Biochemistry, Biophysics, and Structural Biology Commons^™

Examining The Roles Of The Conserved Mrna Deadenylase Complex On Drosophila Neuronal Structures, Megan Mccaughey, Scott Barbee

DU Undergraduate Research Journal Archive

The most common cause of inherited mental deficiency and monogenetic cause of autism is Fragile X Syndrome (FXS). There is little known about the origins of this disease which will be investigated in the present study. The series of experiments conducted examined the potential role of mRNA deadenylation proteins as contributing factors to the pathogenesis of FXS using Drosophila melanogaster as a model organism. One of the main complexes involved in deadenylation is the CNOT complex, which is comprised of many proteins, including POP2, TWIN, and NOT3. Each protein plays a unique role within the CNOT complex. This goal of …

Faculty Spotlight—Dr. Phil Danielson, Hannah Stanley, William Moody

DU Undergraduate Research Journal Archive

Interview with Dr. Phil Danielson

Analyzing The Effect On Ligand Sensitivity For Xenopus Tropicalis Mc1r, Mc3r, Mc4r, And Mc5r As A Result Of Coexpression With Gallus Gallus Mrap1 In Chinese Hamster Ovary Cells, Avery Niemann, Robert Dores

DU Undergraduate Research Journal Archive

Some melanocortin receptors and the accessory protein MRAP1 have been found to interact in novel ways when co-expressed in the same cells following stimulation with either ACTH (1-24) or αMSH. These interactions have been seen for mammalian, bird, and some bony fish melanocortin receptors. Such analysis has not been done yet on the amphibian melanocortin receptors, MC1R, MC3R, MC4R, and MC5R. To this end, this study was done on the effects regarding ligand sensitivity for ACTH (1-24) and αMSH, when the MC1R, MC3R, MC4R, and MC5R paralogs of the amphibian, Xenopus tropicalis were expressed in Chinese Hamster Ovary cells either …

Faculty Spotlight—Dr. Robert Dores, Anit Tyagi, William Moody

DU Undergraduate Research Journal Archive

Robert Dores Interview

Edited by Will Moody

Examining Artifacts Of The Watershed Segmentation, Emily Jo Armitage

Electronic Theses and Dissertations

The watershed segmentation is an algorithm used to systematically track cell intercalary behaviors during germ band extension of the Drosophila embryo. Neighboring cells share a contracting vertical interface, called a T1, which continues contracting to a single point, a T2, and extending in the horizontal direction to create what is called a T3 interface (Fig. 1). Additionally, higher order vertices called rosettes occur when five or more cells meet at a common vertex. Simulated T2 events demonstrate that cell angle and not noise level in the image contributes to the incorrect detection of artifactual T1s in more acute angled cells …

Cellular And Developmental Insights Into The Early Evolution Of Muscle, Jeffrey J. Colgren

Electronic Theses and Dissertations

Whereas a great deal has been learned about the molecular underpinnings of morphological evolution in animals, much less is known about the origin of novel cell and tissue types. During the time in which the earliest animal lineages were diversifying, fundamental cell and tissue types, such as muscles, arose. Sponges are one of two animal lineages that lack muscles, yet they undergo coordinated full body contractions. Whereas the signaling processes have been studied, the physical mechanisms of contraction are completely uncharacterized. The main purpose of this work is to understand the primary contractile tissue of the sponge Ephydatia muelleri, …

Characterization Of The Dimerization And Salt Dependent Aggregation Of The Als-Linked Protein Tdp-43, Elizabeth Ehrhardt

Electronic Theses and Dissertations

Trans-active response (TAR) DNA-binding protein 43 (TDP-43) is essential for RNA processing but can also form toxic cytoplasmic inclusions in neurons of patients with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). RNA-binding has been shown to have the potential to decrease or inhibit the aggregation of TDP-43, indicating that supplying RNA therapeutics may be a solution to treat these neurodegenerative disorders. However, the mechanism of aggregation, transitioning from TDP-43’s native dimeric state to small oligomers to toxic aggregates, is still relatively unknown. This needs to be established before determining how to target and disrupt this aggregation. Using GFP-TDP-43, …

Quantification Of Mitochondrial Zinc Homeostasis And Analysis Of Zinc And Polyamine-Mediated Axonal Trafficking, Dylan Hunt Fudge

Electronic Theses and Dissertations

The zinc ion is an important emerging signaling molecule for biological processes. In this work we engineered improved zinc sensors based on our previously developed fluorescent sensor GZnP1 to provide sensors with a higher fluorescent readout, faster kinetics, and a superior sensitivity to zinc. We utilized these zinc sensors and further developed the sensors to answer questions pertaining to biological zinc. We showed the labile zinc concentration in the mitochondrial matrix was less than 1 pM while the labile zinc concentration in the cytosol and mitochondrial IMS were comparable (~100 pM) across four different cell lines. Using these zinc sensors …

Sorting Of Cargo Proteins Within The Regulated Secretory Pathway: The Peripheral Membrane Protein Hid-1 As A Sorting And Vesicle Biogenesis Factor, Blake H. Hummer

Electronic Theses and Dissertations

Large dense core vesicles (LDCVs) form at the trans-Golgi network (TGN) and mediate the regulated release of neuropeptides and peptide hormones. Despite their central role to physiology, the mechanisms controlling biogenesis and sorting to LDCVs is not well understood. Optimizing the retention using selective hooks (RUSH) method in neuroendocrine cells, we show it is possible to visualize sorting to the constitutive and regulated secretory pathways in real-time and that the bulk of transmembrane LDCV cargoes do not sort directly onto LDCVs, but exit the TGN into non-regulated vesicles to be incorporated to LDCVs at a later step. Additionally, we characterize …

Quantification Of Dynamic Epithelial Sheet Architecture In Botryllus Schlosseri Using 2-D & 3-D Image Analysis, Roopa Madhu

Electronic Theses and Dissertations

Epithelial tubules form critical structures in various body tissues; how- ever, since they are difficult to access experimentally, their architecture and dynamics are not well understood. Here we examine the dynamic remodeling of epithelial tubes in vivo using a novel and uniquely accessible model system: the extracorporeal vasculature of Botryllus schlosseri (sea squirt). In Botryllus, massive retraction of blood vessels can be triggered without loss of barrier function, through (i) disrupting collagen crosslinking in the basement membrane using β-aminopropionitrile (BAPN); or (ii) disrupting the integrin pathway through inhibition of focal adhesion kinase (FAK). We performed stereographic projections of 3-dimensional …

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, …

Rab39 And Klp98a Are Required For Furrow Formation During Early Drosophila Embryogenesis, Megan R. Millage

Electronic Theses and Dissertations

The formation of a plasma membrane furrow is an essential process during development. Furrow formation is necessary for successful cell division and cytokinesis in addition to the ability to create multicellular tissues. Here, I will explore the role of the Golgi-associated Rab protein Rab39 in furrow formation during early Drosophila embryogenesis. Rab39 is one of eight Rab proteins that has been shown to localize to discrete puncta by live imaging in early Drosophila embryos, but its function and pathway have not been well characterized. In this thesis will I show that Rab39 forms dynamic, tubular structures that colocalize with trans-Golgi …