Biochemistry, Biophysics, and Structural Biology Commons^™

Transcriptional Mechanisms Of Neuroprotection In Excitotoxicity Driven Neurodegeneration In C. Elegans, Zelda Z. Mendelowitz

Dissertations, Theses, and Capstone Projects

Excitotoxicity is notorious for triggering neuronal cell death in both developmental and adult-onset neurodegenerative diseases. In excitotoxicity, excessive concentrations of Glutamate in the synapse overstimulate Glutamate Receptors (GluRs) on postsynaptic neurons. While GluR mediated degenerative mechanisms remain obscure, GluR activation was surprisingly found to also have a neuroprotective effect through activation of specific transcriptional programs. To identify evolutionarily conserved transcriptional programs in neuroprotection we use a C. elegans model of excitotoxic necrosis (glt-3;nuIs5). We have identified that non-canonical activation of the transcription factor CRH-1/CREB mediates neuroprotection in our excitotoxicity model. We found the Histone Acetyl Transferase, MYS-1/KAT6, and the neuronal …

Prenatal Choline Supplementation During Maternal Obesity Alters Offspring Response To Western Diets, Hunter W. Korsmo

Dissertations, Theses, and Capstone Projects

Maternal obesity has led to an increase in adverse offspring developmental outcomes and a greater risk for long-term metabolic diseases. Choline, a semi-essential nutrient, can be incorporated into phosphatidylcholine (PC) as well as sphingomyelin (SM) and donate its labile methyl group for the remethylation of homocysteine after choline is oxidized to betaine. Prenatal choline insufficiency has been related to maternal obesity and metabolic diseases, such as metabolic associated fatty liver disease (MAFLD). Choline may interact with maternal obesity to influence the programming offspring.

Chapter 1 presents an introduction of choline and the various clinical outcomes associated with choline supplementation during …

Role Of Nuclear Lamins In Oligodendrocyte Lineage Cells, Camila Yattah

Dissertations, Theses, and Capstone Projects

Differentiation of oligodendrocytes from progenitor cells is a highly regulated process characterized by a series of molecular changes, resulting in nuclear and morphological features unique to the mature oligodendrocyte state. Heterochromatin formation starting at the nuclear periphery, as well as increased nuclear rigidity are characteristically observed. The nuclear periphery is characterized by the presence of the nuclear lamina and it has been implicated in higher-order genome organization in cells. Lamins are the protein components of the nuclear lamina, and their expression is dependent upon the cell differentiation stage of the cells. While Lamin B1 (LMNB1) expression is high in progenitors …

Isolation And Characterization Of Fluorescent Proteins And Small Molecules From Marine Vertebrates, Sara Rose Krivoshik

Dissertations, Theses, and Capstone Projects

Fluorescence is a phenomenon in which a wavelength of light excites a fluorophore and then emits light at a higher, longer wavelength. This occurs throughout the biological world, in both the terrestrial and marine realms. Encompassing a diverse set of mechanisms from small molecules to large protein complexes; fluorescence has been used as a biological tool with a wide range of applications to study molecular and cellular biology for decades. This dissertation looks to identify and characterize novel fluorescent proteins and small molecules to allow for more efficient translation in developing new biotechnologies. Using a combination of RNA-Seq, Mass-Spec, protein …

Determining The Roles Of The Oligomerization And C-Terminal Domains In Mutant P53 Gain-Of-Function Activities, George K. Annor

Dissertations, Theses, and Capstone Projects

The tumor suppressor p53 (TP53) gene is often mutated in cancer, with missense mutations found in the central DNA binding domain, and less often in the oligomerization domain (OD) and C-terminal domain (CTD). The OD and CTD have been found to be critical for the tumor suppressor functionality of wild-type p53 (wtp53). Specific missense mutations in the DNA binding domain have been found to confer new gain-of-function (GOF) activities. Mutations that destabilize tetramer formation, or deletion of key lysine residues within the CTD, downregulate the ability of wtp53 to transactivate (increase the rate of transcription of) its target …

Novel Therapeutic Strategies For Alzheimer’S Disease: Prostaglandin D2 Signaling And Its Human Polymorphisms As Well As A Polypharmacological Approach, Charles H. Wallace

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is an age related neurodegenerative disease with pathology that includes amyloid plaques, neurofibrillary tangles and non-resolving neuroinflammation. Non-resolving neuroinflammation lasts the entire course of the disease and has deleterious effects and is often thought to accelerate AD pathology. Non-Steroidal Anti-inflammatory Drugs (NSAIDs) have commonly been used as therapeutics to treat pain, inflammation and vascular. NSAIDs work by altering the cyclooxygenase (COX) mediated biosynthesis of prostaglandins which are lipid mediators that have many physiological functions, for example nociception, inflammation and vasodilation. Epidemiological studies support the notion that NSAIDs could be used to treat AD. Yet, clinical trials using …

Biochemical And Biophysical Characterization Of Replicative Helicase Loading By Vibrio Cholerae Dcia, Crystal Structure Of A Monoclonal Antibody Bound To A C-Terminal Fragment Of Ebna-1 From Epstein Barr Virus, Nicholas Gao

Dissertations, Theses, and Capstone Projects

DNA replication initiation is mediated by the binding of an initiator protein to genomic origins of replication to begin the process of loading replicative helicases onto the genome. The loading of the helicase requires the action of an accessory protein, named a “loader”. Studies on well-characterized loaders have outlined how the bacterial DnaB replicative helicase is loaded via mechanisms of “Ring-Breaking” by E. coli DnaC (EcDnaC)/protein P from bacteriophage lambda (LP) and “Ring-Making” by B. subtilis DnaI. Mounting evidence points to a recently discovered candidate loader, named DciA, that shows a more widespread distribution throughout bacteria than DnaC and DnaI …

Generation Of Mycobacterium Smegmatis Model Systems For Testing Inhibitors Of The Mycobactin Siderophore Of Mycobacterium Tuberculosis, Gabrielle A. Germain

Dissertations, Theses, and Capstone Projects

Mycobacterium tuberculosis (Mtb) is the pathogenic bacterium causative of tuberculosis. According to the 2021 World Health Organization (WHO) Global Tuberculosis (TB) Report, there were approximately 5.8 million TB cases in 2020, and 1.3 million TB deaths among HIV negative people in that year. The rise of multi-drug resistant Mtb strains has increased the need for more potent microbials against this pathogen. Biosynthesis of iron scavenging molecules, known as siderophores (e.g., mycobactin and carboxymycobactin), has been identified as a potential drug target candidate since iron acquisition has been directly linked to the survival and virulence of Mtb. Salicyl-AMS (Sal-AMS) is …

Conformation Of The U12-U6atac Snrna Complex Of The Minor Spliceosome And Binding By Ntc-Related Protein Rbm22, Joanna Ciavarella

Dissertations, Theses, and Capstone Projects

Splicing of precursor messenger (pre-m)RNA is a critical process in eukaryotes in which the non-coding regions, called introns, are removed and coding regions, or exons, are ligated to form a mature mRNA. This process is catalyzed by the spliceosome, a multi-mega Dalton ribonucleoprotein complex assembled from five small nuclear ribonucleoproteins (snRNP) in the form of small nuclear (sn)RNA-protein complexes (U1, U2, U4, U5 and U6) and >100 proteins. snRNA components catalyze the two transesterification reactions while proteins perform critical roles in assembly and rearrangement. U2 and U6 snRNAs are the only snRNAs directly implicated in catalyzing the splicing of pre-mRNA. …

Novel Therapeutic Strategies For Alzheimer’S Disease: Targeting Toll-Like Receptor Signaling And A Multi-Target Approach, Giovanni Oliveros

Dissertations, Theses, and Capstone Projects

Alzheimer’s disease (AD) is multifactorial, and its hallmarks include the formation of amyloid-beta (Ab) plaques and neurofibrillary tau tangles, accompanied by an increase in glial cell activation, culminating in neurodegeneration, chronic neuroinflammation, and cognitive decline in human patients. AD will cost the United States over $300 million this year alone and is projected to cost over $1 trillion by 2050, AD is a serious concern for the aging population, and efforts need to be redirected towards more effective therapeutic intervention strategies. Drugs aimed at halting AD progression have so far proven unsuccessful due to the development of pharmaceuticals that target …

Methods For Bioconjugation Of Biochemical Sensors Based On Metallic Nanoparticles, Jacob Rolin

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Assessing Biochemistry Students’ Use Of Metabolic Pathway Entities, Nina Fortier

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Assessing Undergraduate Expression Of Biochemical Mechanisms, Lauren Richardson

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Mechanism Of Activation And Regulation Of By-Kinases, A Unique Family Of P-Loop Enzymes, Fatlum Hajredini

Dissertations, Theses, and Capstone Projects

The bacterial tyrosine kinases (BY-kinase) represent a class of membrane-bound enzymes that utilize a cycle of auto-phosphorylation and de-phosphorylation to drive the synthesis and export of exopolysaccharides in both Gram-positive and Gram-negative bacteria. The catalytic domain of BY-kinases utilizes a P-loop nucleoside triphosphatase (NTPase) fold that is commonly used by NTPases and small molecule kinases, being the only protein kinase to do so. In the work presented in this thesis, we aimed to obtain an understanding of the mechanisms of the BY-kinases’ unconventional deployment of P-loop scaffold to phosphorylate on tyrosine. We used the BY-kinase of Escherichia coli (K12) as …

Cell-Intrinsic Melanin Fails To Protect Melanocytes From Ultraviolet-Mutagenesis In The Absence Of Epidermal Melanin, Tirzah J. Weiss, Emma R. Crawford, Valentina Posada, Hafeez Rahman, Tong Liu, Brandon M. Murphy, Tiffany E. Arnold, Shannon Gray, Zhexuan Hu, Rebecca C. Hennessey, Lianbo Yu, John August D'Orazio, Craig J. Burd, Jonathan H. Zippin, Douglas Grossman, Christin E. Burd

Markey Cancer Center Faculty Publications

Melanin is a free-radical scavenger, antioxidant, and broadband absorber of ultraviolet (UV) radiation which protects the skin from environmental carcinogenesis. However, melanin synthesis and UV-induced reactive melanin species are also implicated in melanocyte genotoxicity. Here, we attempted to reconcile these disparate functions of melanin using a UVB- sensitive, NRAS-mutant mouse model, TpN. We crossed TpN mice heterozygous for an inactivating mutation in Tyrosinase to produce albino and black littermates on a C57BL/6J background. These animals were then exposed to a single UVB dose on postnatal day three when keratinocytes in the skin have yet to be melanized. Approximately one-third (35%) …

Helical Remodeling Augments 5-Lipoxygenase Activity In The Synthesis Of Proinflammatory Mediators, Eden M. Gallegos, Tanner D. Reed, Forge A. Mathes, Nelson V. Guevara, David B. Neau, Wei Huang, Marcia E. Newcomer, Nathaniel C. Gilbert

School of Medicine Faculty Publications

The synthesis of proinflammatory leukotrienes implicated in asthma, allergic rhinitis, and atherosclerosis is initiated by the enzyme 5-lipoxygenase (5-LOX). The crystal structure of human Stable-5-LOX revealed a conformation where the catalytic iron was inaccessible to bulk solvent as two aromatic residues on a conserved helix-α2 (Hα2) plugged the substrate access portal. Whether 5-LOX can also adopt a more open conformation has not been resolved. Here, we present a new conformation of 5-LOX where Hα2 adopts an elongated conformation equivalent to that described in other animal lipoxygenase structures. Our observation of the sigmoidal kinetic behavior of 5-LOX, which is indicative of …

Lifestyle Intervention Strategy To Treat Diabetes In Older Adults: A Randomized Controlled Trial, Alessandra Celli, Yoann Barnouin, Bryan Jiang, Dean Blevins, Georgia Colleluori, Sanjay Mediwala, Reina Armamento-Villareal, Clifford Qualls, Dennis T Villareal

Faculty, Staff and Students Publications

OBJECTIVE: Lifestyle intervention is recommended as first-line treatment of diabetes at all ages; however, little is known about the efficacy of lifestyle intervention in older adults with diabetes. We aimed to determine whether lifestyle intervention would improve glycemic control and age-relevant outcomes in older adults with diabetes and comorbidities.

RESEARCH DESIGN AND METHODS: A total of 100 older adults with diabetes were randomly assigned to 1-year intensive lifestyle intervention (ILI) (diet and exercise at a facility transitioned into community-fitness centers and homes) or healthy lifestyle (HL) group. The primary outcome was change in HbA1c. Secondary outcomes included glucoregulation, body composition, …

Limited Utility Of Structural Mri To Identify The Epileptogenic Zone In Young Children With Tuberous Sclerosis, Maaike Nijman, Edward Yang, Camilo Jaimes, Anna K Prohl, Mustafa Sahin, Darcy A Krueger, Joyce Y Wu, Hope Northrup, Scellig S D Stone, Joseph R Madsen, Aria Fallah, Jeffrey P Blount, Howard L Weiner, Leslie Grayson, E Martina Bebin, Brenda E Porter, Simon K Warfield, Sanjay P Prabhu, Jurriaan M Peters, Tacern Study Group

Faculty, Staff and Students Publications

BACKGROUND AND PURPOSE: The success of epilepsy surgery in children with tuberous sclerosis complex (TSC) hinges on identification of the epileptogenic zone (EZ). We studied structural MRI markers of epileptogenic lesions in young children with TSC.

METHODS: We included 26 children with TSC who underwent epilepsy surgery before the age of 3 years at five sites, with 12 months or more follow-up. Two neuroradiologists, blinded to surgical outcome data, reviewed 10 candidate lesions on preoperative MRI for characteristics of the tuber (large affected area, calcification, cyst-like properties) and of focal cortical dysplasia (FCD) features (cortical malformation, gray-white matter junction blurring, …

Sustained Deep-Tissue Voltage Recording Using A Fast Indicator Evolved For Two-Photon Microscopy, Zhuohe Liu, Xiaoyu Lu, Vincent Villette, Yueyang Gou, Kevin L Colbert, Shujuan Lai, Sihui Guan, Michelle A Land, Jihwan Lee, Tensae Assefa, Daniel R Zollinger, Maria M Korympidou, Anna L Vlasits, Michelle M Pang, Sharon Su, Changjia Cai, Emmanouil Froudarakis, Na Zhou, Saumil S Patel, Cameron L Smith, Annick Ayon, Pierre Bizouard, Jonathan Bradley, Katrin Franke, Thomas R Clandinin, Andrea Giovannucci, Andreas S Tolias, Jacob Reimer, Stéphane Dieudonné, François St-Pierre

Faculty, Staff and Students Publications

Genetically encoded voltage indicators are emerging tools for monitoring voltage dynamics with cell-type specificity. However, current indicators enable a narrow range of applications due to poor performance under two-photon microscopy, a method of choice for deep-tissue recording. To improve indicators, we developed a multiparameter high-throughput platform to optimize voltage indicators for two-photon microscopy. Using this system, we identified JEDI-2P, an indicator that is faster, brighter, and more sensitive and photostable than its predecessors. We demonstrate that JEDI-2P can report light-evoked responses in axonal termini of Drosophila interneurons and the dendrites and somata of amacrine cells of isolated mouse retina. JEDI-2P …

Mechanisms Of Substrate Selectivity And Transport By Escherichia Coli Atp- Binding Cassette (Abc) Transporter Metni, Yuchun Chen

Master's Theses

ABC transporters are central in many cellular functions including nutrient uptake, signal transduction membrane assembly, and cellular detoxification. Both structural and functional studies have revealed insights into the high-affinity uptake mechanism of the MetNI methionine ABC transporter. Using the energy from ATP binding and hydrolysis, the MetNI-Q system can import L-Met, D-Met, and other methionine derivatives against concentration gradients. Many mechanistic studies of ABC transporter propose a model in which cognate binding proteins sequester substrates in the periplasm and deliver them to the transporter. In contrast, recent in vivo and crystallographic studies of MetNI-Q suggest that some substrates may be …