viral capsid assembly process was studied by comparing the assembly process of a truncated hepatitis B virus capsid protein Cp149 with its mutant protein D2N/D4N, which has the same conformational structure but four fewer charges per dimer. The capsid protein self-assembly was investigated under a wide range of protein surface charge densities by changing the protein concentration, buffer pH, and solution ionic strength. Lowering the protein charge density favored the capsid formation. However, lowering charge beyond a certain point resulted in capsid aggregation and precipitation. Interestingly, both the wild-type and D2N/D4N mutant displayed …

Effect Of Mutation Of Cvn7 Conservon Genes Sco6796 And Sco6798 Of Streptomyces Coelicolor., Caroline Fulmer

Undergraduate Distinction Papers

Abstract

Streptomyces coelicolor is a gram-positive Actinobacterium. It is a filamentous soil organism that performs complex multicellular development. Its physiological and morphological differentiation produces active secondary metabolite antibiotics that have pharmaceutical applications. Studies of S. coelicolor show that cyclic di-GMP proteins regulate physiological and morphological development. S. coelicolor has 13 copies of an operon that are collectively named “conservon” because they are highly conserved. The operons are named cvn1-13 and genes in each operon are denoted cvnA-D. RNA-Seq data of a cyclic di-GMP phosphodiesterase double mutant showed differential expression between wild type and many of the operons in the …

Identifying Rmda Protein Interactions In Streptomyces Using A Bacterial Two-Hybrid System, Rachel Nguyen

Undergraduate Distinction Papers

Streptomyces is a genus of the phylum actinobacteria most commonly found as soil bacteria and used as a major source of antibiotics. RmdA and RmdB are phosphodiesterases that break down the ubiquitous second messenger cyclic-di-GMP which determines colony morphology and development of Streptomyces. The objective of this research is to identify whether RmdA will have interactions with itself using the Bacterial Adenylate Cyclase Two-Hybrid (BACTH) System. Each gene was fused into one of two BACTH vectors that encode a different domain of a single protein (T18 and T25) and then cotransformed into the BACTH indicator strain. The transformants were …

The Identification And Characterization Of A Putative Chromosome Segregation Gene In Streptomyces Coelicolor, Sean Kirk

Undergraduate Distinction Papers

Streptomyces coelicolor is a soil bacterium that is a model for bacterial development. It is a filamentous, sporulating bacterium known to produce many medically utilized antibiotics. The goal of this research was to examine several developmental mutants and characterize novel genes of interest. Previously generated random transposon insertion mutants were analyzed using visual and microscopic phenotyping. Mutants of interest were further pursued and each transposon disruption site was identified by Inverse PCR and DNA sequencing. One of the novel genes is suspected to be involved in DNA segregation and codes for a putative membrane protein. Staining with propidium iodide was …

Phase Diagram Of Water Confined By Graphene, Zhenghan Gao, Nicolas Giovambattista, Ozgur Sahin

Publications and Research

The behavior of water confined at the nanoscale plays a fundamental role in biological processes and technological applications, including protein folding, translocation of water across membranes, and filtration and desalination. Remarkably, nanoscale confinement drastically alters the properties of water. Using molecular dynamics simulations, we determine the phase diagram of water confined by graphene sheets in slab geometry, at T = 300 K and for a wide range of pressures. We find that, depending on the confining dimension D and density σ, water can exist in liquid and vapor phases, or crystallize into monolayer and bilayer square ices, as observed in …

Investigation Of Alcohol-Induced Changes In Hepatic Histone Modifications Using Mass Spectrometry Based Proteomics, Crystina Leah Kriss

USF Tampa Graduate Theses and Dissertations

Alcohol liver disease (ALD) is a major health concern throughout the world. Currently, in the United States, 17 million people suffer from alcoholism, of which 1.4 million people are receiving treatment [1, 2]. The link between ethanol metabolism, reactive oxygen species (ROS) and liver injury in ALD has been well characterized over the last couple decades [3-10]. Ethanol metabolism relies on the availability of the cofactor NAD+ for the oxidation of ethanol into acetate, consequently causing alterations in redox potential. Redox dysfunction within the mitochondria can affect multiple pathways important in maintaining cellular homeostasis. Chapter 1 provides an introduction to …

The Role Of Phosphohistidine Phosphatase 1 In Ethanol-Induced Liver Injury, Daniel Richard Martin

USF Tampa Graduate Theses and Dissertations

Chronic liver diseases, which includes alcoholic liver disease (ALD), are consistently among the top 15 leading causes of death in the United States. ALD is characterized by progression from a normal liver to fatty liver disease (hepatic steatosis), which can lead to cirrhosis, alcoholic hepatitis, and liver failure. We have identified a novel role of phosphohistidine signaling, mediated through phosphohistidine phosphatase 1 (PHPT1), in the onset of hepatic steatosis. We have identified PHPT1 as a target of selective oxidation following acute ethanol exposure as well as being downregulated following chronic ethanol exposure. We mapped the oxidative modification site and developed …

Elastin-Like Polypeptide Fusion Tag As A Protein-Dependent Solubility Enhancer Of Cysteine-Knot Growth Factors, Tamina L. Johnson

USF Tampa Graduate Theses and Dissertations

Elastin-like peptide (ELP) fusions promote therapeutic delivery and efficacy. Recombinant proteins, like neurotrophins, lack bioavailability, have short in vivo half-lives, and require high manufacturing costs. Fusing recombinant proteins with genetically encodable ELPs will increase bioavailability, enhance in vivo solubilization, as well as provide a cost-effective method for purification without the need for chromatography. During expression of neurotrophin-ELP (N-ELP) fusions, dense water-insoluble aggregates known as inclusion bodies (IBs) are formed. Inclusion bodies are partially and misfolded proteins that usually require denaturants like Urea for solubilization. Strong denaturants arrest ELPs stimuli-responsive property and increase unwanted aggregation, making purification difficult, yet possible. The …

Cloning, Purification, And Preliminary Dna-Binding And Unfolding Results For The Dna Polymerase I From The Psychrophile Psychromonas Ingrahamii, John Tod Baker

LSU Master's Theses

Psychromonas ingrahamii is a psychrophilic bacterium that lives in Arctic polar sea ice and grows at a temperature range of -12 to 10º C. This bacterium resides within veins inside the ice where the salinity is high, resulting in a freezing point depression and liquid water. The large fragment of DNA polymerase I from Psychromonas ingrahamii, called Klenpin, has been cloned, expressed, and purified in our laboratory. Although enzyme kinetic studies have been performed on a few psychrophilic enzymes, the thermodynamics of ligand binding and of protein stability have not been well studied for this class of extremophilic proteins. …

Whole Tart Cherry Improves Disease Activity Index In Rat Model Of Dextran Sulfate Solution – Induced Ulcerative Colitis By Downregulating The Janus 1 And Janus 3 Kinases And Tnf - Alpha, Johana Alexandra Coronel

LSU Master's Theses

Ulcerative colitis (UC) is a disabling inflammatory bowel disease. UC is characterized by chronic, relapsing inflammation of the colon and rectum. Current treatments such as monoclonal antibodies against TNF-α, IL-6, IL-12/p40, adhesion molecules, Janus kinases (JAK) inhibitors have side effects or lose their effects over time. Alternative approaches with fewer side effects for patients are needed. Montmorency tart cherries (Prunus cerasus) are a good source of anti-inflammatory flavonoids. We hypothesized that regular consumption whole tart cherry (TC) standardized to its major anthocyanin content, namely cyanidin-3-glucosyl-rutinoside, would be effective in reducing inflammation in UC. The aim of this research was to …

Breaking Conventions: Ohrr, A Transcriptional Regulator From Burkholderia Thailandensis, Anuja Rajiv Pande

LSU Doctoral Dissertations

Organic peroxides (OPs) are highly toxic oxidants. They directly react with cellular macromolecules rendering them inactive. Soil bacteria live in an oxidative environment rich in OPs from plant exudates and other xenobiotic compounds. Bacteria also face a burst of organic peroxides (lipid peroxides) in the macrophages during host invasion. Prokaryotes sense oxidative changes in environment and modulate their gene expression as an adaptive response for survival. MarR (multiple antibiotic resistance regulators) proteins enable bacteria to respond to such stress. Resistance to organic oxidants has been hypothesized to help bacteria survive in presence of disinfectants. This increases nosocomial infection rate.

Bacteria …

Ef-P Post-Translational Modification Has Variable Impact On Polyproline Translation In Bacillus Subtilis, Anne Witzky, Katherine R. Hummels, Rodney Tollerson Ii, Andrei Rajkovic, Lisa A. Jones, Daniel B. Kearns, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a ubiquitous translation factor that facilitates translation of polyproline motifs. In order to perform this function, EF-P generally requires posttranslational modification (PTM) on a conserved residue. Although the position of the modification is highly conserved, the structure can vary widely between organisms. In Bacillus subtilis, EF-P is modified at Lys³² with a 5-aminopentanol moiety. Here, we use a forward genetic screen to identify genes involved in 5-aminopentanolylation. Tandem mass spectrometry analysis of the PTM mutant strains indicated that ynbB, gsaB, and ymfI are required for modification and that yaaO, yfkA, and …

Monitoring And Quantifying Tetracycline Resistance Genes In A Swine Waste Anaerobic Digester Over A 100-Day Period, Melanie Couch

Masters Theses & Specialist Projects

Unregulated use of growth promoting antibiotics like Tetracyclines in agricultural feeds is becoming an increasing problem in antibiotic resistance. Undigested antibiotics leads to significant concentrations in livestock waste. These concentrations provide continuous selection pressure for the development of antibiotic resistance genes in the environment. Antibiotic resistance related deaths are projected to surpass cancer related deaths by 2050 making antibiotic resistance a pressing public health issue. The purpose of this study is to determine the abundance and persistence of tetracycline (tet) resistance genes in swine waste over a period of 100 days in an anaerobic digester system. Tet(A), tet(B), tet(G), tet(M), …

Advancing Professional Development Strategies For Chemistry And Biochemistry Undergraduates, Christian A. Brown

Senior Theses

In the Department of Chemistry and Biochemistry at the University of South Carolina (the Department), most curriculum-driven professional development is reserved for third- and fourth-year students. Classroom learning occurs at all levels, but the context comes late. Early exposure to career options and hands-on training is imperative for undergraduates to obtain maximum experiential learning. The purpose of this project is to advance the current professional development strategies of the Department, specifically targeting second- and third-year students. The study surveyed students' current involvement in professional development activities. The data on extracurricular experience and post-graduation interest was used to design a workshop …

Molecular Cloning And Functional Analysis Of Salt Overly Sensitive (Sos) Pathway Genes From Local Plants Of The United Arab Emirates, Mariam Obaid Saeed Abdalla Alzaabi

Biology Theses

Salinity is one of the major abiotic stresses that lead to extreme reduction in crop productivity worldwide. Increased soil and water salinity is a major issue in UAE’s agriculture. Some plants however have adapted to grow in high saline conditions, i.e. halophytes. Unfortunately, most crops are glycophytes and cannot tolerate high salinity. During salinity stress, expression of numerous genes is altered to protect the plants. Understanding the differences in gene structure between halophytes and glycophytes could provide insights into developing transgenic crops that can thrive in salinity conditions. The Salt Overly Sensitive (SOS) pathway is a key mechanistic cascade controlling …