Molecular Biology Commons^™

Role Of The Mar-Sox-Rob Regulon In Regulating Outer Membrane Porin Expression, Lon Chubiz, Christopher Rao

Biology Department Faculty Works

Multiple factors control the expression of the outer membrane porins OmpF and OmpC in Escherichia coli. In this work, we investigated the role of the mar-sox-rob regulon in regulating outer membrane porin expression in response to salicylate. We provide both genetic and physiological evidence that MarA and Rob can independently activate micF transcription in response to salicylate, leading to reduced OmpF expression. MarA was also found to repress OmpF expression through a MicF-independent pathway. In the case of OmpC, we found that its transcription was moderately increased in response to salicylate. However, this increase was independent of MarA and Rob. …

Identification Of Physiological Substrates Of Plasmodium Falciparum Pfpk5, A Cdk-Like Kinase, Catherine Sullenberger

HIM 1990-2015

Malaria is one of the most devastating infectious diseases causing 1-3 million fatalities a year. The majority of these cases occur amongst children in developing countries. Malarial strains in these areas are exhibiting increasing resistance to canonical treatments proving the importance of new drug targets for anti-malarials. Identification of new drug targets is dependent upon a better understanding of the molecular biology of the parasitic agent of malaria, Plasmodium. The regulation of Plasmodium's complex life cycle is still not well understood. Elucidation of signaling pathways involved in Plasmodium cell cycle regulation will provide insights into how the parasite thrives in …

Evaluation Of Delivery Conditions For Cutaneous Plasmid Electrotransfer Using A Multielectrode Array, Bernadette Ferraro, Loree C. Heller, Yolmari L. Cruz, Siqi Guo, Amy Donate, Richard Heller

Bioelectrics Publications

Electroporation (EP) is a simple in vivo method to deliver normally impermeable molecules, such as plasmid DNA, to a variety of tissues. Delivery of plasmid DNA by EP to a large surface area is not practical because the distance between the electrode pairs, and therefore the applied voltage, must be increased to effectively permeabilize the cell membrane. The design of the multielectrode array (MEA) incorporates multiple electrode pairs at a fixed distance to allow for delivery of plasmid DNA to the skin, potentially reducing the sensation associated with in vivo EP. In this report, we evaluate the effects of field …

Microrna Regulation Of Prostate Cancer Desensitization To Androgen Receptor Antagonist Drugs During Androgen Deprivation Therapy, Robert A. Lorch

HIM 1990-2015

The current standard treatment of prostate cancer by androgen deprivation therapy involves using drugs such as bicalutamide (Casodex) to antagonistically block androgen receptors that are normally present within prostate cells. Usually, the therapy is successful in the short run at limiting the growth of prostate cancer. However, in virtually all cases tumors begin to grow aggressively again after several months of treatment and new therapies must be started. The mechanism by which these prostate cells transform from androgen sensitive to androgen independent and anti-androgen resistant is unclear. In this study, we investigated the role of microRNAs, small 15 to 18 …

Cross-Talk Of Retinoic Acid And Adrenergic Hormone Signaling May Influence Development Of Cardiac Conduction And Rhythmicity In Utero, Sabikha Alam

HIM 1990-2015

Stress hormones, adrenaline and noradrenaline, have been shown to be critical for heart development. Mice lacking dopamine greek lower case letter beta]-hydroxylase (Dbh), an enzyme responsible for synthesis of these adrenergic hormones, die during mid-gestation due to cardiac failure. Prior research showed that adrenergic cells are found within the electrical conduction system of the heart, and adrenergic deficiency leads to slowed cardiac conduction during embryogenesis. Microarray analysis of wild-type (Dbh+/+) and knockout (Dbh-/-) mouse hearts revealed significant differences in expression of retinoic acid (RA) signaling genes. RA signaling has also been shown to be critical for heart development. These data …

Analysis Of The Repair Of Topoisomerase Ii Dna Damage, Eric D. Goldstein

HIM 1990-2015

A large number of anti-cancer chemotherapeutics target DNA topoisomerases. Etoposide is a specific topoisomerase II poison which causes reversible double strand DNA breaks. The focus of this project is to analyze the repair of DNA damage induced by etoposide.. Double strand DNA break repair is mediated by through either non-homologous end joining (NHEJ) or homologous recombination. NHEJ repairs through direct ligation of a double stranded break while homologous recombination utilizes a homologous template to recover the wild type sequence. A reporter cassette, RYDR-GFP, has been stably integrated into HeLa cells. This reporter contains an ultra-high affinity topoisomerase II cleavage site …

A Tripartile Biosensor For Real-Time Snss Detection In Dna Hairpin Motif, Camha Nguyen

HIM 1990-2015

The hybridization between two complementary strands of nucleic acid is the basis for a number of applications in DNA and RNA analysis, including in vivo RNA monitoring, microarrays, SNPs detection, and so on. The short oligonucleotide probes form Watson/Crick base pairs (A-T and G-C) with the analyzed nucleic acid. Molecular beacon (MB) probe is one of the most advantageous tools for nucleic acid analysis in real-time. A traditional MB probe consists of a DNA strand folded in hairpin motif with a fluorophore attached to the 5'end and a quencher attached to the 3' end. The loop segment is complementary to …

Plant-Made Oral Vaccines Evaluation Of Capsules, James Stewart New

HIM 1990-2015

Antigen expression through the Chloroplast Transformation Technology (CTT) produces bioencapsulated subunit-vaccines, capable of eliciting immune responses when delivered orally. Considerable challenges to effective plant-based vaccines are the normalization of dosage and preservation of accumulated antigen, which is complicated by variable high water content and protease activity. This study critically examines the efficacy of lyophilization in dehydrating plant-tissues and preserving plant-derived antigens with vaccine potential. Lyophilization was optimized through gravimetric analysis using lettuce expressing Protective Antigen (PA) of Bacillus anthracis (LS-HPAG) and the human autoantigen Proinsulin (Pins) fused to Cholera toxin subunit B (LS-CTB-Pins). Lyophilization for 48-hours was sufficient treatment to …

Molecular Modulation Of A-Subunit Visit-Dg Sequence Residue Asp-350 In The Catalytic Sites Of Escherichia Coli Atp Synthase., Sneha R. Jonnalagadda

Electronic Theses and Dissertations

ATP Synthase is the fundamental means of cellular energy production in animals, plants, and almost all microorganisms. In order to understand the mechanism of ATP catalysis, critical amino acid residues involved in Pi binding have to be identified. The αVISIT-DG sequence at the interface of α/β subunits that contains residues from 345-351 is highly conserved and αAsp-350 has been chosen because of its negative charge side chain and its close proximity (~2.8 Å) to the known phosphate binding residue αArg-376. The mutant's αD350R, αD350Q, αD350A, αR376A/D, and αG351R/A/D were generated by site directed mutagenesis and several biochemical assays were performed …

The Role And Mechanism Of The Homeobox Gene Dlx4 In Transforming Growth Factor-B Resistance In Cancer, Bon Q. Trinh

Dissertations and Theses (Open Access)

Transforming growth factor-b (TGF-b) is a cytokine that plays essential roles in regulating embryonic development and tissue homeostasis. In normal cells, TGF-b exerts an anti-proliferative effect. TGF-b inhibits cell growth by controlling a cytostatic program that includes activation of the cyclin-dependent kinase inhibitors p15^Ink4B and p21^WAF1/Cip1 and repression of c-myc. In contrast to normal cells, many tumors are resistant to the anti-proliferative effect of TGF-b. In several types of tumors, particularly those of gastrointestinal origin, resistance to the anti-proliferative effect of TGF-b has been attributed to TGF-b receptor or Smad mutations. However, these mutations are absent from many …

A Novel Function For Aurora B Kinase In The Regulation Of P53 By Phosphorylation, Chris P. Gully

Dissertations and Theses (Open Access)

The mitotic kinase Aurora B plays a pivotal role in mitosis and cytokinesis and governs the spindle assembly checkpoint which ensures correct chromosome segregation and normal progression through mitosis.  Aurora B is overexpressed in breast and other cancers and may be an important molecular target for chemotherapy.  Tumor suppressor p53 is the guardian of the genome and an important negative regulator of the cell cycle. Previously, it was unknown whether Aurora B and p53 had mutual regulation during the cell cycle.  A small molecule specific inhibitor of Aurora B, AZD1152, gave us an indication that Aurora B negatively impacted p53 …

Regulation Of Set1-Mediated Methylation Of Dam1, John A. Latham

Dissertations and Theses (Open Access)

Eukaryotic genomes exist within a dynamic structure named chromatin in which DNA is wrapped around an octamer of histones forming the nucleosome. Histones are modified by a range of posttranslational modifications including methylation, phosphorylation, and ubiquitination, which are integral to a range of DNA-templated processes including transcriptional regulation. A hallmark for transcriptional activity is methylation of histone H3 on lysine (K) 4 within active gene promoters. In S. cerevisiae, H3K4 methylation is mediated by Set1 within the COMPASS complex. Methylation requires prior ubiquitination of histone H2BK123 by the E2-E3 ligases Rad6 and Bre1, as well as the Paf1 transcriptional …

Expression And Regulation Of Human Cytochrome P450 4f Isoforms In Tissue Samples And Under Tnf-Alpha Challenges, Jordan C. Bell

Dissertations and Theses (Open Access)

CYP4F (Cytochrome P4504F) enzymes metabolize endogenous molecules including leukotrienes, prostaglandins and arachidonic acid. The involvement of these endogenous compounds in inflammation has led to the hypothesis that changes in the inflamed tissue environment may affect the expression of CYP4Fs during the pro-inflammatory state, which in turn may modulate inflammatory conditions during the anti-inflammatory state. We demonstrated that inflamed tissues have different levels of CYP4F isoform expression profiles in a number of human samples when compared to the average population. The CYP4F isoform expression levels change with the degree of inflammation present in tissue. Further investigation in cell culture studies revealed …

Stealth Carbon Nanotubes: Strategies To Coat Carbon Nanotubes To Prevent Opsonization And Improve Biodistribution, Nalinikanth Kotagiri

Graduate Theses and Dissertations

Carbon nanotubes (CNT) have recently been in the limelight for its potential role in disease diagnostics and therapeutics. Even before these medical applications can be realized, there is a need to address issues like opsonization, phagocytosis by macrophages and sequestration to liver and spleen for eventual elimination from the body. We believe coating CNT with biocompatible and opsonin resistant moieties will not only help CNT in traversing the blood stream to reach the target organ, but also improve biodistribution tremendously. We set out to achieve this by firstly identifying a new compound, mAmp, which is a fluorescent derivative of the …

Molecular Evolution And Historical Biogeography Of New World Birds, Brian T. Smith

UNLV Theses, Dissertations, Professional Papers, and Capstones

Deciphering the patterns of how biodiversity has evolved across time and space has remained a fundamental objective for biologists for the last 200 years. Researchers are faced with the challenge of interpreting the complexity of evolutionary patterns that have been generated over the deep history of the Earth. The advancement of DNA sequencing technology has yielded a new and powerful genetic toolkit that has allowed biologists to address novel evolutionary questions. For my dissertation research, I used molecular genetics and a statistical framework to study the evolution and historical biogeography of birds distributed in North and South America. My dissertation …

The Role Of Albino3 And The Lipid Environment In Chloroplast Signal Recognition Particle Targeting, Nathan Lewis

Graduate Theses and Dissertations

Signal recognition particles (SRPs) in pro- and eukaryotes function in cotranslational targeting of nascent poplypeptides to an SRP receptor at the target membrane. A unique chloroplast SRP (cpSRP) functions post-translationally to direct light-harvesting chlorophyll-binding proteins (LHCPs) to the receptor cpFtsY at the thylakoid membrane for LHCP insertion in a process involving the integral membrane protein Albino3 (Alb3) and requiring GTP. Work here focuses on understanding cpSRP targeting events at the thylakoid membrane, specifically those involving Alb3 and the lipid environment.

We show an interaction between the novel cpSRP subunit cpSRP43 and the soluble, stromal-exposed C terminus of Albino3 (Alb3-Cterm). We …

Ancient Mitochondrial Dna From Pre-Historic Southeastern Europe: The Presence Of East Eurasian Haplogroups Provides Evidence Of Interactions With South Siberians Across The Central Asian Steppe Belt, Jeremy R. Newton

Masters Theses

Studies of mitochondrial DNA (mtDNA) polymorphism have provided valuable insights for understanding patterns of human migration and interaction. The ability to recover ancient mtDNA sequence data from post-mortem bone and tissue samples allows us to view snapshots of historic gene pools firsthand, provided that great care is taken to prevent sample contamination. In this study, we analyzed the DNA sequence of the first hypervariable segment (HVSI) of the mtDNA control region, as well as a portion of the coding region, in 14 individuals from three collective burials from the Neolithic Dnieper-Donetz culture and three individuals from Bronze Age Kurgan burials, …

Functional Studies Of Human Cellular Detoxification Enzymes, Melanie Neely Willis

Department of Biochemistry: Dissertations, Theses, and Student Research

Cellular detoxification allows for the maintenance of cellular homeostasis and prevention of abnormal cell growth by clearing harmful xenobiotics and endobiotics. After oxygenation by phase I enzymes, phase II enzymes such as glucuronosyltransferases and glutathione-s-transferases conjugate a small molecule to the compound, marking it for subsequent export. Many up-stream enzymes are also essential to cellular detoxification by supplying the small compounds for conjugation. These up-stream enzymes include UDP-glucose dehydrogenase, which synthesizes UDP-glucuronate, and glutamate cysteine ligase, which catalyzes the first and rate-limiting step in the synthesis of glutathione.
UDP-glucose dehydrogenase (UGDH) is an important enzyme in human development and in …

The Release Of Calcium In Bacillus Anthracis Pathogenicity Methods, Natiera Magnuson, Manomita Patra Bhowmik, Maria Elena Reynaga, Ernesto Abel-Santos

Festival of Communities: UG Symposium (Posters)

Anthrax infection starts with germination of Bacillus anthracis spores in macrophages. Some bacteria, including B. anthracis, can sporulate in response to environmental stress, such as starvation. During germination, large concentrations of calcium ions are released from the B. anthracis spore. Calcium ions are hydrophilic secondary messengers, and may therefore interfere with detection of the spore by confusing the cell signaling pathways. We investigated calcium release on infected macrophage viability by replacing the calcium stored in B. anthracis spores for other cations via demineralization/remineralization. It was discovered that calcium ions typically out-performed other cations in germination of B. anthracis.

Characterization Of Ips Pini Ipsdienol Dehydrogenase (Idol Dh), Heidi Pak, Claus Tittiger, William Welch

Festival of Communities: UG Symposium (Posters)

Ipsdienol is an important pheromone component for pine engraver beetle, Ips pini. Ipsdienol is a ten carbon monoterpenoid secondary alcohol and ipsdienone is the corresponding ketone. We are characterizing the activity of recombinant IDOL DH produced in Sf9 (insect) cells. The enzyme has a high stereospecificity: (-) ipsdienol was found to be a substrate while (+)-ipsdienol was neither a substrate nor inhibitor. Closely related monoterpenoids, such as nerol, geraniol, and citral, were neither substrates nor inhibitors. Smaller compounds, such as 2-propanol, also failed to act as an inhibitor or substrate. This indicates the binding site of this enzyme is highly …