Molecular Biology Commons^™

Mechanisms Adopted By Dengue-2 Viruses To Induce Autophagy In Mammalian Cells, Sounak Ghosh Roy

Dissertations, Theses, and Capstone Projects

Dengue, the most rapidly spreading flavivirus, threatens to affect almost half of the human global population. We previously showed that dengue-2 protects canine kidney cells (MDCK) from cytotoxic chemicals. We showed, independently, that cell protection, as well as viral replication and maturation, are positively regulated by PI3K-dependent autophagy. However, we had not identified the specific pathway that induces autophagy in infected cells. The current study explores the role of a specific branch of the endoplasmic reticulum (ER) stress-mediated Unfolded Protein Response (UPR), the PERK/eIF2α/ATF4 pathway in the induction of autophagy by …

Renal Risk Variants Of Apolipoprotein L-1 Form Channels At The Plasma Membrane That Lead To A Cytotoxic Influx Of Calcium, Joseph A. Giovinazzo

Dissertations, Theses, and Capstone Projects

Apolipoprotein L-1 (APOL1) is a secreted protein that provides protection against several protozoan parasites due to its channel forming properties. Recently evolved variants, G1 and G2, increase kidney disease risk when present in two copies. In mammalian cells, overexpression of G1 and G2, but not wild-type G0, leads to swelling and eventual lysis. However, the mechanism of cell death remains elusive with multiple pathways being invoked, such as autophagic cell death mediated by a BH3 domain in APOL1, which we evaluated in this study. We hypothesized that the common trigger for these pathways is the APOL1 cation channel, which is …

N-Terminal Domain Of Human Uracil Dna Glycosylase (Hung2) Promotes Targeting To Uracil Sites Adjacent To Ssdna-Dsdna Junctions, Brian P Weiser, Gaddiel Rodriguez, Philip A Cole, James T Stivers

Rowan-Virtua School of Osteopathic Medicine Departmental Research

The N-terminal domain (NTD) of nuclear human uracil DNA glycosylase (hUNG2) assists in targeting hUNG2 to replication forks through specific interactions with replication protein A (RPA). Here, we explored hUNG2 activity in the presence and absence of RPA using substrates with ssDNA-dsDNA junctions that mimic structural features of the replication fork and transcriptional R-loops. We find that when RPA is tightly bound to the ssDNA overhang of junction DNA substrates, base excision by hUNG2 is strongly biased toward uracils located 21 bp or less from the ssDNA-dsDNA junction. In the absence of RPA, hUNG2 still showed an 8-fold excision bias …

Structural And Functional Characterization Of Hyper-Phosphorylated Grk5 Protein Expressed From E. Coli, Joseph M. Krampen, John Tesmer, Qiuyan Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

G protein-coupled receptor (GPCR) kinases (GRKs) are proteins in the cell responsible for regulating GPCRs located on the cell membrane. GRKs regulate active GPCRs by phosphorylating them at certain sites which causes them to stop normal signaling on the membrane. This ultimately affects how the cell responds to its environment. GRK5 is a kinase of particular interest due to its involvement in the pathology of diseases such as cardiac failure, cancers, and diabetes. Understanding the structure and function of GRK5 is essential for discovering ways to manipulate its behavior with these diseases, but not much is known about how GRK5 …

The Role Of Developmental Timing Regulators In Progenitor Proliferation And Cell Fate Specification During Mammalian Neurogenesis, Jennifer S. Romer-Seibert

Graduate School of Biomedical Sciences Theses and Dissertations

Developmental timing is a key aspect of tissue and organ formation in which distinct cell types are generated through a series of steps from common progenitors. These progenitors undergo specific changes in gene expression that signifies both a distinct progenitor type and developmental time point that thereby specifies a particular cell fate at that stage of development. The nervous system is an important setting for understanding developmental timing because different cell types are produced in a certain order and the switch from stem cells to progenitors requires precise timing and regulation. Notable examples of such regulatory molecules include the RNA-binding …

Inhibition Of Ribosome Biogenesis Through Genetic And Chemical Approaches, Leonid Anikin

Graduate School of Biomedical Sciences Theses and Dissertations

In order to maintain the ability to generate proteins, proliferating cells must continuously generate ribosomes, designating up to 80% of their energy to ribosome biogenesis (RBG). RBG involves transcription of rDNA by RNA polymerases I (Pol I) and III (Pol III), expression of approximately 80 ribosomal proteins, and assembly of these components in a process referred to as ribosome maturation. During maturation, the Pol I transcribed 47S pre-rRNA undergoes a number of processing events, while simultaneously interacting with processing factors and ribosomal proteins that drive pre-ribosome assembly. Inhibition of RBG has become one of the pursued targets for cancer therapy …

Insight Into Translational Activation In Yeast Mitochondria, Julia Lynn Jones

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondrial function depends on over a thousand proteins, of which the majority are nuclear DNA-encoded and approximately one percent are mitochondrial DNA-encoded. The mitochondrial DNA of Saccharomyces cerevisiae contains eight protein-encoding genes, seven of which are required for proper function of the respiratory complexes and one encodes a ribosomal protein. The bigenomic nature of the oxidative phosphorylation complexes requires coordinated expression and regulation from both the nuclear and the mitochondrial genomes. It is currently unclear how this regulatory network operates. However, it is thought that nuclear genome-encoded messengers localized to the mitochondria aid in this coordination.

A family of proteins …

Uncoupling The Folding And Binding Of An Intrinsically Disordered Protein, Anusha Poosapati, Emily Gregory, Wade M. Borcherds, Lucia B. Chemes, Gary Daughdrill

Molecular Biosciences Faculty Publications

The relationship between helical stability and binding affinity was examined for the intrinsically disordered transactivation domain of the myeloblastosis oncoprotein, c-Myb, and its ordered binding partner, KIX. A series of c-Myb mutants was designed to either increase or decrease helical stability without changing the binding interface with KIX. This included a complimentary series of A, G, P, and V mutants at three non-interacting sites. We were able to use the glycine mutants as a reference state and show a strong correlation between binding affinity and helical stability. The intrinsic helicity of c-Myb is 21%, and helicity values of the …

Chronic Cadmium Exposure Alters Erα Dependency And Drug Sensitivity Of Breast Cancer Cells, Mathew Bloomfield

Dissertations, Masters Theses, Capstones, and Culminating Projects

The global prevalence of breast cancer in women illustrates the importance of identifying factors that contribute to disease onset and progression. Endogenous and environmental agents that interact with estrogen receptor alpha (ERα) have been shown to play a role in breast cancer etiology. Evidence from epidemiological studies and animal models has suggested that cadmium, a heavy metal that can activate ERα, contributes to the development and progression of breast cancer. Additionally, our lab showed that chronic cadmium exposure altered the expression of several ERα-responsive genes and increased the malignancy of MCF7 breast cancer cells. Although these studies support cadmium’s function …

The Regulation Of Notch Signaling By Src Kinase And Polyphenolic Compounds, Bryce David Lafoya

Boise State University Theses and Dissertations

Cellular signaling pathways provide cells with the means to sense their environment and communicate with other cells. The Notch signaling pathway is comprised of a set of protein machines which work in unison to coordinate cellular processes in response to stimuli coming from neighboring cells and changing microenvironmental conditions. Notch signaling is an important mode of cellular communication which is crucial to many processes involved in development and disease. During Notch activation, information about the extracellular environment is fed into the cell and relayed to the nucleus through a number of biochemical processes. The information-rich messages carried by Notch signaling …

The Role Of Rad4 In Dna Repair And Its Interplay With Telomeres In Tetrahymena Thermophila, Emily Nischwitz

Graduate Theses/Dissertations

Telomeres are repetitive parts of the genome that act as a protective end cap to the chromosomes. Telomeres are critical to the integrity and stability of the genome, therefore, ensuring that their sequence is maintained, even after damage, is crucial. Much of the pioneering work responsible for explaining telomeres has been conducted in ciliates, specifically in Tetrahymena thermophila. Telomeres in T. thermophila have a high amount of tandem thymine repeats (GGGGTT) and, thus, are susceptible to ultraviolet light (UV) induced lesions called pyrimidine dimers, which must be repaired by nucleotide excision repair (NER). In humans, Xeroderma Pigmentosum C (XPC) …

Identifying The Molecular Functions Of The C-Terminal Region Of The Human Proteins, Surbhi Sharma

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Carboxyl (C-) terminus of proteins is usually disordered and flexible allowing proteins to engage in an induced-fit type of interactions with other molecules. Often, these interactions are mediated through the C- terminal minimotifs, which are peptide sequences of 2-15 contiguous residues found in a protein with a known molecular function. These functions include protein binding, trafficking, and post-translational modifications. In this dissertation, we investigated how many human proteins contain the C-terminal minimotifs. We cataloged 3,593 previously verified C-terminal minimotifs representing 17% of the human proteome. Based on these observations, we asked: Does the remaining 83% of the human proteome …

Computational Analysis Of Genomic Variants Affecting Predicted Microrna:Target Interactions In Prostate Cancer., Angélica Paola Hernández Pérez

KGI Theses and Dissertations

Prostate cancer (PCa) is the most common cancer of men in the United States and is third only to lung and colon as a cause of cancer death. Clinical behavior of the disease is variable and the combination of prostate-specific antigen (PSA) screening and Gleason score staging are currently the best available molecular and pathology tools to predict outcomes. Cancer biology research establishes microRNAs (miRNAs) as key molecular components in both normal and pathological states. Thus, elucidating miRNAs perturbed by genomic alterations will expand our understanding of the molecular taxonomy of PCa with the aim to complement current practices in …

Pias-Family Proteins Negatively Regulate Glis3 Transactivation Function Through Sumo Modification In Pancreatic Β Cells, Tyler M. Hoard, Xiaoping Yang, Anton M. Jetten, Gary T. Zeruth Dr.

Faculty & Staff Research and Creative Activity

Gli-similar 3 (Glis3) is Krüppel-like transcription factor associated with the transcriptional regulation of insulin. Mutations within the Glis3 locus have been implicated in a number of pathologies including diabetes mellitus and hypothyroidism. Despite its clinical significance, little is known about the proteins and posttranslational modifications that regulate Glis3 transcriptional activity. In this report, we demonstrate that the SUMO-pathway associated proteins, PIASy and Ubc9 are capable of regulating Glis3 transactivation function through a SUMO-dependent mechanism. We present evidence that SUMOylation of Glis3 by PIAS-family proteins occurs at two conserved lysine residues within the Glis3 N-terminus and modification of Glis3 by SUMO …

Anemarrhena Asphodeloides Bunge And Its Constituent Timosaponin‐Aiii Induce Cell Cycle Arrest And Apoptosis In Pancreatic Cancer Cells, Catherine B. Marelia, Arielle Sharp, Tiffany A. Shemwell, Y. C. Zhang, Brant R. Burkhardt

Molecular Biosciences Faculty Publications

Pancreatic cancer is one of the most recalcitrant and lethal of all cancers. We examined the effects of Anemarrhena asphodeloides (AA) and timosaponin‐AIII (TAIII), a steroidal saponin present in AA, on pancreatic cancer cell proliferation and aimed to elucidate their potential apoptotic mechanisms of action. Viability assays and cell cycle analysis revealed that both AA and TAIII significantly inhibited pancreatic cancer cell proliferation and cell cycle progression compared to treatment with gemcitabine, the standard chemotherapeutic agent for advanced pancreatic cancer. We identified a dose‐dependent increase in caspase‐dependent apoptosis and activation of pro‐apoptotic PI3K/Akt pathway proteins, with a subsequent downregulation of …

Exploring The Role Of Rna Polymerase Iii Complex Assembly On Ribosomal Dna Silencing In Saccharomyces Cerevisiae, Kyle Thomas Kern

LSU Doctoral Dissertations

The yeast rDNA region is host to a number of transcriptional regulatory elements, which work in conjunction to generate essential RNA subunits of ribosomes, as well as protecting the region from DNA damage. The role of RNA polymerase III complex binding at the 5S gene on rDNA silencing in the NTS2 region was investigated, both by use of a TY1:MET15 reporter insert and a MET15 gene integration at an endogenous SphI site. It was discovered that Pol III complexes do have an effect on reporter expression in the NTS2 region, though the specific effect was different based on the method …

Snf1 Cooperates With The Cwi Mapk Pathway To Mediate The Degradation Of Med13 Following Oxidative Stress, Stephen D Willis, David C Stieg, Kai Li Ong, Ravina Shah, Alexandra K. Strich, Julianne H Grose, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Eukaryotic cells, when faced with unfavorable environmental conditions, mount either pro-survival or pro-death programs. The conserved cyclin C-Cdk8 kinase plays a key role in this decision. Both are members of the Cdk8 kinase module that, along with Med12 and Med13, associate with the core Mediator complex of RNA polymerase II. In Saccharomyces cerevisiae, oxidative stress triggers Med13 destruction, which releases cyclin C into the cytoplasm to promote mitochondrial fission and programmed cell death. The SCFGrr1 ubiquitin ligase mediates Med13 degradation dependent on the cell wall integrity pathway, MAPK Slt2. Here we show that the AMP kinase Snf1 activates a second …

Mapping Molecular Datasets Back To The Brain Regions They Are Extracted From: Remembering The Native Countries Of Hypothalamic Expatriates And Refugees, Arshad Khan, Alice Grant, Anais Martinez, Gully Burns, Brendan Thatcher, Vishwanath Anekonda, Benjamin Thompson, Zachary Roberts, Daniel Moralejo, James Blevins

Selected Works Temporary Series

This article, which includes novel unpublished data along with commentary and analysis,focuses on approaches to link transcriptomic, proteomic, and peptidomic datasets mined frombrain tissue to the original locations within the brain that they are derived from using digital atlasmapping techniques. We use, as an example, the transcriptomic, proteomic and peptidomicanalyses conducted in the mammalian hypothalamus. Following a brief historical overview, wehighlight studies that have mined biochemical and molecular information from the hypothalamusand then lay out a strategy for how these data can be linked spatially to the mapped locations in acanonical brain atlas where the data come from, thereby allowing …

Mapping Molecular Datasets Back To The Brain Regions They Are Extracted From: Remembering The Native Countries Of Hypothalamic Expatriates And Refugees, Khan, Alice Grant, Anais Martinez, Gully Burns, Brendan Thatcher, Vishwanath Anekonda, Benjamin Thompson, Zachary Roberts, Daniel Moralejo, James Blevins

Departmental Papers (Biology)

This article, which includes novel unpublished data along with commentary and analysis,focuses on approaches to link transcriptomic, proteomic, and peptidomic datasets mined frombrain tissue to the original locations within the brain that they are derived from using digital atlasmapping techniques. We use, as an example, the transcriptomic, proteomic and peptidomicanalyses conducted in the mammalian hypothalamus. Following a brief historical overview, wehighlight studies that have mined biochemical and molecular information from the hypothalamusand then lay out a strategy for how these data can be linked spatially to the mapped locations in acanonical brain atlas where the data come from, thereby allowing …

Mathematical Modeling Of Nutrient Signaling And Growth In Saccharomyces Cerevisiae, Amogh P. Jalihal, Pavel Kraikivski, T.M. Murali, John J. Tyson

Biology and Medicine Through Mathematics Conference

No abstract provided.

Gesture: An Online Hand-Drawing Tool For Gene Expression Pattern Search, Chunyan Wang, Yiqing Xu, Xuelin Wang, Li Zhang, Suyun Wei, Qiaolin Ye, Youxiang Zhu, Hengfu Yin, Manoj Nainwal, Luis Tanon-Reyes, Feng Cheng, Tongming Yin, Ning Ye

Molecular Biosciences Faculty Publications

Gene expression profiling data provide useful information for the investigation of biological function and process. However, identifying a specific expression pattern from extensive time series gene expression data is not an easy task. Clustering, a popular method, is often used to classify similar expression genes, however, genes with a ‘desirable’ or ‘user-defined’ pattern cannot be efficiently detected by clustering methods. To address these limitations, we developed an online tool called GEsture. Users can draw, or graph a curve using a mouse instead of inputting abstract parameters of clustering methods. GEsture explores genes showing similar, opposite and time-delay expression patterns with …

Identification Of A Novel Polyamine Scaffold With Potent Efflux Pump Inhibition Activity Toward Multi-Drug Resistant Bacterial Pathogens, Renee Fleeman, Ginamarie Debevec, Kirsten Antonen, Jessie Adams, Radleigh G. Santos, Gregory S. Welmaker, Richard A. Houghten, Marc A. Guilianotti, Lindsey N. Shaw

Molecular Biosciences Faculty Publications

We have previously reported the use of combinatorial chemistry to identify broad-spectrum antibacterial agents. Herein, we extend our analysis of this technology toward the discovery of anti-resistance molecules, focusing on efflux pump inhibitors. Using high-throughput screening against multi-drug resistant Pseudomonas aeruginosa, we identified a polyamine scaffold that demonstrated strong efflux pump inhibition without possessing antibacterial effects. We determined that these molecules were most effective with an amine functionality at R1 and benzene functionalities at R2 and R3. From a library of 188 compounds, we studied the properties of 5 lead agents in detail, observing a fivefold to eightfold decrease …

The Caspase Cascade During Hibernation In The Golden-Mantled Ground Squirrel, Spermophilus Lateralis, Michael David Treat

UNLV Theses, Dissertations, Professional Papers, and Capstones

In several human pathologies like heart attack, stroke, neurodegenerative diseases, and autoimmune disorders, widespread cell death, or apoptosis, is a major cause of organ dysfunction and death. Hibernating golden-mantled ground squirrels, Spermophilus lateralis, experience numerous conditions during the winter that are known to be pro-apoptotic in other mammal systems (e.g. extreme hypothermia, ischemia and reperfusion, acidosis, increased reactive oxygen species, bone and muscle disuse). However, studies suggest that hibernators may invoke a protective phenotype to limit widespread cell damage and loss during the hibernation season. Could regulating apoptosis provide protection against the harmful conditions experienced during the hibernation season? Could …

Till Death Do Us Part: The Marriage Of Autophagy And Apoptosis., Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Autophagy is a widely conserved catabolic process that is necessary for maintaining cellular homeostasis under normal physiological conditions and driving the cell to switch back to this status quo under times of starvation, hypoxia, and oxidative stress. The potential similarities and differences between basal autophagy and stimulus-induced autophagy are still largely unknown. Both act by clearing aberrant or unnecessary cytoplasmic material, such as misfolded proteins, supernumerary and defective organelles. The relationship between reactive oxygen species (ROS) and autophagy is complex. Cellular ROS is predominantly derived from mitochondria. Autophagy is triggered by this event, and by clearing the defective organelles effectively, …

Modeling And Analyzing An Optogenetic System For Photoactivatable Protein Dissociation, Anvin Thomas, James Schaff

Honors Scholar Theses

Computational modeling of cell-cell interactions can grant clues and can answer questions about an experiment, especially for observations about binding interactions and kinetics. This approach was used to investigate an interaction between a light-oxygen-voltage (LOV) domain and an engineered protein called Zdark (Zdk). The LOV domain is membrane-bound while Zdk is cytosolic. The LOV domain and Zdk bind strongly in dark (K_d 26.2 nM), and weakly upon exposure to blue light (K_d > 4 μM). Total internal reflection fluorescence (TIRF) images are acquired of Zdk, the fluorescent species bound to a mCherry tag, and the loss of fluorescence is …

Functional Studies Of The E. Coli Proc And A Putative Ortholog Mrub_1345, Maureen Azar, Dr. Lori Scott

Meiothermus ruber Genome Analysis Project

This project is part of the Meiothermus ruber genome analysis project, which uses the bioinformatics tools associated with the Guiding Education through Novel Investigation –Annotation Collaboration Toolkit (GENI-ACT) to predict gene function. We investigated the biological function of Escherichia coli and Meiothermus ruber proC genes using the complementation assay. In this research project, mutants of varying severity to the functional state of the protein were developed. The results showed that two or more amino acid deletions reduced or eliminated ProC function. Amino acid substitutions, on the other hand, were not severe enough to impact ProC function. Double and triple mutants …

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 …

Regulation Of The Tubulin Homolog Ftsz In Escherichia Coli, Monika S. Buczek

Dissertations, Theses, and Capstone Projects

Escherichia coli is a well-known pathogen, and importantly, a widely used model organism in all fields of biological sciences for cloning, protein purification, and as a model for Gram-negative bacterial species. And yet, researchers do not fully understand how this bacterium replicates and divides. Every year additional division proteins are discovered, which adds complexity to how we understand E. coli undergoes cell division. Due to their specific roles in cytokinesis, some of these proteins may be potential targets for development of antibacterials or bacteriostatics, which are much needed for fighting the current global antibacterial deficit. My thesis work focuses on …

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 …

Mitochondrial Mrna Translation Is Required For Maintenance Of Oxidative Capacity, David Lee

Graduate Theses and Dissertations

Oxidative metabolism is required to produce adequate energy to sustain human life. A primary example of deteriorating oxidative capacity is seen in the cardiac musculature during chronic heart failure. This suggests that by improving oxidative potential, chronic heart disease could be mitigated and one approach to accomplish this may be through targeting the mt-mRNA translation system. Purpose: This investigation’s purpose was to characterize disruptions in mt-mRNA translation machinery in multiple forms of cardiomyopathy and to determine if mitochondrial mRNA translation initiation factor (mtIF2) is necessary to maintain oxidative capacity in cardiomyocytes. Methods Using a combination of animal and cell culture …