Medical Molecular Biology Commons^™

Finding Human Proteins That Bind To A Lassa Virus Protein, Maria Alejandra Pardo Ruge, Veronica J. Heintz, Douglas J. Lacount

The Summer Undergraduate Research Fellowship (SURF) Symposium

Viral hemorrhagic fevers are severe illnesses caused by many different viruses. Lassa Virus is one of these important pathogens in Western Africa, causing hemorrhagic fever and eventually death without early medical treatment. There is no vaccine and there is little information on host-pathogen interactions. Therefore, the interaction between viral proteins and host targets is useful to understand Lassa virus’s lifecycle and pathology, and to develop ways to prevent infection. In this project, we study the nucleoprotein of Lassa virus (NP), which has been reported to have anti-interferon (IFN) activity through elimination of double stranded RNA (dsRNA). These features could be …

Ubqln1 : A Multi-Domain Protein With Multiple Functions., Zimple Kurlawala

Electronic Theses and Dissertations

There are 5 Ubiquilin proteins (UBQLN1-4, UBQLN-L), which are evolutionarily conserved and structurally similar. UBQLN proteins have 3 functional domains: N-terminal ubiquitin-like domain (UBL), C-terminal ubiquitin-associated domain (UBA) and STI chaperone-like regions in the middle. Alterations in UBQLN1 gene have been detected in a variety of disorders including Alzheimer’s disease, Amyotropic Lateral Sclerosis and lung cancer. UBQLN1 has been largely studied in neurodegenerative disorders in the context of protein quality control. Several studies have hypothesized that the UBA domain of UBQLN1 binds to poly-ubiquitin chains of substrate and shuttles it to the proteasome via its UBL domain for degradation. UBQLN1 …

A Comparative Analysis Of Translesion Dna Synthesis Catalyzed By A High-Fidelity Dna Polymerase, Anvesh Dasari, Tejal Deodhar, Anthony J. Berdis

Chemistry Faculty Publications

Translesion DNA synthesis (TLS) is the ability of DNA polymerases to incorporate nucleotides opposite and beyond damaged DNA. TLS activity is an important risk factor for the initiation and progression of genetic diseases such as cancer. In this study, we evaluate the ability of a high-fidelity DNA polymerase to perform TLS with 8-oxo-guanine (8-oxo-G), a highly pro-mutagenic DNA lesion formed by reactive oxygen species. Results of kinetic studies monitoring the incorporation of modified nucleotide analogs demonstrate that the binding affinity of the incoming dNTP is controlled by the overall hydrophobicity of the nucleobase. However, the rate constant for the …

The 11s Proteasomal Activator Regγ Impacts Polyglutamine-Expanded Androgen Receptor Aggregation And Motor Neuron Viability Through Distinct Mechanisms., Jill M. Yersak, Heather L. Montie, Erica S. Chevalier-Larsen, Yuhong Liu, Lan Huang, Martin Rechsteiner, Diane E. Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Spinal and bulbar muscular atrophy (SBMA) is caused by expression of a polyglutamine (polyQ)-expanded androgen receptor (AR). The inefficient nuclear proteasomal degradation of the mutant AR results in the formation of nuclear inclusions containing amino-terminal fragments of the mutant AR. PA28γ (also referred to as REGγ) is a nuclear 11S-proteasomal activator with limited proteasome activation capabilities compared to its cytoplasmic 11S (PA28α, PA28β) counterparts. To clarify the role of REGγ in polyQ-expanded AR metabolism, we carried out genetic and biochemical studies in cell models of SBMA. Overexpression of REGγ in a PC12 cell model of SBMA increased polyQ-expanded AR aggregation …

Structure Activity Relationship Studies Of Novel Diarylpentanoid Analogs Targeting The Androgen Receptor In Prostate Cancer Cells, Haili Coffin, Marco Bisoffi

Student Scholar Symposium Abstracts and Posters

The development of prostate cancer (PCa) relies strongly on the activation of the androgen receptor (AR) signaling pathway by its natural ligand dihydrotestosterone. Furthermore, PCa progression to metastatic disease represents oncogene addiction to AR activity. Androgen ablation therapy is thus a mainstay therapy against this disease, but the development of ligand-independent AR activation and persisting AR expression eventually leads to castration resistant PCa (CRPC). Therefore, down-regulation of AR expression in PCa cells may be an effective therapeutic modality. The diarylpentanoid ca27 has previously been shown to down-regulate AR expression by an unknown mechanism of action. The present work represents a …

Pediatric Leukemia: Diagnosis To Treatment–A Review, Samantha C. Bernard, Ehab H. Abdelsamad, Paisley A. Johnson, Daniel L. Chapman, Madhukiran Parvathaneni

Faculty Works

Leukemia is cancer of the blood and bone marrow, it is the most common cancer found in children and is found to be more than one fourth of pediatric cancers. It causes white blood cells to become abnormal and the body to become weak. This deficiency in the immune system reduces the body's ability to fight infection or simple airborne illnesses, causing extensive treatment of common pathogens and cancer treatment. The present review covers all topics, from diagnosis to treatment of pediatric leukemia, as well as the stages of growth and physiological changes throughout the process. As leukemia has a …

Kinetic Studies Of Dna Repair Enzyme Alkbh2, Michael R. Vittori

Senior Honors Projects

The genomes of living organisms are under constant bombardment from various sources, including chemical modification stemming from processes within the organisms themselves or from exogenous agents, and from radiation. These sources of genomic damage may induce structural changes in the genome’s most basic functional units, the nucleotides that comprise DNA. Damage to an organism’s DNA may result in the production of dysfunctional or nonfunctional proteins. Failure to repair such damage may result in the compounding of successive mutations within the organism’s genome, the pathogenesis of cancer and various genetic disorders in humans. To ensure their viability, organisms have developed unique …

Genome-Scale Precision Proteomics Identifies Cancer Signaling Networks And Therapeutic Vulnerabilities, Hong Wang

Theses and Dissertations (ETD)

Mass spectrometry (MS) based-proteomics technology has been emerging as an indispensable tool for biomedical research. But the highly diverse physical and chemical properties of the protein building blocks and the dramatic human proteome complexity largely limited proteomic profiling depth. Moreover, there was a lack of high-throughput quantitative strategies that were both precise and parallel to in-depth proteomic techniques. To solve these grand challenges, a high resolution liquid chromatography (LC) system that coupled with an advanced mass spectrometer was developed to allow genome-scale human proteome identification. Using the combination of pre-MS peptide fractionation, MS2-based interference detection and post-MS computational interference correction, …

Role Of Dendritic Cells In Pathology Of Respiratory Syncytial Virus Infection In Neonates, Bishwas Shrestha

Theses and Dissertations (ETD)

Respiratory syncytial virus (RSV) is one of the leading causes of bronchiolitis in children. We have shown that neonatal mice respond to primary RSV infection with T helper type 2 (Th2) biased immune responses, which are enhanced following reinfection. Dendritic cells (DCs) including myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) play important roles in driving host responses to RSV infection. mDCs present antigens to help Th cells differentiate, and pDCs protect against viral infection through type I interferons (IFNs). Despite data demonstrating importance of mDCs and pDCs in protection against RSV, it has not been studied in an age appropriate …

Foxo3 Increases Mir-34a To Cause Palmitate-Induced Cholangiocyte Lipoapoptosis., Sathish Kumar Natarajan, Bailey A. Stringham, Ashley M. Mohr, Cody J. Wehrkamp, Sizhao Lu, Mary A. Smith, Dee Harrison-Findik, Justin L. Mott

Journal Articles: Biochemistry & Molecular Biology

Nonalcoholic steatohepatitis (NASH) patients have elevated plasma saturated free fatty acid levels. These toxic fatty acids can induce liver cell death and our recent results demonstrated that the biliary epithelium may be susceptible to lipotoxicity. Here, we explored the molecular mechanisms of cholangiocyte lipoapoptosis in cell culture and in an animal model of NASH. Treatment of cholangiocytes with palmitate (PA) showed increased caspase 3/7 activity and increased levels of cleaved poly (ADP-ribose) polymerase and cleaved caspase 3, demonstrating cholangiocyte lipoapoptosis. Interestingly, treatment with PA significantly increased the levels of microRNA miR-34a, a pro-apoptotic microRNA known to be elevated in NASH. …

Chemical And Structural Characterization Of A Model Post-Termination Complex (Potc) For The Ribosome Recycling Reaction: Evidence For The Release Of The Mrna By Rrf And Ef-G., Nobuhiro Iwakura, Takeshi Yokoyama, Fabio Quaglia, Kaoru Mitsuoka, Kazuhiro Mio, Hideki Shigematsu, Mikako Shirouzu, Akira Kaji, Hideko Kaji

Department of Biochemistry and Molecular Biology Faculty Papers

A model Post-Termination Complex (PoTC) used for the discovery of Ribosome Recycling Factor (RRF) was purified and characterized by cryo-electron microscopic analysis and biochemical methods. We established that the model PoTC has mostly one tRNA, at the P/E or P/P position, together with one mRNA. The structural studies were supported by the biochemical measurement of bound tRNA and mRNA. Using this substrate, we establish that the release of tRNA, release of mRNA and splitting of ribosomal subunits occur during the recycling reaction. Order of these events is tRNA release first followed by mRNA release and splitting almost simultaneously. Moreover, we …

Dysregulated Gpcr Signaling And Therapeutic Options In Uveal Melanoma., Vivian Chua, Dominic Lapadula, Clinita Randolph, Jeffrey L. Benovic, Philip B. Wedegaertner, Andrew E. Aplin

Department of Biochemistry and Molecular Biology Faculty Papers

Uveal melanoma is the most common primary intraocular malignant tumor in adults and arises from the transformation of melanocytes in the uveal tract. Even after treatment of the primary tumor, up to 50% of patients succumb to metastatic disease. The liver is the predominant organ of metastasis. There is an important need to provide effective treatment options for advanced stage uveal melanoma. To provide the preclinical basis for new treatments, it is important to understand the molecular underpinnings of the disease. Recent genomic studies have shown that mutations within components of G protein-coupled receptor (GPCR) signaling are early events associated …

Determining The Protective Effects Of Quercetin Against Cadmium Toxicity In Human Embryonic Kidney Cells, Caroline N. Smith

Undergraduate Theses

Cadmium is a toxic industrial and environmental pollutant found in groundwater, air, soils, food and cigarettes. Chronic intake of low levels of cadmium has been shown to result in renal dysfunction due to cell death which can occur via apoptosis as well as necrosis. Previous studies have shown that plant extracts containing quercetin, a flavonoid found in many fruits and vegetables, protect against cadmium toxicity in rat liver hepatocytes. To determine if quercetin may have a protective effect in a cadmium-treated human embryonic kidney cell line, HEK-293 cells were treated using concentrations of cadmium chloride from 10 to 50 μM …

A Genetically Encoded Fluorescent Trna Is Active In Live-Cell Protein Synthesis., Isao Masuda, Takao Igarashi, Reiko Sakaguchi, Ram G. Nitharwal, Ryuichi Takase, Kyu Young Han, Benjamin J. Leslie, Cuiping Liu, Howard Gamper, Taekjip Ha, Suparna Sanyal, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Transfer RNAs (tRNAs) perform essential tasks for all living cells. They are major components of the ribosomal machinery for protein synthesis and they also serve in non-ribosomal pathways for regulation and signaling metabolism. We describe the development of a genetically encoded fluorescent tRNA fusion with the potential for imaging in live Escherichia coli cells. This tRNA fusion carries a Spinach aptamer that becomes fluorescent upon binding of a cell-permeable and non-toxic fluorophore. We show that, despite having a structural framework significantly larger than any natural tRNA species, this fusion is a viable probe for monitoring tRNA stability in a cellular …

Structural And Functional Analysis Of A Β2-Adrenergic Receptor Complex With Grk5., Konstantin E. Komolov, Yang Du, Nguyen Minh Duc, Robin M. Betz, João P.G.L.M. Rodrigues, Ryan D. Leib, Dhabaleswar Patra, Georgios Skiniotis, Christopher M. Adams, Ron O. Dror, Ka Young Chung, Brian K. Kobilka, Jeffrey L. Benovic

Department of Biochemistry and Molecular Biology Faculty Papers

The phosphorylation of agonist-occupied G-protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) functions to turn off G-protein signaling and turn on arrestin-mediated signaling. While a structural understanding of GPCR/G-protein and GPCR/arrestin complexes has emerged in recent years, the molecular architecture of a GPCR/GRK complex remains poorly defined. We used a comprehensive integrated approach of cross-linking, hydrogen-deuterium exchange mass spectrometry (MS), electron microscopy, mutagenesis, molecular dynamics simulations, and computational docking to analyze GRK5 interaction with the β2-adrenergic receptor (β2AR). These studies revealed a dynamic mechanism of complex formation that involves large conformational changes in the GRK5 RH/catalytic domain interface upon receptor binding. …

Unfair Competition Governs The Interaction Of Pcpi-17 With Myosin Phosphatase (Pp1-Mypt1)., Joshua J. Filter, Byron C. Williams, Masumi Eto, David Shalloway, Michael L. Goldberg

Department of Molecular Physiology and Biophysics Faculty Papers

The small phosphoprotein pCPI-17 inhibits myosin light-chain phosphatase (MLCP). Current models postulate that during muscle relaxation, phosphatases other than MLCP dephosphorylate and inactivate pCPI-17 to restore MLCP activity. We show here that such hypotheses are insufficient to account for the observed rapidity of pCPI-17 inactivation in mammalian smooth muscles. Instead, MLCP itself is the critical enzyme for pCPI-17 dephosphorylation. We call the mutual sequestration mechanism through which pCPI-17 and MLCP interact inhibition by unfair competition: MLCP protects pCPI-17 from other phosphatases, while pCPI-17 blocks other substrates from MLCP's active site. MLCP dephosphorylates pCPI-17 at a slow rate that is, nonetheless, …

Ticks Elicit Variable Fibrinogenolytic Activities Upon Feeding On Hosts With Different Immune Backgrounds, Ashish Vora, Vikas Taank, John F. Anderson, Durland Fish, Daniel E. Sonenshine, John D. Catravas, Hameeda Sultana, Girish Neelakanta

Biological Sciences Faculty Publications

Ticks secrete several anti-hemostatic factors in their saliva to suppress the host innate and acquired immune defenses against infestations. Using Ixodes scapularis ticks and age-matched mice purchased from two independent commercial vendors with two different immune backgrounds as a model, we show that ticks fed on immunodeficient animals demonstrate decreased fibrinogenolytic activity in comparison to ticks fed on immunocompetent animals. Reduced levels of D-dimer (fibrin degradation product) were evident in ticks fed on immunodeficient animals in comparison to ticks fed on immunocompetent animals. Increased engorgement weights were noted for ticks fed on immunodeficient animals in comparison to ticks fed on …

Portal Protein Functions Akin To A Dna-Sensor That Couples Genome-Packaging To Icosahedral Capsid Maturation., Ravi K. Lokareddy, Rajeshwer S. Sankhala, Ankoor Roy, Pavel V. Afonine, Tina Motwani, Carolyn M M. Teschke, Kristin N. Parent, Gino Cingolani

Department of Biochemistry and Molecular Biology Faculty Papers

Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or 'procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity …

Urokinase Plasminogen Activator Expression Is Regulated By P53 Harboring The Lung Cancer-Specific Mutation V157f, Julie Barta, Md, Kristen Pauley, Steven B. Mcmahon, Phd

Department of Biochemistry and Molecular Biology Posters

OBJECTIVES

• To define the mutant p53-regulated transcriptome of lung cancer cells with alterations at V157 and R158 in the p53 tumor suppressor.
• To determine the biological effects of lung-enriched p53 mutations in lung cancer cells.

Cleavage Of Dfna5 By Caspase-3 During Apoptosis Mediates Progression To Secondary Necrotic/Pyroptotic Cell Death., Corey Rogers, Teresa Fernandes-Alnemri, Lindsey Mayes, Diana Alnemri, Gino Cingolani, Emad S. Alnemri

Department of Biochemistry and Molecular Biology Faculty Papers

Apoptosis is a genetically regulated cell suicide programme mediated by activation of the effector caspases 3, 6 and 7. If apoptotic cells are not scavenged, they progress to a lytic and inflammatory phase called secondary necrosis. The mechanism by which this occurs is unknown. Here we show that caspase-3 cleaves the GSDMD-related protein DFNA5 after Asp270 to generate a necrotic DFNA5-N fragment that targets the plasma membrane to induce secondary necrosis/pyroptosis. Cells that express DFNA5 progress to secondary necrosis, when stimulated with apoptotic triggers such as etoposide or vesicular stomatitis virus infection, but disassemble into small apoptotic bodies when DFNA5 …