Molecular Biology Commons^™

Ddrr Acts As A Dna Damage-Induced Cell Division Inhibitor In Acinetobacter Baumannii, Christian P. Lowe, Deborah Cook, Lily Hoard, Mckinnley Martin, Janelle M. Hare

Acinetobacter baumannii DNA Damage Database

An article titled, "DdrR acts as a DNA damage-induced cell division inhibitor in Acinetobacter baumannii" published in the Journal of Bacteriology on September 9, 2026.

Riluzole As A Dual-Targeted Radiosensitizer For Osteosarcoma: Targeting Tumor Cells And Angiogenic Vasculature To Enhance Single High-Dose Radiotherapy Efficacy, Pooja P. Rao

Dissertations, Theses, and Capstone Projects

Osteosarcoma (OS), the most common primary bone malignancy of children and young adults, is intrinsically radioresistant, and outcomes for patients with unresectable or metastatic disease have not improved in over four decades. Single-dose radiation therapy (SDRT) is a potent modality against radioresistant, highly vascularized sarcomas, but its application in OS is constrained by dose-dependent normal tissue toxicity. Radiosensitizers achieving tumor control at lower doses therefore offer a direct route to widening the therapeutic window. Critically, OS radioresistance is not tumor-cell-autonomous. It emerges from two coordinated compartments: aberrant DNA repair and antioxidant capacity intrinsic to the tumor cell, and a radioprotective, …

Characterization Of Mettl3/14-Mediated M6a Modification In Human Transcriptome Using Nanopore Direct Rna Sequencing, Emily Kurtyan, Andrew J. Stein, Kelly J. Abdalla, Zhangerjiao Yuan, Miten Jain, Fadia Ibrahim

Department of Biochemistry and Molecular Biology Faculty Papers

Post-transcriptional RNA modifications modulate diverse aspects of RNA metabolism. N6-methyladenosine (m6A), one of the most abundant internal RNA modifications, is deposited by the core methyltransferase complex, METTL3 and METTL14. Oxford Nanopore Technologies (ONT) platform permits direct, single RNA molecule sequencing while preserving native modifications. However, without rigorous benchmarking, the accuracy and reproducibility of modification detection remain uncertain. Here, we leveraged ONT to comprehensively profile bona fide m6A modifications in cellular RNAs at single-nucleotide resolution by integrating two direct RNA sequencing chemistries (RNA002 and RNA004) with the m6Anet and Dorado modification-detection models. We independently depleted METTL3 and METTL14 in human cells …

Evaluation Of Mdm2 Mrna Expression According To Clinicopathological Characteristics In Oral Squamous Cell Carcinoma (Oscc) Patients, Tirta Wardana

Chulalongkorn Medical Journal

Background: The murine double minute 2 (MDM2) gene encodes an E3 ubiquitin ligase that targets p53 for degradation, thereby influencing the pathogenesis of oral squamous cell carcinoma (OSCC).

Objective. The present study investigates MDM2 mRNA expression and its association with clinical and pathological characteristics in OSCC patients.

Methods: We conducted an observational-analytical study using a cross-sectional design. The study involved 39 OSCC patients. RNA extraction, cDNA synthesis, and quantitative PCR (qPCR) were performed. We quantified relative MDM2 mRNA expression using the Livak method (2-ΔΔCT) and GenEX MultiD software version 6.0. Statistical significance was assessed using independent t-tests.

Results: Although no …

The Defining Role Of Ago4 And Its Catalytic Activity During De Novo Rna-Directed Dna Methylation, Tianyi Li

Arts & Sciences Graduate Student Theses and Dissertations

Plant transposable elements and transgenes are continuously targeted for transcriptional repression via the pathway of RNA-directed DNA methylation (RdDM). Although perpetual RdDM of the endogenous genomic loci has been well studied in the field, much less is known about the de novo RdDM pathway, the pioneering round of DNA methylation responsible for triggering and initiating silencing of new transgenes. Despite being two distinct pathways, both perpetual and de novo mechanisms of RdDM require the production of small interfering RNAs (siRNAs) and the key proteins of the ARGONAUTE4 (AGO4) clade. However, the order and likely mechanism of recruitment of AGO4 to …

Polyphenol Diet And Exercise As Neuroprotection From Effects Of Alzheimer's Disease, Michelle Morgan

Loma Linda University Electronic Theses, Dissertations & Projects

Healthy non-pharmacological lifestyle factors, such as regular physical exercise and a dietary supplementation, have been shown to significantly improve cognitive outcomes over time compared to a more sedentary lifestyle and poor diet. Furthermore, exercise may serve as a potential protective factor in attenuating the effects associated with cognitive decline that are characteristic of neurodegenerative disorders, such as Alzheimer's disease (AD). Further, evidence indicates that certain diet interventions can also attenuate the effects of neurodegeneration and positively impact longevity. Supplementation of polyphenols, such as ellagic acid (EA), which are abundant in pomegranate juice, may help provide neuroprotective benefits and elicit a …

A Genetic Analysis Of The Rare Endemic Astragalus Ripleyi Barneby, Juan Antonio Jaramillo-Chico

Master's Theses

Astragalus ripleyi Barneby is a rare endemic species found in the San Luis Valley of the southern portions of the Rocky Mountains in Colorado and New Mexico. Though not federally listed as endangered, the species is on the Bureau of Land Management’s Sensitive Species List, warranting protection and continued management. This study aims to provide information about the genetic health of the species to inform conservation efforts and provide updated management recommendations. A genetic health analysis was conducted investigating the levels of diversity present in the species, how genetic diversity is structured across the known range of the species and …

The Rpm-1/Phr Signaling Hub Modulates Tau-Induced Neurodegeneration Through Regulation Of Microtubule Stability And Mapk Pathways In C. Elegans, Xinxing Ding

Theses and Dissertations

Neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia, are characterized by the accumulation of pathological tau proteins and progressive neuronal loss. Although research regarding tau-mediated toxicity is extensive, the specific pathology that determine whether neurons maintain homeostasis or succumb to collapse under tau-induced stress remain incompletely elucidated. A central, yet still insufficiently understood, feature of these diseases is the disruption of the microtubule (MT) cytoskeleton . The PHR protein family is evolutionarily highly conserved; within this family, RPM-1 in C. elegans functions as an intracellular signaling hub that regulates axon development, synapse formation, axon termination, and various microtubule-associated processes. This …

Uv Damage Mapping Reveals Different Impacts Of Xpd Mutations On Global Genomic And Transcription-Coupled Dna Repair, Allyson Hoag

Biomedical Sciences ETDs

Nucleotide Excision Repair (NER) is a fundamental cellular process that removes bulky and helical distorting lesions from the genome through the separate responses of its two subpathways – global genomic (GG-NER) and transcription coupled (TC-NER) DNA repair. The pathways converge with the recruitment of the TFIIH complex, a key step that is mediated by the translocase and helicase activities of  its XPD subunit. Germline mutations in XPD result in the clinical disorders, Xeroderma Pigmentosum (XP) and XP combined with Cockayne Syndrome (XP/CS). The goal of this thesis was to understand if XPD XP and XP/CS mutations differentially impact GG-NER and …

Summer Research Internships In Agricultural Biotechnology For Off-Campus Undergraduate Students, Aaron J. Thomas

Funded Research Records

No abstract provided.

Investigation Into Molecular Bases Of Pregnancy-Associated Malaria, Nicole Pozo

Biochemistry and Molecular Biology

Plasmodium falciparum causes the most severe and deadly form of malaria and remains a major global health problem, especially in sub-Saharan Africa (Milner, 2018). The parasite infects and multiplies inside red blood cells, leading to fever, anemia, organ damage, and death if untreated (Milner, 2018; Song et al., 2022). It is especially dangerous because it avoids the immune system by changing surface proteins called Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), which are encoded by more than 60 var genes. By switching between these genes, the parasite hides from immune detection and creates repeated waves of infection (Deitsch & Dzikowski, …

Comparative Screening Of Cytotoxic Potential Of Berberis Aristata And Senna Alexandrina Extracts, Rida Noor Akhtar, Javaria Zahoor, Rizwan Ullah Khan, Aziz Ullah, Naila Malkani

Journal of Bioresource Management

Medicinal plants provide a safe and efficient source of drugs for cancer treatment. Berberis aristata and Senna alexandrina are traditionally used to treat several ailments because they contain compounds with antimicrobial, antitoxic, anti-inflammatory, and other properties. The objective of the study was to prepare crude ethanolic extracts of B. aristata and S. alexandrina and to determine their cytotoxic potential against cancer cells. Ethanolic extracts were prepared for both plants. Hepatocellular carcinoma cells (HepG2) were used for all assays. The cytotoxicity of extracts was determined by 3‑(4,5‑Dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assay using various concentrations of extracts. The obtained sub-lethal concentrations were used …

Rna G-Quadruplexes Function As A Tunable Switch Of Fus Phase Separation, Jenny L. Carey, Miyuki Hayashi, Emily A. Welebob, Laura R. Ganser, Huan Wang, Kerry Buckhaults, Jacquelyn A. Depierro, Zheng Shi, James Shorter, Sua Myong, Aaron R. Haeusler, Lin Guo

Department of Biochemistry and Molecular Biology Faculty Papers

Fused in sarcoma (FUS) undergoes liquid-liquid phase separation (LLPS) to support essential cellular functions, but aberrant phase transitions promote toxic aggregation in neurodegenerative disease. Short RNA oligonucleotides can reverse this behavior, yet the structural determinants that govern RNA activity remain poorly defined. Here, we identify RNA G-quadruplexes (rG4s) as tunable structural motifs that potently modulate FUS LLPS. rG4 activity depends on its concentration and is modulated by rG4 length and stability: increasing repeat number switches rG4s from inhibitor to nucleator of FUS assembly, whereas chemical modifications that stabilize rG4 enhance inhibitory function and render these activities resilient to ionic perturbation. …

Influence Of Smoking On Mlh1 Gene Polymorphism: Insights Into Colorectal Cancer Incidence, Ali Mohammed Al-Abedi, Rand Muhammed Abdul-Hussein Al-Husseini

Al-Bahir

Background: Colorectal cancer (CRC) is a leading cause of cancer-related mortality worldwide. The MutL Homolog 1 (MLH1) gene plays a critical role in DNA mismatch repair (MMR). Evidence suggests cigarette smoking increases CRC risk, potentially interacting with genetic factors.

Materials and Methods: This case-control study involved 50 Iraqi CRC patients and 50 age- and gender-matched healthy controls. The PCR-RFLP technique was employed for genotyping the -93G/A (rs1800734) polymorphism. Statistical analysis included Chi-square, Fisher's Exact Test, and logistic regression adjusted for confounders. Hardy-Weinberg Equilibrium (HWE) was assessed in controls.

Results: The frequency of the rs1800734 variant was significantly higher in CRC …

A Rho5-Cnc1-Dnm1 Signalling Module Coordinates Multi-Organelle Execution Of Regulated Cell Death In Yeast, Justin Bauer

Theses and Dissertations

Regulated cell death is a conserved process with major implications for health and disease, yet how yeast cells integrate stress signals to determine survival versus death remains unclear. This thesis investigates Cyclin C (Cnc1), a conserved Mediator kinase module component with both transcriptional and mitochondrial roles. Together with Cdk8 Cnc1 primarily represses stress response genes, while upon stress it translocates to the mitochondria to induce mitochondrial fragmentation with the dynamin-related GTPase Dnm1. Using structure-guided separation-of-function mutants, I demonstrate that Cnc1-dependent death requires its mitochondrial function rather than its transcriptional role, and that its effector Dnm1 acts as a signaling node …

Elucidating The Function Of Yedk In Response To Dna Damage, Hank Munro

University Honors Theses

Apurinic/Apyrimidinic (AP) sites are one of the most prevalent forms of DNA damage. These lesions arise spontaneously or during base excision repair of modified DNA bases and are potentially mutagenic in both mammalian and bacterial cells. 5-hydroxymethylcytosine binding, ES cell specific (HMCES), a protein found in eukaryotic cells, has been shown to form a stable DNA-protein crosslink with AP sites in single stranded DNA and to reduce the number of AP sites occurring either spontaneously or after alkylative DNA damage, resulting in increased genome stability. YedK, the Escherichia coli ortholog of HMCES exhibits some of the same biochemical properties as …

The Neuroprotective Effect Of Cdc42 Inhibition In The G93a Mutant Hsod1 Mouse Model Of Als, Andrea Koly

Undergraduate Theses, Capstones, and Recitals

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal neurodegenerative disease characterized by the selective loss of upper and lower motor neurons, leading to muscle weakness, neuromuscular junction (NMJ) degeneration, paralysis, and eventual death due to respiratory failure. Despite extensive research, effective disease-modifying therapies remain limited, underscoring the need to identify novel molecular targets involved in ALS pathogenesis. Dysregulation of Rho family GTPases has been implicated in neurodegeneration, with Rac and Rho exerting opposing effects on neuronal survival; however, the role of the closely related GTPase Cdc42 remains poorly understood in ALS. In this study, the therapeutic potential of inhibiting …

Structure-Based Discovery Of Malate Dehydrogenase Inhibitors With Efficacy Against C. Parvum Oocysts, Ankita Bharatbhai Kheni

Biochemistry and Molecular Biology

Cryptosporidium parvum, the etiological agent of Cryptosporidiosis (diarrheal illness) represents a significant global health burden, particularly affecting immunodeficient and pediatric populations. Since the parasite has a highly reduced mitochondrion and relies on glycolysis, enzymes such as C. parvum malate dehydrogenase (CpMDH), which are believed to be indispensable for parasite viability due to their pivotal roles in NAD⁺ regeneration and redox balance, remain largely unexplored as therapeutic targets. The present study employed a multifaceted experimental and computational strategy to evaluate the inhibitory activity of two lead-like and drug-like small molecules, referred to as compound 1.8 and compound 1.5, against the cofactor …

High Mobility Group Motif Proteins’ Role In Fibrosis, Inflammation, And Vascular Injury In Systemic Sclerosis, Fabian A. Mendoza, Sonsoles Piera-Velazquez, Sergio A. Jimenez

Jefferson Institute of Molecular Medicine Papers and Presentations

Systemic Sclerosis (SSc) is an idiopathic systemic autoimmune disease characterized by progressive cutaneous and systemic fibrosis, severe vasculopathy, and multiple humoral and cellular immunological alterations. The pathogenesis of SSc is highly complex and remains incompletely elucidated. The fibrotic process is a crucial component of SSc and is responsible for organ failure and high mortality. Although an increasing understanding of the fibrotic process has enabled the clinical development of antifibrotic therapeutic agents, these agents have limited clinical efficacy. Recently, the potential role of a group of transcription factors containing a High Mobility Group (HMG) motif, in the development and pathological manifestations …

Chromatin Insulators Homie And Nhomie Can Interact With Distant Copies Either Together Or Separately, With Distinct Outcomes For Enhancer-Promoter Interactions, Miki Fujioka, Wenfan Ke, Paul Schedl, James B. Jaynes

Department of Biochemistry and Molecular Biology Faculty Papers

Chromatin insulators, a.k.a. boundary elements, separate regions of the chromosome with distinct chromatin characteristics, including distinct histone modifications. This activity affects gene expression by allowing chromatin domains to be stably regulated and maintained. Insulators also block enhancer-promoter interactions and, somewhat paradoxically, facilitate other interactions, particularly when they stitch together distant regions of the chromosome by pairing with specific partners. Here we explore how long-range interactions facilitated by insulator pairing are affected by the presence of two potentially competing partners. Our results show that when two partners are present, they can reduce each other's effects on distant gene expression, suggesting that …