Genetics and Genomics Commons^™

Connexin-32 Contributes To Radiation Resistance In Thyroid Follicles, Da-Thao Dinh Tran

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this study was to examine the role of gap junctions in the radiation resistance of thyroid follicles. The question of whether gap junctional intercellular communication plays an important role in the “contact effect”, wherein cells in direct apposition are more resistant to the damaging effects of radiation, has been debated for years. We used the Fischer rat thyroid cell line (FRTL-5) to carry out our experiments. This thesis is divided into two parts: 1) characterization of gap junctional properties in FRTL-5 cells and, 2) exposure of these cells to radiation.

We found that, unlike primary thyroid cells, …

Interactions Of Igf-Ii And Cathepsin D In Mcf-7 Breast Cancer Cells, Jesika S. Faridi

Loma Linda University Electronic Theses, Dissertations & Projects

A primary role of the IGF-II/M6P receptor is to target lysosomal enzymes from the golgi to the lysosomes. This receptor has distinct binding sites for IGF-II and M6P, however, reciprocal interactions between these ligands have been observed (Kiess et al. 1989, 1990). Since IGF-II modulates the routing of cathepsin D in MCF-7 cells by blocking the intracellular binding of cathepsin D to the IGF-II/M6P receptor (De León et al. 1996), we hypothesized that expressing a mutant form of IGF-II that does not bind the IGF-II/M6P receptor will not interfere with lysosomal enzyme trafficking.

In our present study, we report the …

The Occurrence Of The Freshwater Clams, Musculium Partumeium (Say) And Pisidium Casertanum (Poli) (Bivalvia: Sphaeriidae), In The Hawaiian Islands, Albert J. Burky, Carl M. Way, Skippy Hau, M. Eric Benbow

Biology Faculty Publications

Sphaeriid clams were collected from an ancient, continuously cultivated taro pond complex at Ke‘anae Peninsula, Maui. Both species are known for adaptations for temporary pond habitats and could have been initially introduced by the earliest Hawaiian settlers transported with moist taro root stock from other areas of Oceania.

Expression And Requirement Of Epithelial Fatty Acid- Binding Protein In Neuronal Axon Growth, Gregory William Allen

Loma Linda University Electronic Theses, Dissertations & Projects

Epithelial fatty acid-binding protein (E-FABP) is expressed in the dorsal root ganglia following sciatic nerve injury and in migrating and differentiating neurons during neuronal development. It was hypothesized that E-FABP expression is required for the robust outgrowth of axons from developing and regenerating neurons. To test this hypothesis, E-FABP expression in both PC12 cells and primary retinal neurons was examined. In PC12 cells, NGF induces E-FABP mRNA and protein during the period of neurite outgrowth, and E-FABP localizes to the perinuclear cytoplasm, nucleus, and growth cone. Furthermore, E-FABP-deficient cell lines exposed to NGF were less differentiated and had shorter neurites …

Function And Properties Of Groe Chaperonins In Bacterial And Mammalian Cells, Gregory M. Nelson

Loma Linda University Electronic Theses, Dissertations & Projects

Molecular chaperones play an integral role in the folding of most polypeptides in vivo, and protect proteins against aggregation when a cell is under stress. The GroESL proteins of Escherichia coli are the best characterized of the ringed chaperones, or chaperonins. Chaperonins of the eukaryotic cytoplasm interact with a limited number of polypeptides, whereas GroEL is promiscuous as it binds and mediates the folding of many polypeptides. This feature makes GroEL an attractive protein for investigating various aspects of protein folding in eukaryotic cells because its substrate interaction is diverse. In this work we have expressed the groES and …

Identification And Characterization Of Aer, An Energy Sensor In Escherichia Coli, Anuradha Rebbapragada

Loma Linda University Electronic Theses, Dissertations & Projects

This study investigated the mechanism of signal transduction by Aer, the aerotaxis transducer in E.coli. A computerized search of GenBank revealed an open reading frame at 69.1 min on the E.co//chromosome that had a C-terminal fragment with 96.7% identity to the highly conserved domain of Tsr. The open reading frame was renamed aer for aerotaxis and energy responses. When the aer gene was inactivated, approximately 50% of aerotaxis responses were eliminated. When both aer and fsr were inactivated, aerotaxis, redox taxis and glycerol taxis were completely abolished. Expressing Aer in aer fsr cells restored aerotaxis responses and the duration …

Novel Function Of Phosphoinositide 3-Kinase In T Cell Ca2+ Signaling. A Phosphatidylinositol 3,4,5-Trisphosphate-Mediated Ca2+ Entry Mechanism., A L Hsu, T T Ching, G Sen, D S Wang, Subbarao Bondada, K S Authi, C S Chen

Microbiology, Immunology, and Molecular Genetics Faculty Publications

This study presents evidence that phosphoinositide (PI) 3-kinase is involved in T cell Ca(2+) signaling via a phosphatidylinositol 3,4, 5-trisphosphate PI(3,4,5)P(3)-sensitive Ca(2+) entry pathway. First, exogenous PI(3,4,5)P(3) at concentrations close to its physiological levels induces Ca(2+) influx in T cells, whereas PI(3,4)P(2), PI(4, 5)P(2), and PI(3)P have no effect on [Ca(2+)](i). This Ca(2+) entry mechanism is cell type-specific as B cells and a number of cell lines examined do not respond to PI(3,4,5)P(3) stimulation. Second, inhibition of PI 3-kinase by wortmannin and by overexpression of the dominant negative inhibitor Deltap85 suppresses anti-CD3-induced Ca(2+) response, which could be reversed by subsequent …

New World Nine-Primaried Oscine Relationships: Constructing A Molecular Framework, John Klicka, Kevin P. Johnson, Scott M. Lanyon

Ornithology Program (HRC)

Historically, a paucity of comparative morphological characters has led to much debate regarding relationships within and among the major lineages of New World nine-primaried oscines. More recently, DNA-DNA hybridization studies have provided novel and testable hypotheses of relationships, although no consensus has been reached. For 40 songbird taxa, we obtained 1,929 base pairs (bp) of DNA sequence from the mitochondrial cytochrome-b (894 bp) and NADH dehydrogenase subunit 2 (1,035 bp) genes. Phylogenetic analyses confirm the monophyly of this assemblage as traditionally defined. The lineages delineated historically on morphological grounds are retained; finches (Fringillinae) are sister to a well-supported clade …

The Skn7 Response Regulator Of Saccharomyces Cerevisiae Interacts With Hsf1 In Vivo And Is Required For The Induction Of Heat Shock Genes By Oxidative Stress, Desmond C. Raitt, Anthony L. Johnson, Alexander M. Erkine, Kozo Makino, Brian Morgan, David S. Gross, Leland H. Johnston

Scholarship and Professional Work – COPHS

The Skn7 response regulator has previously been shown to play a role in the induction of stress-responsive genes in yeast, e.g., in the induction of the thioredoxin gene in response to hydrogen peroxide. The yeast Heat Shock Factor, Hsf1, is central to the induction of another set of stress-inducible genes, namely the heat shock genes. These two regulatory trans-activators, Hsf1 and Skn7, share certain structural homologies, particularly in their DNA-binding domains and the presence of adjacent regions of coiled-coil structure, which are known to mediate protein–protein interactions. Here, we provide evidence that Hsf1 and Skn7 interact in vitro and …

Cell Cycle-Dependent Binding Of Yeast Heat Shock Factor To Nucleosomes, Christina Bourgeois Venturi, Alexander M. Erkine, David S. Gross

Scholarship and Professional Work – COPHS

In the nucleus, transcription factors must contend with the presence of chromatin in order to gain access to their cognate regulatory sequences. As most nuclear DNA is assembled into nucleosomes, activators must either invade a stable, preassembled nucleosome or preempt the formation of nucleosomes on newly replicated DNA, which is transiently free of histones. We have investigated the mechanism by which heat shock factor (HSF) binds to target nucleosomal heat shock elements (HSEs), using as our model a dinucleosomal heat shock promoter (hsp82-ΔHSE1). We find that activated HSF cannot bind a stable, sequence-positioned nucleosome in G₁-arrested …

Application Of Ai In Medicine, Tarmizi Amirul Hisyam

Student Works (2000-2009)

From the beginning of human civilization, mankind have been trying to fins solution on how to make life easier. They create, modify and adapt, as they would please their need. From the smallest things in our life to the biggest part of all technologies, has improved our life tremendously. Computer technology nowadays has an important role in education, communication, medicine, and many more. In the field of medicine, we have seen many support systems had been developed and use to help human in their daily lives. Application of AI in medicine was proposed in this reason in mind, as a …

Construction Of Escherichia Coli Arginine Repressor Fusion Protein And Analysis Of Its Function In Xer Site-Specific Recombination, Kholis Abdulrachim

Student Works (2000-2009)

In addition to its role in L-arginine biosynthesis in Escherichia coli, arginine repressor (ArgR), the product of the argR gene, also plays an essential role as an obligate accessory protein in Xer site-specific recombination system. A structure-function relationship study of ArgR was performed to understand more about its role in Xcr site-specific recombination. Fusion proteins between ArgRWT (wild-type ArgR) and a biotinylated peptide as well as between ArgRNV (a mutant ArgR) and a biotinylated peptide were constructed. The biotinylated peptide was fused in frame to the amino-tenninus of ArgR WT and ArgRNV, respectively. Xer recombination assays showed that the ArgRWT-biotinylated …

Expression And Function Of Hoxc5 And Hoxc6 In The Murine Mammary Gland, Silvia Alejandra Garcia-Gasca

MUSC Theses and Dissertations

Homeotic genes encode transcription factors, believed to regulate cell proliferation, differentiation, as well as cell migration to create positional identities during embryogenesis. In the mouse, the Hox complex consists of at least 39 genes, organized into four clusters, in four different chromosomes. Hoxc5 and Hoxc6 are adjacent genes located in chromosome 15, and are expressed in the developing somites of the thoracic region and central nervous system with overlapping patterns. Both Hoxc5 and Hoxc6 are also expressed in the mammary gland. This study demonstrates that a targeted disruption of the Hoxc6 gene results in a failure of ductal development in …

Haemochromatosis Mutation Analysis In A Normal Irish Population, Fergus Ryan, Joseph Vaughan

Articles

187 Irish blood donors were examined for the presence of C282Y and H63D missense mutations using a multiplex PCR and restriction digest protocol. The allele frequency for C282Y was found to be 12.3% which is higher than reported in other studies and concurs that this mutation is of Celtic origin.

In Vitro Mutagenesis For Structure/Function Studies Of The Bacteriophage T4 Rega Protein And The Murine Ahr Protein, Estel Rick Barbour

MUSC Theses and Dissertations

The bacteriophage T4 regA protein translationally represses over 30 T4 early genes, including the regA gene, by binding to the translation initiation region of the T4 mRNAs (Karam et al., 1981). Although the recognition sequence has been at least partially characterized in a number regA sensitive mRNAs, there is no consensus sequence or structural feature that is recognized by regA in all transcripts (Winter et al., 1987; Webster et al., 1989; Unnithan et al., 1990). Recent studies have identified an RNA binding site on regA protein, but there remains a large gap in our understanding of how regA protein functions …

The Role Of Brn-3.2 In Retinal Ganglion Cell Differentiation, Jerin Marie Wright

Loma Linda University Electronic Theses, Dissertations & Projects

Within the retina, the POU domain of transcription factors brn-3.0, brn-3.1, and brn-3.2 are present only in retinal ganglion cells. These genes are believed to be involved in establishing neural cell lineages in mammals. In this study brn-3.2 was examined by comparing the number of ganglion cells present during postnatal development in normal mice (+/+), in mice homozygous (-/-) for the brn-3.2 gene, and in adult mice with a heterozygous gene deletion (+/-) for brn-3.2. Optic nerve cross sections were imaged by electron microscopy, and axon profiles counted systematically by hand. These counts were then related to the nerve cross …

A Preclinical Model Of Ionizing Radiation And Tnf-Alpha Gene Therapy For Cancer, Jun Li

Loma Linda University Electronic Theses, Dissertations & Projects

Long term control of high-grade brain tumors is rarely achieved with current therapeutic regimens. This study sought to determine if pretreatment with plasmid DNA expressing Tumor Necrosis Factor-α (TNF-α) could enhance the effect of ionizing radiation in an aggressive, rapidly growing glioma tumor (C6) model. Plasmid DNA is an attractive vector system for delivery of foreign genes into eukaryotic cells due to its advantages including low immunogenicity in vivo, lesser toxicity and relatively low cost. We have constructed a plasmid-based mammalian expression vector (pGL1-TNF) to secrete human TNF-α from cancer cells. Plasmid DNA was successfully transfected into C6 cells …

Enhanced Apoptosis Mediates Inhibition Of Ebv-Transformed Lymphoblastoid Cell Line Proliferation By Curcumin., D Ranjan, T D Johnston, K S Reddy, G Wu, Subbarao Bondada, C Chen

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: Epstein-Barr virus (EBV)-associated B-cell lymphomas occur more frequently in immunodeficient states such as organ transplantation and HIV infection. We have previously reported that B cell immortalization with EBV was promoted by cyclosporin A (CyA) and that curcumin (Cur), a natural phenol with known antioxidant and antitumor properties, blocked EBV-induced B cell immortalization. In the following experiments we show that Cur inhibits the proliferation of EBV-transformed lymphoblastoid cell lines (LCL) via enhanced apoptosis.

METHODS: LCL were generated by infecting freshly isolated human B cells with EBV (B95-8) for 12 h and coculturing with predetermined optimal concentrations of CyA (500 ng/ml) …

Evolutionary Patterns Of Morphometrics, Allozymes And Mitochondrial Dna In Thrashers (Genus Toxostoma), Robert M. Zink, Donna L. Dittmann, John Klicka, Rachelle C. Blackwell-Rago

Ornithology Program (HRC)

We examined patterns of variation in skeletal morphometrics (29 characters), allozymes (34 loci), mitochondrial DNA (mtDNA) restriction sites (n = 74) and fragments (n = 395), and mtDNA sequences (1,739 bp from cytochrome b, ND2, ND6, and the control region) among all species of Toxostoma. The phenetic pattern of variation in skeletal morphometrics generally matched traditional taxonomic groupings (based on plumage patterns) with the exceptions of T. redivivum, which because of its large size clusters outside of its proper evolutionary group (lecontei), and T. occelatum, which did not cluster with T. curvirostre. Skull characters contributed highly to species discrimination, suggesting …

Evidence Supporting The Recent Origin And Species Status Of The Timberline Sparrow, John Klicka, Robert M. Zink, Jon C. Barlow, W. Bruce Mcgillivray, Terry J. Doyle

Ornithology Program (HRC)

The Timberline Sparrow (Spizella taverneri), although originally described as a species, is currently classified as a subspecies of the more widespread Brewer's Sparrow (S. breweri). We investigated the taxonomic status and recent evolutionary history of these species by comparison of both morphological and molecular characters. Morphometric comparisons using 6 external and 18 skeletal measurements show that S. taverneri specimens from two widely separated populations (Yukon and southwestern Alberta, Canada) are indistinguishable with respect to size yet are significantly larger (by 3%) than representatives of several breweri populations. Analysis of 1,413 base pairs of mitochondrial DNA (mtDNA) for 10 breweri and …

Functional Analysis Of Human Igfbp-6 In Human Osteoblasts, Tao Yan

Loma Linda University Electronic Theses, Dissertations & Projects

Insulin-like growth factor binding proteins (IGFBPs) are a family of six secreted proteins that bind to and modulate the functions of insulin-like growth factors (IGF-I and IGF-II). As a relatively new member of the IGF system, IGFBP-6 was found to be produced by human osteoblasts and exert significant biological effects on human osteoblasts.

Our previous studies indicated that all-trans retinoic acid (ATRA) caused more than a10 fold increase in IGFBP-6 production and a50-60% reduction of ALP activity in human osteoblasts. Based on these findings, we proposed the hypothesis that ATRA induced human osteoblast differentiation was mediated at least in part …

Use Of Bioinformatics In The Analysis Of Chemotaxis Proteins, Sean Andrew Bulloch

Loma Linda University Electronic Theses, Dissertations & Projects

Bacterial chemotaxis is one of the best-known signal transduction systems. Levels of attractants and repellents are sensed in the surrounding environment by various chemoreceptors. The signal is passed to the excitation pathway via the transfer of a phosphoryl group from the receptor-associated histidine kinase CheA to the response regulator CheY. Phospho-CheY binds to the flagellar motor switching the direction of rotation of the flagella and thus allowing the cell to move towards or away from the attractant or repellent. The phosphatase CheZ removes the phosphoryl group from phospho-CheY restoring default flagellar rotation. Adaptation to stimuli occurs via addition of methyl …

Antitumor Effect Of Il-2, P53, And Bax Naked Gene Transfer In C6 Glioma Cells, Peyman Haghighat

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract not included]

Acute Effects Of Whole-Body Proton Irradiation On The Immune System Of The C57bl/6 Mouse, Eric H. Kajioka

Loma Linda University Electronic Theses, Dissertations & Projects

The acute effects of proton whole-body irradiation (WBI) on leukocytes, lymphocytes, and hematological parameters in the spleen and blood of C57BI/6 mice were examined and compared to the effects of photon (gamma) WBI derived from a 60cobalt (60Co) source. Adult, female C57BL/6 mice were exposed to a single dose (3 Gy, 0.4 Gy/min dose rate) of either proton WBI at the Bragg peak, proton WBI at the entry plateau, or Co WBI, and sacrifice intervals were at 1,4, 7, and 10 days post- WBI. Flow cytometry analysis of the spleen and peripheral blood showed depression in cell counts for all …

Dna-Dna Checkerboard Hybridization To Identify Bacteria In Human Plaque Samples, Jasan Lee Zimmerman

Loma Linda University Electronic Theses, Dissertations & Projects

Previous research has shown that using DNA probes to identify the presence of specific bacteria in human plaque samples is superior to the commonly used anaerobic cultural procedures. Some periodontal pathogens are either uncultivable or very difficult to grow, such as Prevotella intermedia, P. nigrescens, and Eubacterium brachy. Digoxygenin probes were prepared for 15 oral bacteria. These probes were used with a checkerboard DNA-DNA hybridization scheme to analyze whether human plaque samples contained any of the 15 bacterial species. Our results have shown that this method is successful in identifying bacterial DNA present in the subgingival patient plaque …

Engineering Secreted Proteins For Gene Transfer And Dna Vaccination, Jingxue Liu

Loma Linda University Electronic Theses, Dissertations & Projects

In recent years gene therapy has become a promising way of alleviating incurable human ailments, its concept emerging as the ultimate therapy for many infectious and genetic diseases. Two important aspects of the development of successful gene therapy protocols are the ability to monitor gene transfer readily, and the establishment of new protocols for treating specific diseases. In this work, Renilla luciferase and human glutamic acid decarboxylase (GAD) 65 were engineered for secretion to address some aspects of these issues.

Secreted reporter proteins are promising tools to study gene transfer and expression in a non-destructive manner, and bioluminescent proteins are …

Clarification Of The Hybrid Origin Of Carex X Deamii Herm. (Cyperaceae) Based On Macro And Micro Morphological Characters, Paul B. Marcum

Theses, Dissertations and Capstones

The origin of Carex x deamii Herm. has been in question ever since it was named to science in 1938. Collections of the hybrid have always been associated with C. shortiana Dewey and either C. typhina Michx. or C. squarrosa L.. C. typhina and C. squarrosa are closely related taxa (Section Squarrosae) and often are morphologically similar. Because of this similarity, determining the correct parental species to the hybrid has been extremely difficult. It is known that the hybrid is sterile and only reproduces asexually. Pollen was analyzed to ascertain the viability of all four taxa. This study utilizes both …

Cooperative Binding Of Heat Shock Factor To The Yeast Hsp82 Promoter In Vivo And In Vitro, Alexander M. Erkine, Serena F. Magrogan, Edward A. Sekinger, David S. Gross

Scholarship and Professional Work – COPHS

revious work has shown that heat shock factor (HSF) plays a central role in remodeling the chromatin structure of the yeastHSP82 promoter via constitutive interactions with its high-affinity binding site, heat shock element 1 (HSE1). The HSF-HSE1 interaction is also critical for stimulating both basal (noninduced) and induced transcription. By contrast, the function of the adjacent, inducibly occupied HSE2 and -3 is unknown. In this study, we examined the consequences of mutations in HSE1, HSE2, and HSE3 on HSF binding and transactivation. We provide evidence that in vivo, HSF binds to these three sites cooperatively. This cooperativity is seen …

Analysis Of Protein And Rna Interactions Of The Hiv-1 Rev Protein, John Francis

Loma Linda University Electronic Theses, Dissertations & Projects

The HIV-1 Rev protein enters the nucleus via it’s nuclear localization sequence/RNA binding domain and interacts with a ≈234 nt region of viral RNA, termed the Rev Response Element (RRE), which is located in the env region of unspliced and singly-spliced HIV-1 mRNA. The Rev nuclear export sequence (NES) then mediates translocation of the viral transcript to the cytoplasm, allowing for translation of viral structural genes and active virion formation. We report identification of two yeast nucleopore proteins, NUP49 and NUP100, that have been found to interact with Rev in vivo using the yeast two-hybrid system. NUP49 and NUP100 contain …

Identification Of Putative Cytoskeletal Protein Homologues In The Protozoan Host Hartmannella Vermiformis As Substrates For Induced Tyrosine Phosphatase Activity Upon Attachment To The Legionnaires' Disease Bacterium, Legionella Pneumophila, Chandrasekar Venkataraman, Lian-Yang Gao, Subbarao Bondada, Yousef Abu Kwaik

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Legionnaires' disease bacterium, Legionella pneumophila, is a facultative intracellular pathogen that invades and replicates within two evolutionarily distant hosts, free living protozoa and mammalian cells. Invasion and intracellular replication within protozoa are thought to be major factors in the transmission of Legionnaires' disease. We have recently reported the identification of a galactose/N-acetyl-d-galactosamine (Gal/GalNAc) lectin in the protozoan host Hartmannella vermiformis as a receptor for attachment and invasion by L. pneumophila (Venkataraman, C., B.J. Haack, S. Bondada, and Y.A. Kwaik. 1997. J. Exp. Med. 186:537–547). In this report, we extended our studies to the …