Molecular Biology Commons^™

The 2Β Insert Perturbs Folding, Stability And Hydrophobic Exposure Of Stromal Interaction Molecules, Steve Chung

Electronic Thesis and Dissertation Repository

Stromal interaction molecule (STIM)1 and 2 regulate agonist-induced and basal cytosolic calcium (Ca2+) levels through oligomerization and translocation to endoplasmic reticulum (ER)-plasma membrane (PM) junctions. At these junctions, the STIM cytosolic coiled-coil domains couple to PM Orai1 protein subunits to form Ca2+ released activated Ca2+ (CRAC) channels that facilitate store-operated Ca2+ entry (SOCE). One splice variant of STIM2, STIM2β, contains an extra 8-residue (2β insert) located within the coiled-coils and inhibits SOCE through an unresolved mechanism, adding another layer of complexity to Ca2+ regulation in mammals. I hypothesize that the 2β insert perturbs the coiled-coil conformation and dynamics commensurate with …

Characterization Of Interleukin (Il)-1Β Regulatory Elements And Chromatin Conformation In Macrophage Activation, Woohyun Cho

Electronic Thesis and Dissertation Repository

IL-1β is a potent inflammatory cytokine promptly expressed in activated myeloid cells. PU.1 is a lineage-determining transcription factor that regulates myeloid-specific genes by activating distal enhancers. This study addresses the functional importance of a potential enhancer of IL-1β, and how PU.1 regulates its activity state. A putative enhancer RNA (eRNA) was transcribed from the enhancer, and eRNA knock-down with antisense oligonucleotides inhibited IL-1β production. Furthermore, enhancer-promoter interactions in stimulated macrophages were detected via chromatin conformation capture (3C) analysis. The role of PU.1 was examined in PU.1-overexpressed B16-BL6 cells, which responded to LPS and expressed IL-1β mRNA and eRNAs. Enhancer knock-out …

Production Of A Candidate Recombinant Protein Vaccine For Mannheimia Haemolytica In Lettuce And Tobacco Chloroplasts, Coby K. Martin

Electronic Thesis and Dissertation Repository

The cattle industry worldwide is ravaged by bovine respiratory disease (BRD), a bacterial disease caused by Mannheimia haemolytica. Recent efforts to design vaccines against M. haemolytica focus on a virulence factor, leukotoxin, in addition to surface lipoproteins. Plant-based protein production is a safe and inexpensive alternative to traditional methods. Edible vaccines deliver antigens to pharyngeal tissues, which can provide local immunization against M. haemolytica prior to its progression into the lungs. In this project, a chimeric protein containing M. haemolytica antigens was produced in tobacco chloroplasts as a candidate edible vaccine for BRD. Attempts were made to transform lettuce …

Effects Of G Protein Signalling Modulator 3 On Cellular Signalling, Aneta A. Surmanski

Electronic Thesis and Dissertation Repository

G protein coupled receptors (GPCRs) promote G protein heterotrimer (Gα·GDP/Gbg) activation.GPCRsignalling is limited via G protein GTPase activity and b-arrestin-receptor interactions. G Protein Signalling Modulators (GPSMs) are proteins that may influence receptor signalling through G protein activity. GPSM3 modulates their activity by binding to Ga_i-GDP, limiting nucleotide exchange and preventing its re-association to Gbg. The impact of GPSM3 on signalling is unknown.We hypothesize that GPSM3 will decrease Ga_i-dependent signalling while promoting Gbg-dependent signalling in G_i-coupled GPCRs.

GPSM3 significantly inhibited b-arrestin recruitment to α_2A-adrenergic and m-opioid receptors via a Gbg-dependent mechanism, …

Defective Aba-Mediated Sugar Signalling Pathway In An Established Arabidopsis Thaliana Cell Suspension Culture Explains Its Stay-Green Phenotype At High Sugar Concentrations, Avery Mccarthy

Electronic Thesis and Dissertation Repository

An unusual sugar insensitive phenotype was identified in an established cell suspension culture of Arabidopsis thaliana. We characterized the physiology, biochemistry and genetics of the sugar insensitive cell culture, in order to identify factors contributing to the phenotype. Chlorophyll levels of the cell suspension culture were insensitive to high sucrose (6-15% w/v) and maintained a green phenotype. Immunoblotting indicated that levels of key photosynthetic proteins (PsaA, Lhcb2 and Rubisco) increased as a function of external sucrose concentration. The green cell culture was photosynthetically competent based on light-dependent, CO₂-saturated rates of O₂ evolution as well as Fv/Fm …

Detecting A-Series Ganglioside Expression Profile Changes During Microglial Activation, Mona M. Alshaikh

Electronic Thesis and Dissertation Repository

With aging, our brains become more susceptible to disease and injury. Different regions of the brain have differing levels of vulnerability to stress and injury, and this brain region-dependent variability to vulnerability could be partly explained by the existence of glycosphingolipids within the cell’s plasma membrane called gangliosides. Gangliosides are expressed predominantly within the brain and play various roles within the central nervous system including neural repair, cell survival, and neurodegeneration. Our laboratory has demonstrated that gangliosides can shift their composition from GM1 back to GM2 and GM3 following stroke in mice and rats indicating a role for simple gangliosides …

Functional And Structural Mimicry Of A-Kinase Anchoring Proteins By Human Adenovirus E1a, Cason R. King

Electronic Thesis and Dissertation Repository

As an obligate intracellular parasite, human adenovirus (HAdV) must utilize host factors for survival and replication. Early during infection, its multifunctional E1A protein interacts with an impressive range of cellular target proteins to exert control over the cellular environment. Through these virus-host interactions, E1A massively reprograms both viral and cellular transcription to activate the other HAdV genes, downregulate the host’s immune response, and induce the cell cycle. Consequently, E1A converts the infected cell into a compliant state more amenable for HAdV replication, resulting from its numerous protein-protein interactions. I sought to examine E1A’s interaction with cellular protein kinase A (PKA), …

Characterizing The Role Of Thymine Dna Glycosylase In Transcriptional Regulation And Cancer In Vivo, Mohammad Haider Hassan

Electronic Thesis and Dissertation Repository

Cytosine methylation (5mC) is essential for transcriptional control and genomic stability and is often used as a prognostic marker in cancer. Although 5mC has long been considered a relatively stable epigenetic mark, recent studies have demonstrated that it can be reversed enzymatically by TET proteins which oxidize 5mC into 5-hydroxymethylcytosine (5-hmC), and then to 5-formylcytosine (5-fC) and 5-carboxylcytosine (5caC). This mechanism is known as active DNA demethylation and the base excision repair enzyme Thymine DNA Glycosylase (TDG) plays an essential role in this process by removing 5-fC and 5-caC which are subsequently replaced by the unmethylated cytosine. Importantly, homozygous loss …