Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Entire DC Network

Studies Of Dynein Anchoring Protein In Budding Yeast Saccharomyces Cerevisiae, Safia Omer Nov 2018

Studies Of Dynein Anchoring Protein In Budding Yeast Saccharomyces Cerevisiae, Safia Omer

Doctoral Dissertations

Inheritance of equal genomic content is vital for cellular growth and survival. During cell division, the mitotic spindle is built to ensure equal chromosome segregation between dividing cells. Fidelity of segregation is achieved by the precise positioning of the mitotic spindle by force generators located at the cell cortex where they exert pulling on microtubule (MT). Cortical dynein, a minus end directed motor, generates pulling forces via microtubule end-on capture-shrinkage and lateral MT sliding mechanisms. In Saccharomyces cerevisiae, the dynein attachment molecule Num1 interacts with plasma membrane (PM), endoplasmic reticulum (ER), and mitochondria to facilitate spindle positioning across the …


Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho Nov 2018

Epigenetic Regulation Of Genomic Imprinting During Early Mammalian Embryonic Development, Chelsea Marcho

Doctoral Dissertations

Mammalian development involves remarkable changes, starting from a single-cell, totipotent zygote and ending with a developed organism comprised of diverse cells types with distinct morphologies, structures, and functions. Within three days of murine development, the two parental genomes merge into a single nucleus, begin zygotic gene expression, undergo epigenetic remodeling, and make the first lineage decisions. Diversity in cell-types is possible even though cells share the same genome. This diversity is achieved by the tight regulation of differential transcriptional programs. There are many ways these transcriptional programs can be initiated. Epigenetic alterations to the genome can drive transcriptional changes. Epigenetic …


Identifying Functional Components Of The Endoplasmic Reticulum Quality Control And Degradation Factor Edem1, Lydia Lamriben Nov 2018

Identifying Functional Components Of The Endoplasmic Reticulum Quality Control And Degradation Factor Edem1, Lydia Lamriben

Doctoral Dissertations

The ER Degradation-Enhancing Mannosidase-Like protein 1 (EDEM1) is a critical endoplasmic reticulum (ER) quality control factor involved in identifying and directing non-native proteins to the ER-associated protein degradation (ERAD) pathway. However, its recognition and binding properties have remained enigmatic since its discovery. Here we provide evidence for an additional redox-sensitive interaction between EDEM1 and Z/NHK that requires the presence of the single Cys on the α-1 antitrypsin ERAD clients. Moreover, this Cys-dependent interaction is necessary when the proteins are isolated under stringent detergent conditions, ones in which only strong covalent interactions can be sustained. This interaction is inherent to the …


Combination Regimens Using Dietary Components For The Chemoprevention Of Colorectal Cancer And Inflammation, Christina Dimarco-Crook Nov 2018

Combination Regimens Using Dietary Components For The Chemoprevention Of Colorectal Cancer And Inflammation, Christina Dimarco-Crook

Doctoral Dissertations

ABSTRACT COMBINATION REGIMENS USING DIETARY COMPONENTS FOR THE CHEMOPREVENTION OF COLORECTAL CANCER AND INFLAMMATION September 2018 CHRISTINA DIMARCO-CROOK, B.S., IMMACULATA UNIVERSITY M.S., DREXEL UNIVERSITY Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Hang Xiao Dietary components have been found to effectively modulate multiple deregulated signaling pathways associated with the initiation and progression of carcinogenesis and inflammation in cellular and animal models. However, clinical studies have shown mixed results when examining the efficacy of individual dietary components, perhaps suggestive of the synergism that exists between multiple components within a particular food and the diet as a whole. Additional research is needed …


The Interplay Between Polarity Regulators, Calcium, And The Actin Cytoskeleton During Tip Growth, Carlisle Bascom Jr Oct 2018

The Interplay Between Polarity Regulators, Calcium, And The Actin Cytoskeleton During Tip Growth, Carlisle Bascom Jr

Doctoral Dissertations

Plant cell growth is a meticulously regulated process whereby the cell wall is selectively loosened to allow for turgor-pressure driven expansion. The rate of expansion must equal delivery of new material, or the cell will lyse. In many plant cells, this process happens diffusely around the cell. However, a number of plant cells have anisotropic shapes that require exquisite spatial control of secretion. One simple example of anisotropic patterning is tip growth; highly polarized cell expansion utilized by pollen tubes, root hairs, and moss protonemata. Investigating the role various molecules have in tip growth sheds light on how plant cells …


Characterization Of She1 Spindle Role Using Ceullular, Biochemical, And Biophysical Methods, Yili Zhu Jul 2018

Characterization Of She1 Spindle Role Using Ceullular, Biochemical, And Biophysical Methods, Yili Zhu

Doctoral Dissertations

During development, metaphase spindles undergo large movement and/or rotation to determine the cell division axis. While it has been shown that spindle translocation is achieved by astral microtubules pulling and/or pushing the cortex, how metaphase spindle stability is maintained during translocation remains not fully understood. In budding yeast, our lab has previously proposed a model for spindle orientation wherein the mitotic spindle protein She1 promotes spindle translocation across the bud neck by polarizing cortical dynein pulling activity on the astral microtubules. Intriguingly, She1 exhibits dominant spindle localization throughout the cell cycle. However, whether She1 has any additional role on the …


Extrinsic And Intrinsic Factors In Liver Development, Amrita Palaria Jul 2018

Extrinsic And Intrinsic Factors In Liver Development, Amrita Palaria

Doctoral Dissertations

Liver is the largest internal organ of the human body. It performs a multitude of functions. Therefore, it is provided with a huge regenerative capacity however, because of the same reason it is also prone to various diseases. Hence, it is essential to understand liver development in order to understand liver regeneration and liver diseases to provide better therapeutic targets and solutions. Liver development is orchestrated by a variety of intrinsic and extrinsic factors. The major focus of this dissertation thesis is to elucidate the role of BMP signals and YY1/VEGFA regulated signals in liver development. Liver organogenesis initiates with …


Motor Protein Regulation In Mammalian Mitosis, Barbara Mann Jul 2018

Motor Protein Regulation In Mammalian Mitosis, Barbara Mann

Doctoral Dissertations

Developing and maintaining a multicellular organism relies on the fundamental biological process of cell division, which ensures that genetic material is equally segregated between daughter cells. During mitosis, cells completely rearrange their cytoskeleton into a bipolar spindle through the concerted efforts of microtubules, motor proteins, and microtubule-associated proteins, which cells must regulate spatially and temporally to prevent errors such as chromosomal missegregation: a major cause of cancer. Although the mitotic spindle is a validated target for chemotherapy drug resistance and redundant pathways have highlighted the need for new targets. It is therefore important to understand how proteins that help build …


New Approaches In Engineering Somatic Embryogenesis In Loblolly Pine Suspension Cultures, Elizabeth Morgan Cummings Bende Jul 2018

New Approaches In Engineering Somatic Embryogenesis In Loblolly Pine Suspension Cultures, Elizabeth Morgan Cummings Bende

Doctoral Dissertations

Many industries including agriculture and healthcare require efficient methods for replication of plants with optimal traits. The loblolly pine (Pinus taeda) is a valuable crop in the timber industry, occupying 30 million acres of U.S. land, and breeding efforts aim to produce a crop with ideal phenotypic traits, including superior growth and wood quality. One method to large-scale clonal crop propagation is somatic embryogenesis (SE), the process through which asexual (somatic) plant cells undergo differentiation in vitro, resulting in germination-competent embryos. There are three main stages of growth and development that lead to the production of embryos: …


Examining Shsp-Substrate Capture And Chaperone Network Coordination Through Cross-Linking, Keith Ballard Jul 2018

Examining Shsp-Substrate Capture And Chaperone Network Coordination Through Cross-Linking, Keith Ballard

Doctoral Dissertations

Small heat shock proteins (sHSPs) and related α-crystallins are virtually ubiquitous, ATP-independent molecular chaperones linked to protein misfolding diseases. They comprise a conserved core α-crystallin domain (ACD) flanked by an evolutionarily variable N-terminal domain (NTD) and semi-conserved C-terminal extension/domain (CTD). They are capable of binding up to an equal mass of unfolding protein, forming large, heterogeneous sHSP-substrate complexes that coordinate with ATP-dependent chaperones for refolding. To derive common features of sHSP-substrate recognition, I compared the chaperone activity and specific sHSP-substrate interaction sites for three different sHSPs from Arabidopsis (At17.6B), pea (Ps18.1) and wheat (Ta16.9), for which the atomic solution-state structures …


Identification Of The Mesoderm/Endoderm Interactions Involved In Murine Liver And Pancreas Development, Jesse Angelo Jul 2018

Identification Of The Mesoderm/Endoderm Interactions Involved In Murine Liver And Pancreas Development, Jesse Angelo

Doctoral Dissertations

The definitive endoderm, one of the three primary germ layers, arises during gastrulation as a simple epithelial sheet that will produce the entire gut tube and associated organs including the thyroid, lung, liver and pancreas. DiI fate mapping and whole embryo culture were used to determine the endodermal origin of the 9.5 days post coitum (dpc) dorsal and ventral pancreas buds. Our results demonstrate that the progenitors of each bud occupy distinct endodermal territories. Similarly, previous data has shown that the neighboring liver is formed from two separate progenitor populations. Numerous studies have demonstrated that signals secreted from adjacent mesodermal …


Cadherin-11 Ectodomain Signaling In Cranial Neural Crest Migration, Ketan Mathavan Mar 2018

Cadherin-11 Ectodomain Signaling In Cranial Neural Crest Migration, Ketan Mathavan

Doctoral Dissertations

During development, a multi-potent group of cells known as the cranial neural crest (CNC) migrate to form craniofacial structures. Proper migration of these cells requires proteolysis of cell adhesion molecules, such as cadherins. In Xenopus laevis, preventing extracellular cleavage of cadherin-11 impairs CNC migration. However, overexpression of the soluble cleavage product (EC1-3) is capable of rescuing this phenotype. The mechanism by which EC1-3 promotes CNC migration has not been investigated until now. Here we show that EC1-3 stimulates phosphorylation of Akt, a target of PI3K, in X.laevis CNC. Through immunoprecipitation experiments, we determined that EC1-3 interacts with …


Clpxp Functions In Caulobacter As A Universal And Species-Specific Protease, Robert Vass Mar 2018

Clpxp Functions In Caulobacter As A Universal And Species-Specific Protease, Robert Vass

Doctoral Dissertations

Proteolysis shapes many aspects of cellular survival, including protein quality control and cellular signaling. Powered proteolysis couples ATP hydrolysis with a degradation force that actively probes and interrogates the protein population. ClpXP, exemplifies a conserved two-part protease system charged with powered proteolysis. This protease exists as a regulatory element (ClpX), and a compartmentalized, self-contained peptidase element (ClpP). In Caulobacter crescentus, ClpXP degradation plays a crucial role maintaining proteins that exhibit proper activity, and also triggers the start of cellular differentiation. Substrate elimination requires shared aspects of the protease from both quality control and precision protein destruction functions. Here, the regulatory …


Mechanism Of Regulation Of Kinesins Eg5 And Kif15 By Tpx2, Sai Keshavan Balchand Mar 2018

Mechanism Of Regulation Of Kinesins Eg5 And Kif15 By Tpx2, Sai Keshavan Balchand

Doctoral Dissertations

Cell division is the fundamental process by which the replicated genetic material is faithfully segregated to form two identical daughter cells. The mitotic spindle is the macromolecular cytoskeletal structure that is built during every round of cell division to successfully separate the duplicated genome equally into the daughter cells. Errors in spindle formation can thus causegenetic aberrations and can potentially lead to cancer. Understanding the mechanisms that govern proper spindle assembly and function is thus important. Eg5 and Kif15 are two important kinesins which play a major role in establishing and maintaining bipolarity of the mitotic spindle. Both Eg5 and …