Biochemistry, Biophysics, and Structural Biology Commons^™

Alpha-Single Chains Of Collagen Type Vi Inhibit The Fibrogenic Effects Of Triple Helical Collagen Vi In Hepatic Stellate Cells, Christian Freise, Hyunho Lee, Christopher Chronowski, Doug Chan, Jessica Cziomer, Martin Rühl, Tarkan Dagdelen, Maik Lösekann, Ulrike Erben, Andre Catic, Werner Tegge, Detlef Schuppan, Rajan Somasundaram, Ergun Sahin

Faculty, Staff and Students Publications

The interaction of extracellular matrix (ECM) components with hepatic stellate cells (HSCs) is thought to perpetuate fibrosis by stimulating signaling pathways that drive HSC activation, survival and proliferation. Consequently, disrupting the interaction between ECM and HSCs is considered a therapeutical avenue although respective targets and underlying mechanisms remain to be established. Here we have interrogated the interaction between type VI collagen (CVI) and HSCs based on the observation that CVI is 10-fold upregulated during fibrosis, closely associates with HSCs in vivo and promotes cell proliferation and cell survival in cancer cell lines. We exposed primary rat HSCs and a rat …

Mucins, Gut Microbiota, And Postbiotics Role In Colorectal Cancer, Ramesh Pothuraju, Sanjib Chaudhary, Satyanarayana Rachagani, Sukhwinder Kaur, Hemant K Roy, Michael Bouvet, Surinder K Batra

Faculty, Staff and Students Publications

An imbalance in the crosstalk between the host and gut microbiota affects the intestinal barrier function, which results in inflammatory diseases and colorectal cancer. The colon epithelium protects itself from a harsh environment and various pathogenic organisms by forming a double mucus layer, primarily comprising mucins. Recent studies are focusing on how dietary patterns alter the gut microbiota composition, which in turn regulates mucin expression and maintains the intestinal layers. In addition, modulation of gut microbiota by microbiotic therapy (involving fecal microbiota transplantation) has emerged as a significant factor in the pathologies associated with dysbiosis. Therefore, proper communication between host …

Thyroid Storm In A Patient With Covid-19, Angela N Rao, Ruaa Y Al-Ward, Ruchi Gaba

Faculty, Staff and Students Publications

OBJECTIVE: A thyroid storm is a severe exacerbation of thyrotoxicosis that can cause significant morbidity and mortality. The emergence of the novel coronavirus (SARS-CoV-2) that originated in Wuhan, China, has become a worldwide pandemic. We present the first documented case of thyroid storm (as defined by the Burch-Wartofsky criteria) in a patient with COVID-19.

METHODS: Laboratory and diagnostic studies, including thyroid function tests, thyroid antibody testing, SARS-CoV-2 nasopharyngeal polymerase chain reaction testing, and thyroid ultrasound were performed.

RESULTS: A 25-year-old woman presented to the hospital with dry cough, dyspnea, palpitations, weight loss, diarrhea, and anxiety. Physical examination revealed exophthalmos with …

The Association Of Pre-Kidney Transplant Dialysis Modality With De Novo Posttransplant Heart Failure, Colin R Lenihan, Sai Liu, Medha Airy, Carl Walther, Maria E Montez-Rath, Wolfgang C Winkelmayer

Faculty, Staff and Students Publications

BACKGROUND: Heart failure (HF) after kidney transplantation is a significant but understudied problem. Pretransplant dialysis modality could influence incident HF risk through differing cardiac stressors. However, whether pretransplant dialysis modality is associated with the development of posttransplant HF is unknown.

METHODS: We used the US Renal Data System to assemble a cohort of 27,701 patients who underwent their first kidney transplant in the USA between the years 2005 and 2012 and who had Medicare fee-for-service coverage for >6 months preceding their transplant date. Patients with any HF diagnosis prior to transplant were excluded. Detailed baseline patient characteristics and comorbidities were …

Case Report: Dupilumab Successfully Controls Severe Eczema In A Child With Elevated Ige Levels And Recurrent Skin Infections, Tejas P Joshi, Sara Anvari, Meera R Gupta, Carla M Davis, Joud Hajjar

Faculty, Staff and Students Publications

The efficacy of dupilumab in pediatric patients with severe eczema presenting in the setting of elevated immunoglobulin E (IgE) levels and recurrent bacterial skin infections is not well-understood. Here we present the case of a child with elevated IgE levels in whom dupilumab treatment led to remarkable control of his eczema and recurrent skin infections. We also review the use of dupilumab in other patients with molecularly proven cases of hyper IgE (HIGE) syndrome. Our case supports the notion that dupilumab may have a seminal application in treating severe eczema that occurs in the setting of elevated IgE levels and …

Meta-Analysis Comparing Outcomes Of Catheter Ablation For Ventricular Arrhythmia In Ischemic Versus Nonischemic Cardiomyopathy, Indranill Basu-Ray, Dibbendhu Khanra, Sumit K Shah, Anindya Mukherjee, Sudhanva V Char, Bhavna Jain, T Jared Bunch, Michael Gold, Adedayo A Adeboye, Mohammad Saeed

Faculty, Staff and Students Publications

BACKGROUND: Catheter ablation is an effective treatment for ventricular arrhythmia (VA) in ischemic cardiomyopathy (ICM). However, results in non-ICM (NICM) patients are not satisfactory, and studies comparing differences between NICM and ICM are limited. We conducted a meta-analysis of procedural characteristics and long-term outcomes of catheter ablation for VA, comparing results between ICM and NICM.

METHODS: Studies in the PubMed, EMBASE, and Cochrane databases were systematically reviewed. Four studies reporting comparison of catheter ablation of VA between ICM and NICM were examined. The Newcastle-Ottawa Scale was used to appraise study quality. A random-effects model with inverse variance method was used …

Power Washing Pulmonary Alveolar Proteinosis, Tiana R Endicott-Yazdani, Gary S Schwartz, Haiying Zhang, Randall L Rosenblatt, Puneet S Garcha

Faculty, Staff and Students Publications

Pulmonary alveolar proteinosis is an uncommon cause of insidious onset shortness of breath and hypoxemia. It is caused by an accumulation of surfactant within the alveoli. Left untreated, it can be fatal. Standard-of-care treatment is whole-lung lavage; however, in severe cases, the associated hypoxemia can be profound and single-lung ventilation would not be tolerated, potentially preventing a lifesaving treatment. Single cases using veno-venous extracorporeal membrane oxygenation to perform whole-lung lavage have been reported. Here we describe three patients with severe pulmonary alveolar proteinosis who were successfully treated with whole-lung lavage using veno-venous extracorporeal membrane oxygenation for oxygenation support.

Rapid Induction Of The Unfolded Protein Response And Apoptosis By Estrogen Mimic Ttc-352 For The Treatment Of Endocrine-Resistant Breast Cancer, Balkees Abderrahman, Philipp Y Maximov, Ramona F Curpan, Sean W Fanning, Jay S Hanspal, Ping Fan, Charles E Foulds, Yue Chen, Anna Malovannaya, Antrix Jain, Rui Xiong, Geoffrey L Greene, Debra A Tonetti, Gregory R J Thatcher, V Craig Jordan

Faculty, Staff and Students Publications

Patients with long-term estrogen-deprived breast cancer (BC), after resistance to tamoxifen or aromatase inhibitors develops, can experience tumor regression when treated with estrogens. Estrogen’s anti-tumor effect is attributed to apoptosis via the estrogen receptor (ER). Estrogen treatment can have unpleasant gynecological and non-gynecological adverse events thus the development of safer estrogenic agents remains a clinical priority. Here, we study synthetic selective estrogen mimics (SEMs) BMI-135 and TTC-352, and the naturally-occurring estrogen estetrol (E4), which are proposed as safer estrogenic agents compared to 17β-estradiol (E2), for the treatment of endocrine-resistant BC. TTC-352 and E4 are being evaluated in BC clinical trials. …

Open Problems In Extracellular Rna Data Analysis: Insights From An Ercc Online Workshop, Roger P Alexander, Robert R Kitchen, Juan Pablo Tosar, Matthew Roth, Pieter Mestdagh, Klaas E A Max, Joel Rozowsky, Karolina Elżbieta Kaczor-Urbanowicz, Justin Chang, Leonora Balaj, Bojan Losic, Eric L Van Nostrand, Emily Laplante, Bogdan Mateescu, Brian S White, Rongshan Yu, Aleksander Milosavljevic, Gustavo Stolovitzky, Ryan M Spengler

Faculty, Staff and Students Publications

We now know RNA can survive the harsh environment of biofluids when encapsulated in vesicles or by associating with lipoproteins or RNA binding proteins. These extracellular RNA (exRNA) play a role in intercellular signaling, serve as biomarkers of disease, and form the basis of new strategies for disease treatment. The Extracellular RNA Communication Consortium (ERCC) hosted a two-day online workshop (April 19–20, 2021) on the unique challenges of exRNA data analysis. The goal was to foster an open dialog about best practices and discuss open problems in the field, focusing initially on small exRNA sequencing data. Video recordings of workshop …

The E3 Ligase Traf4 Promotes Igf Signaling By Mediating Atypical Ubiquitination Of Irs-1, Wenjuan Yu, Ramesh Singh, Zhao Wang, Bert W O'Malley, Ping Yi

Faculty, Staff and Students Publications

Insulin-like growth factor (IGF) is a potent mitogen that activates the IGF receptor (IGFR)/insulin receptor substrate (IRS) axis, thus stimulating growth in normal cells and uncontrolled cell proliferation in cancer. Posttranslational modifications of IRS such as ubiquitination tightly control IGF signaling, and we previously identified IRS-1 as a potential substrate for the E3 ubiquitin ligase TRAF4 using an unbiased screen. Here we provide evidence that TRAF4-mediated ubiquitination of IRS-1 is physiologically relevant and crucial for IGF signal transduction. Through site-directed mutagenesis we found that TRAF4 promotes an atypical K29-linked ubiquitination at the C-terminal end of IRS-1. Its depletion abolishes AKT …

Ketamine: Neuroprotective Or Neurotoxic?, Divya Choudhury, Anita E Autry, Kimberley F Tolias, Vaishnav Krishnan

Faculty, Staff and Students Publications

Ketamine, a non-competitive N-methyl-D-aspartate receptor (NMDAR) antagonist, has been employed clinically as an intravenous anesthetic since the 1970s. More recently, ketamine has received attention for its rapid antidepressant effects and is actively being explored as a treatment for a wide range of neuropsychiatric syndromes. In model systems, ketamine appears to display a combination of neurotoxic and neuroprotective properties that are context dependent. At anesthetic doses applied during neurodevelopmental windows, ketamine contributes to inflammation, autophagy, apoptosis, and enhances levels of reactive oxygen species. At the same time, subanesthetic dose ketamine is a powerful activator of multiple parallel neurotrophic signaling cascades …

Kv13 Channel Up-Regulation In Peripheral Blood T Lymphocytes Of Patients With Multiple Sclerosis, Ioannis Markakis, Ioannis Charitakis, Christine Beeton, Melpomeni Galani, Elpida Repousi, Stella Aggeloglou, Petros P Sfikakis, Michael W Pennington, K George Chandy, Cornelia Poulopoulou

Faculty, Staff and Students Publications

Voltage-gated Kv1.3 potassium channels are key regulators of T lymphocyte activation, proliferation and cytokine production, by providing the necessary membrane hyper-polarization for calcium influx following immune stimulation. It is noteworthy that an accumulating body of in vivo and in vitro evidence links these channels to multiple sclerosis pathophysiology. Here we studied the electrophysiological properties and the transcriptional and translational expression of T lymphocyte Kv1.3 channels in multiple sclerosis, by combining patch clamp recordings, reverse transcription polymerase chain reaction and flow cytometry on freshly isolated peripheral blood T lymphocytes from two patient cohorts with multiple sclerosis, as well as from healthy …

An International Study Of Interobserver Variability Of “String Sign” Of Pancreatic Cysts Among Experienced Endosonographers, Seifeldin Hakim, Emmanuel Coronel, Graciela M Nogueras González, Philip S Ge, Suresh T Chari, Nirav Thosani, Srinivas Ramireddy, Ricardo Badillo, Tomas Davee, Marc F Catalano, Robert J Sealock, Sreeram Parupudi, Lyndon V Hernandez, Virendra Joshi, Atsushi Irisawa, Surinder Rana, Sundeep Lakhtakia, Peter Vilmann, Adrian Saftoiu, Siyu Sun, Marc Giovannini, Matthew H Katz, Michael P Kim, Manoop S Bhutani

Faculty, Staff and Students Publications

BACKGROUND AND OBJECTIVES: No single optimal test reliably determines the pancreatic cyst subtype. Following EUS-FNA, the "string sign" test can differentiate mucinous from nonmucinous cysts. However, the interobserver variability of string sign results has not been studied.

METHODS: An experienced endosonographer performed EUS-FNA of pancreatic cysts on different patients and was recorded on video performing the string sign test for each. The videos were shared internationally with 14 experienced endosonographers, with a survey for each video: "Is the string sign positive?" and "If the string sign is positive, what is the length of the formed string?" Also asked "What is …

An International Study Of Interobserver Variability Of “String Sign” Of Pancreatic Cysts Among Experienced Endosonographers, Wanda Phipatanakul, David T Mauger, Theresa W Guilbert, Leonard B Bacharier, Sandy Durrani, Daniel J Jackson, Fernando D Martinez, Anne M Fitzpatrick, Amparito Cunningham, Susan Kunselman, Lisa M Wheatley, Cindy Bauer, Carla M Davis, Bob Geng, Kirsten M Kloepfer, Craig Lapin, Andrew H Liu, Jacqueline A Pongracic, Stephen J Teach, James Chmiel, Jonathan M Gaffin, Matthew Greenhawt, Meera R Gupta, Peggy S Lai, Robert F Lemanske, Wayne J Morgan, William J Sheehan, Jeffrey Stokes, Peter S Thorne, Hans C Oettgen, Elliot Israel

Faculty, Staff and Students Publications

Asthma remains one of the most important challenges to pediatric public health in the US. A large majority of children with persistent and chronic asthma demonstrate aeroallergen sensitization, which remains a pivotal risk factor associated with the development of persistent, progressive asthma throughout life. In individuals with a tendency toward Type 2 inflammation, sensitization and exposure to high concentrations of offending allergens is associated with increased risk for development of, and impairment from, asthma. The cascade of biological responses to allergens is primarily mediated through IgE antibodies and their production is further stimulated by IgE responses to antigen exposure. In …

Small-Molecule Inhibitor Of Af9/Enl-Dot1l/Af4/Aff4 Interactions Suppresses Malignant Gene Expression And Tumor Grow, Fangrui Wu, Shenyou Nie, Yuan Yao, Tong Huo, Xin Li, Xiaowei Wu, Jidong Zhao, Yi-Lun Lin, Yinjie Zhang, Qianxing Mo, Yongcheng Song

Faculty, Staff and Students Publications

Chromosome translocations involving mixed lineage leukemia (MLL) gene cause acute leukemia with a poor prognosis. MLL is frequently fused with transcription cofactors AF4 (~35%), AF9 (25%) or its paralog ENL (10%). The AHD domain of AF9/ENL binds to AF4, its paralog AFF4, or histone-H3 lysine-79 (H3K79) methyltransferase DOT1L. Formation of AF9/ENL/AF4/AFF4-containing super elongation complexes (SEC) and the catalytic activity of DOT1L are essential for MLL-rearranged leukemia. Protein-protein interactions (PPI) between AF9/ENL and DOT1L/AF4/AFF4 are therefore a potential drug target.

Methods: Compound screening followed by medicinal chemistry was used to find inhibitors of such PPIs, which were examined for their biological …

A Novel Statistical Method For Interpreting The Pathogenicity Of Rare Variants, Jun Wang, Hehe Liu, Renae Elaine Bertrand, Alejandro Sarrion-Perdigones, Yezabel Gonzalez, Koen J T Venken, Rui Chen

Faculty, Staff and Students Publications

PURPOSE: To achieve the ultimate goal of personalized treatment of patients, accurate molecular diagnosis and precise interpretation of the impact of genetic variants on gene function is essential. With sequencing cost becoming increasingly affordable, the accurate distinguishing of benign from pathogenic variants becomes the major bottleneck. Although large normal population sequence databases have become a key resource in filtering benign variants, they are not effective at filtering extremely rare variants.

METHODS: To address this challenge, we developed a novel statistical test by combining sequencing data from a patient cohort with a normal control population database. By comparing the expected and …

Lrrtm4 Is A Member Of The Transsynaptic Complex Between Rod Photoreceptors And Bipolar Cells, Melina A Agosto, Theodore G Wensel

Faculty, Staff and Students Publications

Leucine rich repeat transmembrane (LRRTM) proteins are synaptic adhesion molecules with roles in synapse formation and signaling. LRRTM4 transcripts were previously shown to be enriched in rod bipolar cells (BCs), secondary neurons of the retina that form synapses with rod photoreceptors. Using two different antibodies, LRRTM4 was found to reside primarily at rod BC dendritic tips, where it colocalized with the transduction channel protein, TRPM1. LRRTM4 was not detected at dendritic tips of ON-cone BCs. Following somatic knockout of LRRTM4 in BCs by subretinal injection and electroporation of CRISPR/Cas9, LRRTM4 was abolished or reduced in the dendritic tips of transfected …

Mitochondrial Regulation Of Diabetic Kidney Disease, Daniel L Galvan, Koki Mise, Farhad R Danesh

Faculty, Staff and Students Publications

The role and nature of mitochondrial dysfunction in diabetic kidney disease (DKD) has been extensively studied. Yet, the molecular drivers of mitochondrial remodeling in DKD are poorly understood. Diabetic kidney cells exhibit a cascade of mitochondrial dysfunction ranging from changes in mitochondrial morphology to significant alterations in mitochondrial biogenesis, biosynthetic, bioenergetics and production of reactive oxygen species (ROS). How these changes individually or in aggregate contribute to progression of DKD remain to be fully elucidated. Nevertheless, because of the remarkable progress in our basic understanding of the role of mitochondrial biology and its dysfunction in DKD, there is great excitement …

Long Noncoding Rnas And Their Therapeutic Promise In Diabetic Nephropathy, Juan D Coellar, Jianyin Long, Farhad R Danesh

Faculty, Staff and Students Publications

Recent advances in large-scale RNA sequencing and genome-wide profiling projects have unraveled a heterogeneous group of RNAs, collectively known as long noncoding RNAs (lncRNAs), which play central roles in many diverse biological processes. Importantly, an association between aberrant expression of lncRNAs and diverse human pathologies has been reported, including in a variety of kidney diseases. These observations have raised the possibility that lncRNAs may represent unexploited potential therapeutic targets for kidney diseases. Several important questions regarding the functionality of lncRNAs and their impact in kidney diseases, however, remain to be carefully addressed. Here, we provide an overview of the main …

Genomic Mapping Of Dna-Repair Reaction Intermediates In Living Cells With Engineered Dna Structure-Trap Proteins, Jingjing Liu, Qian Mei, Sadeieh Nimer, Devon M Fitzgerald, Susan M Rosenberg

Faculty, Staff and Students Publications

Diverse DNA structures occur as reaction intermediates in various DNA-damage and -repair mechanisms, most of which results from replication stress. We harness the power of proteins evolutionarily optimized to bind and "trap" specific DNA reaction-intermediate structures, to quantify the structures, and discern the mechanisms of their occurrence in cells. The engineered proteins also allow genomic mapping of sites at which specific DNA structures occur preferentially, using a structure-trapping protein and ChIP-seq- or Cut-and-Tag-like methods. Genome-wide identification of sites with recurrent DNA-damage intermediates has illuminated mechanisms implicated in genome instability, replication stress, and chromosome fragility. Here, we describe X-seq, for identifying …

Study Of Student Resource Use In Introductory Chemistry Courses, Sarah E. Melvin

College of Graduate Studies: Theses & Dissertations

According to the U.S. Government Accountability Office (GAO), college textbook prices have increased by 186% from 1986 to 2004.1 The impact of rising cost of textbooks is increasingly apparent as students are becoming more selective in the courses they enroll in, as well as more concerned with the quality of the learning experience they receive once enrolled in a course.¹ In response to high textbook prices, open-education resources (OER) are increasingly becoming more accepted for student use as an alternative to traditional textbook options. OERs are open-source textbook and/or materials that are free to use without worrying about copyright …

Transcriptional Repressor Protein Based Macrolide Biosensor Development With Improved Sensitivity, Jayani A. Christopher

Graduate Research Posters

Macrolide antibiotics are in high demand for clinical applications. Macrolides are biosynthesized via giant assembly line polyketide synthases (PKS) which are arranged in a modular fashion. Combinatorial biosynthetic methods have been used to produce diversified macrolides by reprograming these modules and modifying tailoring enzymes required for post synthetic modifications. However it is challenging due to the size and complexity of PKSs. To overcome this challenge, new enzymes for macrolide diversification could be obtained by directed evolution where a large number of enzyme variants need to be screened. Therefore it is important to develop high throughput screening methods to identify the …

The Tumor Suppressor Par-4 Regulates Hypertrophic Obesity, Nathalia Araujo

Theses and Dissertations--Toxicology and Cancer Biology

Prostate Apoptosis Response-4 (Par-4) is a tumor suppressor ubiquitously expressed in all tissues and able to selectively induce apoptosis in cancer cells. Although well established in the context of cancer, relatively little is known about the function of Par-4 in the healthy and non-tumorigenic context. Observations from our lab showed that Par-4 knockout mouse lines were obese and displayed adipocyte hypertrophy under a normal chow diet when compared to Par-4 wild-type mice. These Par-4 knockout mice exhibited hepatic steatosis and hyperinsulinemia as secondary consequences of obesity. Par-4 knockout mice displayed increased intestinal dietary fat absorption and its subsequent storage in …

Initial And Advanced Stages Of Microbiota Establishment Within The Tsetse Fly, Miguel Eduardo Medina Munoz

Graduate Theses, Dissertations, and Problem Reports (ETD)

Symbiosis is a long-term physical association between two or more species, although little is known regarding its evolutionary origins, particularly at the genetic level. Tsetse flies are the vector of African trypanosomes, causative agents of Human and Animal African Trypanosomiases. Tsetse provide an ideal model for studying initial and advanced stages of symbiosis. Tsetse have a simple digestive tract microbiota primarily consisting of two bacteria; the ancient mutualist Wigglesworthia glossinidia and the recently acquired Sodalis glossinidius. This work presents a chronological study in evolutionary terms of the history of a microbial-insect association. First, I present concepts on symbiosis and …

Adenosine Triphosphate (Atp) As A Metric Of Microbial Biomass In Aquatic Systems: New Simplified Protocols, Laboratory Validation, And A Reflection On Data From The Literature, Alexander B. Bochdansky, Alison N. Stouffer, Nyjaee N. Washington

OES Faculty Publications

The use of adenosine triphosphate (ATP) as a universal biomass indicator is built on the premise that ATP concentration tracks biomass rather than the physiological condition of cells. However, reportedly high variability in ATP in response to environmental conditions is the main reason the method has not found widespread application. To test possible sources of this variability, we used the diatom Thalassiosira weissflogii as a model and manipulated its growth rate through nutrient limitation and through exposure to three different temperatures (15°C, 20°C, and 25°C). We simplified the ATP protocol with hot‐water or chemical extraction methods, modified a commercially available …

Marine Phytoplankton Functional Types Exhibit Diverse Responses To Thermal Change, S. I. Anderson, A. D. Barton, Sophie Clayton, S. Dutkiewicz, T. A. Rynearson

OES Faculty Publications

Marine phytoplankton generate half of global primary production, making them essential to ecosystem functioning and biogeochemical cycling. Though phytoplankton are phylogenetically diverse, studies rarely designate unique thermal traits to different taxa, resulting in coarse representations of phytoplankton thermal responses. Here we assessed phytoplankton functional responses to temperature using empirically derived thermal growth rates from four principal contributors to marine productivity: diatoms, dinoflagellates, cyanobacteria, and coccolithophores. Using modeled sea surface temperatures for 1950-1970 and 2080-2100, we explored potential alterations to each group's growth rates and geographical distribution under a future climate change scenario. Contrary to the commonly applied Eppley formulation, our …

Detrital Neodymium And (Radio)Carbon As Complementary Sedimentary Bedfellows? The Western Arctic Ocean As A Testbed, Melissa S. Schwab, Jörg D. Rickli, Robie W. Macdonald, H. Rodger Harvey, Negar Haghipour, Timothy I. Eglinton

OES Faculty Publications

Interactions between organic and detrital mineral phases strongly influence both the dispersal and accumulation of terrestrial organic carbon (OC) in continental margin sediments. Yet the complex interplay among biological, chemical, and physical processes limits our understanding of how organo-mineral interactions evolve during sediment transfer and burial. In particular, diverse OC sources and complex hydrodynamic processes hinder the assessment of how the partnership of organic matter and its mineral host evolves during supply and dispersal over continental margins. In this study, we integrate new and compiled sedimentological (grain size, surface area), organic (%OC, OC-δ¹³C, OC-F¹⁴C), and inorganic …

From Inner Segment To Outer Segment: Palmitoylation Of Photoreceptor Na+, K+-Atpase And The Importance Of Prcd In Photoreceptor Outer Segment Morphogenesis, Emily R. Sechrest

Graduate Theses, Dissertations, and Problem Reports (ETD)

Photoreceptors are specialized neuroepithelial cells which are optimized for efficient capture of light and initiation of visual transduction. These cells have several compartments which are very important for proper visual function and segregation of cellular processes, including the outer segment (OS), inner segment (IS), nucleus, and synapse. The IS houses all of the cellular organelles and biosynthetic molecular machinery the cell requires and is the site of protein synthesis. The light-sensing OS is a highly modified, primary cilium, which contains many stacks of double membranous discs which house proteins required for formation and maintenance of OS structure, as well as …

Huntingtin Aggregation At Interfaces Associated With Membranes And Organelles, Adewale Vincent Adegbuyiro

Graduate Theses, Dissertations, and Problem Reports (ETD)

Huntington’s Disease (HD) is a genetic neurodegenerative disease caused by the expansion of polyglutamine (polyQ) domain within the first exon (exon1) of the huntingtin (htt) protein. Due to this mutation within the polyQ domain, htt aggregates into various toxic species such as oligomers, fibrils, and other amorphous aggregates. While the aggregation of htt strongly correlates with polyQ length, other factors, e.g. interaction with membranes or organelles and posttranslational modifications (PTMs), modulate aggregation. The first 17 N-terminal amino acids (Nt17) that precede the polyQ in htt-exon1 enhances aggregation and facilitated binding of htt to membranous organelles, promoting morphological changes and disfunction. …

The Receptor Basis Of Serotonergic Modulation In An Olfactory Network, Tyler Ryan Sizemore

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neuromodulation is a nearly ubiquitous process that endows the nervous system with the capacity to alter neural function at every level (synaptic, circuit, network, etc.) without necessarily adding new neurons. Through the actions of neuromodulators, the existing neural circuitry can be adaptively tuned to achieve flexible network output and similarly dynamic behavioral output. However, despite their near ubiquity in all sensory modalities, the mechanisms underlying neuromodulation of sensory processing remain poorly understood. In this dissertation, I address three main questions regarding the mechanisms of one modulator (serotonin) within one sensory modality (olfaction). I begin by establishing a "functional atlas" of …