Biochemistry, Biophysics, and Structural Biology Commons^™

Chronic Cadmium Exposure Stimulates Sdf-1 Expression In An Erα Dependent Manner, Esmeralda Ponce, Natalie B. Aquino, Maggie Louie

Collected Faculty Scholarship

Cadmium is an omnipotent environmental contaminant associated with the development of breast cancer. Studies suggest that cadmium functions as an endocrine disruptor, mimicking the actions of estrogen in breast cancer cells and activating the receptor to promote cell growth. Although acute cadmium exposure is known to promote estrogen receptor-mediated gene expression associated with growth, the consequence of chronic cadmium exposure is unclear. Since heavy metals are known to bioaccumulate, it is necessary to understand the effects of prolonged cadmium exposure. This study aims to investigate the effects of chronic cadmium exposure on breast cancer progression. A MCF7 breast cancer cell …

Pitfalls With The Use Of Enhancement Ratios Or Normalized Excess Mixing Ratios Measured In Plumes To Characterize Pollution Sources And Aging, Robert J. Yokelson, Meinrat O. Andreae, S. K. Akagi

Chemistry and Biochemistry Faculty Publications

Normalized excess mixing ratios (NEMRs), also known as enhancement ratios, are a common way to characterize plumes of pollution in atmospheric research. As single-source pollutant plumes disperse in the atmosphere, they are diluted by mixing with the adjacent background air. Changes in the composition of this background air can cause large changes to the NEMR that is subsequently measured by remote-sensing, airborne, or ground-based instruments. This scenario is common when boundary layer plumes enter the free troposphere and could also impact long-range transport or plumes near the top of the troposphere. We provide a context for these issues and an …

Mscs-Like Mechanosensitive Channels In Plants And Microbes, Margaret E. Wilson, Grigory Maksaev, Elizabeth S. Haswell

Biology Faculty Research

The challenge of osmotic stress is something all living organisms must face as a result of environmental dynamics. Over the past three decades, innovative research and cooperation across disciplines have irrefutably established that cells utilize mechanically gated ion channels to release osmolytes and prevent cell lysis during hypoosmotic stress. Early electrophysiological analysis of the inner membrane of Escherichia coli identified the presence of three distinct mechanosensitive activities. The subsequent discoveries of the genes responsible for two of these activities, the mechanosensitive channels of large (MscL) and small (MscS) conductance, led to the identification of two diverse families of mechanosensitive channels. …

Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair

Dartmouth Scholarship

The spread of drug-resistant bacterial pathogens is a growing global concern and has prompted an effort to explore potential adjuvant and alternative therapies derived from nature's repertoire of bactericidal proteins and peptides. In humans, the airway surface liquid layer is a rich source of antibiotics, and lysozyme represents one of the most abundant and effective antimicrobial components of airway secretions. Human lysozyme is active against both Gram-positive and Gram-negative bacteria, ac

Individual Interactions Of The B Subunits Within The Stator Of The Escherichia Coli Atp Synthase., Karsten Brandt, Sarah Maiwald, Brigitte Herkenhoff-Hesselmann, Kerstin Gnirss, Joerg-Christian Greie, Stanley D Dunn, Gabriele Deckers-Hebestreit

Biochemistry Publications

FOF1 ATP synthases are rotary nanomotors that couple proton translocation across biological membranes to the synthesis/hydrolysis of ATP. During catalysis, the peripheral stalk, composed of two b subunits and subunit δ in Escherichia coli, counteracts the torque generated by the rotation of the central stalk. Here we characterize individual interactions of the b subunits within the stator by use of monoclonal antibodies and nearest neighbor analyses via intersubunit disulfide bond formation. Antibody binding studies revealed that the C-terminal region of one of the two b subunits is principally involved in binding of subunit δ, while the other one is accessible …

Phosphorylation Of Calcineurin At A Novel Serine-Proline Rich Region Orchestrates Hyphal Growth And Virulence In Aspergillus Fumigatus, Praveen R. Juvvadi, Christopher Gehrke, Jarrod R. Fortwendel, Frédéric Lamoth, Erik J. Soderblom, Erik C. Cook, Michael A. Hast, Yohannes G. Asfaw, M. Arthur Moseley, Trevor P. Creamer, William J. Steinbach

Molecular and Cellular Biochemistry Faculty Publications

The fungus Aspergillus fumigatus is a leading infectious killer in immunocompromised patients. Calcineurin, a calmodulin (CaM)-dependent protein phosphatase comprised of calcineurin A (CnaA) and calcineurin B (CnaB) subunits, localizes at the hyphal tips and septa to direct A. fumigatus invasion and virulence. Here we identified a novel serine-proline rich region (SPRR) located between two conserved CnaA domains, the CnaB-binding helix and the CaM-binding domain, that is evolutionarily conserved and unique to filamentous fungi and also completely absent in human calcineurin. Phosphopeptide enrichment and tandem mass spectrometry revealed the phosphorylation of A. fumigatus CnaA in vivo at four clustered serine residues …

Biochemistry / Histone Protein Modification - Purdue University, Jake R. Carlson, Katherine Beavis

Data Curation Profiles Directory

The researcher is conducting research on the brain cells of drosophila larvae. Specifically, the goal is to sort nuclei from glial and neuronal cells from the brains of mutant and wild type drosophila larvae. She will do transcriptome and high throughput ChIP-seq analysis on the cell nuclei to examine the distribution of complexes that modify histones and how loss of those complexes affects transcription. The stages of her research involve a long period of methodology development, a shorter data collection period, and then data analysis. The lab notebook contains written documentation of all experiments and trials and links to data, …

A Supramolecular Strategy To Assemble Multifunctional Viral Nanoparticles, Limin Chen, Xia Zhao, Yuan Lin, Yubin Huang, Qian Wang

Faculty Publications

Using a one-pot approach driven by the supramolecular interaction between β-cyclodextrin and adamantyl moieties, multifunctional viral nanoparticles can be facilely formulated for biomedical applications.

Synthesis And Evaluation Of Thermally-Responsive Coatings Based Upon Diels–Alder Chemistry And Renewable Materials, Dahlia N. Amato, Gregory A. Strange, John P. Swanson, Anton D. Chavez, Suzanne E. Roy, Kim L. Varney, Craig A. Machado, Douglas V. Amato, Philip Costanzo

Chemistry and Biochemistry

A soybean based coating with thermally responsive Diels–Alder linkages has been prepared following an automotive 2-component formulation. The resulting coatings displayed the capability to be healed following physical deformation by a thermal stimulus, and such a material has significant potential for end users. Various curing agents were employed, and resulted in variation of scratch resistance and re-healablity. Different thermally responsive soybean resins were synthesized to have varying amounts reversible and nonreversible linkages when incorporated into the coating. Additionally, different isocyanates were added at differing ratios of NCO:OH in search of the optimum coating. It was found through the analysis of …

Acrylamide Reduction In Potato Chips By Selection Of Potato Variety Grown In Iran And Processing Conditions, S. Shojaee-Aliabadi, Hooshang Nikoopour, Farzad Kobarfard, Mahdi Parsapour, Maryam Moslehishad, Hassan Hassanabadi, Jesus Maria Frias, Maryam Hashemi, Ezzat Dahaghin

Articles

Background

Acrylamide as a possible carcinogen is known to form in heated carbohydrate-rich food such as potato chips. In this study, the effect of three potato varieties (Agria, Sante and Savalan) and two blanching conditions ((75˚C for 9 min and 83˚C for 2.5 min) on the concentration of precursors and acrylamide reduction in potato chips was investigated.

Results

Results revealed that potato variety and blanching time-temperature ere important parameters for acrylamide formation in potato chips. Acrylamide content in Sante variety potatoes, which contained the highest amount of reducing sugars, was found to be the highest (8825μg/kg). However, Savalan, containing …

Intra And Extracellular Functions Of Sphingosine-1-Phosphate In Sterile Inflammation., Jessie Yester

Theses and Dissertations

Sterile inflammation is a key component of a variety of diseases including, gout, arthritis, type 1 diabetes, Alzheimer’s disease and multiple sclerosis (MS). Sterile inflammation induces the recruitment of immune cells via chemokines, such as CCL5 and CXCL10. Expression of these chemokines is dependent on IRF-1. Recently the FDA has approved the use of a pro-drug, FTY720 that after phosphorylation becomes a S1P mimetic for the treatment of MS. This report describes two novel and opposing mechanisms of S1P action in sterile inflammation. First, intracellular S1P acts as a cofactor of cIAP2 that inducesIL-1-dependent K63-polyubiquitination of IRF-1, which leads to …

Identification Of Novel Gene Targets And Functions Of P21-Activated Kinase 1 During Dna Damage By Gene Expression Profiling, Mona Motwani, Da-Qiang Li, Anelia Horvath, Rakesh Kumar

Biochemistry and Molecular Medicine Faculty Publications

P21-activated kinase 1 (PAK1), a serine/threonine protein kinase, modulates many cellular processes by phosphorylating its downstream substrates. In addition to its role in the cytoplasm, PAK1 also affects gene transcription due to its nuclear localization and association with chromatin. It is now recognized that PAK1 kinase activity and its nuclear translocation are rapidly stimulated by ionizing radiation (IR), and that PAK1 activation is a component of the DNA damage response. Owing to the role of PAK1 in the cell survival, its association with the chromatin, and now, stimulation by ionizing radiation, we hypothesize that PAK1 may be contributing to modulation …

Mechanism Of Ubiquitin Ligation And Lysine Prioritization By A Hect E3, Hari B. Kamadurai, Yu Qiu, Alan Deng, Joseph S. Harrison, Chris Macdonald, Marcelo Actis, Patrick Rodrigues, Darcie J. Miller, Judith Souphron, Steven M. Lewis, Igor Kurinov, Naoaki Fujii, Michal Hammel, Robert Piper, Brian Kuhlman, Brenda A. Schulman

College of the Pacific Faculty Articles

Ubiquitination by HECT E3 enzymes regulates myriad processes, including tumor suppression, transcription, protein trafficking, and degradation. HECT E3s use a two-step mechanism to ligate ubiquitin to target proteins. The first step is guided by interactions between the catalytic HECT domain and the E2∼ubiquitin intermediate, which promote formation of a transient, thioester-bonded HECT∼ubiquitin intermediate. Here we report that the second step of ligation is mediated by a distinct catalytic architecture established by both the HECT E3 and its covalently linked ubiquitin. The structure of a chemically trapped proxy for an E3∼ubiquitin-substrate intermediate reveals three-way interactions between ubiquitin and the bilobal HECT …

Computational And Biochemical Approaches To Molecular Epidemiology, Michael Calhoun, Hannah Dysinger, David Hobbs, Ph.D., Katie Hailer, Ph.D.

2013 Undergraduate Research

Mining activity in Butte, Montana has taken place, or continues to take place, within the urban residence of Butte itself. This has led to urban areas with high concentrations of toxic metals such as arsenic, lead, copper, zinc, mercury and cadmium. Advances in protein study and gene sequencing has opened the possibility of finding molecular biomarkers whose presence, absence or morphological changes could indicate disease processes in populations exposed to environmental toxins. While in principle, biomarkers can be any chemicals or metabolites, as well as proteins and genes that are indicative of exposure to xenobiotics, this study seeks to identify …

A Study On The Regulation Of Amino Acids And Glucose Sensing Pathways In Saccharomyces Cerevisiae, Mengying Chiang

LSU New Orleans Theses and Dissertations

Nutrient availability regulates eukaryotic cell growth. This study focuses on two signaling pathways, involved in sensing amino acids and carbon sources, which allow cells to respond appropriately to their presence. The first part of this study shows that Ssy1, a plasma membrane localized sensor in the Ssy1-Ptr3-Ssy5 (SPS) amino acid sensing pathway, can detect 19 common L-amino acids with different potencies and affinities based on the physiochemical structure of amino acids. Substituents around alpha carbon are critical for amino acid sensing by Ssy1. Furthermore, a high concentration of cysteine is toxic to cells. Inactivation of SPS signaling confers resistance to …

Sarcoptes Scabiei Mites Modulate Gene Expression In Human Skin Equivalents, Marjorie S. Morgan, Larry G. Arlian, Michael P. Markey

Biochemistry and Molecular Biology Faculty Publications

The ectoparasitic mite, Sarcoptes scabiei that burrows in the epidermis of mammalian skin has a long co-evolution with its hosts. Phenotypic studies show that the mites have the ability to modulate cytokine secretion and expression of cell adhesion molecules in cells of the skin and other cells of the innate and adaptive immune systems that may assist the mites to survive in the skin. The purpose of this study was to identify genes in keratinocytes and fibroblasts in human skin equivalents (HSEs) that changed expression in response to the burrowing of live scabies mites. Overall, of the more than 25,800 …

Preservation Of Biosignature Molecules In Potential Sample Return Container Of The Mars 2020 Mission, Kimberly E. Lykens, Fei Chen Ph.D

STAR Program Research Presentations

Preservation of Biosignature Molecules in Potential Sample Return Container of the Mars 2020 Mission

Kimberly Lykens¹ and Fei Chen²

¹Wittenberg University, Springfield, Ohio 45501 ²Jet Propulsion Laboratory, Pasadena, California, 91109

One requirement for sustainable life on terrestrial planets includes the presence of organic polymers, compounds that are essential for major biological functions such as replication and catalysis. An identified goal of the Mars mission in the year 2020 is to implement a sample-return to identify and validate signs of life on Mars through the discovery of biosignature molecules in Martian core samples. Martian core samples recovered …

Evidence For A Novel Mechanism Of The Pak1 Interaction With The Rho-Gtpases Cdc42 And Rac, Yong Jae Shin, Eun Hye Kim, Adhiraj Roy, Jeong-Ho Kim

Biochemistry and Molecular Medicine Faculty Publications

P21-activated kinase 1 (PAK1) is activated by binding to GTP-bound Rho GTPases Cdc42 and Rac via its CRIB domain. Here, we provide evidence that S79 in the CRIB domain of PAK1 is not directly involved in this binding but is crucial for PAK1 activation. S79A mutation reduces the binding affinity of PAK1 for the GTPases and inhibits autophosphorylation and kinase activity of PAK1. Thus, this mutation abrogates the ability of PAK1 to induce changes in cell morphology and motility and to promote malignant transformation of prostate epithelial cells. We also show that growth of the prostate cancer cell line PC3 …

Modulation Of Bax/Bak Dependent Apoptosis By Sirtuin 3 And Mitochondrial Permeability Transition By Sirtuin 4, Manish Verma

Graduate School of Biomedical Sciences Theses and Dissertations

Mitochondria are dynamic organelles that regulate a myriad of cellular functions, including energy production and metabolic regulation. Mitochondria are also a critical regulator of cell death signaling cascades modulating both apoptotic and necrotic cell death. However, what determines which cell death pathway is activated is still unclear. The mitochondrial/intrinsic pathway of apoptosis is dependent on the activation of pro-apoptotic proteins, Bax and Bak, which induce mitochondrial outer membrane permeabilization (MOMP). Once the integrity of outer mitochondrial membrane (OMM) is compromised, pro-apoptotic intermembrane space proteins like cytochrome c, Smac/Diablo, Omi/HtrA2 and AIF are released into the cytoplasm, which activates the post-mitochondrial …

Med13p Prevents Stress-Independent Mitochondrial Hyperfragmentation And Aberrant Apoptosis Activation In Saccharomyces Cerevisiae By Controlling Cyclin C Nuclear Localization, Svetlana Khakhina

Graduate School of Biomedical Sciences Theses and Dissertations

During aging, and as a result of environmental changes, cells are exposed to elevated levels of reactive oxygen species (ROS). High ROS levels induce lipid oxidation, protein aggregation, mitochondrial hyperfragmentation, DNA damage and programmed cell death (PCD), also called apoptosis. PCD is a highly regulated process and its misregulation has been linked to neurodegenerative diseases and cancer development.

Our hypothesis is that cyclin C plays a role in the initiation of apoptosis. During normal conditions, cyclin C represses the transcription of stress response genes (SRG). In response to stress, cyclin C translocates to the cytoplasm where it facilitates mitochondrial hyperfragmentation …

Effects Of Xanthan/Locust Bean Gum Mixtures On The Physicochemical Properties And Oxidative Stability Of Whey Protein Stabilized Oil-In-Water Emulsions, Goutham Puli

Masters Theses & Specialist Projects

Scientific evidence shows that dietary intake of the omega-3 polyunsaturated fatty acids is beneficial to human health. Fish oil is a rich source of omega-3 fatty acids. However, fish oil with high levels of omega-3 PUFA is very susceptible to oxidative deterioration during storage. The objective of this study was to investigate the effect of xanthan gum (XG)-locust bean gum (LBG) mixtures on the physicochemical properties of whey protein isolate (WPI) stabilized oil-in-water (O/W) emulsions containing 20% v/v menhaden oil. The O/W emulsions containing XG/LBG mixtures were compared to emulsions with either XG or LBG alone. The emulsions were prepared …

Evidence For Sigma Factor Competition In The Regulation Of Alginate Production By Pseudomonas Aeruginosa, Yeshi Yin, T. Ryan Withers, Xin Wang, Hongwei D. Yu

Biochemistry and Microbiology

Alginate overproduction, or mucoidy, plays an important role in the pathogenesis of P. aeruginosa lung infection in cystic fibrosis (CF). Mucoid strains with mucA mutations predominantly populate in chronically-infected patients. However, the mucoid strains can revert to nonmucoidy in vitro through suppressor mutations. We screened a mariner transposon library using CF149, a non-mucoid clinical isolate with a misssense mutation in algU(AlgU^A61V). The wild type AlgU is a stress-related sigma factor that activates transcription of alginate biosynthesis. Three mucoid mutants were identified with transposon insertions that caused 1) an overexpression of AlgU^A61V, 2) an overexpression of …

A Force Of Nature: Molecular Mechanisms Of Mechanoperception In Plants, Gabriele B. Monshausen, Elizabeth S. Haswell

Biology Faculty Research

The ability to sense and respond to a wide variety of mechanical stimuli-gravity, touch, osmotic pressure, or the resistance of the cell wall-is a critical feature of every plant cell, whether or not it is specialized for mechanotransduction. Mechanoperceptive events are an essential part of plant life, required for normal growth and development at the cell, tissue, and whole-plant level and for the proper response to an array of biotic and abiotic stresses. One current challenge for plant mechanobiologists is to link these physiological responses to specific mechanoreceptors and signal transduction pathways. Here, we describe recent progress in the identification …

The Effects Of Growth Hormone And Thyroxine Treatment On The Insulin Signaling Of Female Ames Dwarf Mouse Skeletal Muscle Tissue, Andrew Do

HIM 1990-2015

Ames dwarf (df/df) mice are deficient in anterior pituitary hormones: growth hormone (GH), thyroid stimulating hormone (TSH), and prolactin (PRL) due to a spontaneous, homozygous mutation of prop1[superscript df] gene. These dwarf mice exhibit characteristics such as delayed growth and development coupled with delayed aging, increased lifespan, overall increased insulin sensitivity, as well as resistance to certain diseases and cancers. The mutant mice possess low blood glucose, low serum insulin, and lower body temperature. Their enhanced longevity (about 40-60% longer lifespan than normal mice) is associated with their GH deficiency and disruption in the somatotropic axis (GH/IGF-1 hormonal pathway) as …

Efficacy Of Gold Silica Nanoshells And Gold Nanorods For Photothermal Therapy Of Human Glioma Spheroids, Suyog Jung Chhetri

UNLV Theses, Dissertations, Professional Papers, and Capstones

Gold-based nanoparticles including gold-silica nano-spheres and gold nano-rods have been investigated for a number of therapeutic and diagnostic applications. The ability of these nanoparticles to convert light into heat energy makes them particularly appealing for photothermal therapy in which cancer cells are destroyed via light-induced heat generation. The overall objective of the study is to compare the efficacy of gold-silica nano-spheres and gold nano-rods in an in vitro system consisting of human brain tumor (glioma) spheroids.

Delivery of the nanoparticles to the spheroids was accomplished using murine macrophages. Nanoparticles (spheres or rods) were incubated with macrophages for 24 hours. Thereafter, …

Post-Injury Calcium Chelation Rescues Skeletal Muscle Regeneration In Mice, Matthew D. Magda

Honors Scholar Theses

During aging the ability of skeletal muscle to regenerate after injury wanes until muscle integrity cannot be maintained. In this study it is shown that calcium chelation can restore young-like regenerative ability in an aged mouse model of skeletal muscle regeneration.

Conformational Dynamics Of K-Ras And H-Ras Proteins: Is There Functional Specificity At The Catalytic Domain?, Nandini Rambahal

Dissertations and Theses (Open Access)

Ras proteins serve as crucial signaling modulators in cell proliferation through their ability to hydrolyze GTP and exist in a GTP “on” state and GTP “off” state. There are three different human Ras isoforms: H-ras, N-ras and K-ras (4A and 4B). Although their sequence identity is very high at the catalytic domain, these isoforms differ in their ability to activate different effectors and hence different signaling pathways. Much of the previous work on this topic has attributed this difference to the hyper variable region of Ras proteins, which contains most of the sequence variance among the isoforms and encodes specificity …

Bioengineering The Expression Of Active Recombinant Human Cathepsin G, Enteropeptidase, Neutrophil Elastase, And C-Reactive Protein In Yeast, Eliot T. Smith

Electronic Theses and Dissertations

The yeasts Pichia pastoris and Kluyveromyces lactis were used to express several recombinant human proteins for further biochemical characterization. Two substitution variants of recombinant human enteropeptidase light chain (rhEPL) were engineered to modify the extended substrate specificity of this serine protease. Both were secreted as active enzymes in excess of 1.7 mg/L in P. pastoris fermentation broth. The substitution variant rhEPL R96Q showed significantly reduced specificities for the preferred substrate sequences DDDDK and DDDDR; however, the rhEPL Y174R variant displayed improved specificities for these substrate sequences relative to all other reported variants of this enzyme. The neutrophil serine proteases human …

Osmotic Stress, Not Aldose Reductase Activity, Directly Induces Growth Factors And Mapk Signaling Changes During Sugar Cataract Formation, Peng Zhang, Kuiyi Xing, James Randazzo, Karen Blessing, Marjorie F. Lou, Peter Kador

School of Veterinary and Biomedical Sciences: Faculty Publications

In sugar cataract formation in rats, aldose reductase (AR) actitvity is not only linked to lenticular sorbitol (diabetic) or galactitol (galactosemic) formation but also to signal transduction changes, cytotoxic signals and activation of apoptosis. Using both in vitro and in vivo techniques, the interrelationship between AR activity, polyol (sorbitol and galactitol) formation, osmotic stress, growth factor induction, and cell signaling changes have been investigated. For in vitro studies, lenses from Sprague Dawley rats were cultured for up to 48 hrs in TC-199-bicarbonate media containing either 30 mM fructose (control), or 30 mM glucose or galctose with/without the aldose reductase inhibitors …

Cytochrome B5 Reductase Encoded By Cbr1 Is Essential For A Functional Male Gametophyte In Arabidopsis, Laura L. Wayne, James G. Wallis, Rajesh Kumar, Jennifer E. Markham, John Browse

Department of Biochemistry: Faculty Publications

In all eukaryotes, NADH:cytochrome b5 reductase provides electrons, via cytochrome b5, for a range of biochemical reactions in cellular metabolism, including for fatty acid desaturation in the endoplasmic reticulum. Studies in mammals, yeast, and in vitro plant systems have shown that cytochrome b5 can, at least in some circumstances, also accept electrons from NADPH:cytochrome P450 reductase, potentially allowing for redundancy in reductase function. Here, we report characterization of three T-DNA insertional mutants of the gene encoding cytochrome b5 reductase in Arabidopsis thaliana, CBR1. The progeny of plants heterozygous for the cbr1-2 allele segregated 6% homozygous mutants, while cbr1-3 and cbr1-4 …