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GSBS Dissertations and Theses

2007

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Full-Text Articles in Medicine and Health Sciences

A Role For Histone Modification In The Mechanism Of Action Of Antidepressant And Stimulant Drugs: A Dissertation, Frederick Albert Schroeder Dec 2007

A Role For Histone Modification In The Mechanism Of Action Of Antidepressant And Stimulant Drugs: A Dissertation, Frederick Albert Schroeder

GSBS Dissertations and Theses

Depression and stimulant drug addiction each result in massive losses of health, productivity and human lives every year. Despite decades of research, current treatment regimes for depression are ineffective in approximately half of all patients. Therapy available to stimulant drug addicts is largely ineffective and moreover, dedicated treatments for drug dependence (including abuse of cocaine) are non-existent. Thus, there is a pressing need to further understanding of the molecular mechanisms underlying these disorders in order to develop novel, targeted therapeutic strategies.

Chromatin remodeling, including changes in histone acetylation, has been proposed to play a role in both the etiology and ...


Surface Of Yersinia Pestis: Lcrv, F1 Production, Invasion And Oxygen: A Dissertation, Kimberly Lea Pouliot Dec 2007

Surface Of Yersinia Pestis: Lcrv, F1 Production, Invasion And Oxygen: A Dissertation, Kimberly Lea Pouliot

GSBS Dissertations and Theses

Of the eleven species of bacteria that comprise the genus Yersinia of the family Enterobacteriaceae, three species are pathogenic for humans. Yersinia pseudotuberculosis and Yersinia enterocolitica usually cause a mild, self-limiting mesenteric lymphadenitis or ileitis. Yersinia pestis causes a highly invasive often fatal disease known as plague. All three elaborate a type three secretion system that is essential for virulence and encoded on closely related plasmids. In Y. pestis, all the effectors, structural components and chaperones are encoded on the 70kb plasmid, pCD1.

Of these, LcrV from Y. enterocolitica has been implicated in playing an immunosuppressive role through its interaction ...


Transcript-Specific Cytoplasmic Degradation Of Yra1 Pre-Mrna Mediated By The Yeast Edc3 Protein: A Dissertation, Shuyun Dong Dec 2007

Transcript-Specific Cytoplasmic Degradation Of Yra1 Pre-Mrna Mediated By The Yeast Edc3 Protein: A Dissertation, Shuyun Dong

GSBS Dissertations and Theses

mRNA degradation is a fundamental process that controls both the level and the fidelity of gene expression. Using a combination of bioinformatic, genomic, genetic, and molecular biology approaches, we have shown that Edc3p, a yeast mRNA decay factor, controls the stability of the intron-containing YRA1 pre-mRNA. We found that Edc3p-mediated degradation of YRA1 pre-mRNA: 1) is a component of a negative feedback loop involved in the autoregulation of YRA1, 2) takes place in the cytoplasm, 3) is independent of translation, 4) occurs through a deadenylation-independent decapping and 5΄ to 3΄ exonucleotic decay mechanism, and 5) is controlled by specific cis ...


Probing The Structural Topology Of Hiv-1 Virion Infectivity Factor (Vif): A Dissertation, Jared R. Auclair Dec 2007

Probing The Structural Topology Of Hiv-1 Virion Infectivity Factor (Vif): A Dissertation, Jared R. Auclair

GSBS Dissertations and Theses

Human Immunodeficiency Virus Type 1 (HIV-1), the virus that causes Acquired Immunodeficiency Syndrome (AIDS), attacks the immune system leaving patients susceptible to opportunistic infections that eventually cause death. Highly Active Antiretroviral Therapy, HAART, is the current drug strategy used to combat HIV. It is a combination therapy that includes HIV-1 Reverse Transcriptase and HIV-1 Protease inhibitors. Drug resistant strains arise that evade current HAART treatments; therefore novel drugs are needed.

HIV-1 regulatory proteins such as Tat, Rev, Nef, Vpr, Vpu, and Vif are attractive new drug targets. Of particular interest is the HIV-1 Vif protein and its cellular binding partner ...


Molecular And Neuronal Analysis Of Circadian Photoresponses In Drosophila: A Dissertation, Alejandro D. Murad Oct 2007

Molecular And Neuronal Analysis Of Circadian Photoresponses In Drosophila: A Dissertation, Alejandro D. Murad

GSBS Dissertations and Theses

Most organisms, from cyanobacteria to humans are equipped with circadian clocks. These endogenous and self-sustained pacemakers allow organisms to adapt their physiology and behavior to daily environmental variations, and to anticipate them. The circadian clock is synchronized by environmental cues (i.e. light and temperature fluctuations).

The fruit fly, Drosophila melanogaster, is well established as a model for the study of circadian rhythms. Molecular mechanisms of the Drosophilacircadian clock are conserved in mammals. Using genetic screens, several essential clock proteins (PER, TIM, CLK, CYC, DBT, SGG and CK-II) were identified in flies. Homologs of most of these proteins are ...


Modulation Of CaV1.3 L-Type Calcium Channels By Arachidonic Acid And Muscarinic M1 Receptors: A Dissertation, Mandy L. Roberts-Crowley Oct 2007

Modulation Of CaV1.3 L-Type Calcium Channels By Arachidonic Acid And Muscarinic M1 Receptors: A Dissertation, Mandy L. Roberts-Crowley

GSBS Dissertations and Theses

Membrane excitability, gene expression, and neurotransmitter release are all controlled by voltage-gated L-type Ca2+ (L- )channels. In turn, Ca2+ channels are highly regulated by signal transduction cascades initiated by G protein-coupled receptor (GPCR) activation. In medium spiny neurons of the striatum, both the muscarinic M1 receptors (M1R) and dopaminergic D2 receptors (D2R) specifically inhibit the Cav1.3 L-channel.

In Chapters III and IV, the pathways downstream of M1Rs and D2Rs are examined to determine whether an overlap or intersection in inhibition of Cav1.3 ...


A Genetic Analysis Of Genomic Stability In Caenorhabditis Elegans: A Dissertation, Melissa M. Auclair Sep 2007

A Genetic Analysis Of Genomic Stability In Caenorhabditis Elegans: A Dissertation, Melissa M. Auclair

GSBS Dissertations and Theses

In humans, Bloom’s Syndrome is caused by a mutation of the RecQ helicase BLM. Patients with Bloom’s Syndrome exhibit a high amount of genomic instability which results in a high incidence of cancer. Though Bloom’s Syndrome has been intensively studied, there are still many questions about the function of BLM which need to be answered. While it is clear that loss of BLM increases genomic instability, the other effects of genomic instability on the organism aside from cancer such as a potential effect on aging, have yet to be elucidated.

In Chapter II, I identify new phenotypes ...


Understanding Assembly Of Ago2 Risc: The Rnai Enzyme: A Dissertation, Christian B. Matranga Sep 2007

Understanding Assembly Of Ago2 Risc: The Rnai Enzyme: A Dissertation, Christian B. Matranga

GSBS Dissertations and Theses

In 1990, Richard Jorgensen’s lab initiated a study to test if they could create a more vivid color petunia (Napoli et al. 1990). Their plan was to transform plants with the chalcone synthase transgene––the predicted rate limiting factor in the production of purple pigmentation. Much to their surprise, the transgenic plants, as well as their progeny, displayed a great reduction in pigmentation. This loss of endogenous function was termed “cosuppression” and it was thought that sequence-specific repression resulted from over-expression of the homologous transgene sequence. In 1998, Andrew Fire and Craig Mello described a phenomenon in which double ...


Distinct Behaviors Of Infected And Bystander Dendritic Cells Following Exposure To Dengue Virus: A Dissertation, Zachary Davis Nightingale Sep 2007

Distinct Behaviors Of Infected And Bystander Dendritic Cells Following Exposure To Dengue Virus: A Dissertation, Zachary Davis Nightingale

GSBS Dissertations and Theses

Dengue viruses (DV) are re-emerging mosquito-borne pathogens for which four distinct lineages, grouped based on serology and referred to as serotypes 1-4 (DIV-D4V), have been described. Epidemiological data imply that re-infection with a "heterologous" serotype, i.e, one other than that to which the individual was originally exposed, enhances the risk for development of severe disease, dengue hemorrhagic fever (DHF). The hallmark of DHF is a transient capillary leakage syndrome of rapid onset, temporally associated with the resolution of fever and viremia. In its most grave form, the vascular permeability phenomenon in DHF may progress to dengue shock syndrome (DSS ...


Folding And Assembly Of Multimeric Proteins: Dimeric Hiv-1 Protease And A Trimeric Coiled Coil Component Of A Complex Hemoglobin Scaffold: A Dissertation, Amanda Ann Fitzgerald Aug 2007

Folding And Assembly Of Multimeric Proteins: Dimeric Hiv-1 Protease And A Trimeric Coiled Coil Component Of A Complex Hemoglobin Scaffold: A Dissertation, Amanda Ann Fitzgerald

GSBS Dissertations and Theses

Knowledge of how a polypeptide folds from a space-filling random coil into a biologically-functional, three-dimensional structure has been the essence of the protein folding problem. Though mechanistic details of DNA transcription and RNA translation are well understood, a specific code by which the primary structure dictates the acquisition of secondary, tertiary, and quarternary structure remains unknown. However, the demonstrated reversibility of in vitroprotein folding allows for a thermodynamic analysis of the folding reaction. By probing both the equilibrium and kinetics of protein folding, a protein folding mechanism can be postulated. Over the past 40 years, folding mechanisms have been ...


Autoimmune Diabetes And Transplantation Tolerance Induced By Costimulation Blockade In Nod Mice: A Dissertation, Julie Lambert Aug 2007

Autoimmune Diabetes And Transplantation Tolerance Induced By Costimulation Blockade In Nod Mice: A Dissertation, Julie Lambert

GSBS Dissertations and Theses

NOD mice model human type 1 diabetes and have been used to investigate tolerance induction protocols for islet transplantation in a setting of autoimmunity. Costimulation blockade-based tolerance protocols that induce prolonged skin and permanent islet allograft survival in non-autoimmune mice have failed in NOD mice. To investigate the underlying mechanisms, we generated NOD hematopoietic chimeras. We were able to show that dendritic cell maturation defects seen in NOD mice are partially corrected in mixed hematopoietic chimeras. Furthermore, skin allograft survival was dependent upon the phenotype of the bone marrow donor, demonstrating that in the NOD the resistance to tolerance induction ...


Role Of Notch1 In Cardiac Cell Differentiation And Migration: A Dissertation, Dinh Le Mary Chau Aug 2007

Role Of Notch1 In Cardiac Cell Differentiation And Migration: A Dissertation, Dinh Le Mary Chau

GSBS Dissertations and Theses

The cardiac conduction system is responsible for maintaining and orchestrating the rhythmic contractions of the heart. Results from lineage tracing studies indicate that precursor cells in the ventricles give rise to both cardiac muscle and conduction cells. Using chick embryonic hearts, we have found that Notch signaling plays an important role in the differentiation of cardiac muscle and conduction cell lineages in the ventricles. Notch1 expression coincides with a conduction marker at early stages of conduction system development. Mis-expression of constitutively active Notch1 (NIC) in early heart tubes exhibited multiple effects on cardiac cell differentiation. Cells expressing NIC had a ...


Transfer Of The Ribosome-Nascent Chain Complex To The Translocon In Cotranslational Translocation: A Thesis, Ying Jiang Aug 2007

Transfer Of The Ribosome-Nascent Chain Complex To The Translocon In Cotranslational Translocation: A Thesis, Ying Jiang

GSBS Dissertations and Theses

Cotranslational translocation is initiated by targeting of a ribosome-bound nascent polypeptide chain (RNC) to the endoplasmic reticulum (ER) membrane. The targeting reaction is coordinated by the signal recognition particle (SRP) through its interaction with the RNC and the membrane-bound SRP receptor (SR). A vacant translocon is a prerequisite for the subsequent nascent chain release from SRP-SR-RNC complex. It has been proposed that the protease-accessible cytosolic domains of the Sec61p complex play an important role in posttargeting steps by providing the binding site for the ribosome or interacting with the SR to initiate the signal sequence releasing. In this study, we ...


Neural Diversity In The Drosophila Olfactory Circuitry: A Dissertation, Sen-Lin Lai Jul 2007

Neural Diversity In The Drosophila Olfactory Circuitry: A Dissertation, Sen-Lin Lai

GSBS Dissertations and Theses

Different neurons and glial cells in the Drosophila olfactory circuitry have distinct functions in olfaction. The mechanisms to generate most of diverse neurons and glial cells in the olfactory circuitry remain unclear due to the incomprehensive study of cell lineages. To facilitate the analyses of cell lineages and neural diversity, two independent binary transcription systems were introduced into Drosophila to drive two different transgenes in different cells. A technique called ‘dual-expression-control MARCM’ (mosaic analysis with a repressible cell marker) was created by incorporating a GAL80-suppresible transcription factor LexA::GAD (GAL4 activation domain) into the MARCM. This technique allows the induction ...


Motor Property Of Mammalian Myosin 10: A Dissertation, Kazuaki Homma Jul 2007

Motor Property Of Mammalian Myosin 10: A Dissertation, Kazuaki Homma

GSBS Dissertations and Theses

Myosin 10 is a vertebrate specific actin-based motor protein that is expressed in a variety of cell types. Cell biological evidences suggest that myosin 10 plays a role in cargo transport and filopodia extension. In order to fully appreciate these physiological processes, it is crucial to understand the motor property of myosin 10. However, little is known about its mechanoenzymatic characteristics. In vitro biochemical characterization of myosin 10 has been hindered by the low expression level of the protein in most tissues. In this study, we succeeded in obtaining sufficient amount of recombinant mammalian myosin 10 using the baculovirus expression ...


Identification And Characterization Of Agv1, A Pre-Metazoan Arf Gap: A Dissertation, Kimberly Renee Long Jun 2007

Identification And Characterization Of Agv1, A Pre-Metazoan Arf Gap: A Dissertation, Kimberly Renee Long

GSBS Dissertations and Theses

Human immunodeficiency virus type 1 (HIV-1) is a member of the lentivirus subfamily of retroviruses. HIV-1 expresses multiple genes from a single provirus by alternative splicing. Early in viral expression, fully spliced 2-kb viral RNA is exported from the nucleus and encodes the viral regulatory protein, Rev, which is essential for nuclear transport of partially spliced and unspliced genomic-length RNA. Rev binds to an RNA structural element called the Rev response element (RRE) and mediates nuclear export through the leucine-rich nuclear export signal (NES) pathway. The human Rev Interacting Protein (hRIP) interacts specifically with the Rev NES. Rev NES mutants ...


Mechanism And Function Of Actin Pedestal Formation By Enterohemorrhagic Escherichia Coli O157:H7: A Dissertation, Michael John Brady Jun 2007

Mechanism And Function Of Actin Pedestal Formation By Enterohemorrhagic Escherichia Coli O157:H7: A Dissertation, Michael John Brady

GSBS Dissertations and Theses

Enterohemorrhagic Escherichia coli O157:H7 (EHEC) and enteropathogenic E. coli O127:H7 (EPEC) induce characteristic F-actin rich pedestals on infected mammalian cells. Each pathogen delivers its own translocated intimin receptor (Tir) to the host cell to act as a receptor for the bacterial outer membrane adhesin, intimin. Interaction of translocated Tir with intimin is essential for mammalian cell binding and host colonization, as well as to induce actin pedestal formation in vitro. In spite of these parallels, EHEC and EPEC Tir appear to generate actin pedestals by distinct mechanisms. Further, while the ability to form actin pedestals is a striking ...


How Does Atp Regulate Erythrocyte Glucose Transport?: A Dissertation, Jeffry M. Leitch Jun 2007

How Does Atp Regulate Erythrocyte Glucose Transport?: A Dissertation, Jeffry M. Leitch

GSBS Dissertations and Theses

Human erythrocyte glucose sugar transport displays a complexity that is not explained by available models. Sugar transport was examined in resealed red cell ghosts under equilibrium exchange conditions (intracellular [sugar] = extracellular [sugar]). Exchange 3-O-methylglucose (3MG) import and export are monophasic in the absence of cytoplasmic ATP but are biphasic when ATP is present. Biphasic exchange is observed as the rapid filling of a large compartment (66% cell volume) followed by the slow filling of the remaining cytoplasmic space. Two models for biphasic sugar transport are presented in which 3MG must overcome a sugar-specific, physical (diffusional) or chemical (anomerization) barrier to ...


Molecular And Behavioral Analysis Of Drosophila Circadian Photoreception And Circadian Thermoreception: A Dissertation, Ania Busza May 2007

Molecular And Behavioral Analysis Of Drosophila Circadian Photoreception And Circadian Thermoreception: A Dissertation, Ania Busza

GSBS Dissertations and Theses

Circadian clocks are biological timekeepers that help maintain an organism’s behavior and physiological state optimally timed to the Earth’s day/night cycle. To do this, these internal pacemakers must accurately keep track of time. Equally importantly, they must be able to adjust their oscillations in response to external time cues to remain properly synchronized with the environment, and correctly anticipate environmental changes. When the internal clock is offset from its surrounding day/night cycle, clinically relevant disruptions develop, ranging from inconveniences such as jet-lag to more severe problems such as sleep disorders or mood disorders. In this work ...


The Role Of Cd40 In NaïVe And Memory Cd8+ T Cell Responses: A Dissertation, Maria Genevieve H. Hernandez May 2007

The Role Of Cd40 In NaïVe And Memory Cd8+ T Cell Responses: A Dissertation, Maria Genevieve H. Hernandez

GSBS Dissertations and Theses

Stimulation of CD40 on APCs through CD40L expressed on helper CD4+ T cells activates and “licenses” the APCs to prime CD8+ T cell responses. While other stimuli, such as TLR agonists, can also activate APCs, it is unclear to what extent they can replace the signals provided by CD40-CD40L interactions. In this study, we used an adoptive transfer system to re-examine the role of CD40 in the priming of naïve CD8+ T cells. We find an approximately 50% reduction in expansion and cytokine production of TCR-transgenic T cells in the absence of CD40 on all APCs, and on dendritic cells ...


Cartilage Tissue Engineering: Uses Of Injection Molding And Computer Aided Design For The Fabrication Of Complex Geometries With High Dimensional Tolerances: A Dissertation, Morgan E. Hott May 2007

Cartilage Tissue Engineering: Uses Of Injection Molding And Computer Aided Design For The Fabrication Of Complex Geometries With High Dimensional Tolerances: A Dissertation, Morgan E. Hott

GSBS Dissertations and Theses

Cartilage Tissue Engineering. Joint pain and functional impairment due to cartilage damage from osteoarthritis and other means is a major source of disability for adults the world over. Cartilage is an avascular tissue with a very limited capacity for self repair. Current medical and surgical approaches to cartilage repair also have limited efficacy, and in all cases fail to completely restore a normal, healthy cartilage phenotype. Tissue engineering is a relatively new approach to cartilage repair that seeks to fabricate a replacement tissue, indistinguishable from healthy, native tissue.

The basic idea of the tissue engineering approach is to seed tissue ...


Identification And Characterization Of Components Of The Intraflagellar Transport (Ift) Machinery: A Dissertation, Yuqing Hou May 2007

Identification And Characterization Of Components Of The Intraflagellar Transport (Ift) Machinery: A Dissertation, Yuqing Hou

GSBS Dissertations and Theses

Intraflagellar transport (IFT), the bi-directional movement of particles along the length of flagella, is required for flagellar assembly. The IFT particles are moved by kinesin II from the base to the tip of the flagellum, where flagellar assembly occurs. The IFT particles are then moved in the retrograde direction by cytoplasmic dynein 1b/2 to the base of the flagellum. The IFT particles of Chlamydomonas are composed of ~16 proteins, organized into complexes A and B. Alhough IFT is believed to transport cargoes into flagella, few cargoes have been identified and little is known about how the cargos are transported ...


Cooperative Oncogenesis And Polyploidization In Human Cancers: A Dissertation, Susan Ann Heilman May 2007

Cooperative Oncogenesis And Polyploidization In Human Cancers: A Dissertation, Susan Ann Heilman

GSBS Dissertations and Theses

A common phenotype observed in most cancers is chromosomal instability. This includes both structural and numerical chromosomal aberrations, which can promote carcinogenesis. The fusion gene CBFB/MYH11 is created by the structural chromosomal inversion(16)(p13.1q22), resulting in the fusion protein CBFβ-SMMHC, which blocks differentiation in hematopoietic progenitor cells. This mutation alone, however, is not sufficient for transformation, and at least one additional cooperating mutation is necessary.

The role of wildtype Cbfb in modulating the oncogenic function of the fusion protein Cbfβ-SMMHC in mice was examined. Transgenic mice expressing the fusion protein, but lacking a wild-type copy of Cbfb ...


Functional And Structural Dissection Of The Swi/Snf Chromatin Remodeling Complex: A Dissertation, Xiaofang Yang May 2007

Functional And Structural Dissection Of The Swi/Snf Chromatin Remodeling Complex: A Dissertation, Xiaofang Yang

GSBS Dissertations and Theses

The yeast SWI/SNF complex is the prototype of a subfamily of ATP-dependent chromatin remodeling complexes. It consists of eleven stoichiometric subunits including Swi2p/Snf2p, Swi1p, Snf5p, Swi3p, Swp82p, Swp73p, Arp7p, Arp9p, Snf6p, Snf11p, and Swp29p, with a molecular weight of 1.14 mega Daltons. Swi2p/Snf2p, the catalytic subunit of SWI/SNF, is evolutionally conserved from yeast to human cells. Genetic evidence suggests that SWI/SNF is required for the transcriptional regulation of a subset of genes, especially inducible genes. SWI/SNF can be recruited to target promotors by gene specific activators, and in some cases, SWI/SNF facilitates ...


Collagen And Fibrin Bioplymer Microthreads For Bioengineered Ligament Generation: A Dissertation, Kevin Cornwell May 2007

Collagen And Fibrin Bioplymer Microthreads For Bioengineered Ligament Generation: A Dissertation, Kevin Cornwell

GSBS Dissertations and Theses

Rupture of the anterior cruciate ligament (ACL) of the knee leads to chronic joint instability and reduced range of motion while the long term results are marred by a high prevalence of degenerative joint disease especially osteoarthritis. Bundles of collagen threads have been widely investigated for the repair of torn ACL, but are limited by insufficient tissue ingrowth to repopulate and completely regenerate these grafts. We have developed a novel in vitro method of characterizing fiber-based thread matrices by probing their ability to promote tissue ingrowth from a wound margin as a measure of their ability to promote repopulation and ...


Interaction Of A Mammalian Virus With Host Rna Silencing Pathways: A Dissertation, Bradford Michael Stadler Mar 2007

Interaction Of A Mammalian Virus With Host Rna Silencing Pathways: A Dissertation, Bradford Michael Stadler

GSBS Dissertations and Theses

In the complex relationships of mammalian viruses with their hosts, it is currently unclear as to what role RNA silencing pathways play during the course of infection. RNA silencing-based immunity is the cornerstone of plant and invertebrate defense against viral pathogens, and examples of host defense mechanisms and numerous viral counterdefense mechanisms exist. Recent studies indicate that RNA silencing might also play an active role in the context of a mammalian virus infection. We show here that a mammalian virus, human adenovirus, interacts with RNA silencing pathways during infection, as the virus produces microRNAs (miRNAs) and regulates the expression of ...


Regulation Of Cell Polarization And Map Kinase Signaling In The Saccharomyces Cerevisiae Pheromone Response Pathway: A Dissertation, Shelly Catherine Strickfaden Mar 2007

Regulation Of Cell Polarization And Map Kinase Signaling In The Saccharomyces Cerevisiae Pheromone Response Pathway: A Dissertation, Shelly Catherine Strickfaden

GSBS Dissertations and Theses

Exposure to external stimuli promotes a variety of cellular responses including changes in morphology, gene expression and cell division status. These responses are promoted by signaling pathways composed of modules that are conserved from lower to higher eukaryotes. In Saccharomyces cerevisiae response to the external stimuli provided by mating pheromone is governed by the pheromone response pathway. This pathway is composed of a G protein coupled receptor/heterotrimeric G protein (Gαβγ) module and a MAP kinase cascade. Activation of this pathway allows the heterotrimeric G protein βγ dimer (Gβγ) to recruit polarity proteins to promote changes in cell morphology and ...


Human Erythrocyte Glucose Transporter (Glut1) Structure, Function, And Regulation: A Dissertation, David M. Blodgett Mar 2007

Human Erythrocyte Glucose Transporter (Glut1) Structure, Function, And Regulation: A Dissertation, David M. Blodgett

GSBS Dissertations and Theses

The structure-function relationship explains how the human erythrocyte glucose transport protein (GLUT1) catalyzes sugar transport across the plasma membrane. This work investigates the glucose transport mechanism, the structural arrangement and dynamics of GLUT1 membrane-spanning α-helices, the molecular basis for glucose transport regulation by ATP, and how cysteine accessibility contributes to GLUT1 structure.

A rapid kinetics approach was applied to examine the conformational changes GLUT1 undergoes during the transport cycle. To transition from a global to molecular focus, a novel mass spectrometry technique was developed to resolve GLUT1 sequence that is associated either with membrane embedded GLUT1 subdomains or with water ...


The Argonaute Family Of Genes In Caenorhabditis Elegans: A Dissertation, Erbay Yigit Feb 2007

The Argonaute Family Of Genes In Caenorhabditis Elegans: A Dissertation, Erbay Yigit

GSBS Dissertations and Theses

Members of the Argonaute family of proteins, which interact with small RNAs, are the key players of RNAi and other related pathways. The C. elegans genome encodes 27 members of the Argonaute family. During this thesis research, we sought to understand the functions of the members of this gene family in C. elegans. Among the Argonaute family members, rde-1 and alg-1/2have previously been shown to be essential for RNAi and development, respectively. In this work, we wanted to assign functions to the remaining members of this large family of proteins.

Here, we describe the phenotype of 31 deletion ...


Rethinking Mechanisms Of Actin Pedestal Formation By Enteropathogenic Escherichia Coli In The Context Of Multiple Signaling Cascades: A Dissertation, Pamela Joyce Savage Feb 2007

Rethinking Mechanisms Of Actin Pedestal Formation By Enteropathogenic Escherichia Coli In The Context Of Multiple Signaling Cascades: A Dissertation, Pamela Joyce Savage

GSBS Dissertations and Theses

Enteropathogenic Escherichia coli (EPEC) is one of many bacterial and viral pathogens that can exploit the eukaryotic actin cytoskeleton for its own purposes. EPEC injects its own receptor, Tir, into the host cell plasma membrane where, upon binding the bacterial adhesin, intimin, can trigger actin assembly beneath bound bacteria resulting in characteristic actin "pedestals". The formation of these lesions is thought to be critical for bacterial colonization; and can also provide insight into actin dynamics of mammalian cells. EPEC Tir stimulates multiple signaling pathways converging on a central actin nucleation promoting factor, N-WASP. The best-characterized pathway of actin pedestal formation ...