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Articles 31 - 46 of 46

Full-Text Articles in Molecular Biology

Dietary Carbohydrates Influence The Structure And Function Of The Intestinal Alpha-Glucosidases, Mohammad Chegeni Oct 2014

Dietary Carbohydrates Influence The Structure And Function Of The Intestinal Alpha-Glucosidases, Mohammad Chegeni

Open Access Dissertations

As the primary products of starch digestion by pancreatic α-amylase, maltooligosaccharides (including maltose) are the main substrates for the α-glucosidases at the intestinal brush border. Here, maltose was shown to induce the formation of a higher molecular weight (HMW) sucrase-isomaltase (SI) species in Caco-2 cells that sorts more quickly to the enterocyte surface to act as a digestive enzyme. As this finding suggested a maltose sensing ability of small intestinal enterocytes, molecular mechanisms associated with the maturation and trafficking of HMW SI were further investigated. A pulse-chase experiment using [ 35S]-methionine revealed a higher rate of early trafficking and …


New Strategies To Reveal Protein Candidates In Protein-Protein Interactome Study, Meng-Chieh Chen Oct 2014

New Strategies To Reveal Protein Candidates In Protein-Protein Interactome Study, Meng-Chieh Chen

Open Access Theses

Comprehensive protein-protein interaction network analysis can help reveal protein functions in a system-wide manner. A reliable knowledgebase of interaction networks is not only important for selecting the candidates for drug therapies, but also for evaluating the disease risk. In current interaction databases, 322579 interactions comprised of 56460 proteins have been reported (statistical analysis from APID: Agile Protein Interaction DataAnalyzer; http://bioinfow.dep.usal.es/apid/index.htm). The huge datasets are contributed mainly by yeast -two -hybrid (Y2H) screening and affinity-purification followed by mass spectrometry (AP-MS). High false positive rates and failing to cover certain interaction categories are the limitations of these two methods. Here, we developed …


Effects Of Altered Expression Of The Sumo Conjugating Enzyme, Ubc9 On Mitosis, Meiosis And Conjugation In Tetrahymena Thermophila, Qianyi Yang Oct 2014

Effects Of Altered Expression Of The Sumo Conjugating Enzyme, Ubc9 On Mitosis, Meiosis And Conjugation In Tetrahymena Thermophila, Qianyi Yang

Open Access Dissertations

SUMOylation is a critical posttranslational modification in eukaryotic species. Ubc9p is the E2-conjugating enzyme for SUMOylation and consequently it influences multiple cellular pathways. Nuclear proteins are common targets of SUMOylation and regulate nuclear events such as transcription, DNA repair and mitosis. The segregation of the Tetrahymena thermophila genome into two different nuclear compartments provides an unusual context for the analysis of SUMOylation. Each cell contains a transcriptionally silent, diploid germ line micronucleus (MIC) that divides by mitosis and a polyploid transcriptionally active somatic macronucleus (MAC) that divides by an amitotic mechanism. With the long-term goal to exploit these opportunities we …


Determining The Binding Between Saga Subunits And Spliceosomal Components, Peyton J. Spreacker, Rachel L. Stegeman, Vikki M. Weake Aug 2014

Determining The Binding Between Saga Subunits And Spliceosomal Components, Peyton J. Spreacker, Rachel L. Stegeman, Vikki M. Weake

The Summer Undergraduate Research Fellowship (SURF) Symposium

Proper gene regulation is vital to the health and development of an organism. Determining the relationship between splicing, transcription, and chromatin structure is vital for understanding gene regulation as a whole. There have been previous studies linking these elements pairwise; however, no evidence exists for a direct link between all three. Recent data shows that splicing components of the U2 small nuclear ribonucleic protein (snRNP) co-purify with Spt-Ada-Gcn5-acetyltransferase (SAGA), a highly conserved transcriptional co-activator and chromatin modifier. We hypothesize that SAGA binds with splicing components through a multi-protein binding surface with certain core components based on preliminary yeast two-hybrid data. …


1,25-Dihydroxyvitamin D Alters Lipid Metabolism And Epithelialto- Mesenchymal Transition In Metastatic Epithelial Breast Cancer Cells, Alle Nicole Barnard Jul 2014

1,25-Dihydroxyvitamin D Alters Lipid Metabolism And Epithelialto- Mesenchymal Transition In Metastatic Epithelial Breast Cancer Cells, Alle Nicole Barnard

Open Access Theses

Evidence suggests that high vitamin D status (marked by serum 25-hydroxyvitamin D, 25(OH)2 D) is associated with a decreased risk of breast cancer. It has been established that 1,25-dihydroxyvitamin D (1,25(OH) 2 D) can alter glycolysis and the Krebs cycle of breast cancer cells (Jiang et al., 2010; Zheng et al., 2013) but little information is available on 1,25(OH) 2 D's alterations of lipid metabolism in breast cancer cells. Thus, the current research investigates if there was an effect of 1,25(OH) 2 D on proteins that regulate lipid metabolism in MCF10A, MCF10A-ras, MCF10CA1h, and MCF10CA1a epithelial breast cancer cells. While …


Key Residues Of Human Cytoplasmic Protein Tyrosine Phosphatase-A And -B For Substrate Binding And Specificity, Byunghyun Park Jul 2014

Key Residues Of Human Cytoplasmic Protein Tyrosine Phosphatase-A And -B For Substrate Binding And Specificity, Byunghyun Park

Open Access Theses

Reversible tyrosine phosphorylation plays an important role in signaling pathways that are essential for regulating cellular growth, differentiation and metabolism. Moreover, several human diseases such as diabetes, obesity and cancers are associated with the deregulation of protein tyrosine phosphatases (PTPs). Several studies provide evidence that PTPs not only contribute to cellular differentiation, but over-expression of these molecules also leads to transformation of non-transfomed cells as well. Based on these results, designing specific PTP inhibitors may ultimately function as potential therapeutic agents to treat various diseases including cancer, diabetes, and autoimmune diseases. EphA2 is a receptor tyrosine kinase which is hypo-phosphorylated …


Neurotrophins And Their Effects On Breast Cancer Cell Proliferation And Migration, Kayla Elise Minser Apr 2014

Neurotrophins And Their Effects On Breast Cancer Cell Proliferation And Migration, Kayla Elise Minser

Open Access Theses

Cancer is a large health issue in all parts of the world. In the United States alone, approximately 1 in 4 deaths are cancer related. Breast cancer is a particularly prevalent form, accounting for a little over 14 percent of all cancer incidence. The largest obstacle to overcome for breast cancer morbidity is metastasis. Over 90 percent of all breast cancer related deaths are due to metastasis. Because metastasis is a complex, multi-step process, it is difficult to treat. A recent observation in the Kirshner lab has revealed a type of phenotypic plasticity, where migratory cancer cells have a neuronal-like …


Pharmaceuticals And Personal Care Products: Emerging Contaminants In Aquatic Ecosystems, Jenny E. Zenobio Apr 2014

Pharmaceuticals And Personal Care Products: Emerging Contaminants In Aquatic Ecosystems, Jenny E. Zenobio

Open Access Theses

In recent years, the presence of pharmaceuticals and personal care products (PPCPs) in aquatic systems has led to research on their fate and effects. PPCPs have been found in mixture in wastewater effluents, surface, ground, and drinking water at low concentrations from areas of intense urbanization. Although adverse effects to human health from the current environmental concentrations are unlikely, the impacts to ecological receptors are not clear. We performed field and laboratory studies to quantify and evaluate effects of PPCPs on fish. First, a field study was conducted at the Baca National Wildlife Refuge, Colorado (2010-2012) because a portion of …


Cellular Uptake Mechanism Of Paclitaxel Nanocrystals, Iris K. Archer, Zhaohui Wang, Tonglei Li Oct 2013

Cellular Uptake Mechanism Of Paclitaxel Nanocrystals, Iris K. Archer, Zhaohui Wang, Tonglei Li

The Summer Undergraduate Research Fellowship (SURF) Symposium

Therapeutic options for metastasized human cancer in current practice remain limited and, sadly, there is no cure for metastatic cancer. The typical approach, chemotherapy, has both low efficacy due to poor drug solubility, and cytotoxic side effects to healthy tissue when delivered indiscriminately. To address both of these issues, we are pursuing the use of nanocrystal formulations of current chemotherapeutic agents as delivery platforms. Herein, we have studied cellular uptake mechanisms in cancer cells of nanocrystals of a chemotherapeutic agent, paclitaxel. Our goal in this study is to determine whether the nanocrystals can be taken up via endocytosis, especially when …


The Termite Digestome: Understanding The Digestive Physiology Involved In Lignocellulosic Biomass Degradation, Zachary John Karl Oct 2013

The Termite Digestome: Understanding The Digestive Physiology Involved In Lignocellulosic Biomass Degradation, Zachary John Karl

Open Access Dissertations

The purpose of this research was to advance the understanding of lower termite digestive physiology and discover potential biocatalysts that can aid in the degradation of lignocellulosic biomass. Various protein characterization and gene expression methods were used throughout this research in order to accomplish these objectives. The results of this dissertation indicate that: 1) termites and their symbionts act in a synergistic manner to degrade biomass in vitro, 2) the host fraction of the gut (i.e., foregut and midgut) is the likely site of glucose absorption, 3) the termite and its symbionts contribute specific enzymes to the digestive process, 4) …


Genetic Engineering Of Black Cherry (Prunus Serotina) For Reproductive Sterility And Insect Pest Resistance, Ying Wang Oct 2013

Genetic Engineering Of Black Cherry (Prunus Serotina) For Reproductive Sterility And Insect Pest Resistance, Ying Wang

Open Access Dissertations

Black cherry (Prunus serotina Ehrh.) is one of the most valuable hardwoods for high- end cabinetry, furniture, architectural millwork, paneling, and veneer. However, the damage caused by cambial-mining insect pests triggers gummosis in black cherry, a non-specific defense response in which resinous gum is deposited at the site of injury. The gum defects dramatically decrease the yield of high-quality black cherry lumber, and the value can be reduced by as much as 90%. The goal of this project was to optimize the transformation and in vitro rooting system, and to develop transgenic black cherry for reproductive sterility and insect pest …


Characterization Of Caxck31, A Bacterial Calcium/Proton Antiporter, Marc Robert Ridilla Oct 2013

Characterization Of Caxck31, A Bacterial Calcium/Proton Antiporter, Marc Robert Ridilla

Open Access Dissertations

To better understand a class of transporters known as Calcium/Cation Antiporters (CaCAs), the bacterial calcium/proton antiporter CAXCK31 was purified and characterized. New methods were developed for its heterologous overexpression and purification. These methods help to define stress responses to toxic membrane overproduction in E. coli and may be broadly applicable to studies of membrane proteins. The results from a variety of biochemical and biophysical experiments demonstrated that CAXCK31 exists as a dimer in the membrane and can be purified in the dimeric state. The methods used include chemical cross-linking, FRET, and SEC-MALS. In addition, various transport properties of CAXCK31, including …


Structural Studies On The Rubella Virus Capsid Protein And Its Organization In The Virion, Vidya Mangala Prasad Oct 2013

Structural Studies On The Rubella Virus Capsid Protein And Its Organization In The Virion, Vidya Mangala Prasad

Open Access Dissertations

Rubella virus is a leading cause of birth defects due to infectious agents. When contracted during pregnancy, rubella infection leads to severe damage in fetuses. Despite its medical importance, very little is known about the structure of the pleomorphic rubella virus as compared to its alphavirus relatives. The rubella capsid protein is a critical structural component of virions as well as a key factor in virus-host interactions. Three crystal structures of the structural domain of the rubella capsid protein have been described here. The polypeptide fold of the capsid protomer has not been observed previously. The capsid protein structure, along …


Generation And Statistical Modeling Of Active Protein Chimeras: A Sequence Based Approach, Nicholas Fico Oct 2013

Generation And Statistical Modeling Of Active Protein Chimeras: A Sequence Based Approach, Nicholas Fico

Open Access Dissertations

Generation of active protein chimeras is a valuable tool to probe the functional space of proteins. Statistical modeling is the next logical step, allowing us to build a model of gene fragment replaceability between species. In this thesis I begin to develop the statistical tools that are needed to systematically describe combinatorial protein libraries. I present three sets of diverse chimeric protein libraries developed using sequence information. The statistical model of the human N-Ras and human K-Ras-4B genes reveal a set previously unidetifed surface residues on the N-Ras G-Domain that may be involved in cellular localization. Statistical modeling of a …


Interaction Between Centromeric Histone H3 Variant And Shugoshin, Visarut Buranasudja Jan 2013

Interaction Between Centromeric Histone H3 Variant And Shugoshin, Visarut Buranasudja

Open Access Theses

Precise and faithful segregation of chromosome segregation during mitosis depends on the ability of the cell to regulate chromosome bi-orientation on the mitotic spindle. Shugoshin (Sgo1), the protector of meiotic centromeric cohesin, is required for proper establishment of chromosome bi-orientation. Sgo1 plays a crucial role as part of a mitotic tension sensor between sister chromatids. Recently, Sgo1 has been reported to interact with histone H3 at the pericentromere region, as an important factor for tension sensing and chromosome segregation. However, the role of Sgo1 in tension sensing at centromere is still elusive. The centromere is the region of attachment of …


Biology And Ecology Of Glyphosate-Resistant Giant Ragweed, Kabelo Segobye Jan 2013

Biology And Ecology Of Glyphosate-Resistant Giant Ragweed, Kabelo Segobye

Open Access Theses

Giant ragweed (Ambrosia trifida L.) is a competitive annual plant found in disturbed landscapes and is the most troublesome weed in Indiana and the US Corn Belt. It is one of the most common and problematic weeds in corn and soybean production. The introduction of herbicide glyphosate, N-(phosphonomethyl) glycine in early 1970's provided farmers with a better and low-cost tool to control weeds. The use of glyphosate drastically increased after the development of glyphosate resistant agronomic crops in 1996 and was use as a post-emergence selective herbicide. This led to overreliance and repeated use of glyphosate for weed control especially …