Digital Commons Network^™

Dna Replication And Cytokinesis In Drosophila Melanogaster, Anton Svitin

All ETDs from UAB

DNA replication and cytokinesis are two important parts of the cell division process. Our studies address different aspects of both of these processes and potential links between them. One of the best approaches for studying DNA replication in eukaryotes has been an analysis in cell free in vitro systems. The existing cell free replication systems for Drosophila are relatively ineffective. In the first part of this work, we have developed an optimized in vitro system to study DNA replication using early egg extracts of Drosophila. Our studies indicate that this system proves to be an extremely useful tool for a …

The Structural And Functional Studies Of Yeast Nucleotide Exchange Factor Sil1p And Its Complex With Bip, Ming Yan

All ETDs from UAB

Sil1 is an Endoplasmic Reticulum (ER) localized protein. SIL1 was initially identified as a UPR-regulated gene. Later studies show Sil1 functions as the nucleotide exchange factor of ER lumenal Hsp70--Bip by directly interacting with the ATPase domain of Bip. Currently, the molecular mechanism how Sil1 catalyzes nucleotide exchange of Bip is still elusive. In this study we determine the complex structure of yeast S.cerevisia Sil1 and Bip (also called Kar2) ATPase domain at 2.3Å resolution by Single-anomalous dispersion (SAD) methods. The Sil1-Bip complex structure reveals that one sil1 molecule interacts with one Bip ATPase domain molecule to form the complex. …

Electroconvulsive Shock Ameliorates Disease Processes And Extends Survival In Huntington Mutant Mice, Akanksha Baharani

Electronic Theses and Dissertations

Huntington's disease (HD) is a devastating autosomal dominantly inherited neurological disorder caused by an abnormal expansion of CAG trinucleotide repeats in the gene coding for the Nterminal region of the huntingtin (Htt) protein, which leads to the formation of a polyglutamine stretch. The greater the CAG repeats, the earlier the onset of the disease. The polyglutamine stretch destabilizes the Htt protein leading to misfolding, abnormal processing, aggregation, and inclusion formation. Mutant Htt protein is believed to damage and kill neurons in the striatum by a mechanism involving increased oxidative and metabolic stress, and impaired adaptive cellular stress responses. A large …

The Role Of Methyl Cpg Binding Domain Protein 2 (Mbd2) In The Regulation Of Embryonic And Fetal Β-Type Globin Genes, Merlin Nithya Gnanapragasam

Theses and Dissertations

The reexpression of the fetal γ-globin gene in adult erythrocytes is of therapeutic interest due to its ameliorating effects in β-hemoglobinopathies. We recently showed that Methyl CpG Binding Domain Protein2 (MBD2) contributes to the silencing of the chicken embryonic ρ-globin and human fetal γ-globin genes. We further biochemically characterized an erythroid MeCP1 complex that is recruited by MBD2 to mediate the silencing of these genes. These observations suggest that the disruption of the MeCP1 complex could augment the expression of the fetal/embryonic globin genes. In the studies presented in chapter 2, we have pursued a structural and biophysical analysis of …

Brms1 Coordinately Regulates Microrna To Suppress Breast, Mick D. Edmonds

All ETDs from UAB

The majority of cancer related mortality is attributed to complications associated with metastatic disease. Breast cancer metastasis suppressor 1 (BRMS1) suppresses metastasis of multiple cancer types in vivo and loss of nuclear BRMS1 is associated with ER-negative cancers and a high rate of proliferation. Many groups have shown BRMS1 to regulate the expression of multiple metastatic genes, yet until now no one has been able to account for how these many changes in gene expression occur. In this work, we report that BRMS1 regulates a select set of genes called microRNA (miRNA), and these miRNA themselves can regulate metastasis. Using …

Generation And Analysis Of The Oncolytic Efficacy Of A Conditionally Replicating Adenovirus Bearing Rgd Modifications On Pix And Fiber Capsid Proteins, Lena Jeanelle Gamble

All ETDs from UAB

Ovarian cancer is the leading cause of gynecological disease death in women. For the past two decades, scientists have attempted to perfect the use of adenovirus as an anti-cancer therapeutic agent. One major impediment to ovarian tumor infection with adenovirus has been dearth of adenovirus native receptor, Coxsackie and Adenovirus receptor, (CAR), on the surface of tumor cells. To address this problem, scientists have engineered CAR-independent adenoviruses which target the AlphavBeta3 and AlphavBeta5 by adding an arginine-glycine-aspartate (RGD) motif to the fiber knob of a conditionally replicating adenovirus (CRAd) Delta24FiberRGD CRAd. We hypothesize that incorporation of RGD into the pIX …

The Role Of Usp14 In Regulating Synaptic Development And Function Of The Neuromuscular Junctions, Ping-Chung Chen

All ETDs from UAB

The ubiquitin proteasome system (UPS) plays critical roles in regulating multiple cellular functions, including protein abundance, trafficking, and cell signaling. In the nervous system, the UPS has been implicated in controlling a wide diversity of cellular process such as synaptic transmission, axon outgrowth, axon targeting, and synapse development. Although impairment of the UPS is observed in both neurodegenerative and developmental diseases, the mechanisms underlying how UPS dysregulation contributes to disease pathogenesis are not known. The proteasome, an approximate 2.5 megadaltons protein complex composed of 19S and 20S assemblies, is the site of ubiquitin-dependent protein degradation. Recent studies have demonstrated dysfunction …

Structural And Functional Study Of P58(Ipk), Jiahui Tao

All ETDs from UAB

P58(IPK) is an endoplasmic reticulum (ER)-resident protein which is upregulated during unfolded protein response (UPR). In stressed cells, P58(IPK) functions to restore protein folding equilibrium in ER by suppressing protein aggregation and promoting protein folding. P58(IPK) associates with the unfolded protein via its N-terminal TPR domain and presents it to BiP (binding immunoglobulin protein) for subsequent folding. P58(IPK) belongs to the Hsp40 family. Collectively, P58(IPK) is a stress-inducible ER-resident molecular chaperone. In this dissertation, we report the crystal structure of P58(IPK) TPR domain to 2.5 Å resolution. In the crystal structure, the 43-kDa TPR domain consists of nine tandemly linked …

Roles Of Adiponectin And Its Receptors In Foam Cell Transformation, Ling Tian

All ETDs from UAB

Macrophages play a critical role in the initiation and progression of atherosclerosis by producing pro-inflammatory mediators and transforming into lipid-laden foam cells. The prevention of lipid accumulation and inflammation in macrophage foam cells, therefore, represents a promising target for effective therapy for atherosclerosis. Adiponectin is a circulating cytokine primarily expressed and secreted by adipocytes, and is downregulated in obesity-linked diseases including type 2 diabetes, coronary artery disease and hypertension. In oxidized low-density lipoprotein (oxLDL)-induced human THP-1 macrophage foam cells, adiponectin suppresses lipid accumulation through decreasing lipid uptake and increasing high-density lipoprotein (HDL)-mediated lipid efflux. The potential mechanisms that adiponectin utilizes …

Functional Determinants Of The Porin Mspa And Its Role In Permeabilizing Mycobacterial Outer Membranes, Jason Huff

All ETDs from UAB

Mycobacterium tuberculosis (Mtb) infects one third of the global population and causes approximately 2,000,000 Tuberculosis-related deaths annually. Mycobacteria are Gram positive organisms but contain a unique outer membrane (OM) which is functionally similar but structurally different from those of Gram negative bacteria. The mycobacterial OM presents an efficient permeability barrier towards hydrophilic solutes. Slow permeation kinetics of hydrophilic molecules through membranes and several discoveries of cell wall channel-forming proteins indicate that mycobacterial OMs are functionalized by proteins. MspA is the primary porin of M. smegmatis and mediates diffusion of small, hydrophilic nutrients and antibiotics across the OM. Unlike porins of …

Role Of The Human Cytomegalovirus Tegument Protein Pp150 In The Trafficking And Assembly Of Infectious Virions, Sabarish Vellatheri Indran

All ETDs from UAB

Human cytomegalovirus, a ubiquitous human pathogen, establishes a persistent infection in the infected host. HCMV assembly takes place in the nucleus and cytoplasm of infected cells by a complex and incompletely defined process. The viral DNA is enclosed by the capsid, which is surrounded by a proteinaceous tegument, which is covered by a cell-derived envelope studded with viral glycoproteins. The assembly pathway and protein interactions required for formation of the tegument layer and the function of most of the proteins in the tegument remain poorly understood. In this study, we investigated the functions of an essential abundant tegument protein, pp150, …

Identification And Characterization Of Virulence Factors Of Mycoplasmas, Wenyi Luo

All ETDs from UAB

Mycoplasmas cause a group of diseases that are characterized by their chronicity and resistance to treatment. Diseases caused by the murine pathogens Mycoplasma pulmonis and Mycoplasma arthritidis are often studied as models of human diseases caused by a variety of chronic pathogens that induce a similar pathology. Among several candidate pathogenic factors, superantigens and degradative enzymes such as glycosidases are potentially important but not well characterized. The M. arthritidis mitogen (MAM) is a superantigen secreted by M. arthritidis. Its role with respect to arthritogenicity and toxicity is unclear. To improve the efficiency of transformation and hence enhance efforts to generate …

Translocation And Function Of Akt In The Mitochondria, Keri A. Mans

All ETDs from UAB

The ubiquitously expressed kinase Akt is a known survival protein, and is involved in multiple cell signaling cascades, notably the phosphatidylinositol 3-kinase (PI3K) pathway. Active Akt translocates from the plasma membrane to different subcellular compartments, including mitochondria, where it phosphorylates compartment-specific substrates. The mechanism of this translocation and the specific function of Akt within the mitochondria remains a mystery. The goals of this study were to elucidate the mechanism by which Akt enters the mitochondria and examine the role of Akt in mitochondrial function. Finally, the possibilities of using post-mortem human brain tissue to study mitochondrial function in normal and …

The Contribution Of Different Mechanisms Of Viral Sequence Variation To The Evolution Of Positive-Sense Single-Stranded Rna Viruses, Brett Earl Pickett

All ETDs from UAB

The Flaviviridae family of positive-sense single-stranded RNA (+ssRNA) viruses includes viral taxa which greatly impact public health worldwide. To explore how the viruses within the Flaviviridae family evolve, we examined the extent to which these viral taxa use nucleotide covariance, spontaneous mutation, and/or homologous recombination to vary their genotype as well as the resulting phenotype. We developed and used CovarView to assist us in simultaneously viewing and inspecting the results from whole genome covariance analyses. This resulted in the identification of previously-characterized RNA functional structures in the genomes of hepatitis C virus (HCV), as well as a new RNA functional …

Effect Of Overexpressing Apolipoprotein A-I In An Animal Model Of Alzheimer's Disease, Terry L. Lewis

All ETDs from UAB

Apolipoprotein A-I (apoA-I) is the major protein component of high density lipoprotein (HDL) in circulation and is expressed mainly by the liver and intestine. The levels of apoA-I/HDL are inversely related to the incidence of cardiovascular disease. Because of the connections between heart disease and Alzheimer's disease (AD), it is conceivable that high levels of apoA-I/HDL may be protective against AD. However, the limited literature shows mixed results on the role of apoA-I/HDL in the development of AD. It is hypothesized that increased expression of human apoA-I will ameliorate the behavioral deficits and characteristic amyloid-ß (Aß) plaque formation in a …

Morphological Development Of The Axial Skeletons Of Esox Lucius And Esox Masquinongy (Euteleostei: Esociforms), With Comparisons In Developmental And Mineralization Rates., Amanda Maria Burdi

Master's Theses

Developmental morphology of the axial skeleton of Esox lucius (i.e., northern pike and type species) and E. masquinongy (i.e., muskellunge) was investigated. More than 1,000 specimens were examined ranging in size from approximately 10 mm notochordal length (NL) post-hatching juveniles to over 80 mm standard length (SL) foraging sub-adults. Results show that regardless of individual variation, the relative sequence of bone formation and mineralization is consistent between the two species. This consistent developmental pattern enabled construction of an ontogenetic staging scheme of eight developmental stages, each characterized by one defining criterion. The first appearance in cartilage and/or first sign of …

The Role Of Synaptically Evoked Plateau Potentials In Retinogeniculate Development, Emily Dilger

Theses and Dissertations

We study the activity-dependent refinement of sensory systems by using the mouse retinogeniculate system as a model. Spontaneous retinal waves lead to robust excitatory post-synaptic activity in developing relay cells in the dorsal lateral geniculate nucleus (dLGN) of the thalamus and are reportedly needed to help guide the segregation of retinal inputs into eye-specific domains as well as for the pruning of extraneous retinal inputs onto single dLGN relay cells. The composition of retinally evoked post-synaptic activity activated by these retinal waves in dLGN is largely unknown, but based on our in vitro recordings, such activity seems well suited to …

Subacute Neural Stem Cell Therapy For Traumatic Brain Injury, Mikhail Bogdanov, Philip N Heacock, William Dowhan

Faculty, Staff and Student Publications

A protocol is described using lipid mutants and thiol-specific chemical reagents to study lipid-dependent and host-specific membrane protein topogenesis by the substituted-cysteine accessibility method as applied to transmembrane domains (SCAM). SCAM is adapted to follow changes in membrane protein topology as a function of changes in membrane lipid composition. The strategy described can be adapted to any membrane system.

Biochemical Characterization Of Human Mismatch Recognition Proteins Mutsα And Mutsβ, Lei Tian

University of Kentucky Doctoral Dissertations

The integrity of an organism's genome depends on the fidelity of DNA replication and the efficiency of DNA repair. The DNA mismatch repair (MMR) system, which is highly conserved from prokaryotes to eukaryotes, plays an important role in maintaining genome stability by correcting base-base mismatches and insertion/deletion (ID) mispairs generated during DNA replication and other DNA transactions. Mismatch recognition is a critical step in MMR. Two mismatch recognition proteins, MutSα (MSH2-MSH6 heterodimer) and MutSβ (MSH2-MSH3 heterodimer), have been identified in eukaryotic cells. MutSα and MutSβ have partially overlapping functions, with MutSα recognizing primarily base-base mismatches and 1-2 nt ID mispairs …

Neural Mechanisms Of Sympathetic Activation During Hyperinsulinemia And Obesity-Induced Hypertension, Megan Elyse Bardgett

University of Kentucky Doctoral Dissertations

Obesity afflicts more than 30% of the U.S. population and is a major risk factor for the development of hypertension, type II diabetes, and cardiovascular disease. Studies in humans and animals indicate that obesity is associated with increased sympathetic outflow to the vasculature and kidneys. One mechanism postulated to underlie the increase in sympathetic nerve activity (SNA) in obesity is hyperinsulinemia. Little is known regarding the central circuitry underlying elevated SNA and arterial blood pressure (ABP) during hyperinsulinemia and obesity or if sympathoexcitatory circuits are still responsive to insulin in obesity.

Hyperinsulinemic-euglycemic clamps elevate SNA to the hind limb vasculature …

Authentication Of Biometric Features Using Texture Coding For Id Cards, Jonathan Blackledge, Eugene Coyle

Conference papers

The use of image based information exchange has grown rapidly over the years in terms of both e-to-e image storage and transmission and in terms of maintaining paper documents in electronic form. Further, with the dramatic improvements in the quality of COTS (Commercial-Off-The-Shelf) printing and scanning devices, the ability to counterfeit electronic and printed documents has become a widespread problem. Consequently, there has been an increasing demand to develop digital watermarking techniques which can be applied to both electronic and printed images (and documents) that can be authenticated, prevent unauthorized copying of their content and, in the case of printed …

Pk/Pd Modelling Of Comb-Shaped Pegylated Salmon Calcitonin Conjugates Of Differing Molecular Weights, Sinead Ryan, Jesus Maria Frias, David H. Haddleton, David J. Brayden

Articles

Salmon calcitonin (sCT) was conjugated via cysteine-1 to novel combed-shaped end-functionalised poly(PEG) methyl ether methacrylate) (sCT-P) comb-shaped polymers, to yield conjugates of total molecular weights (MW) inclusive of sCT: 6.5, 9.5, 23 and 40 kDa. The conjugates were characterised by HPLC and their in vitro and in vivo bioactivity was measured by cAMP assay on human T47D cells and following intravenous (i.v.) injection to rats, respectively. Stability against endopeptidases, rat serum and liver homogenates was assessed. There were linear and exponential relationships between conjugate MW with potency and efficacy respectively, however the largest MW conjugate still retained 70% of E …

Early Detection Of Response To Hydroxyurea Therapy In Patients With Sickle Cell Anemia., Samir K. Ballas, William F. Mccarthy, Nan Guo, Carlo Brugnara, Gail Kling, Robert L. Bauserman, Myron A. Waclawiw

Department of Medicine Faculty Papers

Red blood cells (RBC) and reticulocyte parameters were determined on peripheral blood from a subset of patients enrolled in the multicenter study of hydroxyuea (HU) in sickle cell anemia. Multiple blood samples were obtained every 2 weeks. Cellular indices were measured by flow cytometry. Generalized linear models were used to determine the relationship between the longitudinal trajectories of RBC and reticulocyte indices and HU usage. There was a significant relationship between HU usage and most of the RBC and reticulocyte indices. Hydroxyurea produced higher value trajectories than those generated by placebo usage for the hemoglobin (Hb) content of both the …

Differential Genome-Wide Array–Based Methylation Profiles In Prognostic Subsets Of Chronic Lymphocytic Leukemia, Meena Kanduri, Nicola Cahill, Hanna Göransson, Camilla Enström, Fergus Ryan, Anders Isaksson, Richard Rosenquist

Articles

Global hypomethylation and regional hypermethylation are well-known epigenetic features of cancer; however, in chronic lymphocytic leukemia (CLL), studies on genome-wide epigenetic modifications are limited. Here, we analyzed the global methylation profiles in CLL, by applying high-resolution methylation microarrays (27 578 CpG sites) to 23 CLL samples, belonging to the immunoglobulin heavy-chain variable (IGHV) mutated (favorable) and IGHV unmutated/IGHV3-21 (poor-prognostic) subsets. Overall, results demonstrated significant differences in methylation patterns between these subgroups. Specifically, in IGHV unmutated CLL, we identified methylation of 7 known or candidate tumor suppressor genes (eg, VHL, ABI3, and IGSF4) as well as 8 unmethylated genes involved in …

Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets With Alopecia Resulting From A Novel Missense Mutation In The Dna-Binding Domain Of The Vitamin D Receptor., Peter J. Malloy, Jining Wang, Tarak Srivastava, David Feldman

Manuscripts, Articles, Book Chapters and Other Papers

The rare genetic recessive disease, hereditary vitamin D resistant rickets (HVDRR), is caused by mutations in the vitamin D receptor (VDR) that result in resistance to the active hormone 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3) or calcitriol). In this study, we examined the VDR from a young boy with clinical features of HVDRR including severe rickets, hypocalcemia, hypophosphatemia and partial alopecia. The pattern of alopecia was very unusual with areas of total baldness, adjacent to normal hair and regions of scant hair. The child failed to improve on oral calcium and vitamin D therapy but his abnormal chemistries and his bone X-rays normalized …

Autotaxin: A Regulator Of Oligodendrocyte Differentiation, Larra Yuelling

Theses and Dissertations

In order for oligodendrocyte progenitor cells (OPCs) to differentiate into fully mature, myelinating oligodendrocytes, they must be specified at the correct times and undergo coordinated changes in both gene expression and morphology. As oligodendrocytes differentiate, they transition from a bipolar morphology into a morphology characterized by a complex network of multiple processes, which will eventually generate membranous structures necessary for myelination of axonal segments. As changes are observed in cellular morphology, oligodendrocytes also undergo changes in their gene expression profile and express genes necessary for both early and later stages of development such as olig1 and myelin basic protein (mbp), …

Treatment Strategies In Acute Myelogenous Leukemia : Investigating Hsp90 And P53 As Targets, Jennifer M. Napper

Theses, Dissertations and Capstones

Acute myelogenous leukemia (AML) is the deadliest of the lymphatic and bone marrow cancers. Patients diagnosed with AML have a five year survival rate of 23.4%. AML is characterized by an accumulation of undifferentiated and functionless myeloid precursors in the bone marrow and blood. Heat shock protein 90 (Hsp90) inhibitors, such as 17-AAG, an analog of geldanamycin (GM), are currently undergoing phase I, and II and III clinical trials for various cancers with mixed results. I found distinct responses to 17-AAG treatment among the AML cell lines tested. I also discovered two mutant TP53 alleles in Kasumi-3 cells, an AML …

Glucocorticoid-Remediable Aldosteronism: An Uncommon And Often Overlooked Cause Of Adrenal Hypertension, Sindhu Bhat Md, Larry N. Merkle Md

Department of Medicine

No abstract provided.

T Cell Receptor Cross-Reactivity Directed By Antigen-Dependent Tuning Of Peptide-Mhc Molecular Flexibility, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Brian E. Gloor, Daniel R. Scott, Ruth F. Sommese, David K. Cole, Andrew K. Sewell, Brian M. Baker

Food for Health: Publications

Tell mediated immunity requires T cell receptor (TCR) cross-reactivity, the mechanisms behind which remain incompletely elucidated. The αβ TCR A6 recognizes both the Tax (LLFGYPVYV) and Tel1p (MLWGYLQYV) peptides presented by the human class I MHC molecule HLA-A2. Here we found that although the two ligands are ideal structural mimics, they form substantially different interfaces with A6, with conformational differences in the peptide, the TCR, and unexpectedly, the MHC molecule. The differences between the Tax and Tel1p ternary complexes could not be predicted from the free peptide-MHC structures and are inconsistent with a traditional induced-fit mechanism. Instead, the differences were …

Structural Characterization Of The C-Terminus Of The Cochlear Motor Protein Prestin: Intrinsic Disorder Linked To Voltage Sensor Function, Michael S. Podgorski

Theses and Dissertations (ETD)

The sensitivity of mammalian hearing relies upon the ability to amplify sound. Outer hair cells (OHCs) in the cochlea have motile properties that support this function. The motor protein called prestin resides in the lateral wall of the OHCs. Prestin undergoes voltage-dependent conformational changes, which correlates to the movement of charge through the membrane or non-linear capacitance (NLC). This property underlies OHC electromotility. A mechanistic understanding of prestin’s function remains unknown. Previous research has tied prestin’s C-terminus (residues 499-799) to the voltage-dependent events that occur in the membrane. The folding and biochemical properties of prestin’s C-terminus were characterized. This information …