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Full-Text Articles in Cell Biology

Investigating The Antiviral Effects Of Vig-3 From Rainbow Trout, Shanee Herrington-Krause Jan 2019

Investigating The Antiviral Effects Of Vig-3 From Rainbow Trout, Shanee Herrington-Krause

Theses and Dissertations (Comprehensive)

Rainbow trout is the most farmed fish in Ontario, and thus is economically important to the province. Despite this, there is a lack of understanding regarding fish innate immunity, specifically with regards to interferon-stimulated genes (ISGs) and their antiviral effector functions. ISGs are the workhorses of the innate antiviral response, operating together to limit each step of virus replication. The Viral Hemorrhagic Septicemia Virus (VHSV) induced gene (Vig)-3 is a newly identified ISG within many fish species and is homologous to ISG-15 in mammals. It is a small ubiquitin-like protein inducible by type I interferon (IFN-I), and is suggested ...


N-Linked Glycosylation Of The Bone Morphogenetic Protein Receptor Type 2 (Bmpr2) Enhances Ligand Binding, Jonathan W. Lowery Ph.D., Jose M Amich, Alex Andonian, Vicki Rosen Aug 2014

N-Linked Glycosylation Of The Bone Morphogenetic Protein Receptor Type 2 (Bmpr2) Enhances Ligand Binding, Jonathan W. Lowery Ph.D., Jose M Amich, Alex Andonian, Vicki Rosen

Faculty Publications and Research

The bone morphogenetic protein (BMP) signaling pathway is essential for normal development and tissue homeostasis. BMP signal transduction occurs when ligands interact with a complex of type 1 and type 2 receptors to activate downstream transcription factors. It is well established that a single BMP receptor may bind multiple BMP ligands with varying affinity, and this has been largely attributed to conformation at the amino acid level. However, all three type 2 BMP receptors (BMPR2, ACVR2A/B) contain consensus N-glycosylation sites in their extracellular domains (ECDs), which could play a role in modulating interaction with ligand. Here, we show a ...


Characterizing Dsrna Production In Virus-Infected Fish Cells, Amal Brek Aloufi Jan 2014

Characterizing Dsrna Production In Virus-Infected Fish Cells, Amal Brek Aloufi

Theses and Dissertations (Comprehensive)

Viral dsRNA is produced by almost all viruses sometime during their replicative cycle. These viral nucleic acids are potent inducers of both innate and adaptive immune responses, and are therefore considered important immuno-modulators. Previous studies have shown that viruses produce dsRNA when replicating in mammalian cells; however, to date no one has demonstrated viral dsRNA production in virus infected fish cells. Therefore, the goal of this study is to investigate dsRNA production by fish viruses in fish cells, verifying production and performing initial characterization of the dsRNA molecules being produced. Three different rainbow trout cell lines were used in this ...


The Human Phosphotyrosine Signaling Network: Evolution And Hotspots Of Hijacking In Cancer., Lei Li, Chabane Tibiche, Cong Fu, Tomonori Kaneko, Michael F. Moran, Martin Schiller, Shawn Shun-Cheng Li, Edwin Wang Jul 2012

The Human Phosphotyrosine Signaling Network: Evolution And Hotspots Of Hijacking In Cancer., Lei Li, Chabane Tibiche, Cong Fu, Tomonori Kaneko, Michael F. Moran, Martin Schiller, Shawn Shun-Cheng Li, Edwin Wang

Life Sciences Faculty Publications

Phosphotyrosine (pTyr) signaling, which plays a central role in cell-cell and cell-environment interactions, has been considered to be an evolutionary innovation in multicellular metazoans. However, neither the emergence nor the evolution of the human pTyr signaling system is currently understood. Tyrosine kinase (TK) circuits, each of which consists of a TK writer, a kinase substrate, and a related reader, such as Src homology (SH) 2 domains and pTyr-binding (PTB) domains, comprise the core machinery of the pTyr signaling network. In this study, we analyzed the evolutionary trajectories of 583 literature-derived and 50,000 computationally predicted human TK circuits in 19 ...


Regulation Of Meiotic Cohesion And Chromosome Core Morphogenesis During Pachytene In Drosophila Oocytes, Radhika S. Khetani, Sharon E. Bickel Jul 2007

Regulation Of Meiotic Cohesion And Chromosome Core Morphogenesis During Pachytene In Drosophila Oocytes, Radhika S. Khetani, Sharon E. Bickel

Open Dartmouth: Faculty Open Access Scholarship

During meiosis, cohesion between sister chromatids is required for normal levels of homologous recombination, maintenance of chiasmata and accurate chromosome segregation during both divisions. In Drosophila, null mutations in the ord gene abolish meiotic cohesion, although how ORD protein promotes cohesion has remained elusive. We show that SMC subunits of the cohesin complex colocalize with ORD at centromeres of ovarian germ-line cells. In addition, cohesin SMCs and ORD are visible along the length of meiotic chromosomes during pachytene and remain associated with chromosome cores following DNase I digestion. In flies lacking ORD activity, cohesin SMCs fail to accumulate at oocyte ...


Analysis Of A Nuclear Complex Of Proteins That Form A Spindle Matrix During Mitosis In Drosophila , Uttama Rath Jan 2005

Analysis Of A Nuclear Complex Of Proteins That Form A Spindle Matrix During Mitosis In Drosophila , Uttama Rath

Retrospective Theses and Dissertations

A spindle matrix is a macromolecular structure hypothesized to provide a stationary support or strut for the anchorage of motor proteins during force generation, microtubule sliding, and chromosome segregation in mitosis. Previous work in Drosophila has shown Skeletor, as the first putative molecular candidate of spindle matrix structure since it possesses many features consistent with the proposed spindle matrix structure.;We have identified two more putative spindle matrix candidate proteins, Chromator and Megator, using yeast two-hybrid interaction assay, cross-immunoprecipitation and immunocytochemistry. Chromator is a novel and essential chromodomain containing protein that interacts directly with Skeletor and extensively colocalizes with it ...


Structural And Molecular Analysis Of Leech Neuronal Proteins, Calsensin And Filamin , Deepa V. Venkitaramani Jan 2004

Structural And Molecular Analysis Of Leech Neuronal Proteins, Calsensin And Filamin , Deepa V. Venkitaramani

Retrospective Theses and Dissertations

This thesis describes the structural and molecular analysis of two leech neuronal proteins, Calsensin and Filamin. Calsensin is an EF-hand calcium-binding protein expressed by a subset of peripheral sensory neurons which fasciculate into a single tract in the leech central nervous system. Calsensin is a 9 kD protein with two EF-hand calcium-binding motifs. Calsensin can multimerize via disulfide bridge formation involving the two cysteine residues in vitro. Furthermore, Calsensin shows differential gel migration depending on the presence or absence of calcium suggesting a conformational change upon calcium binding. Using multidimensional NMR spectroscopy we have determined the solution structure and backbone ...


The Role Of Integrin Mediated Adhesion And Signaling During Xenopus Retinal Development , Ming Li Jan 2003

The Role Of Integrin Mediated Adhesion And Signaling During Xenopus Retinal Development , Ming Li

Retrospective Theses and Dissertations

Integrins are the major family of cell adhesion receptors for extracellular matrix (ECM) components and are involved in cell-cell and cell-ECM adhesion. Integrins also participate in cytoskeletal rearrangements, activation of signal transductions, and co-regulation of growth factor activities.;In this dissertation, I have investigated the role of beta1 integrin-mediated adhesion and signaling during early Xenopus retinal development. First, I characterized the expression patterns of focal adhesion associated proteins, beta1 integrin, talin, vinculin, paxillin and phosphotyrosine in retinal glial cell line XR1 and in the developing Xenopus retina. These proteins are colocalized at focal adhesions located at the termini of F-actin ...


Molecular Interactions Of Talin And Actin: A Study On The Specific Domains Of Talin Involved In The Interactions , Ho-Sup Lee Jan 2002

Molecular Interactions Of Talin And Actin: A Study On The Specific Domains Of Talin Involved In The Interactions , Ho-Sup Lee

Retrospective Theses and Dissertations

Talin is an essential cytoskeletal protein present in cell-matrix type adherens junctions where it helps in attachment of the actin cytoskeleton to the plasma membrane. The nature of the interaction between talin and actin was examined in this dissertation by investigating three actin binding sites (ABS1--3), with ABS1 located in the 47 kDa N-terminal head and ABS2 and ABS3 present in the 190 kDa C-terminal tail of the talin molecule. Cosedimentation of expressed GST-fusion deletion constructs from the talin head with F-actin showed that actin binding activity of the talin head is contained within residues 271--320. Talin constructs containing the ...


Nitric Oxide In Astrocyte-Neuron Signaling , Nianzhen Li Jan 2002

Nitric Oxide In Astrocyte-Neuron Signaling , Nianzhen Li

Retrospective Theses and Dissertations

Astrocytes, a subtype of glial cell, have recently been shown to exhibit Ca2+ elevations in response to neurotransmitters. A Ca 2+ elevation can propagate to adjacent astrocytes as a Ca2+ wave, which allows an astrocyte to communicate with its neighbors. Additionally, glutamate can be released from astrocytes via a Ca2+ -dependent mechanism, thus modulating neuronal activity and synaptic transmission.;In this dissertation, I investigated the roles of another endogenous signal, nitric oxide (NO), in astrocyte-neuron signaling. First I tested if NO is generated during astrocytic Ca2+ signaling by imaging NO in purified murine cortical astrocyte cultures. Physiological concentrations of a ...


Drosophila Jil-1 Kinase Mediates Histone H3 Ser10 Phosphorylation, Maintains Higher Order Chromatin Structure, And Is Implicated In Dosage Compensation , Yanming Wang Jan 2001

Drosophila Jil-1 Kinase Mediates Histone H3 Ser10 Phosphorylation, Maintains Higher Order Chromatin Structure, And Is Implicated In Dosage Compensation , Yanming Wang

Retrospective Theses and Dissertations

The Drosophila JIL-1 tandem Ser/Thr kinase is associated with chromosomes/chromatin throughout the cell cycle in early embryos and localized to hundreds of sites on the open interband regions on third instar larvae polytene chromosomes. Interestingly, the level of JIL-1 is upregulated on the male X chromosome, which is hypertranscribed for dosage compensation. The distribution of JIL-1 overlaps with that of MSL (male specific lethal) proteins and JIL-1 is associated with the MSL complex.;To further study the function of JIL-1 in vivo, a series of JIL-1 mutants from hypomorphs to null were generated. Analyzing the phenotypes of JIL-1 ...


Mechanisms Of Negative Regulation Of Protein Prenylation: Investigation Of Murine Guanylate-Binding Protein 1 , John Thomas Stickney Jan 2000

Mechanisms Of Negative Regulation Of Protein Prenylation: Investigation Of Murine Guanylate-Binding Protein 1 , John Thomas Stickney

Retrospective Theses and Dissertations

Covalent attachment of isoprenoid lipids to proteins is a post-translational modification that occurs on approximately 2% of all cellular proteins. Proteins that contain a CaaX motif as their final four amino acids are presumed to be targets for the addition of C15 or C20 isoprenoids by farnesyl transferase (FTase) or geranylgeranyl transferase I (GGTase I) respectively. This modification is generally believed to occur stoichiometrically, and irreversibly, in vivo. Thus, if prenylation is to be regulated, this control must occur prior to lipid addition. At the moment, there is little evidence that the enzymatic activity of prenyl transferases can be modulated ...


Tissue Specific Expression And Regulation Of The Mitogen Regulated Protein Genes , John Tollen Fassett Jan 2000

Tissue Specific Expression And Regulation Of The Mitogen Regulated Protein Genes , John Tollen Fassett

Retrospective Theses and Dissertations

Mitogen Regulated Protein (MRP; also called Proliferin; or MRP/PLF) is a member of the Prolactin/Growth Hormone gene family. There is evidence that MRP/PLF is a uterine growth factor and an angiogenesis factor. Between four and six highly homologous MRP/PLF genes (mrp/plf ) exist in the mouse, but the significance of multiple genes has not been determined. MRP/Plf is produced at high levels during mid-gestation by the placenta, where expression is restricted to the trophoblastic giant cells. To better understand the regulation of the mrp/ plf genes in vivo, we have developed an assay to analyze ...


Characterization Of Skeletor: A Novel Nuclear Protein Implicated In Mitotic Spindle Assembly , Diana Lee Walker Jan 2000

Characterization Of Skeletor: A Novel Nuclear Protein Implicated In Mitotic Spindle Assembly , Diana Lee Walker

Retrospective Theses and Dissertations

The mAb 2A labels Drosophila embryos in a novel, dynamic staining pattern that identifies a nuclear meshwork during interphase, which is remodeled to form a spindle structure at metaphase. This intriguing pattern made the antigens recognized by mAb 2A interesting targets for cloning and analysis, Skeletor was found to be encoded by a complex locus. Two alternatively spliced transcripts from the Skeletor locus were identified, Orf1b/Orf2 and Orf1a. Orf1b/Orf2 has an unusual structure, containing two overlapping open reading frames with coding potentials of 87 kD and 81 kD respectively. Analysis of Orf2 amino acid content reveals overall high ...


Novel G-Dna Binding Proteins From The Ciliate Tetrahymena Thermophila: Purification, Characterization, Cloning And Functional Analyses , Quan Lu Jan 1999

Novel G-Dna Binding Proteins From The Ciliate Tetrahymena Thermophila: Purification, Characterization, Cloning And Functional Analyses , Quan Lu

Retrospective Theses and Dissertations

G-DNA is a family of novel four-stranded DNA structures characterized by motifs called G-quartets. Evidence is growing to suggest that G-DNA exists and plays biological roles in vivo. In order to further elucidate the functions of G-DNA, we have studied proteins that specifically bind to the DNA structure;Two G-DNA binding activities, TGPI and TGP3, were purified from the ciliate Tetrahymena thermophila. Based on the peptide sequences obtained from direct internal peptide sequencing, the cDNAs coding for the genes were cloned. Deduced protein sequences showed that TGP1 and TGP3 are novel proteins but share significant homology with each other. Furthermore ...


Gene Expression Studies Of Murine Pregnancy Associated Granulated Metrial Gland And Decidual Cells , Melissa Phillips Allen Jan 1997

Gene Expression Studies Of Murine Pregnancy Associated Granulated Metrial Gland And Decidual Cells , Melissa Phillips Allen

Retrospective Theses and Dissertations

During pregnancy in viviparous mammals, the maternal decidua develops between the embryo and the uterine endometrium. This dissertation describes research on two different cell types present within the rodent decidua during pregnancy, namely, granulated metrial gland (GMG) cells and decidual cells;GMG cells are natural killer cells that proliferate and differentiate within the murine uterus during pregnancy. Their differentiation is associated with the accumulation of cytolytic mediators within cytoplasmic granules. The signaling mechanisms required for GMG cell differentiation, however, are largely unknown. In this study, expression of the genes coding for granzymes D, E, F, and G (granzymes D-G) was ...


Suppressor Analysis Of The Protein Kinase Elm1p, An Enzyme Involved In The Regulation Of Yeast Morphology , Nicholas Patrick Edgington Jan 1997

Suppressor Analysis Of The Protein Kinase Elm1p, An Enzyme Involved In The Regulation Of Yeast Morphology , Nicholas Patrick Edgington

Retrospective Theses and Dissertations

Saccharomyces cerevisiae is an ascomycete that has several developmental options, with concomitant morphological changes, that depend on cell type and nutrient status. In response to these signals, vegetative Saccharomyces cerevisiae cells assume one of two distinct morphologies, the yeast form or the filamentous form. Molecules affecting this morphogenetic response were identified by analyzing transposon-induced or spontaneous suppressor mutations that restore yeast form growth to a strain that constitutively exhibits filamentous form characteristics owing to mutation of the protein kinase Elm1p. One transposon-tagged mutation was isolated and is allelic to the negative regulatory subunit Bcy1p, thus activation of cAMP dependent protein ...


Differential Glycosylation Of Tractin And Leechcam, Two Novel Ig-Superfamily Members, Regulates Neurite Extension And Fascicle Formation , Yueqiao Huang Jan 1997

Differential Glycosylation Of Tractin And Leechcam, Two Novel Ig-Superfamily Members, Regulates Neurite Extension And Fascicle Formation , Yueqiao Huang

Retrospective Theses and Dissertations

Specific carbohydrate structures on neural cell adhesion molecules are promising candidates for assisting in patterning neural connections during development. An excellent system to study the potential function of specific oligosaccharide modifications of neural proteins regulating pathway formation is in the projections of sensillar neurons in leech. At least five different monoclonal antibodies (Lan3-2, Lan2-3, Lan4-2, Laz2-369, Laz7-79) which recognize different glycoepitopes specific to the entire population as well as distinct subsets of these sensillar neurons have been identified. Their expression patterns and antibody perturbation studies are consistent with the hypothesis that a hierarchy of distinct carbohydrate structures expressed by specific ...


Regulation Of Dna Replication In Xenopus Laevis , Jing Fang Jan 1996

Regulation Of Dna Replication In Xenopus Laevis , Jing Fang

Retrospective Theses and Dissertations

The purpose of my research project is to make an attempt to understand some aspects of eukaryotic DNA replication by studying how this process is regulated positively or negatively in different physiological conditions. Using Xenopus egg extracts as the in vitro replication system, I studied the inhibitors of DNA replication found in nuclei of Xenopus quiescent cells. Replication of nuclei isolated from quiescent Xenopus cells was barely detectable in interphase extracts of Xenopus laevis eggs, although Xenopus sperm chromatin was replicated with about 100% efficiency in the same extracts. The evidence of the inhibitors came further from the fact that ...


The Role Of Rat Brain Ptp-1 Surface Basic Residues In Substrate Reactivity , Deborah Sue Baedke Jan 1996

The Role Of Rat Brain Ptp-1 Surface Basic Residues In Substrate Reactivity , Deborah Sue Baedke

Retrospective Theses and Dissertations

Previous work by others has demonstrated that rat brain protein tyrosine phosphatase (rbPTP-1) exhibited increased reactivity toward substrates containing acidic residues N-terminal to phosphotyrosine. We show that substrates containing a single acidic residue C-terminal to the phosphotyrosine also enhanced reactivity with rbPTP-1. A substrate aspartate residue at the P+2 position exhibited the greatest enhancement of reactivity;Surface basic residues of rbPTP-1 were investigated for their role in the increased reactivity due to substrate acidic residues. Mutation of R47 or K120 to alanine decreased the enhancement of reactivity due to acidic residues N-terminal to phosphotyrosine by 78% and 73% respectively ...


Purification, Characterization And Molecular Cloning Of Muscle Paranemin , Philip Mark Hemken Jan 1996

Purification, Characterization And Molecular Cloning Of Muscle Paranemin , Philip Mark Hemken

Retrospective Theses and Dissertations

Paranemin is an incompletely characterized ~280 kilodalton protein previously identified and immunolocalized in embryonic chick skeletal muscle. Paranemin has been purified from the same tissue source, has the same molecular weight by SDS-PAGE, and has the same antibody localization at the Z-lines of adult avian cardiac muscle. The method developed for preparation of purified paranemin from embryonic (chick) skeletal muscle includes homogenization, centrifugation and gel filtration, hydroxyapatite, and DEAE-cellulose chromatography. By using this method, ~2 mg of purified paranemin was routinely obtained. Amino acid analysis revealed that paranemin has a high acidic to basic amino acid ratio, which agrees with ...


Calsensin, A Novel Calcium-Binding Protein Expressed In A Subset Of Peripheral Leech Neurons Fasciculating In A Single Axon Tract , Kristen Kay Briggs Jan 1995

Calsensin, A Novel Calcium-Binding Protein Expressed In A Subset Of Peripheral Leech Neurons Fasciculating In A Single Axon Tract , Kristen Kay Briggs

Retrospective Theses and Dissertations

The lan 3-6 monoclonal antibody recognizes a subpopulation of peripheral neurons whose afferents segregate into a single fascicle within the developing leech central nervous system. The lan 3-6 monoclonal antibody was used to isolate a clone encoding a novel protein, calsensin, which contains two EF-hand calcium-binding domains. In situ hybridizations with calsensin riboprobes, Western blots of lan 3-6 monoclonal antibody immunoprecipitations, and immunohistochemistry with polyclonal antibodies generated against a partially-purified calsensin fusion protein confirmed that the sequence encoding the lan 3-6 antigen has been identified. Partially-purified calsensin fusion protein binds [superscript]45Ca[superscript]2+ in vitro, suggesting that the calsensin ...


Elm1p, A Protein Kinase That Regulates Cell Morphology In Saccharomyces Cerevisiae , Carla Marie Koehler Jan 1995

Elm1p, A Protein Kinase That Regulates Cell Morphology In Saccharomyces Cerevisiae , Carla Marie Koehler

Retrospective Theses and Dissertations

Saccharomyces cerevisiae is a pleimorphic ascomycete, capable of growing in the yeast form or the pseudohyphal form. The pseudohyphal form is characterized by elongated cells that possess a unipolar budding pattern and grow in chains away from the center of the colony. This change in morphology is induced by nitrogen starvation in the presence of carbon. A collection of 14 elm (elongated morphology) mutants previously have been isolated that grow as pseudohyphae constitutively. Of these mutants, the product of the ELM1 gene was identified and coded for a novel protein kinase. From genetic analyses, ELM1 seemingly functioned downstream of STE7 ...


Identification Of Potential Oat Phytochrome A Mrna Degradation Mechanisms , David Charles Higgs Jan 1994

Identification Of Potential Oat Phytochrome A Mrna Degradation Mechanisms , David Charles Higgs

Retrospective Theses and Dissertations

The phytochrome plant photoreceptor is important for perceiving the light environment and initiating plant developmental and environmental responses. When dark-grown oat seedlings are treated with light the phytochrome A (PHYA) mRNA abundance rapidly declines due, in part, to the inherent instability of the PHYA mRNA. Messenger RNA stability is an important process in regulating eukaryotic gene expression. My primary goal was to investigate both the mechanism of oat PHYA mRNA degradation and cis-acting sequences involved in regulating oat PHYA mRNA degradation. An oat protoplast system was established to investigate its use as a quick and reliable system to study plant ...


Genetic Analysis Of Pseudohyphal Growth In The Budding Yeast Saccharomyces Cerevisiae , Melissa Jo Blacketer Jan 1994

Genetic Analysis Of Pseudohyphal Growth In The Budding Yeast Saccharomyces Cerevisiae , Melissa Jo Blacketer

Retrospective Theses and Dissertations

The budding yeast Saccharomyces cerevisiae is a dimorphic organism that can assume either a yeast-like or pseudohyphal form. Nitrogen limitation induces pseudohyphal growth, which is characterized by branched chains of elongated cells. Pseudohyphal cells can grow invasively in agar medium, whereas yeast-like cells do not. To identify factors involved in morphologic differentiation, S. cerevisiae mutants exhibiting a constitutive cell elongation morphology were isolated. Genetic analysis identified 28 recessive and 2 semi-dominant mutations that cause abnormal morphology, and placed these in 14 distinct gene loci, termed ELM, for ELongated Morphology. Many elm mutations cause multiple aspects of pseudohyphal growth, and thus ...


Regulation Of Mitogen Regulated Protein/Proliferin Gene Expression In 3t3 Cells By Basic Fibroblast Growth Factor , Manzoor Ali P. K. Mohideen Jan 1994

Regulation Of Mitogen Regulated Protein/Proliferin Gene Expression In 3t3 Cells By Basic Fibroblast Growth Factor , Manzoor Ali P. K. Mohideen

Retrospective Theses and Dissertations

Mitogen regulated protein/proliferin (MRP/PLF) is a murine uterine growth factor belonging to the prolactin/growth hormone gene superfamily. Basic fibroblast growth factor (bFGF) regulates its expression in 3T3 cells and is speculated to be among its regulators in vivo. In order to gain insights into its regulation, experiments were performed to elucidate the mechanisms by which bFGF regulates mrp/plf gene expression in 3T3 cells. RT-PCR analyses demonstrated that of the three different forms of MRP/PLF proteins only one, PLF1, is expressed in these cells in response to bFGF. PLF1 could be the product of either plf42 ...


Molecular Analysis Of Protein Kinase C In The Sea Urchin Lytechinus Pictus , Terese Louise Rakow Jan 1993

Molecular Analysis Of Protein Kinase C In The Sea Urchin Lytechinus Pictus , Terese Louise Rakow

Retrospective Theses and Dissertations

Protein kinase C (PKC) was originally described as a serine threonine kinase in brain tissue. This activity was found to be dependent upon Ca[superscript]2+ and phosphatidyl serine. Today protein kinase C consists of a family of kinases with nine known members. Some members are Ca[superscript]2+-independent isozymes, and all of them have subtle activation differences. The multiple isozymes with varying activities in addition to different tissue distributions lead to the idea that members of the family have different functions. PKC has been well studied in mammalian systems and it is concluded that PKC is activated in ...


Identification Of The Substrate Specificity Of Three Intracellular Ptp's (Ptp-1, Ptp-5, And Yop-51) And Two Transmembrane Ptp's (Cd45 And Lar) And Evidence For An Active Site Arginine Residue , Keli Lee Hippen Jan 1993

Identification Of The Substrate Specificity Of Three Intracellular Ptp's (Ptp-1, Ptp-5, And Yop-51) And Two Transmembrane Ptp's (Cd45 And Lar) And Evidence For An Active Site Arginine Residue , Keli Lee Hippen

Retrospective Theses and Dissertations

This study has investigated the interaction of protein tyrosine phosphatases (PTP's) with their substrates both at the level of recognition and catalysis using three approaches. First, the one mechanism for substrate recognition by three intracellular PTP's (PTP-1, PTP-5, and YOP-51) and two transmembrane PTP's (CD45 and LAR). Acidic residues in several positions were found to affect peptide reactivity with all the PTP's tested. The intracellular PTP's that were tested all had similar responses to N-terminal acidic residues, but were quite distinct from the transmembrane PTP's (CD45 and LAR), which were also found to differ ...


Age, Gender And Diet Effects On Gene Expression Regulated By 1,25-Dihydroxyvitamin D3 , Julie Ann Johnson Jan 1993

Age, Gender And Diet Effects On Gene Expression Regulated By 1,25-Dihydroxyvitamin D3 , Julie Ann Johnson

Retrospective Theses and Dissertations

Age-related changes often occur in factors involved in regulation of bone mineral metabolism, including 1,25-dihydroxyvitamin D[subscript]3 (1,25(OH)[subscript]2D[subscript]3) and parathyroid hormone (PTH) in plasma, 1,25(OH)[subscript]2D[subscript]3 receptors (VDR) and vitamin D[subscript]3-dependent calcium (Ca) binding proteins (CaBP-28K and CaBP-9K) in target tissues, and the 1[alpha],25-dihydroxyvitamin D-24-hydroxylase (24-hydroxylase);Response to exogenous 1,25(OH)[subscript]2D[subscript]3 was studied in 2.5- and 18-mo-old male and female rats. Additionally, response to dietary Ca deficiency was examined in one- and 18-mo-old male rats;Plasma 1 ...


Cloning And Characterization Of Mink Plasminogen Activator Inhibitor Type 1 (Pai-1) Cdna And The Regulation Of Mink Pai-1 Expression At Mrna Level , Tsung-Hsien Chuang Jan 1992

Cloning And Characterization Of Mink Plasminogen Activator Inhibitor Type 1 (Pai-1) Cdna And The Regulation Of Mink Pai-1 Expression At Mrna Level , Tsung-Hsien Chuang

Retrospective Theses and Dissertations

Mink plasminogen activator inhibitor type 1 (PAI-1) is a glycoprotein with molecular weight about 50 kD and is highly regulated in cultured cells. In mink lung CCL64 epithelial cells, epidermal growth factor (EGF), transforming growth factor-[beta] (TGF-[beta]), and 12-O-tetradecanoyl phorbol-13-acetate (TPA) increase the synthesis of PAI-1. Epidermal growth factor and TGF-[beta] synergistically stimulate the synthesis of PAI-1. The synergistic effect and factors which govern the PAI-1 expression in mink lung CCL64 cells were studied by using a mink PAI-1 cDNA as a probe to detect PAI-1 mRNA;The mink PAI-1 cDNA was cloned from a cDNA library ...