Molecular Biology Commons^™

The Expression Of Recombinant Cas9 Proteins In E. Coli Bl21(De3) Strains, Morgan Reese

Graduate Theses and Dissertations

Abstract Extensively used for genome editing, CRISPR-Cas9 is a relatively new tool that has made a major impact in the genomic engineering landscape. Due to this, the production of CRISPR proteins that are not commercially available can limit research applications. Here, we present methods for optimizing laboratory scale production of CRISPR proteins including Cas9. The method uses IPTG to induce gene expression of the specified Cas9 and nickel column purification to isolate proteins. CRISPR proteins are validated for purity by SDS-PAGE gel, western blot, and for activity by in vitro digestion. We thoroughly validate and compare the effectiveness of BL21(DE3) …

The Contribution Of Micrornas To Rybp Silencing In Glioblastoma Multiforme, Alex B. Lee

Graduate Theses

Glioblastoma multiforme (GBM) is a highly aggressive and invasive tumor of the central nervous system (CNS). Survival rates are abysmal, with only 7.2% of patients alive 5-years after diagnosis. Because of this, understanding epigenetic alterations that give GBM tumors their aggressive phenotypes is critical for the development of more targeted and effective therapies. These alterations frequently affect a group of proteins called the Polycomb group proteins, which play important oncogenic and tumor suppressive roles in cancer. One Polycomb protein, the RING1- and YY1-binding protein (RYBP), is downregulated in a majority of GBM patients, suggesting a strong tumor suppressive property. In …

Cellular Mechanisms Of Embryonic Eye Regrowth In Xenopus Laevis, Randolph L. Grell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The African Clawed Frog, Xenopus laevis, has been an indispensable model organism for over 100 years in the study of embryogenesis and development. In recent years, this vertebrate model has emerged as a robust tool for deciphering the cellular and molecular mechanisms underlying various modes of tissue, limb, and organ regeneration. In the context of eye repair, Xenopus offers a unique model, where the adult frog eye has limited regenerative capacity compared to its pre-metamorphic embryonic and tadpole forms, which exhibit a robust capacity for regrowth. Understanding the intricate molecular mechanisms that underlie this developmental shift in regrowth ability …

Molecular Insights Of Paraoxonase 2 In Advanced Glycation End Product Induced Endothelial Dysfunction, Ramya R

Theses and Dissertations

Diabetes mellitus (DM) is a metabolic disorder associated with various vascular complications and affects the function of the endothelial cells. Elevated blood glucose levels accelerate the formation of advanced glycation end products (AGEs) by Amadori rearrangement and bind to their Receptor for the advanced glycation end product (RAGE) and evoke release of key pro-inflammatory cytokine proteins leading to endothelial dysfunction. Paraoxonase 2 (PON2) is an endogenous intracellular enzyme, localised in mitochondria, endoplasmic reticulum (ER), and nuclear membrane with numerous properties, like anti-inflammatory, anti-apoptotic and anti-oxidant.

Our present study aims to ascertain the effect of AGEs on PON2 activity and expression, …

Using Edna To Assess Impacts Of Oyster Restoration On Ecosystem Biodiversity At A Heavily Impacted Coastal Lagoon, Dominique Di Domenico, Emily Bonacchi, Elizabeth Suter

Molloy Multidisciplinary Undergraduate Research Conference

The Great South Bay (GSB), a bar-built, temperate, coastal lagoon on the south shore of Long Island, New York, USA, is a highly modified estuary due to heavy urbanization and suburbanization in the last century. GSB historically provided up to 50% of the nation’s hard clam (Mercenaria mercenaria) harvest, and is the legal home of the “Blue Point” oyster (eastern oyster; Crassostrea virginica). However, due to overexploitation as well as persistent stress from ongoing nitrogen pollution and harmful algal blooms, shellfish populations are fractions of their original abundances. Restoration efforts in GSB, driven both by community efforts …

Trna Anticodon Cleavage By Target-Activated Crispr-Cas13a Effector, Ishita Jain, Matvey Kolesnik, Konstantin Kuznedelov, Leonid Minakhin, Natalia Morozova, Anna Shiriaeva, Alexandr Kirillov, Sofia Medvedeva, Alexei Livenskyi, Laura Kazieva, Kira S Makarova, Eugene V Koonin, Sergei Borukhov, Konstantin Severinov, Ekaterina Semenova

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Type VI CRISPR-Cas systems are among the few CRISPR varieties that target exclusively RNA. The CRISPR RNA–guided, sequence-specific binding of target RNAs, such as phage transcripts, activates the type VI effector, Cas13. Once activated, Cas13 causes collateral RNA cleavage, which induces bacterial cell dormancy, thus protecting the host population from the phage spread. We show here that the principal form of collateral RNA degradation elicited by Leptotrichia shahii Cas13a expressed in Escherichia coli cells is the cleavage of anticodons in a subset of transfer RNAs (tRNAs) with uridine-rich anticodons. This tRNA cleavage is accompanied by inhibition of protein synthesis, thus …

Predictive And Prognostic Biomarkers And Tumor Antigens For Targeted Therapy In Urothelial Carcinoma, Aditya Eturi, Amman Bhasin, Kevin Zarrabi, William Tester

Department of Medical Oncology Faculty Papers

Urothelial carcinoma (UC) is the fourth most prevalent cancer amongst males worldwide. While patients with non-muscle-invasive disease have a favorable prognosis, 25% of UC patients present with locally advanced disease which is associated with a 10-15% 5-year survival rate and poor overall prognosis. Muscle-invasive bladder cancer (MIBC) is associated with about 50% 5 year survival when treated by radical cystectomy or trimodality therapy; stage IV disease is associated with 10-15% 5 year survival. Current therapeutic modalities for MIBC include neoadjuvant chemotherapy, surgery and/or chemoradiation, although patients with relapsed or refractory disease have a poor prognosis. However, the rapid success of …

Upregulation Of The Predominant Cystic Fibrosis Causing Mutation Df508-Cftr By Triazole Compounds In Epithelial Cells, Maggie Taylor

Undergraduate Research Conference

Cystic fibrosis is a common genetic disease that is caused by a mutation in the plasma membrane protein CFTR, which stands for Cystic Fibrosis Transmembrane-conductance Regulator. When this membrane protein is mutated, it impairs its chloride ion channel function, blocking the movement of chloride ions that travel in and out of the cell. Previous studies have demonstrated that the most prevalent CFTR mutation, ∆F508-CFTR, can be partially reversed using small molecules (Heda and Marino, BBRC, 271:659-664, 2000). In this study, I have investigated the effects of several triazole compounds known to bind and transport chloride ions in cultured cells, on …

Lysine 473 Regulates The Activity And Trafficking Of The Cystine/Glutamate Transporter, System XC-, Anna Koppin

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

System x_c^- is a membrane transport system that plays a critical role in mitigating oxidative stress. Past work in our lab has shown that System x_c^- localizes to the plasma membrane allowing for increased activity to support production of antioxidants during oxidative stress. In this study, we sought to determine if post-translational modification (PTM) of the transporter regulates its trafficking. A C-terminal 3KR mutant (K422,472,473R) exhibited decreased membrane localization and activity, suggesting that PTM at one of these sites increases activity. Further, we observed that K473R exhibits a 7 kD decrease in the molecular weight, indicating …

Ubiquitination Of Xct: Impacts On The Protein's Stability, Turnover Rate, And Localization, Sofia Rosenberger

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

System x_c^- imports cystine and exports glutamate. Its presence on the plasma membrane has been shown to increase directly with oxidative insults. Ubiquitin, a small protein, is directly involved in the trafficking and degradation of numerous proteins within cells and has been shown to bind to System x_c^-. Moreover, upon oxidative insult, protein ubiquitination increases. However, it is not understood how ubiquitination of the transporter impacts its activity. Therefore, the objective of this project is to directly assess how ubiquitination affects the protein’s stability, turnover rate, and localization in the context of oxidative stress. We …

Lc-Ms/Ms For Proteomic Analysis Of Post-Translational Modifications On Xct, Connor Bricco

23rd Annual A. Paul and Carol C. Schaap Celebration of Undergraduate Research and Creative Activity (2024)

Membrane protein xCT and its heavy chain component 4F2HC make up the xc- transport system. 4F2HC may be necessary for membrane localization of the heterodimer and xCT is responsible for transport activity. Under basal conditions, xCT resides in endosomes, but upon oxidative insult, xCT moves to the membrane and functions to reduce oxidative stress. We hypothesize the movement of xCT to the membrane is directed by changes in posttranslational modifications (PTMs) such as phosphorylation, ubiquitination and glycosylation. The overall goal of this project is to use mass spectrometry to detect the PTMs of xCT isolated from cells grown under basal …

Multivalency Of The Mdmx Acidic Domain Slims Use Different Binding Modes To Inhibit Mdmx And P53, Malissa Fenton

USF Tampa Graduate Theses and Dissertations

Regulation of protein binding through autoinhibition commonly occurs via interactions involving intrinsically disordered regions (IDRs). These intramolecular interactions can directly or allosterically inhibit intermolecular protein or DNA binding, regulate enzymatic activity, and control the assembly of large macromolecular complexes. Autoinhibitory interactions mediated by protein disorder are inherently transient, making their identification and characterization challenging. In this work, we explore the structural and functional diversity of disorder-mediated autoinhibition for a variety of biological mechanisms, with a focus on the role of multivalency and effective concentration. We also discuss the evolution of disordered motifs that participate in autoinhibition using examples where sequence …

Discovery Of A Small-Molecule Inhibitor That Traps Polθ On Dna And Synergizes With Parp Inhibitors, William Fried, Mrityunjay Tyagi, Leonid Minakhin, Gurushankar Chandramouly, Taylor Tredinnick, Mercy Ramanjulu, William Auerbacher, Marissa L Calbert, Timur Rusanov, Trung Hoang, Nikita Borisonnik, Robert Betsch, John Krais, Yifan Wang, Umeshkumar Vekariya, John Gordon, George Morton, Tatiana Kent, Tomasz Skorski, Neil Johnson, Wayne Childers, Xiaojiang Chen, Richard Pomerantz

Department of Biochemistry and Molecular Biology Faculty Papers

The DNA damage response (DDR) protein DNA Polymerase θ (Polθ) is synthetic lethal with homologous recombination (HR) factors and is therefore a promising drug target in BRCA1/2 mutant cancers. We discover an allosteric Polθ inhibitor (Polθi) class with 4-6 nM IC₅₀ that selectively kills HR-deficient cells and acts synergistically with PARP inhibitors (PARPi) in multiple genetic backgrounds. X-ray crystallography and biochemistry reveal that Polθi selectively inhibits Polθ polymerase (Polθ-pol) in the closed conformation on B-form DNA/DNA via an induced fit mechanism. In contrast, Polθi fails to inhibit Polθ-pol catalytic activity on A-form DNA/RNA in which the enzyme binds in …

Social Media Does Not Elicit A Physiological Stress Response As Measured By Heart Rate And Salivary Cortisol Over 20-Minute Sessions Of Cell Phone Use, Suzanne Oppenheimer, Laura Bond, Charity Smith

Biomedical Research Institute Publications and Presentations

The pervasive use of social media has raised concerns about its potential detrimental effects on physical and mental health. Others have demonstrated a relationship between social media use and anxiety, depression, and psychosocial stress. In light of these studies, we examined physiological indicators of stress (heart rate to measure autonomic nervous system activation and cortisol to assess activity of the hypothalamic-pituitary-adrenal axis) associated with social media use and investigated possible moderating influences of sex, age, and psychological parameters. We collected physiological data from 59 subjects ranging in age from 13 to 55 across two cell phone treatments: social media use …

The Impact Of Mutations In The Arabidopsis Apetela (Ap3) Gene, Hazel R. Frans, Tara Phelps-Durr

SACAD: Scholarly Activities

The purpose of this research is to understand the molecular functioning of the Arabidopsis thaliana Apetela (Ap3) gene. We created mutations in two sites of the gene, AP3-3 and AP3-5. These are predicted to change AP3 protein structure, which may result in a mutated flower. Analyzing the effects of new mutations allows an understanding of protein formation both in plants and humans.

Maldi-Msi Identification Of Tissue-Level N-Glycomic And Proteomic Molecular Biomarkers Of Aggressive Prostate Cancer, Jordan Paige Hartig

MUSC Theses and Dissertations

Prostate Cancer (PCa) poses a significant clinical challenge, characterized by debates on screening efficacy and continuous issues with distinguishing aggressive from non-aggressive tumors. Despite treatment advancements, poor patient outcome at late stages and clinical overtreatment of indolent disease emphasizes the urgent need for markers of PCa aggression. Aberrant glycosylation and extracellular matrix (ECM) remodeling are two complex molecular processes necessary for PCa progression, highlighting a novel area for biomarker discovery. Leveraging formalin-fixed paraffin-embedded tissues, tissue microarrays (TMAs), and matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), distinct N-glycan and ECM profiles are identified. Elevated bisecting, multi-antennary, and fucosylated N-glycans indicate early …

Parp2 Promotes Break Induced Replication-Mediated Telomere Fragility In Response To Replication Stress, Daniela Muoio, Natalie Laspata, Rachel L Dannenberg, Caroline Curry, Simone Darkoa-Larbi, Mark Hedglin, Shikhar Uttam, Elise Fouquerel

Department of Biochemistry and Molecular Biology Faculty Papers

PARP2 is a DNA-dependent ADP-ribosyl transferase (ARTs) enzyme with Poly(ADP-ribosyl)ation activity that is triggered by DNA breaks. It plays a role in the Base Excision Repair pathway, where it has overlapping functions with PARP1. However, additional roles for PARP2 have emerged in the response of cells to replication stress. In this study, we demonstrate that PARP2 promotes replication stress-induced telomere fragility and prevents telomere loss following chronic induction of oxidative DNA lesions and BLM helicase depletion. Telomere fragility results from the activity of the break-induced replication pathway (BIR). During this process, PARP2 promotes DNA end resection, strand invasion and BIR-dependent …

In Silico Identification Of Small Molecule Agonist Binding Sites On Kcc2, Kenyon Mitchell, Alfred Amendolara, Ruth Hunter, Jaden Miner, Andrew Payne

Annual Research Symposium

Purpose: Potassium-Chloride Cotransporter 2 (KCC2) is a neuronal membrane protein specific to the central nervous system. It is responsible for removing Cl- ions from the intracellular space, maintaining a normal Cl- gradient essential for proper function at inhibitory synapses. Dysregulation causes an upward shift in the Cl- reversal potential resulting in a hyperexcitable state of the postsynaptic neuron. Existing literature indicates that KCC2 may be involved in the addiction pathway of a variety of drugs of abuse, including opioids and alcohol. This makes KCC2 an attractive potential drug target when treating substance use disorders. A novel direct KCC2 agonist, VU0500469, …

Neurotensin Modulates Ovarian Vascular Permeability Via Adherens Junctions, Andrew Pearson, Ketan Shrestha, Thomas E. Curry, Diane M. Duffy

UK CARES Faculty Publications

Neurotensin (NTS) is a 13-amino acid peptide which is highly expressed in the mammalian ovary in response to the luteinizing hormone surge. Antibody neutralization of NTS in the ovulatory follicle of the cynomolgus macaque impairs ovulation and induces follicular vascular dysregulation, with excessive pooling of red blood cells in the follicle antrum. We hypothesize that NTS is an essential intrafollicular regulator of vascular permeability. In the present study, follicle injection of the NTS receptor antagonist SR142948 also resulted in vascular dysregulation. To measure vascular permeability changes in vitro, primary macaque ovarian microvascular endothelial cells (mOMECs) were enriched from follicle aspirates …

Tools For Biomolecular Modeling And Simulation, Xin Yang

Mathematics Theses and Dissertations

Electrostatic interactions play a pivotal role in understanding biomolecular systems, influencing their structural stability and functional dynamics. The Poisson-Boltzmann (PB) equation, a prevalent implicit solvent model that treats the solvent as a continuum while describes the mobile ions using the Boltzmann distribution, has become a standard tool for detailed investigations into biomolecular electrostatics. There are two primary methodologies: grid-based finite difference or finite element methods and body-fitted boundary element methods. This dissertation focuses on developing fast and accurate PB solvers, leveraging both methodologies, to meet diverse scientific needs and overcome various obstacles in the field.