Biochemistry Commons^™

Developing A Comprehensive Genome-Scale Metabolic Model For The Arabidopsis Thaliana Root System, Lohani Esterhuizen

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Arabidopsis thaliana (Arabidopsis) is the most well-established model plant to date. Being the first plant to have its genome mapped, studies on Arabidopsis have provided insurmountable insights into the physiological and biochemical nature of plants. Methods that allow us to computationally study the metabolism of organisms include the use of genome-scale metabolic models (GEMs). Despite its popularity, no GEM currently maps the metabolic activity in the root system of Arabidopsis, which is the first organ to face and respond to stress conditions in the soil. This work aims to develop and implement a comprehensive GEM of the Arabidopsis root system …

Elevating Plk1 Overcomes Beti Resistance In Prostate Cancer Via Triggering Brd4 Phosphorylation-Dependent Degradation In Mitosis, Yanquan Zhang, Ka-Wing Fong, Fengyi Mao, Ruixin Wang, Derek B. Allison, Dana Napier, Daheng He, Jinpeng Liu, Yeqing Zhang, Jing Chen, Yifan Kong, Chaohao Li, Guangbing Li, Jinghui Liu, Zhiguo Li, Haining Zhu, Chi Wang, Xiaoqi Liu

Markey Cancer Center Faculty Publications

Bromodomain-containing protein 4 (BRD4) has emerged as a promising therapeutic target in prostate cancer (PCa). Understanding the mechanisms of BRD4 stability could enhance the clinical response to BRD4-tar- geted therapy. In this study, we report that BRD4 protein levels are significantly decreased during mitosis in a PLK1-dependent manner. Mechanistically, we show that BRD4 is primarily phosphorylated at T1186 by the CDK1/cyclin B complex, recruiting PLK1 to phosphorylate BRD4 at S24/S1100, which are recognized by the APC/CCdh1 complex for proteasome pathway degradation. We find that PLK1 overexpression lowers SPOP mutation-stabilized BRD4, consequently rendering PCa cells re-sensitized to BRD4 inhibitors. Intrigu-ingly, we …

Mutant Androgen Receptor Induces Neurite Loss And Senescence Independently Of Are Binding In A Neuronal Model Of Sbma, Jordyn Karliner, Y Liu, Diane Merry

Department of Biochemistry and Molecular Biology Faculty Papers

Spinal and bulbar muscular atrophy (SBMA) is a slowly progressing neuromuscular disease caused by a polyglutamine (polyQ)-encoding CAG trinucleotide repeat expansion in the androgen receptor (AR) gene, leading to AR aggregation, lower motor neuron death, and muscle atrophy. AR is a ligand-activated transcription factor that regulates neuronal architecture and promotes axon regeneration; however, whether AR transcriptional functions contribute to disease pathogenesis is not fully understood. Using a differentiated PC12 cell model of SBMA, we identified dysfunction of polyQ-expanded AR in its regulation of neurite growth and maintenance. Specifically, we found that in the presence of androgens, polyQ-expanded AR inhibited neurite …

Functional And Structural Analysis Of The Neimann-Pick Disease Type C Pathway To Include Caveolin-1, Anthony Michael Seat

Chemistry and Chemical Biology ETDs

Human disease is often thought of as an all or nothing prospect, either one has the disease or one does not. This does not bear out in clinical or personal experiences, instead demonstrating that disease occurs within a spectrum ranging from presumed unaffected to demonstrably and detrimentally affected.Neimann-Pick disease is one example of this spectrum look into diseased states, with multiple named versions of a phenotypically similar disease. We focus on Neimann-Picktype C (NPC), which is the result of a disruption in the efflux of cholesterol and sphingolipids from the endocytic pathway. NPC demonstrates this concept of a spectrum of …

Exploring The Effects Of An Alfalfa Leaf-Derived Adsorbent On Microbial Community, Ileal Morphology, Barrier Function, And Immunity In Turkey Poults During Chronic Aflatoxin B1 Exposure, Maria De Jesus Nava-Ramirez, Jing Liu, Juan Omar Hernandez-Ramirez, Xochitl Hernandez-Velasco, Juan D. Latorre, Alma Vazquez-Duran, Guolong Zhang, Roberto Señas-Cuesta, Sergio Gomez-Rosales, Andressa Stein, Billy M. Hargis, Guillermo Tellez-Isaias, Abraham Mendez-Albores, Jesus A. Maguey-Gonzalez

Poultry Science Faculty Publications and Presentations

This article follows-up on our recently published work, which evaluated the impact of the addition of an alfalfa leaf-derived adsorbent in the aflatoxin B₁ (AFB₁)-contaminated diet in regard to the production parameters, blood cell count, serum biochemistry, liver enzymes, and liver histology of turkey poults. This paper presents complementary results on microbial community, ileal morphology, barrier function, and immunity. For this purpose, 350 1-day-old female turkey poults were randomly distributed into five groups: (1) Control, AFB₁-free diet; (2) AF, AFB₁-contaminated diet at 250 ng/g; (3) alfalfa, AFB₁-free diet + 0.5% ( …

Wee1 And Cell Size Control In Fission Yeast By The Protein Kinase Cdr2, Rachel Berg-Murante

Dartmouth College Ph.D Dissertations

The mechanisms that govern cell size have long been topics of study in the field of cell biology. In eukaryotic cells this size control is tied to checkpoints, a set threshold of minimum necessary growth linked to cyclin dependent kinase activity regulation. In the fission yeast Schizosaccharomyces pombe, the Cdk1 regulatory network is conserved, and G2/M represents the major size checkpoint. Prior to mitosis, Cdk1 is inhibited by phosphorylation applied by Wee1 during G2 phase. Once S. pombe cells have satisfied the size checkpoint, Cdk1 is activated through dephosphorylation by Cdc25. Wee1 is a dose-dependent regulator of mitotic entry …

Carbon-Based Nanocomposite Membranes For Membrane Distillation: Progress, Problems And Future Prospects, Chhabilal Regmi, Yuwaraj K. Kshetri, S. Ranil Wickramasinghe

Chemical Engineering Faculty Publications and Presentations

The development of an ideal membrane for membrane distillation (MD) is of the utmost importance. Enhancing the efficiency of MD by adding nanoparticles to or onto a membrane’s surface has drawn considerable attention from the scientific community. It is crucial to thoroughly examine state-of-the-art nanomaterials-enabled MD membranes with desirable properties, as they greatly enhance the efficiency and reliability of the MD process. This, in turn, opens up opportunities for achieving a sustainable water–energy–environment nexus. By introducing carbon-based nanomaterials into the membrane’s structure, the membrane gains excellent separation abilities, resistance to various feed waters, and a longer lifespan. Additionally, the use …

Identifying And Training Deep Learning Neural Networks On Biomedical-Related Datasets, Alan E. Woessner, Usman Anjum, Hadi Salman, Jacob Lear, Jeffrey T. Turner, Ross Campbell, Laura Beaudry, Justin Zhan, Lawrence E. Cornett, Susan Gauch, Kyle P. Quinn

Computer Science and Computer Engineering Faculty Publications and Presentations

This manuscript describes the development of a resources module that is part of a learning platform named 'NIGMS Sandbox for Cloud-based Learning' https://github.com/NIGMS/NIGMS-Sandbox. The overall genesis of the Sandbox is described in the editorial NIGMS Sandbox at the beginning of this Supplement. This module delivers learning materials on implementing deep learning algorithms for biomedical image data in an interactive format that uses appropriate cloud resources for data access and analyses. Biomedical-related datasets are widely used in both research and clinical settings, but the ability for professionally trained clinicians and researchers to interpret datasets becomes difficult as the size and …

Adipose-Derived Mesenchymal Stem Cells And Their Derived Epidermal Progenitor Cells Conditioned Media Ameliorate Skin Aging In Rats, Mohamed M. Kamal, Omar Ibrahim Badr, Tasnim Mahmoud

Pharmacy

BACKGROUND: Skin alterations are among the most prominent signs of aging, and they arise from both intrinsic and extrinsic factors that interact and mutually influence one another. The use of D-galactose as an aging model in animals has been widely employed in anti-aging research. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) are particularly promising for skin anti-aging therapy due to their capacity for effective re-epithelization and secretion of various growth factors essential for skin regeneration. Accordingly, we aimed to examine the potential utility of Ad-MSCs as a therapy for skin anti-aging. METHODS: In this study, we isolated and characterized adipose-derived mesenchymal …

Frontotemporal Dementia-Like Disease Progression Elicited By Seeded Aggregation And Spread Of Fus, Sonia Vazquez-Sanchez, Britt Tilkin, Fatima Gasset-Rosa, Sitao Zhang, Diana Piol, Melissa Mcalonis-Downes, Jonathan Artates, Noe Govea-Perez, Yana Verresen, Lin Guo, Don Cleveland, James Shorter, Sandrine Da Cruz

Department of Biochemistry and Molecular Biology Faculty Papers

RNA binding proteins have emerged as central players in the mechanisms of many neurodegenerative diseases. In particular, a proteinopathy of fused in sarcoma (FUS) is present in some instances of familial Amyotrophic lateral sclerosis (ALS) and about 10% of sporadic Frontotemporal lobar degeneration (FTLD). Here we establish that focal injection of sonicated human FUS fibrils into brains of mice in which ALS-linked mutant or wild-type human FUS replaces endogenous mouse FUS is sufficient to induce focal cytoplasmic mislocalization and aggregation of mutant and wild-type FUS which with time spreads to distal regions of the brain. Human FUS fibril-induced FUS aggregation …

Snpaimer: R Package For Evaluating Ancestry Informative Marker Contributions In Non-Model Population Diagnostics, Kim L. Vertacnik, Oksana V. Vernygora, Julian R. Dupuis

Entomology Faculty Publications

Motivation: Single nucleotide polymorphism (SNP) markers are increasingly popular for population genomics and inferring ancestry for individuals of unknown origin. Because large SNP datasets are impractical for rapid and routine analysis, diagnostics rely on panels of highly informative markers. Strategies exist for selecting these markers, however, resources for efficiently evaluating their performance are limited for non-model systems.

Results: snpAIMeR is a user-friendly R package that evaluates the efficacy of genomic markers for the cluster assignment of unknown individuals. It is intended to help minimize panel size and genotyping effort by determining the informativeness of candidate diagnostic markers. Provided genotype data …

Machine-Learning Qsar-Based Novel Drug Identification To Inhibit Retinoblastoma Extracellular Vesicle Release And Metastatic Signaling, Kunhui Huang

Dissertations, Theses, and Capstone Projects

Extracellular vesicles (EVs) are lipid-enclosed particles that are generated by most types of cells and have been identified as an important mechanism for cell communication aside from cell direct contact. EVs contain a variety of functional macromolecules including proteins, lipids, RNA, which can be transferred from the host cells to target cells at a distance. The molecular pathways of EV biogenesis have been studied intensely in recent decades and the process involves several key genes and proteins. Cancer cell released EVs target distant tissues and upregulate signals that are attractive to cancer cell homing, playing a role in tumor progression …

Quantitative Proteomic Strategies To Determine Substrate Specificities Of Phosphoprotein Phosphatases, Hieu Trung Nguyen

Dartmouth College Ph.D Dissertations

Reversible phosphorylation is a crucial regulatory mechanism of cellular signaling pathways. Being the most prevalent post-translational modification (PTM) in the cells, with over 75% of all proteins detected to be phosphorylated, phosphorylation regulates a significant number of important cellular processes that have implications in various diseases. Phosphorylation is carried out by protein kinases, which have been extensively studied. However, the opposite reaction, carried out by protein phosphatases, has lagged significantly, exposing a gap of knowledge that is required to be investigated to delineate the kinase-substrate-phosphatase relationship. Phosphoprotein phosphatase family (PPPs), containing seven members of phospho-Serine (pS) and phospho-Threonine (pT) phosphatases, …

Towards A New Role Of Mitochondrial Hydrogen Peroxide In Synaptic Function, Cliyahnelle Z. Alexander

Student Theses and Dissertations

Aerobic metabolism is known to generate damaging ROS, particularly hydrogen peroxide. Reactive oxygen species (ROS) are highly reactive molecules containing oxygen that have the potential to cause damage to cells and tissues in the body. ROS are highly reactive atoms or molecules that rapidly interact with other molecules within a cell. Intracellular accumulation can result in oxidative damage, dysfunction, and cell death. Due to the limitations of H₂O₂ (hydrogen peroxide) detectors, other impacts of ROS exposure may have been missed. HyPer7, a genetically encoded sensor, measures hydrogen peroxide emissions precisely and sensitively, even at sublethal levels, during …

The Effect Of Novel Microtubule Modulators On Experimental Lewy Body Disease, Anuj S. Jamenis

Electronic Theses and Dissertations

In Lewy body disorders, α-synuclein aggregates are believed to destabilize the microtubular framework. However, microtubules are a challenging therapeutic target, as excessive rigidity or flexibility afforded by microtubule modulators may be neurotoxic. Thus, the objective of the present study was to evaluate dual-acting microtubule- stabilizing/destabilizing agents in cellular and animal models of early-stage Lewy body disease.

In Aim 1 we tested the dual-acting tricylic pyrimido[4,5-b]indole analogs AG161-47 and AG161-41 in an in vitro preformed fibril induced model of Lewy body disease. We found that both compounds reduced preformed fibril-seeded α-synucleinopathy without toxicity in primary hippocampal cultures. AG161-47 subtly impacted microtubule …

Unveiling The Nexus Of Cellular Quality Control: Exploring The Interplay Between Ribosome-Associated Protein Quality Control And Mitochondrial Quality Control Pathways, Foozhan Tahmasebinia

Biological Sciences Theses and Dissertations

In eukaryotic cells, the intricate interplay between cellular quality control mechanisms is crucial for maintaining homeostasis and safeguarding the integrity of vital processes, spanning from macromolecule synthesis to the renewal of entire cellular organelles.

Disruption of these networks can lead to severe diseases such as metabolic disorders, underscoring the interconnected nature and feedback control mechanisms inherent in biological systems, including cellular quality control systems. This interconnectedness extends to the intricate communication between organelles, enabling coordinated functioning and adaptation to changing cellular conditions, particularly in response to stressors.

While the exact mechanisms governing these communications within cellular quality control systems remain …

Protein Oxidation In Aging And Alzheimer’S Disease Brain, Rukhsana Sultana, D. Allan Butterfield

Markey Cancer Center Faculty Publications

Proteins are essential molecules that play crucial roles in maintaining cellular homeostasis and carrying out biological functions such as catalyzing biochemical reactions, structural proteins, immune response, etc. However, proteins also are highly susceptible to damage by reactive oxygen species (ROS) and reactive nitrogen species (RNS). In this review, we summarize the role of protein oxidation in normal aging and Alzheimer’s disease (AD). The major emphasis of this review article is on the carbonylation and nitration of proteins in AD and mild cognitive impairment (MCI). The oxidatively modified proteins showed a strong correlation with the reported changes in brain structure, carbohydrate …

Predicting The Pathway Involvement Of Metabolites Based On Combined Metabolite And Pathway Features, Erik D. Huckvale, Hunter N. B. Moseley

Markey Cancer Center Faculty Publications

A major limitation of most metabolomics datasets is the sparsity of pathway annotations for detected metabolites. It is common for less than half of the identified metabolites in these datasets to have a known metabolic pathway involvement. Trying to address this limitation, machine learning models have been developed to predict the association of a metabolite with a “pathway category”, as defined by a metabolic knowledge base like KEGG. Past models were implemented as a single binary classifier specific to a single pathway category, requiring a set of binary classifiers for generating the predictions for multiple pathway categories. This past approach …

Identifying The Molecular Determinants Of Lung Metastatic Adaptation In Prostate Cancer, Grace M. Waldron

Theses & Dissertations

Prostate cancer (PC) stands as the primary diagnosed cancer in men in the US at approximately 299,010 cases in 2024 and ranks second globally, posing a significant public health challenge. Clinical presentations vary widely, from indolent to aggressive forms, necessitating stage-specific treatment regimens. Understanding its metastatic nature is critical due to the impact of cancer cell dissemination on disease morbidity, with bone and visceral organs serving as key sites of metastasis. Despite bone metastasis being the most common site for metastasis, visceral metastases at sites such as the liver and lungs correlate with poorer survival, emphasizing the role of microenvironmental …

Mucins: Drivers Of Cancer Cell And Microenvironment Crosstalk In Pancreatic Cancer, Xiaoqi Li

Theses & Dissertations

Mucins facilitate the pancreatic cancer (PC) initiation, progression, and metastasis. Among mucins, MUC4 has been reported to inhibit lymphokine-activated cell killing and induce the apoptosis of cytotoxic T-cells. Counterintuitively, MUC4 expression is upregulated by multiple T-cell-secreted cytokines, such as IFN-γ, IL-17, and stroma-secreted factors like retinoic acid. Previously, we have identified that nuclear receptor coactivator 3 (NCOA3) regulates the MUC1 and MUC4 expression by increasing chromatin accessibility and maintaining protein stability. However, the comprehensive crosstalk mediated by MUC4 in cancer cells and T-cells and how its upstream regulator, NCOA3, modifies the cancer cell-intrinsic behavior is still elusive. Here, we show …

Understanding The Non-Canonical Regulation Of Srebp In Aspergillus Fumigatus, Muhammad Abubakar Khan

Dartmouth College Ph.D Dissertations

Aspergillus fumigatus is an opportunistic fungal pathogen causing invasive pulmonary aspergillosis (IPA), with high mortality rates in immunocompromised individuals. Adaptation to the hypoxic microenvironment of IPA is crucial for fungal virulence. The transcription factor SrbA, a Sterol Regulatory Element-Binding Protein (SREBP) homolog, plays a key role in this hypoxic response and regulates genes involved in hypoxic growth, sterol biosynthesis, and azole resistance, making it an attractive therapeutic target.

However, SrbA activation in A. fumigatus lacks critical components of the canonical SREBP pathway, such as SCAP, Site-1 protease (S1P), and Site-2 protease (S2P). Instead, the rhomboid protease RbdB, signal peptide peptidase …

A Review Of Rheb Activation Of Mtorc1 And The Great Mystery Of One Missing Gef, Jack Gregory

Senior Honors Theses

The mTORC1 pathway is involved in the regulation of cell growth and translation. The pathway has a complex web of activators and inhibitors to activate mTORC1. mTORC1 is regulated via a small GTPase called Rheb, which interacts directly with mTORC1. This GTPase and its GTPase activating protein (GAP), TSC1/2, have been widely studied to understand how the variety of regulators of mTORC1 interact with these proteins. Despite this, the guanine nucleotide exchange factor (GEF) of Rheb has yet to be identified. This review broadly analyzes Rheb and mTORC1, their structures, regulations, and interactions, and explores the mystery of the missing …

Pipecolic Acid And Novel Insights Into Cerebral Malaria, Akua E. Mensah

Theses and Dissertations

Cerebral malaria (CM), a severe manifestation of Plasmodium infection, prompts our investigation into the nuanced role of pipecolic acid in its pathophysiology. To unravel the molecular intricacies, we conducted in vitro lysine labeling techniques of mice infected with P. berghei ANKA parasites, and human P. falciparum grown in vitro, aiming to discern the impact of Plasmodium on pipecolic acid production. Previous observations indicated an elevation in pipecolic acid levels correlating with neurological decline in children with CM. In our study, confirming elevated pipecolic acid presence in the plasma and brain tissues of CM patients and the animal model of CM, …

Plant Model Of Α-Synucleinopathy: Expression Of Α-Synuclein A53t Variant In Hairy Root Cultures Leads To Proteostatic Stress And Dysregulation Of Iron Metabolism, Jasmina Kurepa, Kristen A. Bruce, Greg A. Gerhardt, Jan A. Smalle

Neurology Faculty Publications

Synucleinopathies, typified by Parkinson’s disease (PD), entail the accumulation of α- synuclein (αSyn) aggregates in nerve cells. Various αSyn mutants, including the αSyn A53T variant linked to early-onset PD, increase the propensity for αSyn aggregate formation. In addition to disrupting protein homeostasis and inducing proteostatic stress, the aggregation of αSyn in PD is associated with an imbalance in iron metabolism, which increases the generation of reactive oxygen species and causes oxidative stress. This study explored the impact of αSyn A53T expression in transgenic hairy roots of four medicinal plants (Lobelia cardinalis, Artemisia annua, Salvia miltiorrhiza, and Polygonum multiflorum). In all …

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 …

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 …

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.

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 …