Biochemistry, Biophysics, and Structural Biology Commons^™

The Role Of A Transcription Factor In Regulating Rice Response To Drought Stress, Diana Ha, Liyuan A. Zhang, Jeffery Shen

Undergraduate Research Opportunities Program (UROP)

The current water shortage is a major concern in regard to our global climate change crisis. A decrease in the availability of water will have direct effects on the development of plants. Some crops, such as Oryza sativa, or commonly known as rice, requires an abundant amount of water for adequate growth. With the water shortage crisis, it will become extremely difficult to harvest such crops to meet the world’s food demand. However, many plants have evolved mechanisms for overcoming and tolerating stresses such as drought. My research focuses on studying the proteins involved with these mechanisms. The WRKY superfamily …

Identification Of Nitrifying Bacteria Contained In A Commercial Inoculant Using Molecular Biology Techniques, Anthony Harrington, John Perry, Penny S. Amy

Undergraduate Research Opportunities Program (UROP)

Nitrifying bacteria play an important role in aquatic and terrestrial environments through the nitrogen cycle. Nitrification, one of the processes of the nitrogen cycle, refers to the oxidation of ammonia to nitrate. This process requires two types of chemoautotrophic bacteria, ammonia-oxidizing bacteria (AOB), and nitrite-oxidizing bacteria (NOB). These bacteria are essential in maintaining an optimal environment for plants and aquatic organisms, such as fish. Current applications of nitrifiers include: inoculants for aquariums, biofertilizers, and nitrogen removal in wastewater treatment plants. This study wants to identify a consortium of nitrifers that can be used to produce sufficient nitrate for plants in …

Ubiquitylation Of Proteins In The Frozen Wood Frog, Alexa Khan, Michael Ulrich, Kenneth Storey, Frank Van Breukelen

Undergraduate Research Opportunities Program (UROP)

Wood frogs (Rana sylvatica) are able to withstand freezing. Respiratory and cardiac activity ceases when frozen. Homeostatic functions like protein synthesis and degradation presumably must also be compromised. We investigated the fate of ubiquitin-dependent proteolysis in the freeze-thaw cycle and how that might gives clues to wood frog survival. We performed western blots for ubiquitin conjugates

Novel Thermophilic Cellulolytic Isolates Belonging To The Phylum Chloroflexi, Maryknoll Palisoc, Jessica K. Guy, Joseph P. Peacock, Duy C. Trinh, Jeremy A. Dodsworth, Brian P. Hedlund

Undergraduate Research Opportunities Program (UROP)

Current biofuel technologies utilize valuable foodstuffs, such as corn kernels and cane sugar, as sources of easily metabolized sugars. Microbes are used to ferment these sugars into bioethanol, a first-generation biofuel. However, in order to avoid diverting foodstuffs from the food supply, the development of second-generation biofuels technology is necessary. Second-generation biofuels are produced by converting structurally complex lignocellulosic biomass, such as agricultural and municipal wastes, to fermentable sugars or directly to biofuels.

The major technological hurdle limiting the mass production of second-generation biofuels is the difficulty in efficiently converting structurally complex lignocellulosic materials to fermentable sugars or directly to …

Inactivation Of Spo0a Gene Increases Stationary Phase Mutagenesis In Bacillus Subtilis, Denisse Reyes, Amanda Prisbrey, Holly Martin, Eduardo Robleto

Undergraduate Research Opportunities Program (UROP)

Stationary phase mutagenesis occurs when a population of cells acquires mutations conferring escape from nongrowing or stress conditions. This type of mutations is observed in nutritionally starved cells. Because the mutations occur after the onset of stress and in cells that are in non-replicative conditions, elucidating the underlying mechanisms contributes novel views to the process of evolution and apply to the formation of cancer in human cells and antibiotic resistance in microbial pathogens. Studies have shown that in Bacillus subtilis, the Mfd protein which is a transcription repair coupling factor is necessary for this phenomenon to occur. Here, we investigate …

Synthesis Of Chimeric Receptors Essential For Spore Germination, Christopher Yip, Christian Ross, Eduardo Robleto, Ernesto Abel-Santos

Undergraduate Research Opportunities Program (UROP)

Various species of bacteria have been reported to form an endospore, a metabolically dormant cell, during times of nutrient deficiencies and extreme stress. These said structures are outstandingly resistant to harsh chemicals, extreme temperatures, and can revert back to a metabolically active cell, through a process known as germination, when the necessary conditions are met. The rigid membrane of the endospore contains various germination (Ger) receptors which sense the external environment for necessary metabolites and germinants. Ger receptors are encoded by tricistronic operons that produce three distinct membrane proteins, the A, B, and C subunits. Although the function of the …

Investigating The Origin Of Coprolites From Three Great Basin Caves, Chelsey Vandrisse, Duane P. Moser, David Rhode

Undergraduate Research Opportunities Program (UROP)

The study of coprolites (mummified feces) is a relatively new endeavor, which enables investigations of the health and diet of ancient people and provides some of the oldest evidence to date for the human habitation in North America (2). In this project, 18 coprolites were examined from archeological digs at three Great Basin caves: the Bonneville Estates Rockshelter (UT), Hidden Cave (NV), and Top of the Terrace Rockshelter (UT). The main objectives were: 1) to verify human origin through the presence of mitochondrial DNA (mtDNA) and 2) assuming human origin, characterize intestinal microflora of Native Americans prior to European contact. …

The Role Of An Abc Transporter As A Steroid Antagonist In Drosophila, Gregory King, Andrew Andres

Undergraduate Research Opportunities Program (UROP)

Drosophila melanogaster are holometabolous insects that have several distinct life stages including larvae and a winged adult. The larval stage is mainly a time of feeding and growth, while the adult stage is optimized for sexual reproduction and dissemination. The larval stage can itself be divided into three time periods, or instars: 1st (L1), 2nd (L2), and 3rd (L3) (Figure 1). Larval growth – both between instars and beyond – depends on specific signaling pathways controlled by a cholesterol derived steroid, 20-hydroxyecdysone (20E). Although 20E is a systemic developmental signal, little is known about the molecular details of how different …

Cell Migration Dynamics After Alteration Of Cell-Cell Contacts In Fibrosarcoma And Glioblastoma Cell Lines, Hassan S. Rizvi, Ronald K. Gary

Undergraduate Research Opportunities Program (UROP)

Cell migration is a vital component of metastasis. In this study, our intent was to study cell migration by alteration of the Wnt/GSK-3 Pathway. Since BeSO4 is a known GSK-3 kinase inhibitor, we hypothesized that this agent would cause cell migration to decrease as a result of β-catenin stabilization. Two human cell lines, HT-1080 (fibrosarcoma) and A172 (glioblastoma), were used to observe migration levels in the presence and absence of BeSO4. Our results show that cell migration is diminished for cells that were pre-treated with BeSO4, in comparison to the untreated (control) cells.

Isolation, Characterization, And Genome Sequence Of The First Representative Of A Novel Class Within The Chloroflexi That Is Abundant In Some U.S. Great Basin Hot Springs And May Play Important Roles In N And C Cycling, Jeremy A. Dodsworth, Senthil K. Murugapiran, Jonathan Gevorkian, James Han, Tanja Woyke, Susan M. Lucas, Sam Pitluck, Len Pennacchio, Lynne Goodwin, Brian P. Hedlund

Undergraduate Research Opportunities Program (UROP)

A thermophilic, facultatively microaerophilic, heterotrophic bacterium, designated strain JAD2, was isolated from sediments of Great Boiling Spring (GBS), an ~80oC, circumneutral hot spring in the Great Basin GB). The strain grew anaerobically on yeast extract or peptone with an optimal growth temperature of 70-75oC. Growth was stimulated by addition of 0.01 atm O2 to the culture vessel headspace, but was inhibited by higher concentrations (0.2 atm). Cells of JAD2 formed non-motile filaments ranging from 10 to >300 μm in length, which typically decreased in length during stationary phase. 16S rRNA gene-targeted pyrotag sequencing and clone library data suggest that close …

Dna Secondary Structures And Their Contribution To Mutagenesis In B. Subtilis Stationary Phase Cells, Carmen Vallin, Holly Martin, Christian Ross, Ronald Yasbin, Eduardo Robleto

Undergraduate Research Opportunities Program (UROP)

It is widely known and accepted that the cause of many mutations in cells are generated during the replication process of actively dividing cells, however more recent research has shown that mutations also arise in non growing conditions, a phenomenon known as stationary phase mutagenesis. Much of what is known come from studies in eukaryotic and bacterial models. It has been proposed that in non~growing cells, the process of transcription plays an important role in mutagenesis. We test the hypothesis that DNA secondary structures, formed during transcription, promote mutagenesis. The transcription-generated structures are speculated to be prone to mutations by …

Regulation Of The Shigella Flexneri Icsp Gene And H-Ns Dependent Repression, Rosa Ojeda, Amanda Wigley, Dustin Harrison, Helen Wing

Undergraduate Research Opportunities Program (UROP)

The gram negative bacterium Shigella flexneri is known to cause dysentery in humans and primates. In order to help prevent the spread of shigellosis, gene regulation must be understood. Studies show that the virulence genes in S .flexneri are thermo regulated. At 30°C histone-like nucleoid structuring protein (H-NS) represses transcription of virulence genes and at 37°C VirB derepresses virulence genes. One of the genes that contribute to the virulence of S. flexneri is icsP. My project focuses on the regulation of the S. flexneri icsP gene and has two main goals. The first is to identify the sequence of H-NS …

Synthesis Of A Chemical Probe For Identification Of Ger Receptor Proteins Of Bacillus Anthracis, Hyelee Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bacillus anthracis,a gram positive, endospore-forming, rod-shaped, aerobic bacterium, is the causative agent of anthrax. A key step in the pathogenic cycle is the spore germination, where the dormant spore transforms into a metabolically active cell. This allows B. anthracis to proliferate and secrete toxins. It is believed that spore germination is triggered when small molecules, known as germinants, are recognized by germination (Ger) receptor proteins located in the inner membrane of spores. Most Ger proteins are encoded by tricistronic operons, resulting in three distinct products, the A-, B-, C-subunits. Genomic sequencing showed that B. anthracis has seven ger receptor …

Hivtoolbox, An Integrated Web Application For Investigating Hiv, David P. Sargeant, Sandeep Deverasetty, Yang Luo, Angel Villahoz Baleta, Stephanie Zobrist, Viraj Rathnayake, Jacqueline C. Russo, Jay Vyas, Mark A. Muesing, Martin Schiller

Life Sciences Faculty Research

Many bioinformatic databases and applications focus on a limited domain of knowledge federating links to information in other databases. This segregated data structure likely limits our ability to investigate and understand complex biological systems. To facilitate research, therefore, we have built HIVToolbox, which integrates much of the knowledge about HIV proteins and allows virologists and structural biologists to access sequence, structure, and functional relationships in an intuitive web application. HIV-1 integrase protein was used as a case study to show the utility of this application. We show how data integration facilitates identification of new questions and hypotheses much more rapid …

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 …

Accumulation Of Polonium-210 In Different Species Of Fish In Lake Mead, Suraj Ghevarghese John, Shungmugam Nallaperumal, Vernon Hodge

Festival of Communities: UG Symposium (Posters)

Discovered by Pierre Curie and Marie Skłodowska-Curie in 1898, polonium is a chemical element with an atomic number of 84. This rare naturally occurring radioactive element is chemically similar to bismuth and tellurium, and forms in uranium ores. Polonium-210 is an naturally occurring radioactive element with a half-life of 138.376 days(1). This element is found in trace amounts in most organisms. Our research is focused on the accumulation of polonium-210 in fish that occupy in Lake Mead.

The sample species is chosen based on varying lake stratification (layers of the lake). This gives us a good idea of the difference …

Construction And Use Of A Direct Calorimeter To Estimate Energy Expenditure In Hibernators, Mark S. Burger, Frank Van Breukelen

Festival of Communities: UG Symposium (Posters)

Metabolic rates have traditionally been estimated through indirect calorimetry (gas exchange or respirometry) due to its ease and availability. Oxygen consumption neglects the contributions of anaerobic metabolism, while direct calorimetry (heat production) estimates both anaerobic and aerobic metabolism. Walsberg and Hoffman (2005) report anaerobic metabolism may be more important to small rodents than was previously thought. During the non-steady state of mammalian hibernation, we hypothesize that anaerobic processes may play an even greater role in fueling metabolism. To address this question, we constructed a very sensitive calorimeter that utilizes the Seebeck effect from a thermoelectric element (Peltier device). We describe …

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 …

Effect Of Temperature And Oxygen Levels On Lactate Production In Palaemonetes Pugio, Robin Schofield, Teresa Mika, Carl Reiber

Festival of Communities: UG Symposium (Posters)

Oxygen delivery rates must keep pace with the increased metabolic rate observed in poikilothermic animals exposed to increased temperature if aerobic metabolism is to be maintained. Physical failure of the oxygen delivery system to meet these demands may be a mechanism of cardiac failure in crustaceans at temperature extremes. As part of the determination of the effect of temperature on the cardio-respiratory system, we are measuring whole animal lactate levels in grass shrimp acclimated to 20°C over temperature ranges in normoxic and hyperoxic conditions. Lactate levels are measured as an indicator of a switch from aerobic to anaerobic metabolism. Animals …

Scireader Enables Reading Of Medical Content With Instantaneous Definitions, Patrick R. Gradie, Megan Litster, Rinu Thomas, Jay Vyas, Martin Schiller

Life Sciences Faculty Research

Background

A major problem patients encounter when reading about health related issues is document interpretation, which limits reading comprehension and therefore negatively impacts health care. Currently, searching for medical definitions from an external source is time consuming, distracting, and negatively impacts reading comprehension and memory of the material.

Methods

SciReader was built as a Java application with a Flex-based front-end client. The dictionary used bySciReader was built by consolidating data from several sources and generating new definitions with a standardized syntax. The application was evaluated by measuring the percentage of words defined in different documents. A survey was used …

Development Of Novel Biomarkers In Cancer: Detection Of Circulating Mir-141 As A Potential Prognostic Marker For Prostate Cancer, Jason Cadaoas Gonzales

UNLV Theses, Dissertations, Professional Papers, and Capstones

Prostate cancer (CAP) is the most common epithelial malignancy and the second leading cause of cancer deaths in American men. The identification of predictive and prognostic biomarkers in CAP patients is critical for improving clinical outcomes. Although the measurement of prostate-specific antigen (PSA) and radiographic studies are clinically approved to predict response to therapy, these tests can oftentimes prove to be inadequate in certain patients. Thus, it is important to discover new biomarkers to improve chances of survivability. We and others have shown that longitudinal measurements of circulating tumor cells (CTC) and lactate dehydrogenase (LDH) may aid in predicting response …

Production, Purification And Crystallization Of Membrane Integrated Multimeric Bax, Adelbert Mark Villoso

UNLV Theses, Dissertations, Professional Papers, and Capstones

Apoptosis, or programmed cell death, is a vital process intimately involved in the embryonic development and homeostatic maintenance of all multicellular organisms. The committing step to apoptosis is regulated by a key protein, Bax, and its ability to integrate and form a pore structure at the outer mitochondrial membrane.

Unfortunately, the molecular details of apoptosis remain largely unclear due to the lack of structural data of integral membrane (IM) Bax. Experimental limitations of membrane protein production have slowed the pursuit of an IM-Bax structure simply because standard protocols for producing recombinant IM-Bax are inefficient in producing adequate quantities of IM-Bax …

Transcriptional Regulation Of Shigella Virulence Plasmid-Encoded Genes By Virb And Crp, Christopher Thomas Hensley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella flexneri is a species of Gram-negative intracellular pathogens that causes bacillary dysentery in humans. Shigella relies on the precise transcriptional regulation of virulence genes, encoded by a large virulence plasmid, for invasion and infection of human colonic epithelial cells. The transcription of most identified virulence genes are regulated through a cascade controlled by the primary regulator of virulence genes, VirF, and the global transcriptional regulator, VirB. Currently, few studies have addressed how individual Shigella virulence genes are precisely regulated for optimal expression during specific stages of pathogenesis and within the constraints of the regulatory cascade. This work addresses how …

The Larval Salivary Gland Of Drosophila Melangogaster: A Model System For Temporal And Spatial Steroid Hormone Regulation, Benjamin Constantino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Drosophila melanogaster provides an ideal model organism to test genetic and molecular biological mechanisms within the context of a living animal. For over one hundred years Drosophila continues to produce a boundless extent of informative and important scientific data providing crucial insight into development, disease progression and genetic interactions. A century as a model organism allowed for the development of an abundance of unique genetic and molecular tools allowing researchers to tease apart cellular mechanisms with very little limitation. From the whole adult body to tissue function to molecular networks, if a biological question arises it most likely can be …

Mimosa: A System For Minimotif Annotation, Jay Vyas, Ronald J. Nowling, Thomas Meusburger, David P. Sargeant, Krishna Kadaveru, Michael R. Gryk, Vamsi Kundeti, Sanguthevar Rajasekaran, Martin Schiller

Life Sciences Faculty Research

BACKGROUND:

Minimotifs are short peptide sequences within one protein, which are recognized by other proteins or molecules. While there are now several minimotif databases, they are incomplete. There are reports of many minimotifs in the primary literature, which have yet to be annotated, while entirely novel minimotifs continue to be published on a weekly basis. Our recently proposed function and sequence syntax for minimotifs enables us to build a general tool that will facilitate structured annotation and management of minimotif data from the biomedical literature.

RESULTS:

We have built the MimoSA application for minimotif annotation. The application supports management of …

Bacillus Cereus And Bacillus Anthracis Germination Kinetics: A Michaelis-Menten Approach, Helen Luu

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bacillus species are rod-shaped, gram-positive bacteria that are capable of producing endospores. In this dormant stage, the endospores can persist in hostile physical and chemical environments. Once conditions become favorable, the spores germinate into actively dividing cells, vegetative cells. Germination is a crucial step for the pathogenicity of the Bacilli in affecting a host organism.

Our study applies mathematical approaches to spore germination to determine whether the binding of one germinant will affect the binding of another germinant. We pursued this approach with two different species, B. cereus and B. anthracis, both pathogenic organisms. B. cereus is a widely known …

Antimicrobial Activity Of D-Lenolate®, Andy Phui

UNLV Theses, Dissertations, Professional Papers, and Capstones

Olive trees are one of the most important fruit trees in the Mediterranean. Although not validated by research, olive leaves are traditionally believed to fight off fever and infections. It has been shown that olive leaf extracts possess antimicrobial activity. Olive leaf extracts contain polyphenols. One of the major phenolic compounds is oleuropein. Oleuropein and other polyphenols have been shown to exhibit antimicrobial activity. East Park Research (EPR) developed an extraction process that they claim does not alter the chemical composition of the olive leaves. The extract is known by the commercial name d-lenolate®. Studies have provided evidence that d-lenolate®, …

Partitioning Of Minimotifs Based On Function With Improved Prediction Accuracy, Sanguthevar Rajasekaran, Tian Mi, Jerlin Camilus Merlin, Aaron Oommen, Patrick R. Gradie, Martin R. Schiller

Life Sciences Faculty Research

Background

Minimotifs are short contiguous peptide sequences in proteins that are known to have a function in at least one other protein. One of the principal limitations in minimotif prediction is that false positives limit the usefulness of this approach. As a step toward resolving this problem we have built, implemented, and tested a new data-driven algorithm that reduces false-positive predictions.

Methodology/Principal Findings

Certain domains and minimotifs are known to be strongly associated with a known cellular process or molecular function. Therefore, we hypothesized that by restricting minimotif predictions to those where the minimotif containing protein and target protein have …

From The Valleys To The Mountains: The Biographic History Of Antelope Squirrels, Bats, And Chipmunks In Western North America, Stacy James Mantooth

UNLV Theses, Dissertations, Professional Papers, and Capstones

Genetic differentiation within and between species often coincides with significant geological or climatic changes that have shaped the sizes and locations of their geographic ranges and altered the connectivity between populations over time. Across western North America, many endemic taxa experienced high levels of initial divergence associated with geological transformations of the Neogene, with subsequent diversification and geographic structuring of populations associated with climatic changes during the Quaternary. As such, we can use a combination of molecular markers and genetic analyses to effectively examine the evolutionary and biogeographic histories of populations, species, and regional biotas whose signatures of differentiation are …