Biochemistry, Biophysics, and Structural Biology Commons^™

The Role Of Fbxl16 In Regulating Erk3 Stability And Cell Migration, Seth Charles Murdock

Browse all Theses and Dissertations

Extracellular signal-regulated kinase 3 (ERK3) is a member of the atypical mitogen-activated protein kinase (MAPK) family. While ERK3’s role in promoting cell migration and invasion in multiple types of cancer has been well-documented, its activation and regulation remain poorly understood. Unlike other typical MAPK proteins, whose activation is regulated via the phosphorylation of an upstream kinase, ERK3 is regulated through its abundance, as it is constitutively phosphorylated when present in the cell. While USP20 has been established as a deubiquitinating protein that stabilizes ERK3 by preventing its degradation, both TRIM21 and FBXW7 have been identified as E3 ligases that target …

Optimization Of L-Citrulline Production In Corynebacterium Glutamicum, And The Effect Of The Human Small Intestine Environment, Simran S. Ghulldu

Honors Undergraduate Theses

L-citrulline is a crucial amino acid involved in nitric oxide production, which supports cardiovascular health, physical performance, and intestinal well-being. Nitric oxide deficiency is linked to conditions like hypertension, highlighting the need for efficient L-citrulline production. This study attempts to enhance L-citrulline synthesis in Corynebacterium glutamicum, a bacterium widely used in industrial amino acid production, as well as test a The hypothesis is that overexpressing carAB, which encodes carbamoyl phosphate synthetase, will increase carbamoyl phosphate levels and boost L-citrulline production. Two C. glutamicum strains were used: a wild type and the CRBG strain, which has mutations that promote …

Investigating Mono-Driver Versus Multi-Driver Oncogenesis Via Alterations To Cell Signaling Pathways, Abygail Chapdelaine

Open Access Dissertations

The latest edition of Global Cancer Statistics released by the American Cancer Society reported approximately 20 million newly diagnosed cancer cases worldwide in 2022 with 9.7 million deaths. This ranks cancer as the second leading cause of death worldwide. For the majority of cancer patients, the standard treatment approach is chemotherapy and/or radiation therapy, and while this has been successful in some patients, a lack of specificity to cancer cells causes severe side-effects when these agents damage healthy cells. Despite extensive efforts that have gone into developing targeted cancer therapeutics that block functions specific to cancer, they have not been …

Temporal Dynamics Of Programmed Genome Rearrangement In Sea Lamprey Embryogenesis: A Deep Learning & Lightsheet Imaging Approach To Studying Early Developmental Transitions, Kasturi Rajandran

Theses and Dissertations--Biology

Programmed genome rearrangement (PGR) in the sea lamprey (Petromyzon marinus) leads to the elimination of ~0.5Gb (20%) of the germline genome during early embryogenesis, yet its timing relative to the maternal-to-zygotic transition (MZT) remains unclear. In this study, we imaged embryos cleared at 3-hour intervals (up to 72 hours post fertilization (hpf)) using high-resolution lightsheet fluorescence microscopy and a custom deep-learning image-analysis pipeline (~80% accuracy) to quantify nuclei and micronuclei counts. Micronuclei, which are the hallmarks of PGR first appear between 24 to 27hpf (vs ~36hpf previously reported) indicating PGR starts earlier than previously reported in the sea …

The Adiponectin-Pparγ Axis In Hepatic Stellate Cells Regulates Liver Fibrosis, Shangang Zhao, Qingzhang Zhu, Wang-Hsin Lee, Jan-Bernd Funcke, Zhuzhen Zhang, May-Yun Wang, Qian Lin, Bianca Field, Xue-Nan Sun, Guannan Li, Mbolle Ekane, Toshiharu Onodera, Na Li, Yi Zhu, Christine M. Kusminski, Terry D. Hinds Jr., Philipp E. Scherer

Markey Cancer Center Faculty Publications

Hepatic stellate cells (HSCs) are key drivers of local fibrosis. Adiponectin, conventionally thought of as an adipokine, is also expressed in quiescent HSCs. However, the impact of its local expression on the progression of liver fibrosis remains unclear. We recently generated a transgenic mouse line (Lrat-rtTA) that expresses the doxycycline-responsive transcriptional activator rtTA under the control of the HSC-specific lecithin retinol acyltransferase (Lrat) promoter, which enables us to specifically and inducibly overexpress or eliminate genes in these cells. The inducible elimination of HSCs protects mice from methionine/choline-deficient (MCD) diet-induced liver fibrosis, confirming their causal involvement in fibrosis development. We generated …

Urobilin Derived From Bilirubin Bioconversion Binds Albumin And May Interfere With Bilirubin Interacting With Albumin: Implications For Disease Pathology, Kevin I. Williams, Priyanka Suryadevara, Chang-Guo Zhan, Terry D. Hinds Jr., Zachary A. Kipp

Markey Cancer Center Faculty Publications

Background/Objectives: Bilirubin is a hydrophobic molecule that binds the carrier protein albumin for transport through systemic circulation. Bilirubin is cleared from the body through the liver and excreted into the intestines, where the microbiota modifies the chemical structure, forming urobilin, which can be reabsorbed into circulation by the hepatic portal vein. Urobilin has no known function. It is also unknown whether urobilin binds albumin for transport in circulation. We hypothesized that because of the likeness of their chemical structures, urobilin would also bind albumin like bilirubin does. Methods: First, we used in silico docking to predict if urobilin would bind …

Dissecting The Biophysical Mechanisms Of Oleate Hydratase Association With Membranes, William A. Lathram, Robert J. Neff, Ashley N. Zalla, James D. Brien, Vivekanandan Subramanian, Christopher D. Radka

Markey Cancer Center Faculty Publications

This study investigates the dynamics of oleate hydratase (OhyA), a bacterial flavoenzyme from Staphylococcus aureus, and its interactions with lipid membranes, focusing on the factors influencing membrane binding and oligomerization. OhyA catalyzes the hydration of unsaturated fatty acids, playing a key role in bacterial pathogenesis by neutralizing host antimicrobial fatty acids. OhyA binds the membrane bilayer to access membrane-embedded substrates for catalysis, and structural studies have revealed that OhyA forms oligomers on membrane surfaces, stabilized by both protein-protein and protein-lipid interactions. Using fluorescence correlation spectroscopy (FCS), we examined the effects of membrane curvature and lipid availability on OhyA binding to …

Investigating Rna Dysfunction Of Inherited Neuromuscular And Neurodevelopmental Disease, Jacob H. Schroader

Electronic Theses & Dissertations (2024 - present)

ITPase deficiency is a rare but fatal, autosomal recessive enzyme deficiency involving encephalopathy, microcephaly, congenital cataracts, hypotonia, developmental delay, and dilated cardiomyopathy. Within a decade since the original description of the severe form in humans, there are huge gaps in the field regarding the underlying molecular mechanisms driving pathogenesis resulting from ITPase deficiency. Past studies have focused on characterization of the organism level ITPase-deficient phenotype, but the molecular and cellular characterization remains to be fully described. Due to the biochemical function and established biological role of the ITPase enzyme, investigation into the consequences of inosine accumulation and misincorporation into RNA …

Technological Development Of In-Cell Nmr: Microfluidic, Metabolomic, And Fluxomic Approaches, Nicholas Sciolino

Electronic Theses & Dissertations (2024 - present)

In the fields of structural biology, metabolomics, and fluxomics, there is a driving, technique-based concern when it comes to high-resolution spectrometry and its marriage to biological and physiological relevance. Sample preparation often involves cellular perturbation, lysate separation schemes, combinations with non-biological reagents, and timeline slack. Conceptually, the farther we get from the cell, the greater the potential disparity between what exists in vivo and our in vitro manipulations. This is particularly true when seeking to collect data on transfected targets of interest, and on sensitive metabolic equilibria that occur on the order of minutes. The question remains: if we are …

Conserved A-Rich Regions In The 3’ Utr Of Zika Virus Differentially Affect Viral Gene Expression, Kristen Kaytes

Electronic Theses & Dissertations (2024 - present)

Following its discovery in 1947, Zika virus garnered little attention in the global stage until a rapidly spreading epidemic brough the virus to the global stage in 2015. Continuous advances in research have begun to further the understanding of the molecular biology of Zika virus, however much is still unknown. Much of our understanding of the virus comes from cross reference to other viruses within the same family, such as Dengue virus and West Nile virus. A commonality of these viruses is that they resemble cellular mRNAs and have a single-stranded positive-sense RNA genome that contains a 5’-cap but lacks …

Kinetic Model Of Glycolysis And Glutaminolysis Interplay Developed In Matlab Simbiology, Zohreh Mirveis, Hugh J. Byrne, Nitin Patil

Datasets

This dataset contains a kinetic model developed in MATLAB SimBiology to simulate the metabolic dynamics of glycolysis and glutaminolysis and their interconnection. The model was used in the study ‘Experimental and computational investigation of the kinetic evolution of the glutaminolysis pathway and its interplay with the glycolysis pathway’ (Mirveis et al., 2024). The dataset includes the original SimBiology project file together with the experimental data used for model training. These resources enable reproduction of the simulations reported in the publication and provide a reusable framework for further computational exploration of metabolic pathway kinetics.

Developing Novel Therapeutic Strategies For Mcrc With A Brafv600e Mutation, Mariah Geisen

Theses and Dissertations--Toxicology and Cancer Biology

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. The overall incidence rates of CRC have decreased in those over 50, but there is an increasing incidence rate in those under 50. Risk factors for CRC include diet, family history, and a sedentary lifestyle. Early detection of CRC is key to patient survival and treatment response. Localized CRC has a survival rate of 90% and allows for surgical resection and chemotherapy. The 5-year survival for metastatic CRC (mCRC) is significantly reduced to around 14%. Despite early detection, 50% of patients will develop metastasis after surgical resection and …

Swinging Lever Mechanism Of Myosin Directly Shown By Time-Resolved Cryo-Em, David P. Klebl, Sean N. Mcmillan, Cristina Risi, Eva Forgacs, Betty Virok, Jennifer L. Atherton, Sarah A. Harris, Michele Stofella, Donald A. Winkelmann, Frank Sobott, Vitold E. Galkin, Peter J. Knight, Stephen P. Muench, Charlotte A. Scarfi, Howard D. White

Department of Biomedical and Translational Sciences Faculty Publications

Myosins produce force and movement in cells through interactions with F-actin¹. Generation of movement is thought to arise through actin-catalysed conversion of myosin from an ATP-generated primed (pre-powerstroke) state to a post-powerstroke state, accompanied by myosin lever swing²,³. However, the initial, primed actomyosin state has never been observed, and the mechanism by which actin catalyses myosin ATPase activity is unclear. Here, to address these issues, we performed time-resolved cryogenic electron microscopy (cryo-EM)⁴ of a myosin-5 mutant having slow hydrolysis product release⁵,⁶. Primed actomyosin was predominantly captured 10 ms after …

Analysis Of Differential Gene Expression In Androgen-Independent Clones Derived From The Mycap Pca Cell Line, Jessie L. Tignor, Melanie Sinanian, Richard Inho Joh, David Gewirtz, Jason Reed

Undergraduate Research Posters

Androgen deprivation therapy (ADT) is a primary treatment strategy for prostate cancer (PCa), yet many tumors eventually develop androgen independence, leading to treatment resistance. To investigate the molecular changes underlying this transition, we analyzed differential gene expression in four androgen-independent (AI) clones derived from the Myc-CaP prostate cancer cell line using RNA sequencing. Gene expression profiles were compared to the parental Myc-CaP line, and differentially expressed genes (DEGs) were identified using DESeq2 and edgeR. The AI clones exhibited significant downregulation of senescence-associated genes, including Ezh2 and lamin B1, suggesting a loss of senescence-related chromatin repression. Additionally, upregulation of Wnt pathway …

Nature, Nurture, And Serial Murder: A Biocriminological Analysis Of Jeffrey Dahmer And Aileen Wuornos, Dori W. Jal

Honors Thesis

In recent years, there has been an increase in public fascination with serial killers, however current criminological explanations continue to focus on social and psychological factors, lacking commentary on potential biological implications. This thesis addresses a gap in the literature by examining how biological processes, specifically epigenetic, neurobiological, and endocrinological mechanisms, interact with environmental stressors to shape serial homicidal behavior. The goal is to determine whether serial murder can be more effectively understood through a biosocial framework that integrates biological vulnerability with lived experience, rather than relying on singular explanatory models.

Using a qualitative multiple-case study methodology, this research analyzes …

Bacteria-Engineered Vesicles For Cancer Immunotherapy: From Immunomodulation In Vitro To Anti-Tumor Effects In Melanoma Models, Lan Li

Theses and Dissertations--Chemistry

Bacterial vesicles hold immense potential in various biomedical fields. Among these, outer membrane vesicles (OMVs) produced by Gram-negative bacteria are the most extensively studied. While the exact mechanism of OMV production remains unclear, numerous environmental factors have been shown to influence both their yield and composition. In this study, we investigated the effect of three different antimicrobial families on OMV production by E. coli. Interestingly, antimicrobials within the same family did not provide the same effects on OMV yield, suggesting that OMV production may not directly correlate with the antimicrobial mechanism of action. OMVs have demonstrated tumor-inhibitory activity in multiple …

Redox Control In A Fused Electron Transfer Flavoprotein From A Thermophilic Archaeon And Expanded Significance Of A Hydrogen Bond From A Conserved Histidine Residue That Contributes To Flavin Redox Tuning And Activation For Covalent Modification, Debarati Das

Theses and Dissertations--Chemistry

In absence of O₂ as terminal electron acceptors in anaerobic bacteria and archaea, carbohydrate metabolism is 15 times less efficient compared to aerobic energy metabolism resulting in energy deficit conditions. Despite their meager resources these anaerobes were able to generate H₂ and a chemiosmotic potential able to drive energy demanding reactions such as CO₂ or N₂ fixation. These observations raised concerns as production of high energy reductants (H₂) from mediocre fuels (NADH) defied the laws of thermodynamics.

In 2008, a known mechanism “electron bifurcation” but with flavins as redox mediators instead of quinones was …

P23h Rhodopsin Accumulation Disrupts Synaptic Protein Levels In Rod Photoreceptors, Samantha Thompson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rod photoreceptors are specialized neurons located in the retina, the neural tissue that lines the back of the eye. Rod photoreceptors are necessary for dim light and peripheral vision through the photoactivation rhodopsin (Rho). Rho is synthesized in the inner segment of rods before being unidirectionally trafficked to the outer segment. In diseases such as retinitis pigmentosa (RP), Rho trafficking can be disrupted, leading to progressive rod cell death. In many cases of RP, Rho is mislocalized to the rod photoreceptor synapse (“spherule”). The impact of Rho mislocalization on spherule structure and protein organization is poorly understood. We hypothesize that …

Characterization Of Adaptive Quorum Sensing In Pseudomonas Aeruginosa, Kayla Simanek

Electronic Theses & Dissertations (2024 - present)

Pseudomonas aeruginosa is an opportunistic pathogen that is highly antibiotic resistant and causes tens of thousands of infections each year. It persists in hospitals by forming biofilms on medical equipment like ventilators and catheters, making it difficult to eradicate. Biofilm formation, among other virulence factors of P. aeruginosa, is regulated through quorum sensing, a mechanism of bacterial communication. Quorum sensing is primarily coordinated through LuxI-R type systems comprised of an autoinducer synthase and receptor, respectively. Canonically, the first system to be expressed is LasI-R, and LasR upregulates the second arm of the quorum sensing network, the RhlI-R system. Research …

Characterizing The Targeting Of Toc159 Receptors To The Chloroplast Outer Envelope Membrane And Their Role In The Assembly Of Distinct Toc Complexes, Michael Fish

Theses and Dissertations (Comprehensive)

Global agriculture and food security face challenges from climate change, population growth, and other human-driven pressures. Enhancing our understanding of plant biology, particularly chloroplast function, is critical for improving crop yield and stress resilience. As the sites of photosynthesis and key regulators of plant responses to environmental cues, chloroplasts depend on the precise import of thousands of nuclear-encoded proteins to maintain their biogenesis and function. While much is known about the core translocon components in the chloroplast outer envelope membrane that form the TOC complex, the mechanisms underlying their targeting, assembly, and regulation remain incompletely understood.

Plastids, including chloroplasts, evolved …

Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux

Theses and Dissertations (Comprehensive)

Antimicrobial resistance continues to be a burden on the global healthcare system with an estimated cost of billions of dollars and millions of deaths each year. Recently, there has been little to no development on new antibiotics to treat bacterial infection, and any that are developed become resisted to within a few years. Both Gram-positive and Gram-negative bacteria contain a mesh-like layer called peptidoglycan (PG) that surrounds their cells providing strength, cell shape, and protection from their environments. This layer is a polymer of N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) connected via a b-1,4-glycosidic bond, with each strand being cross-linked …

Structural Insights Into Peptidoglycan O-Acetylation In Gram-Negative Bacteria, Tyler Malloch

Theses and Dissertations (Comprehensive)

The Centres for Disease Control has acknowledged that we are entering a post-antibiotic era, where increasing numbers of bacterial pathogens are becoming resistant to known antibiotics. One of the most successfully targeted features of bacteria is also the main component of the cell wall, peptidoglycan (PG). PG is a heteropolymer of alternating sugar residues, namely N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) which are joined together by b-(1,4)-glycosidic bonds and crosslinked via stem peptide chains. PG is a target, readily lysed by exogenous and endogenous autolysins, such as lysozyme and lytic transglycosylase, respectively. This event leads to cell death …

Exploring The Interconnections Between Mitochondrial Carrier Proteins Involved In Energy Transfer: The Case Of Uncouplig Proteins 2 And 4, Adenine Nucleotide Translocase, And Phosphate Translocase, Marzieh Tabefam

Theses and Dissertations (Comprehensive)

Mitochondrial carrier (MC) proteins play an essential role in cellular energy metabolism by mediating the transport of solutes and protons across the mitochondrial inner membrane (MIM). This thesis explores the structural and functional characteristics of three groups of MC proteins—Uncoupling Proteins (UCPs), Adenine Nucleotide Translocase (ANT), and Phosphate Translocase (P_iT)—to elucidate their individual and interrelated cooperative roles in mitochondrial proton transport and energy regulation.

The study develops and applies novel methodologies for the overexpression, purification, and reconstitution of MC proteins into model lipid bilayers mimicking the native mitochondrial inner membrane environment. These methods ensure proteins maintain their native-like …

Regulation And Function Of Mec-2 Alternative Splicing In Single Cells, Canyon Calovich-Benne

Biological Sciences Theses and Dissertations

One mechanism for generating diversity at the single cell level is selective expression of a unique set of transcription factors (TFs) and RNA binding proteins (RBPs). These regulatory factors contribute to functions of cells by controlling cell fate, turning genes on and off, and processing of transcripts either co- or post-transcriptionally. Many genes, especially neuronal genes, have multiple different splicing events, promoters, and/or polyadenylation sites. Post-transcriptional coordination is in the infancy of being studied and the functional consequences of this coupling at the single cell level has yet to be explored. Here we show, mec-2 coordination of alternative transcription start …

Interactions Of The Sars-Cov-2 Viral Genome 3’-Untranslated Region With Viral And Host Rnas, Caleb Frye, Mihaela Rita Mihailescu

Electronic Theses and Dissertations

This dissertation focuses on the characterization of RNA-RNA interactions within the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and with host microRNAs. As the causative agent of coronavirus disease 2019 (COVID-19), SARS-CoV-2 has evolved rapidly since its appearance. This has warranted prompt characterization of the virus particularly of its single stranded RNA (ssRNA) genome. By using a combination of bioinformatics, biophysics, and/or biological assays, we analyzed the SARS-CoV-2 viral genomic RNA and uncovered interactions of genomic RNA with host RNAs, highlighting an underutilized method of targeting RNA viruses. We showed here that the conserved elements in the viral genomic …

P85Α Degradation Mediated By Ubiquitin E3 Ligase Fbxo21 Offers Therapeutic Potential In Leukemia, Kasidy K. Weber

Theses & Dissertations

Acute myeloid leukemia (AML) is a complex and heterogeneous disease characterized by the clonal expansion of myeloid blasts in the bone marrow. Despite significant therapeutic advances over the years, the prognosis for AML patients remains dismal, with high relapse rates and poor overall survival. The ubiquitin-proteasome system (UPS) plays a critical role in maintaining cellular homeostasis by regulating the degradation of proteins involved in essential processes such as cell cycle control, DNA repair, apoptosis, and various signaling pathways. Given this vital function, targeting ubiquitin E3 ligases within the UPS presents a promising strategy for developing more effective and targeted therapies …

Investigating Tumor Growth And Regulation In Supratentorial Ependymomas; The Impact Of Dlk1 And Egr1 Knockout, Om Sinojia

Honors Scholar Theses

Ependymomas (EPNs) are primary brain tumors that often arise from radial glial cells lining the ventricular system. Supratentorial ependymomas (ST-EPNs) are particularly aggressive, and understanding the molecular factors driving their growth is critical for developing targeted therapies. This study investigates the roles of DLK1 and EGR1, key regulators in cellular differentiation and tumorigenesis, in the development of ST-EPNs. We utilized genetically engineered mouse models to induce postnatal knockouts of DLK1 and EGR1 and evaluated tumor growth using histological and imaging techniques. Tumor area was quantified across multiple brain sections from both male and female mice. DLK1 knockout brains exhibited consistent …

Targeting Myeloid Cell Iron Metabolism In Salmonella-Induced Colitis, Mariella Arcos Padilla

Biomedical Engineering ETDs

Salmonellosis is a severe infection caused by Salmonella enterica serovar Typhimurium, leading to significant global morbidity and mortality.

Previous studies have shown that mice lacking the iron storage protein ferritin heavy chain (FTH1) in myeloid cells exhibit worsened Salmonella infection. Nuclear receptor co-activator 4 (NCOA4) directs FTH1 autophagic degradation to release iron from storage during conditions of low iron. However, the role of myeloid NCOA4 in regulating bacterial infections remains unclear.

Here, we found that myeloid NCOA4 deficiency augments spleen iron levels and increases cellular iron accumulation, oxidative stress, and ferroptosis in bone marrow-derived macrophages (BMDM) cells. This deficiency also …

A Kinetic Model For Compound Heterozygous Pathogenic Variants In Tyrosyl-Trna Synthetase Gene Yars2-Associated Neonatal Phenotype, Thomas W Christian, Sunita Maharjan, Sitao Yin, Yuka Yamaki, Isao Masuda, Fenglin Li, Colleen Muraresku, Sheila Clever, Rebecca Ganetzky, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Human genetic disorders are often caused by mutations of compound heterozygosity, where each allele of the mutant gene harbors a different genetic lesion. However, studies of such mutations are hampered due to the lack of an appropriate model. Here we describe a kinetic model of compound heterozygous variants in an obligate enzyme dimer that contains one mutation in one monomer and the other mutation in the second monomer. This enzyme is encoded by human YARS2 for mitochondrial tyrosyl-tRNA synthetase (mt-TyrRS), which aminoacylates tyrosine to mt-tRNA^Tyr. YARS2 is a member of the genes for mt-aminoacyl-tRNA synthetases, where pathogenic mutations …

Angiogenin-Catalyzed Cleavage Within Trna Anticodon-Loops Identified By Cp-Rna-Seq, Megumi Shigematsu, Ryuma Matsubara, Justin Gumas, Takuya Kawamura, Yohei Kirino

Computational Medicine Center Faculty Papers

Angiogenin (Ang), an endoribonuclease belonging to the RNase A superfamily, cleaves the anticodon-loops of tRNAs to produce tRNA-half molecules. Although previous studies have demonstrated the involvement of Ang in the pathobiology of neurodegenerative disorders, the characterization of Ang-generated tRNA halves in neuronal cells remains limited. This is partly due to the technical limitations of standard RNA-seq methods, which cannot capture Ang-generated RNAs containing a 2',3'-cyclic phosphate (cP). In this report, we established an Ang-treatment model using SH-SY5Y, a human neuroblastoma cell line, and demonstrated Ang-dependent accumulation of tRNA halves. By performing cP-RNA-seq, which selectively captures cP-containing RNAs, we identified Ang-generated …