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GSBS Dissertations and Theses

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Role Of Recurrent Hydrophobic Residues In Catalyzing Helix Formation By T Cell-Presented Peptides: A Thesis, Shan Lu Dec 1990

Role Of Recurrent Hydrophobic Residues In Catalyzing Helix Formation By T Cell-Presented Peptides: A Thesis, Shan Lu

GSBS Dissertations and Theses

The overall objective of this study was to understand the mechanisms that control antigen processing and binding of peptides to major histocompatibility complex (MHC) molecules. Towards this goal I investigated (a) the structural features of T cell-presented peptides with a focus on the role of recurrent hydrophobic residues in catalysis of helix formation by these peptides and (b) the biochemical events that determine the fates of the invariant chain molecule (Ii) in its various post-translational processing pathways.

In the structural studies, I tested the hypothesis that the recurrence of hydrophobic amino acids in a polypeptide at positions falling in an ...


Functional And Structural Characterization Of A Human H4 Histone Gene Promoter: A Thesis, Kenneth Lynn Wright Nov 1990

Functional And Structural Characterization Of A Human H4 Histone Gene Promoter: A Thesis, Kenneth Lynn Wright

GSBS Dissertations and Theses

Expression of the cell cycle dependent FO10S human H4 histone gene is regulated at both the transcriptional and post-transcriptional levels. We have investigated the 5' promoter elements mediating the transcriptional aspects of its regulation. A detailed in vivo and in vitro transcriptional analysis of promoter deletion mutants from this gene has identified three positive regulatory elements and two potentially negative regulatory elements within the first 1000 base pairs upstream of the transcription initiation site. In addition, the minimal promoter located within the first 70 base pairs is required for accurate transcription initiation and contains one of two in vivo identified ...


Regulation Of Β-Adrenergic-Induced Protein Phosphorylation In The Myocardium: A Dissertation, Edward E. George Oct 1990

Regulation Of Β-Adrenergic-Induced Protein Phosphorylation In The Myocardium: A Dissertation, Edward E. George

GSBS Dissertations and Theses

The purpose of this investigation was to examine selected biochemical mechanisms known to influence contractility and energy metabolism in the myocardium, with particular emphasis placed on the regulatory role of protein phosphorylation in the ventricular myocardium. The investigation was conducted in three phases; initially the cardiac contraction cycle was examined to determine whether reported fluctuations in myocardial cAMP levels were associated with other biochemical events known to be cAMP-dependent. The second phase involved the determination of specific kinase activities and endogenous substrates in a highly purified cardiac sarcolemmal preparation. In the final phase, ventricular myocytes were utilized to examine the ...


The Structure, Function, And Regulation Of Insulin-Like Growth Factor Ii/Mannose 6-Phosphate Receptor Forms: A Thesis, Kevin B. Clairmont Oct 1990

The Structure, Function, And Regulation Of Insulin-Like Growth Factor Ii/Mannose 6-Phosphate Receptor Forms: A Thesis, Kevin B. Clairmont

GSBS Dissertations and Theses

In mammals a single receptor protein binds both insulin-like growth factor II (IGF-II) and mannose 6-phosphate (Man 6-P) containing ligands, most notably lysosomal enzymes. However, in chick embryo fibroblasts IGF-II binds predominantly to a type 1 IGF receptor, and no IGF-II/Man 6-P receptor has been identified in this species. In order to determine if chickens possess an IGF-II/Man 6-P receptor, an affinity resin (pentamannosyl 6-phosphate (PMP) Sepharose) was used to purify receptors from chicken membrane extracts by their ability to bind mannose 6-phosphate. Then 125I-IGF-II was used to evaluate their ability to bind IGF-II. These experiments demonstrate ...


Mutually Dependent Elements In The Neurotensin/Neuromedin N Gene Promoter Integrate Multiple Environmental Stimuli In Pc12 Cells: A Thesis, Edward H. Kislauskis Jun 1990

Mutually Dependent Elements In The Neurotensin/Neuromedin N Gene Promoter Integrate Multiple Environmental Stimuli In Pc12 Cells: A Thesis, Edward H. Kislauskis

GSBS Dissertations and Theses

This thesis examines the structure and regulated expression of the gene encoding the neuroendocrine peptides neurotensin and neuromedin N (NT/N gene). Previous studies have shown that expression of NT/N mRNA and NT peptide in PC12 cells are strictly dependent on simultaneous exposure to combinations of nerve growth factor (NGF), glucocorticoids, activators of adenylate cyclase, and lithium ion. My objective was to characterize the cis-regulatory DNA sequences involved in regulated expression of this gene.

The initial focus of this study was an analysis of the structure, tissue-specific expression, and exon evolution of the rat NT/N gene. Nucleotide sequence ...


The Stimulation Of Luteinizing Hormone Secretion From Anterior Pituitary Cells In Culture By Substance P: A Dissertation, Maureen Shamgochian May 1990

The Stimulation Of Luteinizing Hormone Secretion From Anterior Pituitary Cells In Culture By Substance P: A Dissertation, Maureen Shamgochian

GSBS Dissertations and Theses

The observations that substance P (SP) is localized in the anterior pituitary gland (AP) and is regulated by the hormonal status of the animal, as well as the demonstration of SP binding sites in the AP, have led to the idea that SP may participate in the regulation of AP function. Numerous and sometimes contradictory reports of SP effects on AP hormone secretion, particularly on luteinizing hormone (LH), left the question of whether SP acts directly at the level of the AP to regulate LH secretion still unanswered. To investigate a possible physiological function of SP in the AP, the ...


Genetic Analysis Of The Saccharomyces Cerevisiae Pheromone Response Pathway: A Thesis, Dmitry B. Blinder May 1990

Genetic Analysis Of The Saccharomyces Cerevisiae Pheromone Response Pathway: A Thesis, Dmitry B. Blinder

GSBS Dissertations and Theses

The cell division of Saccharomyces cerevisiae is controlled by the action of pheromones at the G1 phase of the cell cycle. A general method was developed for the isolation of constitutive mutants in the pheromone response pathway. Recessive alleles of the SCG1 gene (encoding the α subunit of a G protein) were isolated as well as a dominant mutation in the STE4 gene (encoding the β subunit of a G protein). Analysis of double mutants suggested that the STE4 gene product functions after the SCG1 product but before the STE5 gene product. Double mutants carrying either scg1 or STE4Hp1 ...


Development Of Selective Inhibitors Of Dna Polymerase Delta: A Thesis, Robert Vincent Talanian Aug 1989

Development Of Selective Inhibitors Of Dna Polymerase Delta: A Thesis, Robert Vincent Talanian

GSBS Dissertations and Theses

This thesis is divided into three parts, united by the theme of the development of selective inhibitors of mammalian cell DNA polymerase delta (pol δ). The first part consists of an investigation of the cytotoxic mechanism(s) of certain 2-substituted adenine analogs, selected on the basis of their inhibitory properties towards DNA polymerase alpha (pol α) and mammalian cell DNA synthesis. The second is a direct search for inhibitors of isolated pol δ, and an investigation of inhibitory mechanisms. The third consists of measurement of the effects of a selective pol δ inhibitor on cellular DNA synthesis.

Mechanism of Cytotoxicity ...


Proteolytic Cleavages Of Molecules Involved In Antigen Processing And Presentation: A Thesis, Lawrence James Thomas Aug 1989

Proteolytic Cleavages Of Molecules Involved In Antigen Processing And Presentation: A Thesis, Lawrence James Thomas

GSBS Dissertations and Theses

The overall goal of my thesis research was to understand better the mechanisms that control antigen processing and presentation by class II MHC molecules. Towards this goal I investigated ways in which the physical structure and post-translational modifications of the class II MHC alpha and beta chains and associated molecules might serve to regulate antigen processing and presentation. Specifically, I investigated (1) a hypothesis that Ii might aid binding of foreign antigenic peptides to the class II MHC foreign antigen binding site (desetope), and the application of this hypothesis to the prediction of class II-presented peptides; (2) the proteolytic ...


Plasma Membrane Processes In Smooth Muscle: Characterization Of Ca2+ Transport And Muscarinic Cholinergic Receptors: A Thesis, Pamela A. Lucchesi Apr 1989

Plasma Membrane Processes In Smooth Muscle: Characterization Of Ca2+ Transport And Muscarinic Cholinergic Receptors: A Thesis, Pamela A. Lucchesi

GSBS Dissertations and Theses

The thesis research was designed to study the characteristics of two important physiological processes in smooth muscle: Ca2+ transport mediated by the plasmalemmal Ca2+-ATPase and muscarinic receptor-G protein interactions. In resting smooth muscle, several Ca2+ extrusion or sequestration processes offset the passive inward leak of Ca2+. Although biochemical evidence suggests that the plasmalemmal Ca2+ pump plays a key role in this process, the precise role of this enzyme could not be proven until a reliable estimate of the inward Ca2+ leak was measured. Recent studies using dispersed smooth muscle cells from the toad ...


Structural Determinants Of Mrna Turnover In Yeast: A Thesis, David Herrick Jan 1989

Structural Determinants Of Mrna Turnover In Yeast: A Thesis, David Herrick

GSBS Dissertations and Theses

Large differences exist in the decay rates of individual mRNAs yet the molecular basis for such differences is substantially unknown. We have developed a procedure for the measurement of individual mRNAs in the yeast Saccharomyces cerevisiae which utilizes northern or dot blotting to quantitate the levels of individual mRNAs after thermal inactivation of RNA polymerase II in an rpb1-1 temperature-sensitive mutant strain (RY260). To assess the reliability of half-life measurements obtained in this manner, we have compared the results of this procedure to results obtained by three other procedures (pulse-chase analysis, approach to steady-state labeling, and inhibition of transcription with ...


Myc And E1a Oncogenes Alter The Response Of Pc12 Cells To Nerve Growth Factor And Block Differentiation: A Thesis, Susan C. Schiavi Aug 1988

Myc And E1a Oncogenes Alter The Response Of Pc12 Cells To Nerve Growth Factor And Block Differentiation: A Thesis, Susan C. Schiavi

GSBS Dissertations and Theses

PC12 rat pheochromocytoma cells respond to nerve growth factor (NGF) by neuronal differentiation and partial growth arrest. Mouse c-myc and adenovirus E1A genes were introduced into PC12 cells to study the influence of these nuclear oncogenes on neuronal differentiation. Expression of myc and E1A blocked morphological differentiation and caused NGF to stimulate rather than inhibit cell proliferation. NGF binding to cell surface receptors, activation of ribosomal S6 kinase, and ornithine decarboxylase induction were similar in myc and E1A expressing clones compared with wild-type PC12 cells, suggesting that changes in the cellular response to NGF were at a post-receptor level. The ...


Characterization Of Antigen-Specific Antigen Processing By The Resting B Cell: A Thesis, Edmund J. Gosselin Mar 1988

Characterization Of Antigen-Specific Antigen Processing By The Resting B Cell: A Thesis, Edmund J. Gosselin

GSBS Dissertations and Theses

An optimal antibody response to a thymus-dependent antigen requires cooperation between the B cell and an antigen-specific helper T cell. Major histocompatibility complex restriction of this interaction implies that the helper T cell recognizes antigen on the B cell surface in the context of MHC molecules, and that the antigen-specific B cell gets help by acting as an antigen presenting cell for the helper T cell. However, a number of studies have shown that normal resting B cells are ineffective as antigen presenting cells, implying that the B cell must leave the resting state before it can interact specifically with ...


A Genetic And Structural Analysis Of P22 Lysozyme: A Thesis, Dale Rennell Feb 1988

A Genetic And Structural Analysis Of P22 Lysozyme: A Thesis, Dale Rennell

GSBS Dissertations and Theses

P22 lysozyme, encoded by gene 19, is an essential phage protein responsible for hydrolyzing the bacterial cell wall during lytic infection. P22 lysozyme is related to T4 lysozymein its mode of action, substrate specificities, and in its structure. Gene 19 was located on the phage genome, subcloned, and then sequenced. lysozyme was produced in large quantities and purified for biochemical characterization and for crystallograpic studies. Gene 19consists of 146 codons, and encodes a protein with a molecular weight of 16,117.

Amber mutations were created in gene 19 by in vitro primer-directed mutagenesis. The mutations were crossed by homologous ...


Cytotoxic Lymphocytes In Viral Hepatitis: A Thesis, Kim W. Mcintyre Apr 1987

Cytotoxic Lymphocytes In Viral Hepatitis: A Thesis, Kim W. Mcintyre

GSBS Dissertations and Theses

The immunological mechanisms involved in virus-induced hepatitis were examined by measuring the cytotoxic capabilities and the morphological and antigenic phenotypes of leukocytes isolated from the livers of virus-infected mice. Large granular lymphocytes (LGL) of both natural killer (NK) cell and cytotoxic T lymphocyte (CTL) phenoytpes [phenotypes] accumulated in livers of mice infected with lymphocytic choriomeningitis virus (LCMV) of either the nonhepatotropic Armstrong strain (LCMV-ARM) or the hepatotropic WE strain (LCMV-WE). NK cell activity and LGL number increased 3- to 4-fold between days 1 and 5 postinfection (p.i.). These LGL were characterized as NK cells on the basis of cell ...


Biochemical Studies On The Hemolymph Trypsin Inhibitors Of The Tobacco Hornworm Manduca Sexta: A Thesis, Narayanaswamy Ramesh Mar 1986

Biochemical Studies On The Hemolymph Trypsin Inhibitors Of The Tobacco Hornworm Manduca Sexta: A Thesis, Narayanaswamy Ramesh

GSBS Dissertations and Theses

Trypsin inhibitory activity from the hemolymph of the tobacco hornworm, Manduca sexta, was purified by affinity chromatography on immobilized trypsin and resolved into two fractions with molecular weights of 13700 (inhibitor A) and 8000 (inhibitor B) by Sephadex G-75 gel filtration. SDS-polyacrylamide gel electrophoresis under non-reducing conditions gave a molecular weight estimate of 15000 for inhibitor A and 8500 for inhibitor B. Electrophoresis of these inhibitors under reducing conditions on polyacrylamide gels gave molecular weight estimates of 8300 and 9100 for inhibitor A and inhibitor B, respectively, suggesting that inhibitor A is a dimer. Isoelectro-focusing on polyacrylamide gels focused inhibitor ...


The Role Of Natural Killer Cells And Interferon In Virus Infections: A Thesis, Jack F. Bukowski Aug 1984

The Role Of Natural Killer Cells And Interferon In Virus Infections: A Thesis, Jack F. Bukowski

GSBS Dissertations and Theses

Definitive evidence that natural killer (NK) cells mediate an antiviral effect in vivo was obtained using murine cytomegalovirus (MCMV) as a model system. Adoptive transfer studies using a variety of physical and immunochemical techniques to enrich and deplete NK cell activity showed that the cell population capable of mediating resistance (as assayed by enhanced survival and reduction in spleen virus titers) had the phenotype of an NK cell: a nylon wool nonadherent, asialo GM1+, NK 1.2+, ly 5+, Thy-1-, Ia-, low-density lymphocyte. Adoptive transfer of IL-2-dependent cloned NK cells (but not T cells) also provided resistance. NK cells did ...