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Full-Text Articles in Life Sciences
Interactions Between Nova And Brptb Proteins In Alternative Splicing And Nuclear Localization, Alexandros Demetrios Polydorides
Interactions Between Nova And Brptb Proteins In Alternative Splicing And Nuclear Localization, Alexandros Demetrios Polydorides
Student Theses and Dissertations
The Nova paraneoplastic antigens are neuron-specific RNA-binding proteins that are essential for neuronal viability and participate in the control of alternative splicing. In this study, the yeast two-hybrid system is used to isolate Nova-interacting proteins. A novel RNA-binding protein named brPTB is identified, that is closely related to the polypyrimidine tract-binding protein (PTB) and is ennched in the brain at the mRNA and protein levels. brPTB interacts with Nova proteins in vitro and in vivo. Splicing assays in kidney epithelial cell lines show that brPTB inhibits the effect of Noval in the inclusion of alternatively spliced exons in two target …
Genetic Studies On The Circadian Clock In The Model Organism Drosophila Melanogaster, Sebastian Martinek
Genetic Studies On The Circadian Clock In The Model Organism Drosophila Melanogaster, Sebastian Martinek
Student Theses and Dissertations
Although the basic neural mechanism that regulates circadian behavior in Drosophila is known in quite some detail, several aspects of this biological process still remain to be elucidated. In this study a variety of genetic and molecular approaches was used to identify and characterize genes that are involved in circadian rhythms and that may shed light on the gaps in the model. In an F1 screen for altered period length of the circadian locomotor activity cycle the new mutation 2ob9 was isolated. Cloning and sequencing identified the affected gene as a Drosophila homolog of the yeast RNA helicase and splicing …
Molecular Anatomy Of A Living Nerve Terminal: Actin And Synapsin In The Synaptic Vesicle Cycle, Ona E. Bloom
Molecular Anatomy Of A Living Nerve Terminal: Actin And Synapsin In The Synaptic Vesicle Cycle, Ona E. Bloom
Student Theses and Dissertations
Neurotransmission is based on a series of events termed the synaptic vesicle cycle. Several molecular components contributing to the synaptic vesicle cycle are known, including the cytoskeletal protein actin and the synaptic vesicle-associated phosphoprotein synapsin. The studies presented in this thesis were designed to investigate the role of the interaction between synapsin and actin in an intact model of synaptic transmission, the lamprey reticulospinal synapse. To establish the role of actin in the presynaptic terminal, several actin-directed compounds were injected into reticulospinal axons. Axons were maintained at rest or stimulated under various conditions, fixed, and the ultrastructure of the terminal …
Emerging Auditory Selectivity In The Caudomedial Neostriatum Of The Zebra Finch Songbird, Caroline Wan-Yin Ang
Emerging Auditory Selectivity In The Caudomedial Neostriatum Of The Zebra Finch Songbird, Caroline Wan-Yin Ang
Student Theses and Dissertations
The ability to identify and interpret auditory stimuli from the environmental milieu is of particular importance in species that communicate using learned vocalizations. By chronically recording multiunit neuronal responses in awake, behaving zebra finch songbirds, I have demonstrated that the caudomedial neostriatum (NCM), a telencephalic nucleus in the ascending auditory pathway, exhibits responses that range from unselective to highly selective for species-specific stimuli. Sites demonstrating habituating responses are also found and are arranged heterogeneously with selective sites that do not habituate. During the act of singing, activity changes at the habituating sites becoming nonhabituating with neuronal firing occurring at distinct …
Antigenic Variation And Telomere Structure In Trypanosoma Brucei, Jorge Luis Munoz Jordan
Antigenic Variation And Telomere Structure In Trypanosoma Brucei, Jorge Luis Munoz Jordan
Student Theses and Dissertations
Trypanosoma brucei survives immune attack in its mammalian hosts by periodically changing the variant surface glycoprotein (VSG). From the -1000 VSG genes (VSGs) scattered throughout the genome, a few are located at telomere loci called expression sites (ESs) one is expressed at any time, suggesting a stringent regulatory mechanism. Here, it is demonstrated that trypanosomes engineered to express two VSGs simultaneously from the same ES can multiply in cultures and infect animals normally. Mechanisms involved in the control ES-associated gene expression are thought to involve some kind of telomere position effect. Telomeres typically contain simple DNA repeats (TTAGGG in animals …
Mechanisms Of Trafsignaling, Joseph R. Arron
Mechanisms Of Trafsignaling, Joseph R. Arron
Student Theses and Dissertations
This thesis describes the investigation of the mechanisms of signal transduction activated by tumor necrosis factor (TNF) superfamily proteins. Ligands of the TNF family engage TNF receptor (TNFR) family proteins, leading to a wide variety of cellular effects, these interactions are implicated in inflammation, immune regulation, bone homeostasis, and development. TNFR proteins lack intrinsic enzymatic activity, and are coupled to intracellular signaling cascades by TNFR associated factor (TRAF) proteins, which are cytoplasmic adaptor molecules. The roles of TRAF1, TRAF2, and TRAF6 are investigated structurally and functionally in the activation of NF-kB, AP-1, and Src-family kinases. Cbl proteins are identified as …
Impact Of Thymectomy On The Peripheral T Cell Pool In The Context Of Siv Infection, Sarah Tuttleton Arron
Impact Of Thymectomy On The Peripheral T Cell Pool In The Context Of Siv Infection, Sarah Tuttleton Arron
Student Theses and Dissertations
The thymus is the primary lymphoid organ responsible for T cell production. It is of particular interest in the context of human immunodeficiency virus (HIV)-l infection, in which the progressive loss of CD4+ T cells leads to immunodeficiency and opportunistic infection. CD4+ T cell loss is thought to result from direct and indirect killing of C D 4 cells in the periphery as well as from pathogenic effects of the virus on the thymus. However, it is not fully understood which is the greater factor in viral-induced CD4+ T cell decay. The development of an assay to detect T cell …
Receptor- G Protein Interactions In The Visual System: A Study Of Structures And Mechanisms That Couple The Cytoplasmic Surface Of Rhodopsin To The Nucleotide-Binding Pocket Of Transducin, Ethan P. Marin
Student Theses and Dissertations
The intermolecular interaction between the photoreceptor rhodopsin and the heterotrimeric G protein transducin (Gt) initiates the vertebrate phototransduction cascade. This interaction also serves as a model system for the study of the molecular basis of related G protein-coupled receptor mediated signal transduction systems. Photoactivated rhodopsin (R*) activates Gt by catalyzing the exchange of bound G D P for G T P on its alpha subunit (Ga). The structure of the R*-Gt complex and the mechanism of nucleotide exchange are unknown. We studied the function of the fourth cytoplasmic loop (C4) of rhodopsin in interactions with Gt. Chimeric mutants of rhodopsin …
Functional Analysis Of The Human Telomeric Protein Trf2, Agata Smogorzewska
Functional Analysis Of The Human Telomeric Protein Trf2, Agata Smogorzewska
Student Theses and Dissertations
TTAGGG Repeat Binding Factor 2 (TRF2) is a ubiquitous human telomeric protein present at all telomeres throughout the cell cycle. TRF2 has been proposed remodel telomeres into large lasso-like structures named t-loops. Removal of TRF2 from telomeres by expression of a dominant negative allele of TRF2 (TRF2ABAM) led dissolution of these structures and appearance of end-to-end fusions visible in metaphase and anaphase cells. Fusion formation was accompanied by the loss of Goverhang, but not by the loss of double stranded telomeric DNA, which can be documented to persist at the sites of fusions. Fusions were covalent and their formation was …
Genetic And Molecular Analysis Of Islet-And Liver-Enriched Transcription Factors In Metabolism And Development, David Quan Shih
Genetic And Molecular Analysis Of Islet-And Liver-Enriched Transcription Factors In Metabolism And Development, David Quan Shih
Student Theses and Dissertations
Maturity-onset diabetes of the young (MODY) are monogenic forms of type 2 diabetes that are characterized by an early disease-onset, autosomal dominant inheritance, and defects in insulin secretion. Genetic studies have identified mutations in at least six genes associated with different forms of MODY. The majority of the MODY subtypes are caused by mutations in transcription factors that include hepatocyte nuclear factor (HNF)-4α,HNF-1α, PDX-1, HNF-1β, and NEURO-D1/BETA-2. In addition, genetic defects in the glucokinase gene, the glucose sensor of the pancreatic β-cells, and the insulin gene also lead to impaired glucose tolerance. Using molecular and genetic approaches, we demonstrated that …