Molecular Biology Commons^™

A Microrna Imparts Robustness Against Environmental Fluctuation During Development, Xin Li, Justin J. Cassidy, Catherine A. Reinke, Stephen Fischboeck, Richard W. Carthew

Faculty Publications

The microRNA miR-7 is perfectly conserved from annelids to humans, and yet some of the genes that it regulates in Drosophila are not regulated in mammals. We have explored the role of lineage restricted targets, using Drosophila , in order to better understand the evolutionary significance of microRNA-target relationships. From studies of two well characterized developmental regulatory networks, we find that miR-7 functions in several interlocking feedback and feedforward loops, and propose that its role in these networks is to buffer them against perturbation. To directly demonstrate this function for miR-7, we subjected the networks to temperature fluctuation and found …

An Rnai Screen Targeting The Protein Tyrosine Kinases Identifies Bruton's Tyrosine Kinase (Btk) As A Breast Cancer Cell Survival Factor, Cheryl Lynne Eifert

Legacy Theses & Dissertations (2009 - 2024)

The receptor protein tyrosine kinases (RPTKs) and the non- receptor protein tyrosine kinases (PTKs) are among the most commonly up-regulated genes found in all types of cancers. Although, a large body of data implicates a majority of tyrosine kinases (TKs) in cancer, few have been extensively evaluated for any potential therapeutic benefit in any of the many subtypes of breast cancer. We have used RNA interference (RNAi) to perform a large-scale loss-of-function analysis to facilitate the identification of individual factors necessary for the survival of an ErbB2 positive breast cancer cell line. We have found that 30% of the TKs …

Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos, Elizabeth Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The kinetics and amplitude of the salicylic acid-responsive pathogenesis-related (PR) genes and the cytochrome P450 gene ItCYP79B2 in the compatible interaction between Puccinia thlaspeos and dyer’s woad (Isatis tinctoria) during the first 72 hours of inoculation were examined. Immediately following penetration of the host by the rust pathogen, there was a modest up-regulation of PR genes but a significant down-regulation of ItCYP79B2 expression. During haustoria formation, a significant pathogen-mediated suppression of PR genes was observed with a corresponding up-regulation of ItCYP79B2. This potentially facilitates haustoria formation by P. thlaspeos. After haustoria formation, a more …

Bmp Signaling Goes Posttranscriptional In A Microrna Sort Of Way, Catherine A. Reinke, Richard W. Carthew

Faculty Publications

Aberrant microRNA (miRNA) expression correlates with human diseases such as cardiac disorders and cancer. Treatment of such disorders using miRNA-targeted therapeutics requires a thorough understanding of miRNA regulation in vivo. A recent paper in Nature by Davis et al. expands our understanding of miRNA biogenesis and maturation, elucidating a mechanism by which extracellular signaling directs cell differentiation via posttranscriptional regulation of miRNA expression.

Identification Of Lactic Acid Bacteria In Michigan Cherry Wines, Emily Henk, Margaret Dietrich, Terri Weese

Student Summer Scholars Manuscripts

Many factors contribute to the final flavor of wine. One factor is malolactic fermentation, during which lactic acid bacteria (LAB) transform the harsh tasting malic acid into a more drinkable lactic acid in grape wine. The role of LAB in the production of cherry wine is completely unknown. The goal of this study is to identify the species of LAB in cherry wine and compare them to those found in grape wines. Bacteria from cherry wine were grown on general media plates and plates fortified with malic acid, which may provide optimal growing conditions for the LAB. To identify the …

Subcellular Localization Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein, Kimberly Anne Fryrear

Theses and Dissertations in Biomedical Sciences

Human T-cell Leukemia Virus Type 1 (HTLV-1) is a transforming retrovirus that gives rise to Adult T-cell Leukemia (ATL) and a variety of other subneoplastic conditions such as HTLV-Associated Myelopathy/Tropical Spastic Paraperesis (HAM/TSP). In ATL, the transformation and immortalization of T-lymphocytes has been attributed to the expression and activity of a single HTLV-1 viral protein, namely the trans-activating protein Tax. Although the exact mechanism of Tax-mediated transformation is uncertain, current studies support a model in which Tax induces genomic instability in the host cell through interference with DNA repair mechanisms, dysregulation of cell cycle progression, transcriptional activation of cellular …

Gene Therapy Using Tet-Repressor System To Modulate Prostate Tumor Microenvironment, Nazita Yousefieh

Theses and Dissertations in Biomedical Sciences

Prostate cancer is the most commonly diagnosed malignancy in men in the United States and is projected to be the third most frequent cause of male cancer-related deaths in 2007 after lung and skin cancers. The initial treatment for prostate cancer at early stages is prostatectomy or radiation, which usually is curative. However, approximately 20% of patients are not cured by such treatments and their cancer recurs, sometimes with long latencies. In other patients prostate cancer is diagnosed only after the cancer has metastasized and there are no effective therapies at this stage. Therefore immunotherapy seems to be a promising …

Mutations Affecting A Putative Mutla Endonuclease Motif Impact Multiple Dna Mismatch Repair Functions, Naz Erdeniz, Megan Nguyen, Suzanne M. Deschênes, R. Michael Liskay

Biology Faculty Publications

Mutations in DNA mismatch repair (MMR) lead to increased mutation rates and higher recombination between similar, but not identical sequences, as well as resistance to certain DNA methylating agents. Recently, a component of human MMR machinery, MutLα, has been shown to display a latent endonuclease activity. The endonuclease active site appears to include a conserved motif, DQHA(X)₂E(X)₄E, within the COOH-terminus of human PMS2. Substitution of the glutamic acid residue (E705) abolished the endonuclease activity and mismatch-dependent excision in vitro. Previously, we showed that the PMS2-E705K mutation and the corresponding mutation in Saccharomyces cerevisiae were …

Myod Synergizes With The E-Protein Heb Beta To Induce Myogenic Differentiation, Maura H. Parker, Robert L.S. Perry, Melanie C. Fauteux, Charlotte A. Berkes, Michael A. Rudnicki

Biology Faculty Publications

The MyoD family of basic helix-loop-helix transcription factors function as heterodimers with members of the E-protein family to induce myogenic gene activation. The E-protein HEB is alternatively spliced to generate alpha and beta isoforms. While the function of these molecules has been studied in other cell types, questions persist regarding the molecular functions of HEB proteins in skeletal muscle. Our data demonstrate that HEB alpha expression remains unchanged in both myoblasts and myotubes, whereas HEB beta is upregulated during the early phases of terminal differentiation. Upon induction of differentiation, a MyoD-HEB beta complex bound the E1 E-box of the myogenin …

Development Of An In Vitro Protocol To Study The Effect Of Estrogen On Osteoblast Activity, Sourik Ganguly

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Sourik Ganguly on July 7, 2006.

Cloning And Overexpression Of Imp/Osta, An Essential Escherichia Coli Outer Membrane Protein With A Possible Role In Lipid Transport, Leslie Lekatz

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Nanosecond Pulsed Electric Field Effects On Cell Cycle And Apoptosis, Emily H. Hall

Theses and Dissertations in Biomedical Sciences

Apoptosis, programmed cell death, is a highly regulated and complex pathway essential for embryonic development, immune-system function and maintenance of tissue homeostasis where cells induce their own cell death. Cells undergoing apoptosis exhibit a distinctive phenotype characterized by maintenance of membrane integrity, cell shrinkage, phosphatidylserine (PS) externalization at the plasma membrane, caspase protease activation, DNA fragmentation, release of cytochrome c from the mitochondrion, and membrane blebbing. An important regulatory protein in the apoptotic pathway is p53. The p53 protein functions to modulate the cell cycle by arresting cells in the G1 and G 2 phases to repair DNA damage, and/or …

The Study Of Nitric Oxide Synthase Expression, Function, And Regulation In The Renal Vasculature During Postnatal Renal Development, Brian Blake Ratliff

Theses and Dissertations in Biomedical Sciences

The newborn kidney is vulnerable to vasomotor acute renal failure (ARF) from adverse perinatal events or complications of prematurity. Nitric oxide (NO) vasodilation is vitally protective in this type of ARF, but its relationship with other vasoactive factors, such as angiotensin II (AII) has not been examined. In the immature kidney, nitric oxide synthase (NOS) isoforms, specifically eNOS and nNOS, are developmentally regulated, but their specific role and regulation are unknown.

The enhanced vasodilatory role of NO in the immature kidney was hypothesized to be attributed to regulatory, expressional, and functional differences in eNOS and nNOS isoforms from the adult. …

Modulation Of Tgfβ-Induced Pai -1 Expression By Changes In Actin Polymerization In Human Mesangial Cells, Keyur Patel

Theses and Dissertations in Biomedical Sciences

Chronic renal diseases show increased deposition of extracellular matrix (ECM) in the glomerulus (glomerulosclerosis). Glomerulosclerosis is associated with activation of normally quiescent glomerular mesangial cells into myofibroblast-like cells. The overall objective of this study is to delineate cellular mechanism/s of myofibroblast-differentiation in disease states. In cultured mesangial cells certain characteristics of myofibroblast differentiation (α-smooth muscle actin (α-SMA) and hypertrophy) are associated with an increase in polymeric actin microfilaments (stress fibers). It is likely that other genes are also regulated in an actin cytoskeleton-dependent manner during myofibroblast differentiation. In these studies, we therefore examined the hypothesis that changes in the actin …

Linking Ligand-Induced Alterations In Androgen Receptor Structure To Differential Gene Expression: A First Step In The Rational Design Of Selective Androgen Receptor Modulators, Dmitri Kazmin, Tatiana Prytkova, C. Edgar Cook, Russell Wolfinger, Tzu-Ming Chu, David Beratan, J. D. Norris, Ching-Yi Chang, Donald P. Mcdonnell

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We have previously identified a family of novel androgen receptor (AR) ligands that, upon binding, enable AR to adopt structures distinct from that observed in the presence of canonical agonists. In this report, we describe the use of these compounds to establish a relationship between AR structure and biological activity with a view to defining a rational approach with which to identify useful selective AR modulators. To this end, we used combinatorial peptide phage display coupled with molecular dynamic structure analysis to identify the surfaces on AR that are exposed specifically in the presence of selected AR ligands. Subsequently, we …

Isolation And Functional Mapping Of Human T-Cell Leukemia Virus Type 1 Tax Oncoprotein Dna-Damage Complexes, Sarah Saionz Durkin

Theses and Dissertations in Biomedical Sciences

Human T-cell Leukemia Virus Type 1 (HTLV-1) is a transforming retrovirus which causes Adult T-cell Leukemia (ATL) and HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). Cellular transformation can be caused by a single viral trans-activating protein, Tax. Tax may contribute to transformation through interaction with components of the DNA damage response pathway, promoting cellular genomic instability. We examined cellular Tax complexes in an effort to elucidate potential protein-protein interactions that can model the Tax-induced molecular events.

We also investigated the role of post-translational modification in regulating Tax function. We employed a direct physical analysis of Tax complexes isolated from mammalian …

Never Let Me Clone? Countering An Ethical Argument Against The Reproductive Cloning Of Humans, Yvette Pearson

Philosophy Faculty Publications

In the March 2006 issue of EMBO reports, Christof Tannert, a bioethicist at the Max Delbrück Research Centre in Berlin, Germany, presented a moral argument against human reproductive cloning on the basis of Immanuel Kant’s categorical imperative (Tannert, 2006). In this article, I address some problems with Tannert’s views and show that our concerns about this prospective procedure should prompt us to scrutinize carefully the conventional procreative practices and attitudes. Indeed, if we set aside objections that are grounded in genetic determinism, many of the offensive features of human cloning are identical to problems with procreation by more conventional means, …

Myod Targets Chromatin Remodeling Complexes To The Myogenin Locus Prior To Forming A Stable Dna-Bound Complex, Ivana L. De La Serna, Yasuyuki Ohkawa, Charlotte A. Berkes, Donald A. Bergstrom, Caroline S. Dacwag, Stephen J. Tapscott Fred Hutchinson Cancer Research Center, Anthony N. Imbalzano

Biology Faculty Publications

The activation of muscle-specific gene expression requires the coordinated action of muscle regulatory proteins and chromatin-remodeling enzymes. Microarray analysis performed in the presence or absence of a dominant-negative BRG1 ATPase demonstrated that approximately one-third of MyoD-induced genes were highly dependent on SWI/SNF enzymes. To understand the mechanism of activation, we performed chromatin immunoprecipitations analyzing the myogenin promoter. We found that H4 hyperacetylation preceded Brg1 binding in a MyoD-dependent manner but that MyoD binding occurred subsequent to H4 modification and Brg1 interaction. In the absence of functional SWI/SNF enzymes, muscle regulatory proteins did not bind to the myogenin promoter, thereby providing …

The Effect Of Rooibos Tea (Aspalathus Linearis) On The Survival And Transformation Of C3h-Bt1 Mouse Fibroblasts, Krista M. Beach, Paul J. Smith

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

The Antitumor Agent, Arglabin-Dma, Preferentially Induces Apoptosis In Human Colon Tumor Cells, Sung Wook Kwon

Theses and Dissertations in Biomedical Sciences

Arglabin-DMA, an analog of farnesyl pyrophosphate (FPP), reportedly inhibits farnesyltransferase (FTase) directly by competitively blocking the binding of Ras protein and its posttranslational modification, as suggested in previous studies. But, the mechanisms by which Arglabin-DMA inhibits tumor growth in vivo and in vitro are still relatively poorly characterized. To determine the mechanism by which this drug inhibits tumor growth, the effects of Arglabin-DMA in two human colon tumor cell lines (mutant K-ras HCT 116 and wild-type ras HT-29) were explored on cell proliferation, apoptosis, and cell cycle kinetics in vitro. In cell viability studies, we showed that Arglabin-DMA …

Regulation Of Sparc Gene Expression By The Activator Protein 1 Transcription Factor, Joseph William Briggs

Theses and Dissertations in Biomedical Sciences

Overexpression of the c-Jun proto-oncogene in MCF7 breast cancer cells results in a variety of phenotypic changes related to malignant progression including a shift to estrogen independent growth, increased cell motility and invasion. Concurrent with these phenotypic changes are alterations to cellular gene expression patterns. One gene that becomes highly upregulated is SPARC (secreted protein acidic and rich in cysteine). Increased SPARC expression is associated with malignant progression in a variety of different cancers, although little is known regarding the mechanisms of SPARC gene regulation. Therefore, the objectives of this study were: (1) to determine the mechanisms by which c-Jun …

The Quantitative Assessment Of Osteoinductivity Of Human Demineralized Bone Matrix And Cdna Array Analysis Of Osteogenic Differentiation In Human Periosteal Cells, Sittisak Honsawek

Theses and Dissertations in Biomedical Sciences

Demineralized bone matrix (DBM) has been extensively utilized in orthopeadic, periodontal, and maxillofacial applications. DBM comprises bone morphogenetic proteins (BMPs) that are essential regulators for endochondral bone formation. The current study was undertaken to establish the quantitative in vitro assays for determining the osteoinductive potential of human DBM and the use of cDNA gene expression array technology for examining gene expression profiles during osteoblast differentiation in human periosteal cells.

BMP-4 is one of the most osteoinductive factors and has been investigated for clinical applications. For this reason, BMP-4 was designated as the osteoinductive protein for use in the quantitative in …

Involvement Of Platelet-Derived Growth Factor, Pdgf Receptor Signaling, Focal Adhesion Kinase And Src In Pressure-Induced Vascular Smooth Muscle Hypertrophy, Darian Clark Rice

Theses and Dissertations in Biomedical Sciences

Elevated blood pressure is associated with varying degrees of arterial remodeling. The mechanisms by which extracellular mechanical stress is converted into intracellular alterations in signal transduction and gene expression have yet to be fully elucidated. Our goal was to investigate the early events in the vascular smooth muscle response to acute hypertension and to identify mediators involved in long-term hypertensive remodeling.

In the acute phase of hypertension we targeted cell surface integrin and growth factor receptors thought to be mechanically sensitive. The signaling molecules FAK, Src and ERK-MAPK are known to be triggered by integrin engagement and growth factor receptor …

Construction Of Rhas And Rhar Overexpression Plasmids And The Effects Of Crp Mutants On E.Coli L-Rhamnose Gene Expression, Amber Bromenshenkel, Susan Egan

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Comparison Of Tnf-A Levels Produced By Macrophages Treated With Brucella Abortus And Escherichia Coli Lps, Tajie Harris

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Prostate Specific Membrane Antigen (Psma): Immunoassay Development And Characterization Of Transcriptional Regulation, Zhen Xiao

Theses and Dissertations in Biomedical Sciences

Prostate cancer (PCA) is the most common cancer and the second leading cause of death among American men. The high mortality is greatly attributed to the lack of early detection tools and effective treatment for metastasis and relapses. Biomarkers that can discriminate benign from malignant tumor and signal the development of androgen independent and metastatic tumor are needed. A biomarker designated prostate specific membrane antigen (PSMA) has the potential to fulfill this need. The objective of this study is to develop a clinically useful immunoassay for quantitation of serum PSMA and to study the molecular mechanism underlying the upregulation of …

Actin Dynamics Regulate Myosin Assembly In Muscle Cells, John Dylan Cook

Inquiry: The University of Arkansas Undergraduate Research Journal

During muscle cell (i.e. myocyte )development, organization of actin and myosin into the contractile unit (i.e. sarcomere) is required for proper muscle contraction. By disrupting the processes of muscle cell development, I am able to see which steps play important roles in proper maturation of myocytes. Elucidation of the key pathways in muscle development could lead to a better understanding of human cardiac hypertrophies and muscle myopathies. Since actin filament formation precedes myosin organization, I am using actin assembly inhibitors to determine if actin filaments are a necessary prerequisite for myosin organization. It is hypothesized that disruption of actin will …

Characterization Of The Biological Activities Of Recombinant Fusion Protein Green Fluorescent Protein/Human Zona Pellucida Protein 3 (Gfp/Hzp3), Zhiyong Lin

Theses and Dissertations in Biomedical Sciences

Despite numerous reports indicating the successful production of bioactive recombinant ZP3, no report has shown the rhZP3 having direct binding activity with human sperm. Recombinant ZP3 generated from our previous study displayed binding activity with human sperm through indirect evidence from hemizona assay (HZA).

This present study focused on the production of recombinant ZP3 with direct binding activity with human sperm. Through the application of a pEGFP expression vector, fusion protein GFP/ZP3 was successfully generated and expressed. The expression of GFP/ZP3 was evidenced by RT-PCR and western blot. The fusion protein was partially purified by Ni-NTA affinity column from cell …

Intracellular Transport, Assembly, And Degradation Of Wild-Type And Disease-Linked Mutant Gap Junction Proteins, Judy K. Vanslyke, Suzanne M. Deschênes, Linda S. Musil

Biology Faculty Publications

More than 130 different mutations in the gap junction integral plasma membrane protein connexin32 (Cx32) have been linked to the human peripheral neuropathy X-linked Charcot–Marie–Tooth disease (CMTX). How these various mutants are processed by the cell and the mechanism(s) by which they cause CMTX are unknown. To address these issues, we have studied the intracellular transport, assembly, and degradation of three CMTX-linked Cx32 mutants stably expressed in PC12 cells. Each mutant had a distinct fate: E208K Cx32 appeared to be retained in the endoplasmic reticulum (ER), whereas both the E186K and R142W mutants were transported to perinuclear compartments from which …

Human Gonadotropin-Releasing Hormone (Hgnrh) Gene Expression And Hormone Regulation In Human Placental Jeg-3 Cells, Heming Zheng

Theses and Dissertations in Biomedical Sciences

Using the human placental choriocarcinoma JEG-3 cell line as an in vitro human placental model, I studied the mechanisms of the tissue-specific expression and steroid hormone regulation of the hGnRH gene in the human placenta. The results showed that all of the previously identified four elements are required for the full activity of the hGnRH upstream promoter in JEG-3 cells, while the element 4 (FP4, −987/−968) is the most important. Studies performed with 5′ end deletion of this region confirmed these observations. Further, supershift assay using Oct-1 antibody demonstrated the involvement of Oct-1 in the FP4 DNA-protein interaction in JEG-3 …