Molecular Biology Commons^™

Molecular Mechanisms Of Tandem Cbd Of Clostridium Histolyticum, Dawn Weir

Chemistry & Biochemistry Undergraduate Honors Theses

In order to spread infections, bacterial collagenases methodically unravel collagen fibril in tissues. Collagen is the most abundant protein in the body, and can be found in the skin, bone and cartilage [1]. Two collagenases, ColG and ColH, synergistically dismantle collagen fibrils by seeking different weak links in the collagen structure. The collagen-binding domain (CBD) of these collagenases binds to most vulnerable regions in collagen [8]. Without CBDs, collagen fibril cannot be degraded. Cells express collagen receptors in order to anchor themselves, which is a critical step in cell proliferation. Binding sites for some collagen receptors, such as integrin and …

Characterization Of Ghrelin O-Acyltransferase Active Site, Leslie Patton

Renée Crown University Honors Thesis Projects - All

Ghrelin, first discovered in 1999, is a 28-amino acid peptide hormone involved in the regulation of appetite, insulin secretion and sensitivity, and many neurological effects such as learning, memory, and depression.^1-6 Ghrelin has been identified to have a unique posttranslational octanoylation carried out by the enzyme ghrelin O-acyltransferase (GOAT). This distinctive modification is a point of interest in studying GOAT whereby blocking the acylation of the ghrelin could potentially halt the activity of the peptide hormone and provide a means of treating obesity, diabetes, and other diseases affected by ghrelin levels. The duration of my project involved working …

Role Of C-Kit In The Growth, Migration And Differentiation Of Human Cardiac Progenitor Cells., Bathri Narayan Vajravelu

Electronic Theses and Dissertations

The belief that adult mammalian heart lacks regenerative potential was challenged by the identification of c-kit positive cardiac progenitor cells (CPCs) in the heart. A recent phase I clinical trial (SCIPIO), has shown that autologous c-kit positive CPCs improve cardiac function and quality of life when transplanted into ischemic heart disease patients. c-Kit is a type III receptor tyrosine kinase and a common stem cell antigen. Stem cell factor (SCF) is the only known ligand for c-kit. Although c-kit is extensively used as an invariable marker of resident CPCs and shown to be important in the context of different cell …

Investigations Into The Molecular Mechanisms Of Bacterial Pathogen–Host Interactions: Construction Of A Dual Plasmid System For Incorporation Of Unnatural Amino Acids Into Pseudomonas Syringae Pv. Tomato Dc3000, Scotty D. Raber

Department of Chemistry: Dissertations, Theses, and Student Research

A dual plasmid system for the incorporation of unnatural amino acids into plant pathogen, Pseudomonas syringae pv. tomato DC3000, has been designed. This invention is expected to allow (a) mutations of proteins synthesized by the bacterium, P. syringae pv. tomato DC3000, that can capture molecular targets, especially for such modified proteins secreted by the phytopathogen into the host plant cells of A. thaliana and S. lycopersicum, (b) expression of biological probes in the bacterial species to monitor changes in redox, nutritional, and other small molecule states over pre-, post- and in situ disease stages, and secretion of such biological …

The Effect Of Activation Induced Cytidine Deaminase Phosphorylation And Herpes Virus Uracil Dna Glycosylase On Antibody Diversification, Marc Macaluso

Dissertations and Theses (Open Access)

Activation-induced cytidine deaminase (AID) is a mutagenic enzyme that is expressed in mammalian B-cells and initiates the antibody diversification processes of somatic hypermuntation (SHM) and isotype class switch recombination (CSR). AID is targeted to the immunoglobulin gene locus where it deaminates cytosines to generate uracil residues in DNA. This generates guanine-uracil (U:G) mismatch lesion which are recognized by uracil DNA glycosylase (UNG), a DNA repair enzyme that removes uracil from DNA and triggers downstream repair of the lesion. While UNG is a ubiquitously expressed DNA repair enzyme, its recognition and removal of AID introduced uracils is essential in both SHM …

Dna Polymerase Θ (Polq) And The Cellular Defense Against Dna Damage, Matthew J. Yousefzadeh

Dissertations and Theses (Open Access)

In mammalian cells, DNA polymerase θ (POLQ) is an unusual specialized DNA polymerase whose in vivo function is under active investigation. The protein is comprised of an N-terminal helicase-like domain, a C-terminal DNA polymerase domain, and a large central domain that spans between the two. This arrangement is also found in the Drosophila Mus308 protein, which helps confer resistance to DNA interstrand crosslinking agents. Homologs of POLQ and Mus308 are found in eukaryotes, including plants, but a comparison of phenotypes suggests that not all of these genes are functional orthologs. Flies with defective Mus308 are sensitive to DNA interstrand crosslinking …

Investigating The Roles Of P63 And P73 Isoforms To Therapeutically Treat P53-Altered Cancers, Avinashnarayan Venkatanarayan

Dissertations and Theses (Open Access)

Investigating the roles of p63 & p73 isoforms to therapeutically treat

p53-altered cancers

Avinashnarayan Venkatanarayan, M.S.

Supervisory Professor: Elsa R. Flores, Ph.D.

The TP53 tumor suppressor is mutated in approximately 50% of human cancers rendering cancer therapies ineffective. p53 reactivation suppresses tumor formation in mice. However, this strategy has proven difficult to implement therapeutically. An alternate approach to overcome p53 loss is to manipulate the p53-family members, p63 and p73, which interact and share structural similarities to p53. p63 and p73, unlike p53 are less frequently mutated and have two major isoforms with distinct functions …

Measuring Single Cell Responses To Lapatinib In A Heterogeneous Population, Preety Priya

Dissertations and Theses (Open Access)

Cancer is notonedisease butasaga of diseases and is the outcome of disturbed homeostasis in the normal cells due to the deregulation of its genetic makeup. With advent of technologies thatallowdetailed molecular characterizationoftumors, targeted therapies have emerged as a more promising and specific mode of treatment. However, a major challenge with targeted therapy is the acquired resistance in the cancer cells to these therapies, quite often very rapidly in the course of a few months. One of the major targets in cancer has been the EGFR/ErbB2 network in breast and other cancer types. Prior work from our lab and others have …

Regulation Of Cell Adhesion By The Ferm Proteins, Ptpn14 And Merlin, Patty Dimarco Hewitt

Dissertations and Theses (Open Access)

Cell-cell adhesion is critical for the control of tissue organization and homeostasis. A family of proteins that regulate cell-cell adhesions is the FERM (4.1 protein, Ezrin, Radixin, Moesin) domain-containing proteins.One FERM domain protein, the non-receptor tyrosine phosphatase PTPN14, is mutated or deleted in several human cancers suggesting that it may be involved in tumor development and/or progression. Additionally, the loss of the FERM domain protein Merlin is associated with tumor development and metastasis.Both PTPN14 and Merlin have been shown to localize and possibly regulate adherens junction (AJ) functions. This work sought to determine if …

Phenotypic And Functional Genomics Analyses Of Salmonella For Food Safety Applications, Turki Dawoud

Graduate Theses and Dissertations

Non-typhoidal Salmonella species have been major foodborne zoonotic pathogens causing serious problems in public health and food industry for several decades. Numerous Salmonella species have frequently been associated with different food commodities mainly poultry meat, eggs, and their products. This dissertation begins with a literature reviews discussing many aspects of Salmonella generally; and subsequently focused on two serotypes, Salmonella Enteritidis and S. Typhimurium as they are at the top of all other serovars responsible for most illness cases and outbreaks. In addition, some Salmonella strains have exhibited their ability to tolerate and survive many food processing treatments. We can divide …

Functional Significance Of Gill Claudin Proteins In Rainbow Trout (Oncorhynchus Mykiss) Osmoregulation, Joanna Katarzyna Bujak

Graduate Theses and Dissertations

Claudin proteins, a key element of tight junction complexes, are known to control paracellular permeability. In euryhaline fish, changes in claudin abundance and localization are critical during salinity acclimation. In seawater, a leaky paracellular pathway that facilitates sodium extrusion is hypothesized to be controlled by claudin proteins. The aim of this study was to evaluate the role of Claudin-10c, -10d -10e and Claudin-30 in gill function in freshwater (FW) and seawater (SW) rainbow trout (Oncorhynchus mykiss). I examined mRNA and protein abundance along with cellular localization. A tissue distribution survey showed that all of the claudins studied were predominantly expressed …

Impacts Of Micrornas On Skeletal Muscle Protein Synthesis And Mitochondrial Quality, David Lee

Graduate Theses and Dissertations

microRNA (miRNA) post-transcriptional modification is becoming a well-established mechanism for controlling mRNA translation. microRNAs -1, -133, and -206 are under the control of skeletal muscle promoters and affect muscle plasticity and metabolic health. A detailed review on the generation and processing of miRNAs with a view to skeletal muscle brings up intriguing connections in the transcriptional connections between multiple miRNAs. Additionally, exciting new research has defined a role of miRNAs in skeletal muscle mitochondria showing an additional, direct link to metabolic function. Multiple investigations in models of exercise, aging, hypertrophy, and injury have shown how these interventions can affect miRNA …

The Cancer Genome Atlas (Tcga): Breast And Ovarian Cancers, Laura Ann Riccio

Senior Honors Projects

The field of genomics originated in the 1970’s starting with the sequencing of small organisms’ genomes such as the bacterium, Haemophilus influenzae, and the yeast, Saccharomyces cerevisiae. A genome is the complete ordered sequence of DNA bases (A, C, G, and T) comprising all of the protein- and RNA-coding genes, as well as all of the regulatory sequences necessary for the construction of an organism. Over time, scientists sequenced the genomes of larger and more complex organisms, eventually leading to the sequencing of the human genome. The Human Genome Project (HGP) was initiated in 1990 and took over ten …

Local Modulation And Measurement Of Macrophage-Derived Bioactive Proteins From Implanted Biomaterials In Rat, Geetika Bajpai

Graduate Theses and Dissertations

Fibrosis around the implanted medical devices is a severe problem that can plague long-term device reliability. Activation of macrophage phenotype (macrophage polarization) has emerged as a new and possible means for reducing fibrosis in the fields of biomaterials and regenerative medicine. Macrophages are phagocytic cells that respond to microenvironmental cues that direct their phenotype. Macrophage activation has been widely studied in mouse and human in the context of tumor biology, yet little information is available regarding how macrophage activation could be used in a biomaterials context. Further, rats rather than mice are the common subjects in biomaterials experiments. A significant …

Developing An Application For Evolutionary Search For Computational Models Of Cellular Development, Nicolas Scott Cornia

Boise State University Theses and Dissertations

VPEvolve is a free and open source application that utilizes a Visual Programming Environment (VPE) for the setup of the Genetic Algorithm (GA), for optimization of computational models. Specifically, the User Interface uses connected glyphs to represent the genetic operators of mutation, reproduction, fitness and selection. These glyphs give the user an intuitive way to set the parameters for the GA, and better visualization of the population's flow through these operators.

VPEvolve is currently being developed alongside research being done in Biocomputing to create models of cellular regeneration based on the regenerative properties of Planaria or flatworms. Since these models …

Development Of Genetic Goat And Hamster Models Of Atrial Fibrillation And Long Qt Syndrome; And Genetic Hamster Models Of Middle East Respiratory Syndrome, Dane A. Rasmussen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Atrial fibrillation (AF) and long QT syndrome (LQTS) are potentially lethal heart rhythm disorders that can be caused by mutations in the potassium channel gene KCNQ1. Middle East Respiratory Syndrome (MERS) is a viral infection with the potential to replicate the devastating effects of the SARS outbreak in 2003. All three of these diseases are in need of genetic animal models.

To address these needs, my thesis project focused on the development of genetic goat and hamster models of AF and LQTS, and genetic hamster models of MERS. Because of the goat’s similar organ size/physiology and the hamster’s similar lipid …

Heterogeneous Dynamics In Dna Site Discrimination By The Structurally Homologous Dna-Binding Domains Of Ets-Family Transcription Factors, Gaofei He, Ana Tolic, James Bashkin, Gregory Poon

Chemistry & Biochemistry Faculty Works

The ETS family of transcription factors exemplifies current uncertainty in how eukaryotic genetic regulators with overlapping DNA sequence preferences achieve target site specificity. PU.1 and Ets-1 represent archetypes for studying site discrimination by ETS proteins because their DNA-binding domains are the most divergent in sequence, yet they share remarkably superimposable DNA-bound structures. To gain insight into the contrasting thermodynamics and kinetics of DNA recognition by these two proteins, we investigated the structure and dynamics of site discrimination by their DNA-binding domains. Electrophoretic mobilities of complexes formed by the two homologs with circularly permuted binding sites showed significant dynamic differences only …

Repsa-Directed Identification Of Dna-Binding Specificity For Orphan Transcription Factors, Kamir Hiam

Symposium of Student Scholars

The function of many genes and the biological roles of their encoded products are still not well characterized. Given the sequence-specific DNA-binding properties of transcription factor proteins, it is possible to purify them, identify the responsible polypeptide(s), determine their consensus binding sequences, and identify their genomic binding sites. Thus, one can go from cellular extract to proposed biological regulatory roles in relatively short order. Our goal is to identify and characterize orphan DNA-binding proteins in the model organism E. coli K12 using the novel combinatorial technique, REPSA (Restriction Endonuclease Protection Selection Amplification), as well as further develop the REPSA to …

Determining Lung Cancer Subtypes, Classifications, And Potential Gene Markers, Daniel L. Johnson

Student Theses and Dissertations

Lung Cancer is the leading cause of cancer-related deaths in the United States. The key to surviving this disease is early discovery and treatment. Precise diagnosis is critical when selecting the treatment for the patient. Diagnosis of the patient will depend upon the location of the tumor, the stage of the tumor, and the class of the tumor. Clinically, lung cancer is divided into two classes: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Non small-cell lung cancer accounts for 85% of all lung cancer. NSCLC can be separated into three major subtypes: adenocarcinoma, squamous-cell, and large-cell …

The Effect Of Red Maple Leaf Toxicosis On Reduced Glutathione Levels In Equine Erythrocytes In Vitro, Madeline A. Rohl

Undergraduate Honors Thesis Projects

Red maple leaf toxicosis is an equine blood disorder resulting from the consumption of wilted red maple (Acer rubrum L.) leaves by horses. Compounds within the leaves of red maple have oxidative effects on equine erythrocytes and can cause hemolysis of erythrocytes, the conversion of hemoglobin to methemoglobin, and the production of Heinz bodies. Reduced glutathione is important in the protection of equine erythrocytes from these oxidative events; however, in the presence of red maple toxin, glutathione is rapidly oxidized and is unavailable. The objective of this study is to determine whether the presence of vitamin C alters levels …

Consumption Of Oral Nicotine: Its Effects On The Reproductive System And Nicotine Metabolism Of Female Sprague-Dawley Rats, Swapnali Halder

Student Theses and Dissertations

Smoking is a major preventable cause of death throughout the world and the need for cessation is unanimously supported by clinicians and scientists. Nicotine in cigarettes is believed to cause tobacco dependence and addiction and low doses of nicotine are found in nicotine replacement therapies (NRT) to mitigate withdrawal symptoms and improve cessation efforts. In addition to smoking associated health risks that are common for men and women, women smokers are more likely to suffer from pregnancy or other reproductive health related complications than non-smokers. Studies show that female smokers are more vulnerable to smoking, and find it harder to …

Characterization Of Hessian Fly From Israel, Alisha J Johnson

Open Access Dissertations

Mayetiola destructor Say, the Hessian fly, is a gall midge and a member of the Dipteran family Cecidomyiidae. It is a common pest of wheat found throughout all of the major wheat growing areas of the world and poses a serious economic threat to the United States (US), particularly in the Southeast winter wheat region. Damage to wheat is done solely by feeding first and second in-star larvae. Hessian fly (Hf) infestations result in a loss in grain yield by the stunting and/or killing of seedling wheat plants in the winter and by causing breakage at the nodes of the …

Analysis Of Chd Remodelers During Development: A Tale In Two Organisms, Brett Bishop

Open Access Dissertations

The correct development of different organisms requires the precise timing of genes important for development transitions. Organisms have recruited ATP-dependent chromatin remodelers to ensure the correct timing of gene expression during developmental transitions. Here I show how different CHD ATP-dependent chromatin remodelers regulate developmental transitions of different organisms. I show that PICKLE not only promotes H3K27me3 during development to repress developmental genes but also is targeted to these genes. The association of PICKLE to these genes suggests that both repression and H3K27me3 levels is a direct action of PICKLE on these loci. Using zebrafish as a model system, I show …

Biochemical Investigation Of The Ubiquitin Carboxyl-Terminal Hydrolase Family, Joseph Rashon Chaney

Open Access Dissertations

The proteasome is the machinery in eukaryotic cells that degrades protein and recycles the amino acids. Protein degradation is a highly regulated process which starts by the attachment of chains of ubiquitin, which serves as a tag that marks a protein for degradation. This function involves the work of several proteins at the proteasome that work either as ubiquitin chaperones, ubiquitin binders or cleave ubiquitin from the protein that is to be degraded. As this is a highly regulated process, various irregularities can have deleterious effects including the onset of disease, including cardiovascular, cancer, and neurological. ^ The focus of …

Identification Of Perilipin 5 Interaction Partners, Emily E. Burton

Undergraduate Honors Thesis Projects

Perilipin 5 is one of the more recently discovered in the PAT protein family. Several studies on this protein have shown that it resides in multiple intracellular locations such as the endoplasmic reticulum, the cytosol, the mitochondria, and most interestingly on lipid droplets. These lipid droplets have proven not to be just clumps of fat, but to be very complex intracellular organelles, with a core of lipids surrounded by a phospholipid monolayer coated by specific proteins, one of those being perilipin 5. Some proteomic studies have revealed these lipid droplets to be involved in intracellular trafficking, signaling, cytoskeletal organization and …

Conditional Regulation Of Puf1p, Puf4p, And Puf5p Activity Alters Yhb1 Mrna Stability For A Rapid Response To Toxic Nitric Oxide Stress In Yeast, Joseph Russo, Wendy Olivas

Biology Department Faculty Works

Puf proteins regulate mRNA degradation and translation through interactions with 3' untranslated regions (UTRs). Such regulation provides an efficient method to rapidly alter protein production during cellular stress. YHB1 encodes the only protein to detoxify nitric oxide in yeast. Here we show that YHB1 mRNA is destabilized by Puf1p, Puf4p, and Puf5p through two overlapping Puf recognition elements (PREs) in the YHB1 3' UTR. Overexpression of any of the three Pufs is sufficient to fully rescue wild-type decay in the absence of other Pufs, and overexpression of Puf4p or Puf5p can enhance the rate of wild-type decay. YHB1 mRNA decay …

Promoting Genome Stability Via Multiple Dna Repair Pathways, Scott Cukras

USF Tampa Graduate Theses and Dissertations

Maintaining genome integrity is indispensible for cells to prevent and limit accruement of deleterious mutations and to promote viable cell growth and proliferation. Cells possess a myriad of mechanisms to detect, prevent and repair incurred cellular damage. Here we discuss various proteins and their accompanying cellular pathways that promote genome stability. We first investigate the NEDD8 protein and its role in promoting homologous recombination repair via multiple Cullin E3 ubiquitin ligases. We provide specific mechanisms through which, UBE2M, an E2 conjugating enzyme, neddylates various Cullin ligases to render them catalytically active to degrade their substrates by the proteasome. We show …

A Functional Chlorophyll Biosynthesis Pathway Identified In The Kleptoplastic Sea Slug, Elysia Chlorotica, Julie A. Schwartz

USF Tampa Graduate Theses and Dissertations

The sacoglossan sea slug, Elysia chlorotica, feeds upon and sequesters plastids from the heterokont alga, Vaucheria litorea, and maintains the metabolically active organelles for up to nine months under starvation conditions while utilizing the photosynthate to survive and reproduce. The photosynthetic pigment, chlorophyll a (Chla), is found in all oxygenic photosynthetic organisms and is responsible for capturing photons of light and converting them into chemical energy. Chlorophyll and its associated proteins involved in the light capturing process are subject to photo oxidative damage and must be continually replaced for ongoing photosynthesis to continue; however, genes encoding these proteins are present …

G-Quadruplex Dna Structures And Site Specific Genetic Instability, Jonathan David Williams

Theses and Dissertations

Repetitive DNA comprises a majority of the human genome yet functions and overall impacts on site-specific genetic instability are not fully defined. Repetitive G-rich sequences have the propensity to form G-quadruplex (G4), which are stable non-B form DNA structures. G4 structures are conspicuously found at regions of site-specific instability. Even so, human genomic loci capable of forming this structure and their connection to DNA rearrangements are just beginning to be elucidated. My dissertation focuses on G4 structures and their capacity to promote site-specific changes in the human genome, particularly at oncogenes. I identified and investigated new biologically relevant G4 loci …

Escherichia Coli O157:H7 Bacteriophage Φ241 Isolated From An Industrial Cucumber Fermentation At High Acidity And Salinity, Zhongjing Lu, Fred Breidt

Faculty Articles

A novel phage, Φ241, specific for Escherichia coli O157:H7 was isolated from an industrial cucumber fermentation where both acidity (pH ≤ 3.7) and salinity (≥5% NaCl) were high. The phage belongs to the Myoviridae family. Its latent period was 15 min and average burst size was 53 phage particles per infected cell. The phage was able to lyse 48 E. coli O157:H7 strains, but none of the 18 non-O157 strains (including E. coli O104:H7) or the 2 O antigen-negative mutants of O157:H7 strain, 43895Δper (also lacking H7 antigen) and F12 (still expressing H7 antigen). However, the phage was able to …