Biochemistry Commons^™

Trim24-Regulated Estrogen Response Is Dependent On Specific Histone Modifications In Breast Cancer Cells, Teresa T. Yiu

Dissertations & Theses (Open Access)

In this dissertation, I discovered that function of TRIM24 as a co-activator

of ERα-mediated transcriptional activation is dependent on specific histone

modifications in tumorigenic human breast cancer-derived MCF7 cells. In the first

part, I proved that TRIM24-PHD finger domain, which recognizes unmethylated

histone H3 lysine K4 (H3K4me0), is critical for ERα-regulated transcription.

Therefore, when LSD1-mediated demethylation of H3K4 is inhibited, activation of

TRIM24-regulated ERα target genes is greatly impaired. Importantly, I

demonstrated that TRIM24 and LSD1 are cyclically recruited to estrogen

responsive elements (EREs) in a time-dependent manner upon estrogen

induction, and depletion of their expression exert corresponding time-dependent

effect …

Biochemical Characterization Of Binding Partners Of Two Hsp70 Co-Chaperones In Saccharomyces Cerevisiae, Jacob Verghese

Dissertations & Theses (Open Access)

Cells are exposed to a variety of environmental and physiological changes including temperature, pH and nutrient availability. These changes cause stress to cells, which results in protein misfolding and altered cellular protein homeostasis. How proteins fold into their three-dimensional functional structure is a fundamental biological process with important relevance to human health. Misfolded and aggregated proteins are linked to multiple neurodegenerative diseases, cardiovascular disease and cystic fibrosis. To combat proteotoxic stress, cells deploy an array of molecular chaperones that assist in the repair or removal of misfolded proteins.

Hsp70, an evolutionarily conserved molecular chaperone, promotes protein folding and helps maintain …

A Study On The Function Of 14-3-3sigma In Regulating Cancer Energy Metabolism, Liem M. Phan, Liem M. Phan

Dissertations & Theses (Open Access)

Metabolic reprogramming has been shown to be a major cancer hallmark providing tumor cells with significant advantages for survival, proliferation, growth, metastasis and resistance against anti-cancer therapies. Glycolysis, glutaminolysis and mitochondrial biogenesis are among the most essential cancer metabolic alterations because these pathways provide cancer cells with not only energy but also crucial metabolites to support large-scale biosynthesis, rapid proliferation and tumorigenesis. In this study, we find that 14-3-3σ suppresses all these three metabolic processes by promoting the degradation of their main driver, c-Myc. In fact, 14-3-3s significantly enhances c-Myc poly-ubiquitination and subsequent degradation, reduces c-Myc transcriptional activity, and down-regulates …

Characterization Of A Tumour Suppressor Function Of Ranbpm, Elnaz Atabakhsh

Electronic Thesis and Dissertation Repository

Ran-binding protein M (RanBPM) is an evolutionarily conserved nucleocytosolic protein that has been proposed to regulate various cellular processes, including protein stability, gene expression, receptor-mediated signalling pathways, cell adhesion, development, and apoptosis. Despite the multitude of functions attributed to RanBPM however, little is known regarding the precise mechanisms by which RanBPM executes these cellular roles. In this work, we seek to address this matter by describing functions for RanBPM in the regulation of apoptotic and pro-survival signalling pathways, and in cellular transformation.

We first identify RanBPM as a pro-apoptotic protein that regulates the activation of the intrinsic apoptotic signalling pathway …

Effect Of Paired Apertures In A Periodic Hole Array On Higher Order Plasmon Modes, Fang-Tzu Chuang

Fang-Tzu Chuang

We demonstrate that the transmission of higherorder surface plasmon modes in the mid-infrared range can be enhanced through rectangular hole array on the basis of paired apertures. Experiments prove that enhanced high-order transmission can be generated by either identical shapes or combinations of different hole shapes in pairs. The structure factor is adopted to explain the observed intensity of enhanced transmission. Numerical simulations of the enhanced secondorder mode verify a significant field enhancement in a unit cell of pairs. It is clarified that the separation between the paired apertures and the paired resonance is the key to determine certain higher-order …

Two Infrared Emission Modes With Different Wavelengths And Orthogonal Polarization In A Waveguide Thermal Emitter, Fang-Tzu Chuang

Fang-Tzu Chuang

This study investigates a Au/SiO2/Au waveguide thermal emitter incorporating a metallic grating embedded in the SiO2 layer. The metal grating acts as a beam splitter, dividing the device into two waveguide structures determined by the polarization of the waveguide modes. The thermal radiation spectrum exhibits two peaks with orthogonal polarization. The emitted wavelengths of the two waveguide modes can be adjusted by controlling the thickness of the SiO2 layers on both sides of the metallic grating during the fabrication process. The emission peaks have ratios of the full width at half maximum to the peak wavelength of 0.057 and 0.05 …

Endogenous Inhibitor Proteins That Connect Ser/Thr Kinases And Phosphatases In Cell Signaling., Masumi Eto, David L Brautigan

Department of Molecular Physiology and Biophysics Faculty Papers

Protein phosphatase activity acts as a primary determinant of the extent and duration of phosphorylation of cellular proteins in response to physiological stimuli. Ser/Thr protein phosphatase-1 (PP1) belongs to the PPP superfamily, and is associated with regulatory subunits that confer substrate specificity, allosteric regulation, and subcellular compartmentalization. In addition, all eukaryotic cells contain multiple heat-stable proteins that originally were thought to inhibit phosphatase catalytic subunits released from the regulatory subunits, as a fail-safe mechanism. However, discovery of C-kinase-activated PP1 inhibitor, Mr of 17 kDa (CPI-17) required fresh thinking about the endogenous inhibitors as specific regulators of particular phosphatase complexes, acting …

Breast Tumour Initiating Cell Fate Is Regulated By Microenvironmental Cues From An Extracellular Matrix, Sharmistha Saha, Pang-Kuo Lo, Xinrui Duan, Hexin Chen, Qian Wang

Faculty Publications

Cancer stem cells, also known as tumour-initiating cells (TICs), are identified as highly tumorigenic population within tumours and hypothesized to be main regulators in tumour growth, metastasis and relapse. Evidence also suggests that a tumour microenvironment plays a critical role in the development and progression of cancer, by constantly modulating cell–matrix interactions. Scientists have tried to characterize and identify the TIC population but the actual combination of extracellular components in deciphering the fate of TICs has not been explored. The basic unanswered question is the phenotypic stability of this TIC population in a tissue extracellular matrix setting. The in vivo …

Inhibition Of Burkholderia Multivorans Adhesion To Lung Epithelial Cells By Bivalent Lactosides, Ciara Wight, Rosaria Leyden, Paul V. Murphy, Máire Callaghan, Trinidad Velasco-Torrijos, Siobhan Mcclean

Articles

Burkholderia cepacia complex (Bcc) is an opportunistic pathogen in cystic fibrosis patients which is inherently resistant to antimicrobial agents. The mechanisms of attachment and pathogenesis of Bcc, a group of 17 species, are poorly understood. The most commonly identified Bcc species in newly colonised patients, Burkholderia multivorans, continues to be acquired from the environment. Development of therapies which can prevent or reduce the risk of colonization on exposure to Bcc in the environment would be a better alternative to antimicrobial agents. Previously, it has been shown that Bcc strains bound to many glycolipid receptors on lung epithelia. Using a …

An Analysis Of The Redox Properties And Stability Of Chlamydomonas Reinhardtii Cytochrome F, Cytochrome C6, And Mutants Thereof, Nicole Lynn Vanderbush

Graduate Theses and Dissertations

This body of work presents mutagenesis studies conducted on two c-type cytochromes from Chlamydomonas reinhardtii. Cytochrome f, a unique c-type cytochrome, is investigated in regards to its redox potential, the dependence of the redox potential, and the thermal stability of the protein. The mutations made were Y1F, Y9F, Y160F, Y160L, R156L, and R156K. The residues that were mutated surround the heme. It was found that, relative to the wild-type, only the Y160L and R156 mutants showed any difference in midpoint potential at pH 7. Wild-type and mutants both had a midpoint potential that was dependent upon pH indicating that none …

Plant Lectin Can Target Receptors Containing Sialic Acid, Exemplified By Podoplanin, To Inhibit Transformed Cell Growth And Migration, Jhon Ochoa-Alvarez, Harini Krishnan, Yongquan Shen, Nimish Acharya, Min Han, Dean Mcnulty, Hitoki Hasegawa

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN) is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors …

The Role Of Argininosuccinate Synthase Serine 328 Phosphorylation In Nitric Oxide Production, Ricci Haines

USF Tampa Graduate Theses and Dissertations

Until recently, the main mechanism of argininosuccinate synthase (AS) regulation was described to exist mainly at the level of transcription. Transcriptional regulation of AS has been shown to be coordinate with eNOS in response to shear stress, hypoxia, tumor necrosis factor á (TNF-á), and PPAR ã agonist troglitizone. However, it is now understood that one level of NO regulation is cellular control of arginine availability to eNOS via post-translational modifications of AS such as phosphorylation. The purpose of this investigation was to determine under what conditions AS is phosphorylated at S328, identify the pathway that AS phosphorylation at S328 plays …

Nanoprojection Lithography Using Self-Assembled Interference Modules For Manufacturing Plasmonic Gratings, Fang-Tzu Chuang

Fang-Tzu Chuang

Abstract—A new nanoprojection lithography (NPL) is proposed to manufacture plasmonic nanogratings. Here, low-cost self-assembly elastomeric polydimethylsiloxane wavy structures are used as the interference modules, with their periods and amplitudes largely controlled by the applied mechanical strain in the synthesis process. Well defined plasmonic grating couplers with desired feature sizes and wavelengths of operation were obtained. This NPL may enable large-area and flash manufacturing of plasmonic nanogratings with tunable array periods.

Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser

Lawrence University Honors Projects

Plants contain innate immune systems that deter pathogen infection. Pattern recognition receptors bind microbe-associated molecular patterns (MAMPs), triggering immunity. MAMPs are proteins exclusive to pathogens that are typically indispensable for their survival. For this reason, MAMPs cannot be mutated or removed without causing pathogen death. However, this does not necessitate constitutive expression of MAMPs. In this study, the MAMP response of Arabidopsis thaliana was utilized to determine differential detection of MAMPs expressed by Pseudomonas syringe pv. tomato DC3000 when pretreated with A. thaliana. Results demonstrated that more MAMPs are detected when P. syringae had previously encountered A. thaliana, …

Mutation And Complementation Of A Cellulose Synthase (Cesa) Gene, Ahmed Y. El-Araby

Senior Honors Projects

Cellulose is a carbohydrate polymer that is composed of repeating glucose subunits. Being the most abundant organic compound in the biosphere and comprising a large percentage of all plant biomass, cellulose is extremely plentiful and has a significant role in nature. Cellulose is present in plant cell walls, in commercial products such as those made from wood or cotton, and is of interest to the biofuel industry as a potential alternative fuel source. Although indigestible by humans, cellulose is nutritionally valuable, serving as a dietary fiber. Because of its ubiquity and importance in many areas, studying cellulose will prove to …

Elucidating The Effect Of Silver On Ethylene Signaling In Arabidopsis Thaliana, Brittany Kathleen Mcdaniel

Masters Theses

Ethylene, a gaseous plant hormone, is involved in numerous plant developmental processes such as seed germination, senescence, and fruit ripening. In Arabidopsis thaliana, ethylene is perceived by a family of five membrane-bound receptors, which upon binding ethylene trigger downstream effects. At the receptor level, it is known that the coordination of a copper ion is necessary for ethylene to bind, resulting in a conformational change of the receptor and the initiation of the ethylene signal transduction pathway. Interestingly, silver ions are also able to support binding of ethylene but ethylene responses are blocked in the presence of silver. When …

Interaction Of Environmental B. Cenocepacia Strains With Cystic Fibrosis And Non-Cystic Fibrosis Bronchial Epithelial Cells In Vitro., Annamaria Bevivino, Luisa Pirone, Ruth Pilkington, Noemi Cifani, Claudia Dalmastri, Máire Callaghan, Fiorentina Ascenzioni, Siobhan Mcclean

Articles

Burkholderia cenocepacia is an important human pathogen in patients with cystic fibrosis (CF). Non-clinical reservoirs may play a role in the acquisition of infections, so it is important to evaluate the pathogenic potential of environmental B. cenocepacia isolates. In this study, we investigated the interactions of two environmental B. cenocepacia strains (Mex1 and MCII-168) with two bronchial epithelial cell lines,16HBE14o- and CFBE41o-, which have a non-CF and a CF phenotype, respectively.

The environmental strains showed a significantly lower level of invasion into both CF- and non-CF cells in comparison with the clinical B. cenocepacia LMG16656^T strain. Exposure of polarized …

Mass Spectrometry-Based Proteomics Analysis Of The Matrix Microenvironment In Pluripotent Stem Cell Culture, Christopher Hughes

Electronic Thesis and Dissertation Repository

The stem cell microenvironment contains soluble factors, support cells, and components of the extracellular matrix (ECM) that combine to effect cellular behavior. Mass spectrometry based proteomics offers the opportunity to directly assay components of extracellular microenvironments, thereby providing a sensitive means for obtaining insight into the stem cell niche. In this study we present the generation and analysis of human embryonic stem cell (hESC) and human induced pluripotent stem cell (hiPSC) matrix microenvironments using an MS-based proteomics approach.

One of the primary limitations in the proteomics analysis of hESCs and hiPSCs is the reproducible generation of sufficient cell numbers amenable …

Alteration In 5ht1a Receptor Activity From A Prenatal Exposure To Dexamethasone In A Stressed And Non-Stressed Adult Male Rat, Darshan S. Shah

Honors Theses

Synthetic glucocorticoids (GC) are used as a clinical therapeutic to stimulate lung development in fetuses that present the risk of preterm delivery. Previous studies have shown that a prenatal exposure to Dexamethasone (DEX) causes a disturbance in normal GC mediation of neuritic outgrowth, cell signaling, and serotonergic systems. Our hypothesis is that a prenatal exposure to DEX during the third trimester of pregnancy alters 5HT1A receptor function. Pregnant dams were injected daily with 150μg/ml/kg of DEX from gestation day 14 through 19. Control dams were treated with and equal volume of saline. Swim stress followed by elevated plus maze testing …

Guanosine Diphosphatase Is Required For Protein And Sphingolipid Glycosylation In The Golgi Lumen Of Saccharomyces Cerevisiae, Claudia Abeijon, Ken Yanagisawa, Elisabet Mandon, Alex Hausler, Kelley Moremen, Carlos Hirschberg, Phillips Robbins

Elisabet Mandon

Current models for nucleotide sugar use in the Golgi apparatus predict a critical role for the lumenal nucleoside diphosphatase. After transfer of sugars to endogenous macromolecular acceptors, the enzyme converts nucleoside diphosphates to nucleoside monophosphates which in turn exit the Golgi lumen in a coupled antiporter reaction, allowing entry of additional nucleotide sugar from the cytosol. To test this model, we cloned the gene for the S. cerevisiae guanosine diphosphatase and constructed a null mutation. This mutation should reduce the concentrations of GDP-mannose and GMP and increase the concentration of GDP in the Golgi lumen. The alterations should in turn …

[Accepted Article Manuscript Version (Postprint)] Plant Peroxisomes: Biogenesis And Function, Jianping Hu, Alison Baker, Bonnie Bartel, Nicole Linka, Robert Mullen, Sigrun Reumann, Bethany Zolman

Biology Department Faculty Works

Peroxisomes are eukaryotic organelles that are highly dynamic both in morphology and metabolism. Plant peroxisomes are involved in numerous processes, including primary and secondary metabolism, development, and responses to abiotic and biotic stresses. Considerable progress has been made in the identification of factors involved in peroxisomal biogenesis, revealing mechanisms that are both shared with and diverged from non-plant systems. Furthermore, recent advances have begun to reveal an unexpectedly large plant peroxisomal proteome and have increased our understanding of metabolic pathways in peroxisomes. Coordination of the biosynthesis, import, biochemical activity, and degradation of peroxisomal proteins allows for highly dynamic responses of …

The Role Of Cad,Flash And Fam129b In Cancer Cell Survial And Apoptosis, Song Chen

Wayne State University Dissertations

Apoptosis is a normal process in the human body. However, apoptosis is desregulated in cancer cells. Most cancer cells gain resistance to apoptosis, leading to uncontrolled proliferation. In this dissertation, we identified three proteins, associated with apoptosis pathway. 1) CAD, a large multifunctional complex that is invariably elevated in tumor cells, 2) FLASH, a large protein with multiple growth related functions and 3) FAM129B. We demonstrate that CAD could interact with FLASH by using yeast two hybrid, co-immunopreciptation and fluorescence microscopy. In addition, functional analysis using siRNA technology further indicated that CAD could co-operate with FLASH and play roles in …

Cdk1 And Plk1 Mediate A Clasp2 Phospho-Switch That Stabilizes Kinetochore–Microtubule Attachments, Ana R. R. Maia, Zaira Garcia, Lilian Kabeche, Marin Barisic

Dartmouth Scholarship

Accurate chromosome segregation during mitosis relies on a dynamic kinetochore (KT)-microtubule (MT) interface that switches from a labile to a stable condition in response to correct MT attachments. This transition is essential to satisfy the spindle-assembly checkpoint (SAC) and couple MT-generated force with chromosome movements, but the underlying regulatory mechanism remains unclear. In this study, we show that during mitosis the MT- and KT-associated protein CLASP2 is progressively and distinctively phosphorylated by Cdk1 and Plk1 kinases, concomitant with the establishment of KT-MT attachments. CLASP2 S1234 was phosphorylated by Cdk1, which primed CLASP2 for association with Plk1. Plk1 recruitment to KTs …

Arachidonic Acid Signaling In Invasive And Non-Invasive Breast Cancer Cells, Debarshi Roy

Open Access Theses & Dissertations

Breast cancer is the second largest cause of cancer-related deaths in women all over the world. Epidemiological studies suggest that the consumption of high-fat diets can promote the incidence of breast cancers in both developed and developing countries. In particular, the lipid-rich diet contains arachidonic acid (AA, a C20:4 polyunsaturated fatty acid), which has been shown to be associated with tumor formation in breast tissues. Nevertheless, the actual mechanism by which AA induces the metastatic transformation and malignancy is not well understood. The goal of my dissertation, therefore, is to identify the molecules and unravel the pathways that participate in …

Oxidative Effects Of Nanosecond Pulsed Electric Field Exposure In Cells And Cell-Free Media, Olga N. Pakhomova, Vera A. Khorokhorina, Angela M. Bowman, Raminta Rodaitė-Riševičienė, Gintautas Saulis, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

Nanosecond pulsed electric field (nsPEF) is a novel modality for permeabilization of membranous structures and intracellular delivery of xenobiotics. We hypothesized that oxidative effects of nsPEF could be a separate primary mechanism responsible for bioeffects. ROS production in cultured cells and media exposed to 300-ns PEF (1–13 kV/cm) was assessed by oxidation of 2′, 7′-dichlorodihydrofluoresein (H₂DCF), dihidroethidium (DHE), or Amplex Red. When a suspension of H₂DCF-loaded cells was subjected to nsPEF, the yield of fluorescent 2′,7′dichlorofluorescein (DCF) increased proportionally to the pulse number and cell density. DCF emission increased with time after exposure in nsPEF-sensitive Jurkat …

Electric Field Exposure Triggers And Guides Formation Of Pseudopod-Like Blebs In U937 Monocytes, Mikhail A. Rassokhin, Andrei G. Pakhomov

Bioelectrics Publications

We describe a new phenomenon of anodotropic pseudopod-like blebbing in U937 cells stimulated by nanosecond pulsed electric field (nsPEF). In contrast to "regular," round-shaped blebs, which are often seen in response to cell damage, pseudopod-like blebs (PLBs) formed as longitudinal membrane protrusions toward anode. PLB length could exceed the cell diameter in 2 min of exposure to 60-ns, 10-kV/cm pulses delivered at 10-20 Hz. Both PLBs and round-shaped nsPEF-induced blebs could be efficiently inhibited by partial isosmotic replacement of bath NaCl for a larger solute (sucrose), thereby pointing to the colloid-osmotic water uptake as the principal driving force for bleb …

Bacterial Host Interactions In Cystic Fibrosis, Máire Callaghan, Siobhan Mcclean

Articles

Chronic infection is a hallmark of cystic fibrosis (CF) and the main contributor to morbidity. Microbial infection in CF is complex, due to the number of different species that colonise the CF lung. Their colonisation is facilitated by a host response that is impaired or compromised by highly viscous mucous, zones of hypoxia and the lack of the cystic fibrosis transmembrane regulator (CFTR). Successful dominant CF pathogens combine an effective arsenal to establish infection and counter-attack the host response, together with an ability to adapt readily to an unfavourable environment. Hypermutability is common among CF pathogens facilitating adaptation and as …

Protein Folding By 'Levels Of Separation': A Hypothesis, Lesley H. Greene, Terri M. Grant

Chemistry & Biochemistry Faculty Publications

The protein folding process has been studied both computationally and experimentally for over 30 years. To date there is no detailed mechanism to explain the formation of long-range interactions between the transition and native states. Long-range interactions are the principle determinants of the tertiary structure. We present a theoretical model which proposes a mechanism for the acquisition of these interactions as they form in a modified version of ‘degrees of separation’, that we term ‘levels of separation’. It is based on the integration of network science and biochemistry. (C) 2012 Federation of European Biochemical Societies.

Viability Of Lactic Acid Bacteria And Sensory Evaluation In Cinnamomum Verum And Allium Sativum-Bio-Yogurts Made From Camel And Cow Milk, Ahmad Salihin Hj Baba, Shori A. B.

Ahmad Salihin Hj Baba

The present study investigate the effect of herbal water extract prepared from Allium sativum and Cinnamomum verum on the viability of lactic acid bacteria (Lactobacillus spp and Streptococcus thermophilus) in cow- and camel-milk yogurts during 21 day refrigerated storage. The organoleptic properties of fresh-yogurts were evaluated. Lactobacillus spp count for fresh cow milk-yogurts (0 day) in both present and absent of C. verum and A. sativum was ranged from 1.4×0 6 to 2.1×10 6 cfu/mL. These values were not significantly changed throughout the 21 days of refrigerated storage. Lactobacillusspp count in fresh plain camel milk- yogurt was 13.2×10 6 cfu/mL …