Biochemistry, Biophysics, and Structural Biology Commons^™

Dissecting The Interplay Of Protein Synthesis And Degradation Pathways In Cellular Adaptation To Stress, Brittany Friedson

Theses and Dissertations

Adaptation to stress requires cells to reprogram transcription, translation, and proteolytic pathways. Although much is known about the response of each program, it remains unclear how they coordinate following stress. My studies in S. cerevisiae identified the Cdk8 kinase module (CKM) of the Mediator complex as a new player in coordinating these processes. It is well established that the CKM consists of four highly conserved proteins (cyclin C, its cognate kinase Cdk8, and two structural proteins Med12 and Med13) and predominantly represses a subset of stress responsive genes in yeast. We demonstrated for the first time that the CKM also …

Non-Redundant Roles For The Human Mrna Decapping Cofactor Paralogs Dcp1a And Dcp1b, Ivana Vukovic, Samantha M. Barnada, Jonathan W. Ruffin, Jon Karlin, Ravi Kumar Lokareddy, Gino Cingolani, Steven B. Mcmahon

Department of Medicine Faculty Papers

Eukaryotic gene expression is regulated at the transcriptional and post-transcriptional levels, with disruption of regulation contributing significantly to human diseases. The 5' m7G mRNA cap is a central node in post-transcriptional regulation, participating in both mRNA stabilization and translation efficiency. In mammals, DCP1a and DCP1b are paralogous cofactor proteins of the mRNA cap hydrolase DCP2. As lower eukaryotes have a single DCP1 cofactor, the functional advantages gained by this evolutionary divergence remain unclear. We report the first functional dissection of DCP1a and DCP1b, demonstrating that they are non-redundant cofactors of DCP2 with unique roles in decapping complex integrity and specificity. …

Engineered Nls-Chimera Downregulates Expression Of Aggregation-Prone Endogenous Fus, Miyuki Hayashi, Amandeep Girdhar, Ying-Hui Ko, Kevin Kim, Jacquelyn Depierro, Joseph R. Buchler, Nikhita Arunprakash, Aditya Bajaj, Gino Cingolani, Lin Guo

Department of Biochemistry and Molecular Biology Faculty Papers

Importin β-superfamily nuclear import receptors (NIRs) mitigate mislocalization and aggregation of RNA-binding proteins (RBPs), like FUS and TDP-43, which are implicated in neurodegenerative diseases. NIRs potently disaggregate RBPs by recognizing their nuclear localization signal (NLS). However, disease-causing mutations in NLS compromise NIR binding and activity. Here, we define features that characterize the anti-aggregation activity of NIR and NLS. We find that high binding affinity between NIR and NLS, and optimal NLS location relative to the aggregating domain plays a role in determining NIR disaggregation activity. A designed FUS chimera (FUS_IBB), carrying the importin β binding (IBB) domain, is …

Malat1 Mediates Tet2 Loss Of Function-Driven Oncogenic Inflammation Via Rna Shielding Of Nf- Kappa B P65, Nana Adjoa Ben-Crentsil

USF Tampa Graduate Theses and Dissertations

TET2 is a dioxygenase that regulates gene expression and hematopoiesis by oxidizing 5-methylcytosine residues on DNA to 5-hydroxymethylcytosine. TET2 mutations are common genetic events in hematological disorders. For example, TET2 is the most frequently mutated gene in Chronic Myelomonocytic Leukemia and occurs in about 33% of other myeloid malignancies. It is also the second commonest mutation in clonal hematopoiesis of indeterminate potential (CHIP), a common premalignant condition in the elderly. TET2 mutations arise in founding clones and are implicated in many non-hematological sequelae seen in CHIP like atherosclerotic disease, chronic liver disease, and severe microbial infections.

The development of TET2-deficient …

Uncovering The Contribution Of Desmoplakin Isoforms To Desmosome Structure And Function, Krishna Patel

All ETDs from UAB

UNCOVERING THE CONTRIBUTION OF DESMOPLAKIN ISOFORMS TO DESMOSOME STRUCTURE AND FUNCTION KRISHNA PATEL MULTIDISCIPLINARY BIOMEDICAL SCIENCE ABSTRACT Desmosomes are cell-cell junctions that maintain the integrity of tissues that experience significant mechanical stress, such as the skin and heart. Desmosomal plaque proteins are connected to the intermediate filaments by desmoplakin (DP), and genetic variants in DP are associated with several skin and heart pathologies, including erythrokeratodermia and arrhythmogenic cardiomyopathy. DP contains three domains: an N-terminal plakin head, a central rod, and an intermediate filament-binding C-terminal tail. Furthermore, DP has three splice isoforms (DPI, DPIa, and DPII) that differ only in the …

Biochemical Characterization Of Rna Polymerases Across The Domains Of Life, Stephanie Lois Cooper

All ETDs from UAB

RNA polymerases perform the essential function of RNA synthesis from a DNA template. This process, known as transcription, is critical for all living species and a key point for regulation of gene expression. The function of RNA polymerases allow species from all domains of life to not only survive, but also respond to environmental changes such as heat and nutrient deprivation. In biological taxonomy, the highest classification is domain. The three domains are Eukarya, Bacteria, and Archaea. The domain Eukarya contains all eukaryotic organisms, ranging from yeast, to plants, to metazoans. Bacteria and Archaea are both prokaryotic domains, the species …

Elucidating The Nanoscale Architecture Of The Desmosome, William F. Dean

All ETDs from UAB

Desmosomes are intercellular anchoring junctions that are crucial for maintaining the mechanical integrity of tissues routinely subjected to large forces, such as epithelia and cardiac muscle. Adhesion in desmosomes is mediated by a specialized class of transmembrane glycoproteins known as the desmosomal cadherins (DCs). Defects in desmosomal adhesion are associated with severe disease of the heart and skin and are frequently linked to mutations in the DCs. It is therefore important to understand the relationship between DC architecture and desmosome function. Accordingly, several groups have attempted to elucidate DC architecture—primarily using electron tomography (ET). However, ET studies of the desmosome …

Use Of Molecular Dynamics Simulations To Characterize Structural Interactions Of Protein And Drug In Antiviral Drug Discovery, Caitlin Joan Smith

All ETDs from UAB

Since 2019, the novel coronavirus SARS-CoV-2 the etiological cause of the COVID-19 pandemic has led researchers and physicians to look for effective antiviral treatments as interventions in mitigating COVID-19 disease. The severity of the disease and the limitations of current treatments have led to antiviral drug research beyond currently approved antiviral drugs. Many antivirals exist and are currently approved by the Food and Drug Administration (FDA) for other viral illnesses, yet currently only remdesivir and nirmatrelvir/ritonivir are approved for COVID-19 (October 2020, May 2023, respectively), while molnupiravir is still under emergency FDA use authorization [1, 2, 3]. Here, we have …

Combination Of 64/67cu Theranostics And Immunotherapy Targeting Fibroblast Activation Protein In Triple Negative Breast Cancer, Fnu Sharmila Sridhar

All ETDs from UAB

Triple negative breast cancer (TNBC) makes up 10-20% of breast cancer cases. Even with advancements in science, TNBC is treatment resistant due to the lack of any type of hormonal receptors on the cell surface making it difficult for targeted hormonal therapy. New research avenues have led to studies of the Tumor-microenvironment (TME) in detail. TME is a complex network of stromal cells, extracellular matrix (ECM) and cancer associated fibroblasts (CAFs) with pro-tumorigenic properties and plays a major role in tumor growth. Fibroblast activation protein (FAP) is a marker of CAF and promotes ECM remodeling through several pathways and has …

Biologic Evaluation Of 64cu & 67cu As Potential Theranostic Agents For Cancer Radiotherapy, Lakshmi Madhusoodanan

All ETDs from UAB

Immunotherapy has become a mainstay in the treatment of several types of cancer, with the potential to induce durable remission, albeit in a limited percentage of patients. More recently, radiopharmaceuticals have gained recognition in cancer treatment due to their ability to localize within cancer cells and deliver radiation, reducing adverse effects precisely. Cancer radiotherapy has the potential to synergize with immunotherapy due to its induction of immunogenic cell death (ICD), which results in distinct cellular injuries such as the formation of single-strand breaks (SSBs) and double-stranded breaks (DSBs), disruption of mitochondrial integrity, and the excessive generation of reactive oxygen species …

Determination Of Readthrough Susceptibility Among Different Schwann Cell Lines Carrying Nonsense Mutations, Trushali Vansadia

All ETDs from UAB

Neurofibromatosis Type 1 (NF1) is a genetic disorder that affects the nervous system through the formation of tumors or neurofibromas. Encoded by the NF1 gene, neurofibromin functions as a tumor suppressor by converting active GTP-Ras to inactive GDP-Ras. 20% of NF1 patients carry a genomic nonsense mutation, which generates a premature termination codon (PTC) in the NF1 mRNA, leading to the formation of a truncated neurofibromin protein. Termination at PTCs can be suppressed by the incorporation of an amino acid at the site of the PTC, also known as readthrough. Readthrough results in continued translation elongation downstream of the PTC …

A Histone Methyltransferase Contributes To Treatment Resistance In Npm1c Aml, Neha Srinivas

All ETDs from UAB

Acute myeloid leukemia (AML) is a blood cancer marked by the rapid growth of abnormal myeloid cells, driven by various genetic mutations. AML accounts for approximately 1% of all cancers and presents complicated prognosis and treatment. Menin inhibitors have shown potential in targeting AML. However, resistance to these inhibitors presents a significant clinical obstacle, as patients treated with menin inhibitors are increasingly developing resistance to the treatment. Using CRISPR-Cas9 mediated screening, we identified an epigenetic regulator contributing to resistance against menin inhibitors in AML. Utilizing knockout (KO) models of the epigenetic regulator in-vitro, ex-vivo, and in-vivo, we observed a growth …

Serum Proteomic Profile Of Subclinical Babesia Bovis Infection In Pcr-Positive Eld's Deer Using Serum Protein Electrophoresis Coupled With Lc-Ms/Ms, Vichayanee Pumpitakkul, Sittiruk Roytrakul, Narumon Phaonakrop, Gunnaporn Suriyaphol Assoc. Prof.

The Thai Journal of Veterinary Medicine

Subclinical babesiosis observed in captive Eld’s deer, which act as reservoirs for ticks, poses a risk to healthy herds. However, the knowledge of biomarkers for subclinically infected Eld’s deer and host-parasite interactions is limited. This study aimed to investigate the serum proteomic profiles and protein interactions of Babesia bovis and subclinically infected Eld’s deer, PCR-positive for B. bovis, using automated serum protein electrophoresis and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The findings revealed albumin and four globulin fractions: alpha-1, alpha-2, beta, and gamma globulin. Albumin protein (ALB) was consistently detected across all fractions, highlighting its role in maintaining osmotic balance …

Mechanistic Study Of Dna Ligase Iv-Mediated Double-Strand Break Repair In Non-Homologous End Joining, Tasmin Naila, Alan E. Tomkinson

Biomedical Sciences ETDs

Non-homologous end joining (NHEJ) is a crucial double-strand break repair pathway in mammalian cells, resolving DNA damage from ionizing radiation and during V(D)J recombination. Although DNA Ligase IV is the only mammalian DNA ligase involved in NHEJ, it functions as a single-turnover enzyme in vitro. Recent cryo-electron microscopy (cryo-EM) studies revealed two LigIV molecules at the NHEJ synapse, supporting the hypothesis that two ligase molecules are needed for DSB repair by NHEJ. This study aims to validate this hypothesis by providing evidence for coordinated ligation at optimal distance and polarity preference for catalytic activity by LigIV. We determined that coordination …

Regulatory, Structural And Functional Studies Of The Adp-Glucose Pyrophosphorylase From Photosynthetic And Heterotrophic Organisms, Gabriela Martinez-Ramirez

Dissertations

The production of biofuels like ethanol has increased with the transition to renewable energy. Starch can be converted into ethanol through chemical modification. Increasing the availability of starch is crucial to fight back climate change thus, researchers have focused on the biotechnological modification of plants. This modification is known as transgenics, where a plant is modified by the insertion of genes, to make it as productive as possible. The genes inserted code for enzymes that control pathways responsible for the synthesis of certain biomolecules, in this case starch. The synthesis of starch in plants (as glycogen in both photosynthetic and …

Methane Fluxes In Tidal Marshes Of The Conterminous United States, Ariane Arias-Ortiz, Jaxine Wolfe, Scott D. Bridgham, Sara Knox, Gavin Mcnicol, Brian A. Needelman, Julie Shahan, Ellen J. Stuart-Haëntjens, Lisamarie Windham-Myers, Patty Y. Oikawa, Dennis D. Baldocchi, Joshua S. Caplan, Margaret Capooci, Kenneth M. Czapla, R. Kyle Derby, Heida L. Diefenderfer, Inke Forbrich, Gina Groseclose, Jason K. Keller, Cheryl Kelley, Amir E. Keshta, Helena S. Kleiner, Ken W. Krauss, Robert R. Lane, Sarah Mack, Serena Moseman-Valtierra, Thomas J. Mozdzer, Peter Mueller, Scott C. Neubauer, Genevieve Noyce, Katrina V. R. Schäfer, Rebecca Sanders-Demott, Charles A. Schutte, Rodrigo Vargas, Nathaniel B. Weston, Benjamin Wilson, J. Patrick Megonigal, James R. Homquist

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Methane (CH4) is a potent greenhouse gas (GHG) with atmospheric concentrations that have nearly tripled since pre-industrial times. Wetlands account for a large share of global CH4 emissions, yet the magnitude and factors controlling CH4 fluxes in tidal wetlands remain uncertain. We synthesized CH4 flux data from 100 chamber and 9 eddy covariance (EC) sites across tidal marshes in the conterminous United States to assess controlling factors and improve predictions of CH4 emissions. This effort included creating an open-source database of chamber-based GHG fluxes (https://doi.org/10.25573/serc.14227085). Annual fluxes across chamber and EC sites averaged 26 ± 53 g CH4 …

Myc Induces Oncogenic Stress Through Rna Decay And Ribonucleotide Catabolism In Breast Cancer, Jitendra K Meena, Jarey H Wang, Nicholas J Neill, Dianne Keough, Nagireddy Putluri, Panagiotis Katsonis, Amanda M Koire, Hyemin Lee, Elizabeth A Bowling, Siddhartha Tyagi, Mayra Orellana, Rocio Dominguez-Vidaña, Heyuan Li, Kenneth Eagle, Charles Danan, Hsiang-Ching Chung, Andrew D Yang, William Wu, Sarah J Kurley, Brian M Ho, Joseph R Zoeller, Calla M Olson, Kristen L Meerbrey, Olivier Lichtarge, Arun Sreekumar, Clifford C Dacso, Luke W Guddat, Dominik Rejman, Dana Hocková, Zlatko Janeba, Lukas M Simon, Charles Y Lin, Monica C Pillon, Thomas F Westbrook

Faculty, Staff and Students Publications

Upregulation of MYC is a hallmark of cancer, wherein MYC drives oncogenic gene expression and elevates total RNA synthesis across cancer cell transcriptomes. Although this transcriptional anabolism fuels cancer growth and survival, the consequences and metabolic stresses induced by excess cellular RNA are poorly understood. Herein, we discover that RNA degradation and downstream ribonucleotide catabolism is a novel mechanism of MYC-induced cancer cell death. Combining genetics and metabolomics, we find that MYC increases RNA decay through the cytoplasmic exosome, resulting in the accumulation of cytotoxic RNA catabolites and reactive oxygen species. Notably, tumor-derived exosome mutations abrogate MYC-induced cell death, suggesting …

Developing Coexpression Systems To Introduce Hydroxyproline Into Protein Engineered Collagen Peptides Utilizing Hydroxylase From Acanthamoeba Polyphaga Mimivirus, Jennifer Soldatich

Theses and Dissertations

A major challenge of developing collagen mimetic peptides (CMPs) by bacterial expression is to include hydroxyproline for biomedical applications. Coexpression of Prolyl-4-hydroxylase from A.mimivirus with CMPs was investigated. Additionally, four expression designs were created for potential applications in mammalian cells to utilize their natural ability of proline-hydroxylation by post-translational modification.

Predicting The Association Of Metabolites With Both Pathway Categories And Individual Pathways, Erik D. Huckvale, Hunter Moseley

Markey Cancer Center Faculty Publications

Metabolism is a network of chemical reactions that sustain cellular life. Parts of this metabolic network are defined as metabolic pathways containing specific biochemical reactions. Products and reactants of these reactions are called metabolites, which are associated with certain human-defined metabolic pathways. Metabolic knowledgebases, such as the Kyoto Encyclopedia of Gene and Genomes (KEGG) contain metabolites, reactions, and pathway annotations; however, such resources are incomplete due to current limits of metabolic knowledge. To fill in missing metabolite pathway annotations, past machine learning models showed some success at predicting the KEGG Level 2 pathway category involvement of metabolites based on their …

Voltage Set Points For Sodium Channel Inactivation: Intrinsic And Modulatory Mechanisms, Akshay Sharma

Dissertations, Theses, and Capstone Projects

During an action potential, voltage-gated sodium channels (VGSC) control sodium ion flow into the cytoplasm of cells by using membrane voltage to alter channel conformation. These membrane proteins exhibit three main functional conformations: closed, open, and fast-inactivated, with transitions between these states dependent on membrane voltage and kinetics. The channels open within 1 millisecond and swiftly transition from open to fast-inactivated within 1-2 milliseconds following membrane depolarization. Subsequent membrane repolarization resets the channels to the closed state. Notably, even at mildly depolarized potentials that preclude channel opening, VGSCs can undergo transitions between the closed and inactivated states, known as closed-state …