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Full-Text Articles in Life Sciences
The Role Of Ehd2 In Endothelial Cells, Rachael Judson
The Role Of Ehd2 In Endothelial Cells, Rachael Judson
Electronic Theses and Dissertations
The role of EHD2 in terms of Cav1 interaction had not been previously characterized and was the main goal of this research. Cav1 has been shown to lead to the ubiquitination of Rac1. Because of this, the role of EHD2 in Rac1 regulation was investigated. An increase in long-term migration in endothelial cells was observed and suggested that EHD2 impacts the RhoA pathway instead of the Rac1 pathway. This lead to the hypothesis that EHD2 controls a part of the RhoA pathway. This hypothesis is supported by the loss of filamentous actin and an increase in serrated junctions in cells …
Environmental Gradients Impact Key Leaf Traits In Riparian Trees, Amanda Malone
Environmental Gradients Impact Key Leaf Traits In Riparian Trees, Amanda Malone
Electronic Theses and Dissertations
Specific leaf area (SLA) reflects a plant’s carbon investment per area and relates to generalized leaf economics spectrum growth strategies (LES). To fill gaps of knowledge about intraspecific SLA variation and why it is often inconsistent with the LES, we studied the response of two riparian tree species along the urban-rural gradient in Northeastern Colorado: an invasive, nitrogen-fixer with broad tolerances and a nitrogen-limited and shade-intolerant native. Despite these differences, the two species responded similarly, apart from the response to the urban-rural gradient, in which lower nitrogen in rural areas was associated with a more conservative strategy in the native …
Optimized Microbial Recombinant Production Of Hiv-1 Anti-Envelope Antibody Fragments With Applications To Single Particle Tracking Of Virus Assembly, Merissa Michelle Bruns
Optimized Microbial Recombinant Production Of Hiv-1 Anti-Envelope Antibody Fragments With Applications To Single Particle Tracking Of Virus Assembly, Merissa Michelle Bruns
Electronic Theses and Dissertations
In my findings, I have established a set series of protocols to recombinantly produce, purify and apply various fluorescent probes in vitro for the fluorescent labeling and study of the human immunodeficiency virus type 1 (HIV-1) envelope (Env) protein during HIV viral assembly. There remains insufficient knowledge about the molecular dynamics and interactions of HIV-1 Env protein with its counterpart, Gag, on the inner host cell surface during assembly of a mature virus particle. There also remains an insufficient amount of data for the understanding and clarification of the mechanism of action of a known host cell HIV-1 restriction factor, …
Understanding Patterns And Functional Impacts Of An Invasive Tree And Its Biological Control In A Riparian System, Annie L. Henry
Understanding Patterns And Functional Impacts Of An Invasive Tree And Its Biological Control In A Riparian System, Annie L. Henry
Electronic Theses and Dissertations
Invasive species have become an inextricable part of the landscape, particularly in riparian plant communities, and removal is often a key component of restoration programs. Biological control (biocontrol) is a method of removal that is often both efficient and effective. However, the impact of biocontrol on target species and indirect effects from invasive species removal can be hard to predict. While monitoring the impact of invasive species removal usually involves some species-based assessment such as changes in diversity, historically dominant species or native species, these strategies do not typically provide insight into the mechanisms underlying plant community response to removal. …
Development Of Endoplasmic Reticulum Targeted Probes And Red Fluorescent Probes For Detecting Zinc, Drew Maslar
Development Of Endoplasmic Reticulum Targeted Probes And Red Fluorescent Probes For Detecting Zinc, Drew Maslar
Electronic Theses and Dissertations
Zinc (Zn2+) is the second most abundant transition metal in the body and is important in various biological functions. Fluorescent sensors based on circularly permuted fluorescent proteins (cpFPs) have been previously made to detect labile, or unbound, Zn2+ within the cytoplasm of cells. These sensors have proven invaluable for studying Zn2+, however, these sensors are limited to their use in the cytoplasm and by the fact that only green cpFP have been utilized to create fluorescent Zn2+ sensors. In this thesis, we use a combination of peptide targeting sequences, site-directed mutagenesis, and rational design …
Notch Regulates Vascular Collagen Iv Basement Membrane Through Modulation Of Lysyl Hydroxylase 3 Trafficking, Stephen J.B. Gross
Notch Regulates Vascular Collagen Iv Basement Membrane Through Modulation Of Lysyl Hydroxylase 3 Trafficking, Stephen J.B. Gross
Electronic Theses and Dissertations
Collagen type IV (Col IV) is a basement membrane protein associated with early blood vessel morphogenesis and is essential for blood vessel stability. Defects in vascular Col IV deposition are the basis of heritable disorders, such as small vessel disease, marked by cerebral hemorrhage and drastically shorten lifespan. To date, little is known about how endothelial cells regulate the intracellular transport and selective secretion of Col IV in response to angiogenic cues, leaving a void in our understanding of this process. Our aim was to identify trafficking pathways that regulate Col IV deposition during angiogenic blood vessel development. We have …
Cellular And Organismal Ramifications Of De Novo Purine Synthesis Dysregulation, Randall Craig Mazzarino
Cellular And Organismal Ramifications Of De Novo Purine Synthesis Dysregulation, Randall Craig Mazzarino
Electronic Theses and Dissertations
Purines are a class of nitrogenous bases and are essential small molecules to life. Purines are used within the cell as genetic information carriers, energy currency, signaling molecules, and cofactors for multiple processes. They are formed through de novo and salvage pathways found in cells across the phylogenetic tree. The substrates of enzymes within de novo purine synthesis are known to influence other processes within the cell, such as energy homeostasis. In humans, de novo purine synthesis disorders are rare, with around 100 people identified. These patients exhibit a range of phenotypes, with varying degrees of mental retardation, seizure activity, …
Actin Regulation And Furrow Dynamics During Early Drosophila Embryogenesis, Yi Xie
Actin Regulation And Furrow Dynamics During Early Drosophila Embryogenesis, Yi Xie
Electronic Theses and Dissertations
Drosophila embryogenesis starts with a single nucleus undergo 13 rounds of nuclear divisions called syncytial cycles. Staring at cycle 10 when nuclei migrate to the surface of the embryo, massive and dynamic cortical actin structures and cleavage furrow formations occur. How actin regulators coordinate into an organized network directing three-dimension actin structures in the developing organisms is an unsolved question. Here, I present an in-depth characterization of actin cap dynamics: the actin caps go through expansion, stabilization, elongation and fragmentation phases in each cycle. Arp2/3 is the major contributor to actin cap formation. The functions of 7 different actin and …
Characterization Of Vps41 And Its Role In The Regulated Secretory Pathway, Christian Henry Burns
Characterization Of Vps41 And Its Role In The Regulated Secretory Pathway, Christian Henry Burns
Electronic Theses and Dissertations
Insulin secretory granules (SGs) mediate the regulated secretion of insulin, which is essential for glucose homeostasis. The basic machinery responsible for this regulated exocytosis consists of specific membrane proteins present both at the plasma membrane and on insulin SGs. The protein composition of insulin SGs thus dictates their release properties, yet the mechanisms controlling insulin SG formation, which determines this molecular composition, remain poorly understood. VPS41, a component of the endolysosomal tethering HOPS complex, was recently identified as a cytosolic factor involved in the formation of neuroendocrine/neuronal granules. We now find that a stable pool of VPS41 exists outside of …
Qualitative And Quantitative Fitness Consequences Of Advanced Maternal Age, Claudia Jean Hallagan
Qualitative And Quantitative Fitness Consequences Of Advanced Maternal Age, Claudia Jean Hallagan
Electronic Theses and Dissertations
Parental age can affect offspring fitness across taxa and through various mechanisms. However, the effect(s) of advanced maternal age on offspring, particularly in insects, has not been comprehensively reviewed making it difficult to draw conclusions about the effects of advanced maternal age on offspring in insects. In my first chapter, I reviewed maternal age literature and found overall negative effects of advanced maternal age on offspring fitness. However, results vary depending on which fitness measures were used, the life stages at which offspring were measured, and the experimental design of the study. In my second chapter, I conducted an experiment …
Spg Directs Arp2/3 Mediated F-Actin Networks To Support Syncytial Furrow Ingression In Drosophila, Shannon M. Henry
Spg Directs Arp2/3 Mediated F-Actin Networks To Support Syncytial Furrow Ingression In Drosophila, Shannon M. Henry
Electronic Theses and Dissertations
In the Drosophila embryo, nuclear divisions 10-13 occur in a syncytium with transient membrane furrows separating neighboring nuclei before the occurrence of cellularization. This process is driven by cytoskeletal and membrane trafficking networks, and while RalA and Rab8 have been identified to drive membrane addition to furrows, less is known about the control of dynamic F-actin networks needed for furrow formation. Here, the role of the DOCK protein Sponge (Spg) in furrow formation is explored through shRNA knockdown and live-imaging of syncytial Drosophila embryos. I have found that Spg is required for furrow ingression and that without Spg, furrows can …
The Ecology Of Land Managers In Riparian Restoration, Lisa Buie Clark
The Ecology Of Land Managers In Riparian Restoration, Lisa Buie Clark
Electronic Theses and Dissertations
While previous studies in restoration ecology have focused on the efficacy of direct management actions, the driving forces on management decisions (e.g., managers' characteristics or attitudes, environmental conditions) and the indirect impacts on restoration outcomes from management decisions (such as whether to collaborate) are quantified here for the first time. As a case study, I used data from 244 sites across the riparian Southwest US where the invasive shrubby tree Tamarix sp. was removed using various different methods. I surveyed and interviewed the 45 land managers who were responsible for the removal projects to determine their characteristics, attitudes, and …
Small Rho Gtpase Family Member Cdc42 And Its Role In Neuronal Survival And Apoptosis, Noelle Christine Punessen
Small Rho Gtpase Family Member Cdc42 And Its Role In Neuronal Survival And Apoptosis, Noelle Christine Punessen
Electronic Theses and Dissertations
Neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Alzheimer's and Parkinson's disease are caused by a progressive and aberrant destruction of neurons in the brain and spinal cord. These disorders lack effective long term treatments, and existing options focus primarily on either delaying disease onset or alleviating symptomology. Dysregulated programmed cell death, known as apoptosis, is one of the most significant contributors to neurodegeneration, and is controlled by a number of different factors. Rho GTPases are a protein class with recognized importance in proper neuronal development and migration, and have more recently emerged as regulators of apoptosis and neuronal survival. …
Metabolomics Of Mammalian And Cellular Models Of Aging, Nathan Gonzales Duval
Metabolomics Of Mammalian And Cellular Models Of Aging, Nathan Gonzales Duval
Electronic Theses and Dissertations
Aging is often associated with impaired cognition and a progressive loss of organ function over time accompanied by an increased susceptibility for many disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), heart disease, osteoporosis, type II diabetes, and many forms of cancer. With a rapidly aging population, the negative impacts of aging and age-related disorders is a major cause of increased human suffering both for affected individuals and for families and caregivers. Metabolic changes are also apparent in normal aging, but may increase in magnitude or nature with accompanying disease states or with accelerated aging. Thus, studying aging in a …
The Role Of P38 Mapk In Protein Homeostasis And Aging, Sarah Mae Ryan
The Role Of P38 Mapk In Protein Homeostasis And Aging, Sarah Mae Ryan
Electronic Theses and Dissertations
Aging is characterized by a failure to maintain proper protein homeostasis, potentially leading to tissue dysfunction. Though a variety of genes have been found to regulate lifespan and age-related behaviors how these genetic factors contribute to protein homeostasis has not been fully explored. Here, we report that the evolutionarily conserved aging gene p38 MAPK (p38Kb) regulates age-dependent protein homeostasis. Over-expression of p38Kb results in reduced protein aggregation, while knockout of p38Kb leads to increased protein aggregation. Furthermore, we find that p38Kb regulates protein homeostasis, lifespan, and age-dependent locomotor functions through an interaction with the Chaperone Assisted Selective Autophagy complex; a …
Neuroprotection Comparison Of Different Nutraceutical Compounds Against Mechanistically Distinct Cell Death Inducing Agents, Faten I. Taram
Neuroprotection Comparison Of Different Nutraceutical Compounds Against Mechanistically Distinct Cell Death Inducing Agents, Faten I. Taram
Electronic Theses and Dissertations
Neurodegenerative diseases like Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS), include the progressive loss of structure and function of neurons leading to neuronal death. All of these diseases are fatal, as there is no cure for them. The causes of these diseases are unknown; however, there are many proposed mechanisms that lead to neurodegenerative diseases. Oxidative stress is the leading cause of cell death in neurodegenerative diseases, in addition to other mechanisms including endoplasmic reticulum stress, proteasome inhibition, nitrosative stress, inflammation and excitotoxicity. More understanding of the death mechanisms at work in neurodegeneration is necessary to …
Regulation Of Synaptogenesis By The Mirna Pathway And Fmr/P Bodies, Jacqueline Rochelle Furlong
Regulation Of Synaptogenesis By The Mirna Pathway And Fmr/P Bodies, Jacqueline Rochelle Furlong
Electronic Theses and Dissertations
Post-transcriptional regulation of mRNA is facilitated by different mechanisms, such as microRNA (miRNA) induced gene silencing or fragile X mental retardation protein (FMRP) mediated repression either independent of or acting through cytoplasmic RNA Processing bodies (P bodies). DPTP99A, Lar, and Wg have known functions during synaptogenesis and may be targets of miR-8. Here, we provide evidence that miR-8 regulates DPTP99A in vitro. Non-endogenous miR-8 expressed using an UAS driver regulates Lar. Endogenous miR-8 may regulate DPTP99A in vivo. Here we show that FMRP is capable of colocalizing with the P body components: DCP1, HPat, and Me31B, but not …
Activity-Regulated Micrornas: Modulators Of Synaptic Growth At The Drosophila Neuromuscular Junction, Katherine Ruth Nesler
Activity-Regulated Micrornas: Modulators Of Synaptic Growth At The Drosophila Neuromuscular Junction, Katherine Ruth Nesler
Electronic Theses and Dissertations
It is well established that long-term changes in synaptic structure and function are mediated by rapid activity-dependent gene transcription and new protein synthesis. A growing body of evidence supports the involvement of the microRNA (miRNA) pathway in these processes. We have used the Drosophila neuromuscular junction (NMJ) as a model synapse to characterize activity-regulated miRNAs and their important mRNA targets. Here, we have identified five neuronal miRNAs (miRs-1, -8, -289, -314, and -958) that are significantly downregulated in response to neuronal activity. Furthermore we have discovered that neuronal misexpression of three of these miRNAs (miR-8, -289, and -958) is capable …
A Role For Dynamin-Dependent Endocytosis During Drosophila Gastrulation, Marissa Kay Kuhl
A Role For Dynamin-Dependent Endocytosis During Drosophila Gastrulation, Marissa Kay Kuhl
Electronic Theses and Dissertations
Gastrulation, a process conserved among many higher organisms, is the directed migration of cells into layers that will establish various tissues targeted to become anatomical structures. This process is accomplished through another conserved morphogenetic event, known as cell intercalation. Early in development, this movement of cells within an organized tissue leads to unique cellular arrangements where neighboring cells contract their shared interfaces in order to meet at a shared vertex. In this thesis, I present work that demonstrates a requirement for Dynamin-dependent endocytosis during these contraction events. Using quantitative analysis, I have identified varied cell behaviors during experiments which knockdown …
Evolution Of Melanocortin-2 Receptor Activations: Studies On A Mammal And A Fish, Liang Liang
Evolution Of Melanocortin-2 Receptor Activations: Studies On A Mammal And A Fish, Liang Liang
Electronic Theses and Dissertations
The structure and function relationship between melanocortin-2 receptor (MC2R) and ACTH are the most complicated in melanocortin receptor gene family. A comparative study on the activation of human and rainbow trout MC2R will provide a useful model system for understanding how ACTH emerged as the sole ligand for the MC2R of bony vertebrates. This dissertation will discuss how studies utilizing analogs of hACTH(1-24) have revealed two critical amino acid motifs in this ligand (HFRW and KKRRP) which are required for the activation of MC2R. In addition, the KKRRP motif functioned as the unique binding site for MC2R that directly contributes …
Micrornas 9a, 9b, 9c And 315 Regulate Expression Of A Reporter For The Neuronal Microtubule-Associated Protein Futsch/Map1b, Leslie M. Rozeboom
Micrornas 9a, 9b, 9c And 315 Regulate Expression Of A Reporter For The Neuronal Microtubule-Associated Protein Futsch/Map1b, Leslie M. Rozeboom
Electronic Theses and Dissertations
Fragile X syndrome (FXS) is the most common form of inherited mental retardation in humans. FXS is caused by loss of the Fragile X Mental Retardation Protein (FMRP), an important regulator of neuronal mRNA translation. Patients with FXS display cognitive deficits including memory problems. Protein synthesis-dependent long-term changes in synaptic plasticity are involved in the establishment and maintenance of long-term memory. One prevalent theory of FXS pathology predicts that FMRP is required to negatively regulate the translation of important mRNAs at the synapse. We are investigating microRNAs (miRNAs) as a potential regulator of synaptic FMRP-regulated mRNAs that have previously been …
Acute Synaptic Activity Causes Differential Mirna Expression In The Drosophila Melanogaster Larval Central Nervous System, Robert Ian Sand
Acute Synaptic Activity Causes Differential Mirna Expression In The Drosophila Melanogaster Larval Central Nervous System, Robert Ian Sand
Electronic Theses and Dissertations
The primary goal of this thesis was to determine if spaced synaptic stimulation induced the differential expression of microRNAs (miRNAs) in the Drosophila melanogaster central nervous system (CNS). Prior to attaining this goal, we needed to identify and validate a spaced stimulation paradigm that could induce the formation of new synaptic growth at a model synapse, the larval neuromuscular junction (NMJ). Both Channelrhodopsin- and high potassium-based stimulation paradigms adapted from (Ataman, et al. 2008) were tested. Once validation of these paradigms was complete, we sought to characterize the miRNA expression profile of the larval CNS by miRNA array. Following attainment …
Plasma Membrane Dynamics In The Drosophila Embryo, Amelia E. Zommer
Plasma Membrane Dynamics In The Drosophila Embryo, Amelia E. Zommer
Electronic Theses and Dissertations
Convergent extension is a highly conserved process among mammals, in which the tissue narrows in one axis, and extends across another. Tissue elongation is directed by the regulation of cell interface behaviors, which guides cell intercalation and rosette formation. Rosette formation occurs through the contraction of vertically oriented cell interfaces, and the subsequent elongation of new horizontal interfaces. It has been shown that actomyosin-generated tension functions to direct rosette formation. In this thesis, I have tested the function of regulators of F-actin networks, as well as endocytic and exocytic mechanisms, to identify new components that control interface behaviors and cell …
Assessing Crosstalk Between Calcium And Camp In Pancreatic Alpha Cells, Julianne Michelle Imseis
Assessing Crosstalk Between Calcium And Camp In Pancreatic Alpha Cells, Julianne Michelle Imseis
Electronic Theses and Dissertations
Blood glucose levels are regulated by the interactions between insulin and glucagon. Pancreatic alpha cells release glucagon in response to a drop in blood sugar. Pancreatic alpha cells appear to be regulated through multiple signaling pathways. One potential method of regulation occurs from α-MSH or epinephrine stimulated production of the intracellular messenger cyclic AMP. Exocytosis of dense core vesicles containing glucagon ultimately requires an increase in cytosolic calcium. This study focused on the link between cyclic AMP and calcium in pancreatic alpha cells which allows alpha cell regulation. Interactions between calcium and cyclic AMP in pancreatic alpha cells consists of …
Amino Acid Residues Implicated In The Interaction Of Melanocortin Ligands And Their Receptors: A Study Of Mc2r Selectivity, Kristopher D. Veo
Amino Acid Residues Implicated In The Interaction Of Melanocortin Ligands And Their Receptors: A Study Of Mc2r Selectivity, Kristopher D. Veo
Electronic Theses and Dissertations
Melanocortin receptor ligand selectivity has been a question not easily answered. The inability to functionally express melanocortin 2 receptor (MC2R) has inhibited the study of why MC2R is only stimulated by ACTH, a melanocortin hormone. With the recent discovery of the MC2R accessory protein (MRAP), creating a heterologous system is now feasible. Using a general cell line like CHO-K1 cells, which do not express endogenous MCRs, we were able to create a heterologous expression system and test the selectivity of MC2R using analog variants of ACTH(1-24). Our results indicate an amino acid requirement in the C-terminal portion of ACTH(1-24) for …