Life Sciences Commons^™

Molecular Mechanisms Of Aberrant Protein Glycosylation In Pancreatic Cancer Stemness And Metastasis, Frank Leon

Theses & Dissertations

A myriad of genetic and other abnormal changes underlies the aggressiveness and dissemination properties observed in pancreatic cancer (PC). Aberrant protein glycosylation is a commonly observed feature in PC. The modification of protein O-glycosylation is mediated by glycosyltransferases, which attach and sequentially elongate monosaccharides on Serine/Threonine (Ser/Thr) motifs. Aberrant glycosylation is recognized as an emerging hallmark of cancer where a disruption in normal glycosylation results in irregular O-glycans.

This dissertation research has investigated the consequences of aberrant protein glycosylation on stemness and enhancement of metastatic properties in pancreatic ductal adenocarcinoma (PDAC). Several publications have reported aberrant O-glycosylation increases in oncogenic …

Purification And Functional Characterization Of The Iron-Responsive Transcription Factor Aft1 From C. Glabrata, Jade Ikahihifo-Bender

Senior Theses

Due to its unique ability to serve as both an electron donor and acceptor, iron is utilized as a co-factor for many biological processes, including electron transfer, oxygen binding, and vitamin synthesis. Iron is also a key factor during fungal infections as the human host and invading pathogens battle over limited iron pools. The primary iron-responsive transcription factor Aft1 in the opportunistic pathogenic yeast Candida glabrata responds to iron deficiency by activating expression of iron acquisition genes. However, the mechanisms for sensing intracellular iron levels and regulating Aft1 activity in response to iron are unknown. The C. glabrata iron regulation …

Lions, Tigers, And Hemes - Oh My! A Dynamic Look At The Electronic Effects Of Porphyrin Substitution On Cytochrome P450 Olet, Alexis J. Holwerda

Senior Theses

OleT, a member of the CYP152 family of cytochrome P450s (CYPs), decarboxylates fatty acids using hydrogen peroxide as an oxidant. The resultant products are a terminal alkene and carbon dioxide. This C–C cleavage reaction is highly atypical for CYPs, which prototypically oxygenate substrates, and provides a potential means to enzymatically produce drop-in fuels. OleT contains a heme-iron cofactor that facilitates decarboxylation through the activation of hydrogen peroxide. The catalytic cycle, as determined by transient kinetics, includes two ferryl intermediates known as Compound I (Ole-I) and Compound II (Ole-II). Ole-I performs substrate hydrogen abstraction and subsequent single electron transfer to Ole-II …

Microsatellites And Their Association With Break Induced Replication, French J. Damewood Iv

Browse all Theses and Dissertations

To study microsatellites instability and their repair pathways a dual fluorescent (DF2) and selectable (ganciclovir sensitive/ thymidine kinase (TK) expressing) cell system was assayed using replication fork stalling agents hydroxyurea and telomestatin. These cell lines carried ectopically integrated microsatellites derived from the Dystrophia Myotonica Protein Kinase (DMPK) gene ((CTG)102 microsatellite), or an 88 bp polypurine/ polypyrimidine (Pu/Py) repeat from the PKD-1 locus, inserted into a FLP recombinase target site. These microsatellites form non-B DNA structures in -vivo and in-vitro causing replication fork stalling and double strand breaks. DF2 myc (CTG)102 -TK cells treated with hydroxyurea were assayed for mutagenesis of …

Enzymatic Post-Translational Halogenation For Adding Functionality To Biomaterials, Alexander L. Compean

Browse all Theses and Dissertations

Silk fibroin from the silkworm, Bombyx mori, is a unique biomaterial that has been extensively studied for a variety of applications due to its promising properties such as controllable self-assembly, robust mechanical properties, and biological compatibility. Previously, there have been numerous methods describing the chemical modification of silk fibroin that utilize synthetic or enzymatic means that do not use halogens as a means of functionalization. Herein, a halogenation strategy is presented to modify silk fibroin with the aim of developing a novel functional material through the carbon-halogen (C-X) bond. Modification with NaX (X = Cl, Br, and I) salts, hydrogen …

Development Of Linked-Domain Protein Inhibitors Of The E2-Conjugating Enzyme Ube2d, Anneroos E. Nederstigt

University of the Pacific Theses and Dissertations

In most eukaryotic organisms, the ubiquitination pathway is one of the most important and versatile signaling systems in use. It is integral to processes such as protein degradation and homeostasis, DNA repair cell cycle regulation, signaling and regulation, epigenetics, and many more. Ubiquitin (Ub) is a short polypeptide of 8.6 kDa, 76 residues that functions as a reversible post-translation modification (PTM). It furthermore contains 7 different lysine residues (K6, K11, K27, K29, K33, K48, K63), all of which can form isopeptide linkages with one another to link individual Ub moieties to form unique polyUb chains onto substrates. The type of …

The F-Box Protein Fbw7 Negatively Regulates The Stability Of Erk3 Protein, Nicole Walters

Browse all Theses and Dissertations

Extracellular signal-regulated kinase 3 (ERK3) is a member of the atypical mitogen-activated protein kinase (MAPK) subfamily, whose members have been shown to play important roles in a number of cellular processes including proliferation, differentiation, migration, and apoptosis. While signals regulating ERK3 kinase activity remain unclear, ERK3 is known to be an unstable protein with function tightly regulated via ubiquitination and proteasomal turnover. The deubiquitinating enzyme USP20 has been shown to regulate ERK3 by stabilizing the kinase, but presently, no destabilizing ubiquitin ligases have been identified. The SKP1-CUL1-F-box protein (SCF) E3 ligases are a subfamily of ubiquitin E3 ligases composed of …

Quantitated Effects Of Nutritional Supplementation On Exercise Induced Sweat, Andrew Blake Austin Browder

Browse all Theses and Dissertations

Discovery studies have identified many metabolites contained in human sweat. However, quantitative analysis of the sweat metabolome content remains mostly unknown. Furthermore several attributes, including rate, have been defined to affect sweat metabolite content, while other effectors, like diet, remain unknown. This study works to quantitatively define the metabolite impact caused by nutritional supplementation. To better understand the effect diet plays, a LC-MS method was developed focusing on improving resolution and peak width. While the literature provided examples of how diet affected sweat metabolite concentrations, the long-term effects of diet have not been explored. The experiment described here attempts to …

Microsatellites And Their Association With Break Induced Replication, French J. Damewood Iv

Browse all Theses and Dissertations

To study microsatellites instability and their repair pathways a dual fluorescent (DF2) and selectable (ganciclovir sensitive/ thymidine kinase (TK) expressing) cell system was assayed using replication fork stalling agents hydroxyurea and telomestatin. These cell lines carried ectopically integrated microsatellites derived from the Dystrophia Myotonica Protein Kinase (DMPK) gene ((CTG)102 microsatellite), or an 88 bp polypurine/ polypyrimidine (Pu/Py) repeat from the PKD-1 locus, inserted into a FLP recombinase target site. These microsatellites form non-B DNA structures in -vivo and in-vitro causing replication fork stalling and double strand breaks. DF2 myc (CTG)102 -TK cells treated with hydroxyurea were assayed for mutagenesis of …

Potential Drug Treatment For Duchenne Muscular Dystrophy Which Could Be Through Upregulation Of Lipin1, Rajsi Y. Thaker

Browse all Theses and Dissertations

Duchenne muscular dystrophy (DMD) is a genetic disorder leading to progressive muscle degeneration and weakness due to mutation in dystrophin gene, which is very important for maintaining muscle membrane integrity. Dystrophin is the largest gene in the human genome therefore more prone to mutation. There is currently no cure for DMD. Our lab recently found that Lipin1 deficient myofibers showed upregulation of necroptosis correlated with the loss of muscle membrane integrity. Our primary approach for ameliorating dystrophic phenotype in DMD is through reduction of necroptosis using drugs which can potentially upregulate Lipin1 expression. In this study, we identified two drugs …