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Molecular Biology

2019

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Articles 1 - 30 of 146

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Immediate-Early Genes And Delayed Primary Response Genes Regulated By Nmu In Skbr3 Her-2 Positive Breast Cancer Cell Line, Jessica Murphy, Sweta Rani Sep 2019

Immediate-Early Genes And Delayed Primary Response Genes Regulated By Nmu In Skbr3 Her-2 Positive Breast Cancer Cell Line, Jessica Murphy, Sweta Rani

Sure-J: Science Undergraduate Research Journal

Background
Breast cancer is a heterogeneous disease that consists of varying genetic, cellular and molecular subtypes with unique characteristics. Due to the multiple subtypes and molecular markers of breast cancer, successful clinical treatment is hampered by the lack of reliable biomarkers. HER2-positive breast cancer is an aggressive subtype associated with poor patient prognosis. Although survival rates have dramatically increased due to the development of Trastuzumab in 1997, many patients develop a resistance to this therapeutic treatment and relapse over time. Rani et al. (2014), have associated the acquirement of resistance to HER2-treatment with Neuromedin U, but the mechanisms by which ...


Creating A Molecular Map Of The Pediatric Lung, Quinlen F. Marshall Sep 2019

Creating A Molecular Map Of The Pediatric Lung, Quinlen F. Marshall

Forum Lectures

The newborn lung undergoes vast biochemical and physiological changes during adaptation from the intrauterine to the extrauterine environment. Lung morphogenesis continues from birth into early childhood, mediated by dynamic gene expression and a diversity of pulmonary cell types that exhibit remarkable heterogeneity. (Whitsett, JA. et al. Physiol. Rev, 2019). Surprisingly, few studies have solely focused on human lung development during this critical period, and many current studies of lung maturation rely on adult, murine, or diseased samples, limiting their insights and applicability to longitudinal pediatric lung development. Understanding the molecular and physiological nuances of pulmonary development has important clinical relevance ...


Gene Pyramids And The Balancing Act Of Keeping Pests At Bay, Gustavo C. Macintosh Sep 2019

Gene Pyramids And The Balancing Act Of Keeping Pests At Bay, Gustavo C. Macintosh

Biochemistry, Biophysics and Molecular Biology Publications

Pyramiding R genes is a common strategy used by breeders to enhance resistance and increase durability of resistance in crops. However, the molecular mechanisms that mediate R gene interactions are not known. Kamphuis et al. (2019) analyzed Medicago truncatula plants carrying two genes that confer resistance to bluegreen aphids. They identified a potential phytohormone crosstalk triggered by the combined R gene action in response to aphid feeding that enhances resistance and minimizes R gene-associated fitness costs to the plant.


The Central Role Of The Tail In Switching Off 10s Myosin Ii Activity, Shixin Yang, Kyounghwan Lee, John L. Woodhead, Osamu Sato, Mitsuo Ikebe, Roger Craig Sep 2019

The Central Role Of The Tail In Switching Off 10s Myosin Ii Activity, Shixin Yang, Kyounghwan Lee, John L. Woodhead, Osamu Sato, Mitsuo Ikebe, Roger Craig

Radiology Publications and Presentations

Myosin II is a motor protein with two heads and an extended tail that plays an essential role in cell motility. Its active form is a polymer (myosin filament) that pulls on actin to generate motion. Its inactive form is a monomer with a compact structure (10S sedimentation coefficient), in which the tail is folded and the two heads interact with each other, inhibiting activity. This conformation is thought to function in cells as an energy-conserving form of the molecule suitable for storage as well as transport to sites of filament assembly. The mechanism of inhibition of the compact molecule ...


Engineering Of Escherichia Coli 2-Oxoglutarate Dehydrogenase Complex With Mechanistic And Synthetic Goals, Joydeep Chakraborty Aug 2019

Engineering Of Escherichia Coli 2-Oxoglutarate Dehydrogenase Complex With Mechanistic And Synthetic Goals, Joydeep Chakraborty

Dissertations

The Escherichia coli 2-oxoglutarate dehydrogenase complex (OGDHc) compromises multiple copies of three enzymes - 2-oxoglutarate dehydrogenase (E1o), dihydrolipoyl succinyltransferase (E2o), and dihydrolipoyl dehydrogenase (E3). OGDHc is found in the Krebs cycle and catalyzes the formation of the all-important succinyl-Coenzyme A (succinyl-CoA). OGDHc was engineered to understand the catalytic mechanism and optimized for chemical synthetic goals.

Succinyl-CoA formation takes place within the catalytic domain of E2o via a transesterification reaction. The succinyl group from the thiol ester of S8-succinyldihydrolipoyl-E2o is transferred to the thiol group of CoA. Mechanistic studies were designed to investigate enzymatic transthioesterification. His375 and Asp374 was shown to be ...


A Unified Encyclopedia Of Human Functional Dna Elements Through Fully Automated Annotation Of 164 Human Cell Types, Maxwell W. Libbrecht, Oscar L. Rodriguez, Zhiping Weng, Jeffrey A. Bilmes, Michael M. Hoffman, William Stafford Noble Aug 2019

A Unified Encyclopedia Of Human Functional Dna Elements Through Fully Automated Annotation Of 164 Human Cell Types, Maxwell W. Libbrecht, Oscar L. Rodriguez, Zhiping Weng, Jeffrey A. Bilmes, Michael M. Hoffman, William Stafford Noble

Open Access Articles

Semi-automated genome annotation methods such as Segway take as input a set of genome-wide measurements such as of histone modification or DNA accessibility and output an annotation of genomic activity in the target cell type. Here we present annotations of 164 human cell types using 1615 data sets. To produce these annotations, we automated the label interpretation step to produce a fully automated annotation strategy. Using these annotations, we developed a measure of the importance of each genomic position called the "conservation-associated activity score." We further combined all annotations into a single, cell type-agnostic encyclopedia that catalogs all human regulatory ...


Mechanism For Apobec3g Catalytic Exclusion Of Rna And Non-Substrate Dna, William C. Solomon, Wazo Myint, Shurong Hou, Tapan Kanai, Rashmi Tripathi, Nese Kurt Yilmaz, Celia A. Schiffer, Hiroshi Matsuo Aug 2019

Mechanism For Apobec3g Catalytic Exclusion Of Rna And Non-Substrate Dna, William C. Solomon, Wazo Myint, Shurong Hou, Tapan Kanai, Rashmi Tripathi, Nese Kurt Yilmaz, Celia A. Schiffer, Hiroshi Matsuo

Schiffer Lab Publications

The potent antiretroviral protein APOBEC3G (A3G) specifically targets and deaminates deoxycytidine nucleotides, generating deoxyuridine, in single stranded DNA (ssDNA) intermediates produced during HIV replication. A non-catalytic domain in A3G binds strongly to RNA, an interaction crucial for recruitment of A3G to the virion; yet, A3G displays no deamination activity for cytidines in viral RNA. Here, we report NMR and molecular dynamics (MD) simulation analysis for interactions between A3Gctd and multiple substrate or non-substrate DNA and RNA, in combination with deamination assays. NMR ssDNA-binding experiments revealed that the interaction with residues in helix1 and loop1 (T201-L220) distinguishes the binding mode of ...


Promotion Of Adipogenesis By Jmjd6 Requires The At Hook-Like Domain And Is Independent Of Its Catalytic Function, Pablo Reyes-Gutierrez, Jake W. Carrasquillo-Rodriguez, Anthony N. Imbalzano Aug 2019

Promotion Of Adipogenesis By Jmjd6 Requires The At Hook-Like Domain And Is Independent Of Its Catalytic Function, Pablo Reyes-Gutierrez, Jake W. Carrasquillo-Rodriguez, Anthony N. Imbalzano

Open Access Articles

JMJD6 is a member of the Jumonji C domain containing enzymes that demethylate and/or hydroxylate substrate proteins. It is a multi-functional protein that has been implicated in disparate aspects of transcriptional and post-transcriptional control of gene expression, including but not limited to enhancer and promoter binding, release of paused RNA polymerase II, control of splicing, and interaction with the translation machinery. JMJD6 contributes to multiple aspects of animal development, including adipogenesis modeled in culture. We mutated proposed or characterized domains in the JMJD6 protein to better understand the requirement for JMJD6 in adipogenic differentiation. Mutation of JMJD6 amino acids ...


Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli Aug 2019

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 ...


Janani Subramaniam Thesis.Pdf, Janani Subramaniam Aug 2019

Janani Subramaniam Thesis.Pdf, Janani Subramaniam

Janani Subramaniam

Distinctly organized domains of receptors, ion channels, transporters, signaling molecules, cell adhesion molecules, and contractile proteins are crucial to cardiac function. Interactions between adaptor proteins such as ankyrins and cytoskeletal proteins such as obscurin play a pivotal role in organizing these functional domains in cardiomyocytes. Therefore, dysfunction of both ankyrin as well as obscurin lead to a host of cardiovascular diseases such as arrhythmias and cardiomyopathies. Alternative splicing of ankyrin yields numerous isoforms that interact with obscurin at various sub-cellular domains. And while some of these obscurin-ankyrin complexes have been studied, many others have not been characterized. Further, previous studies ...


Insulin Receptor Substrate-1 (Irs-1) And Irs-2 Expression Levels Are Associated With Prognosis In Non-Small Cell Lung Cancer (Nsclc), Andrew J. Piper, Jennifer L. Clark, Jose R. Mercado-Matos, Asia N. Matthew-Onabanjo, Chung-Cheng Hsieh, Ali Akalin, Leslie M. Shaw Aug 2019

Insulin Receptor Substrate-1 (Irs-1) And Irs-2 Expression Levels Are Associated With Prognosis In Non-Small Cell Lung Cancer (Nsclc), Andrew J. Piper, Jennifer L. Clark, Jose R. Mercado-Matos, Asia N. Matthew-Onabanjo, Chung-Cheng Hsieh, Ali Akalin, Leslie M. Shaw

Open Access Articles

The insulin-like growth factor-1 (IGF-1) signaling pathway has been implicated in non-small cell lung cancer (NSCLC) outcomes and resistance to targeted therapies. However, little is known regarding the molecular mechanisms by which this pathway contributes to the biology of NSCLC. The insulin receptor substrate (IRS) proteins are cytoplasmic adaptor proteins that signal downstream of the IGF-1R and determine the functional outcomes of this signaling pathway. In this study, we assessed the expression patterns of IRS-1 and IRS-2 in NSCLC to identify associations between IRS-1 and IRS-2 expression levels and survival outcomes in the two major histological subtypes of NSCLC, adenocarcinoma ...


Iron-Sulfur Cluster Assembly; In Vivo Analysis Of The Methanogenic Suf System, Evan Dunkle Aug 2019

Iron-Sulfur Cluster Assembly; In Vivo Analysis Of The Methanogenic Suf System, Evan Dunkle

LSU Master's Theses

Iron-sulfur (Fe-S) clusters are among the most ancient and prevalent of all biological cofactors. Their assembly into associated proteins is a tightly regulated process with many organisms employing multiple cluster assembly pathways. Much is known about Fe-S cluster assembly in aerobic organisms such as Escherichia coli (E. coli) but little is known in regards to cluster assembly in more ancient organisms such as methanogens. Methanogens are members of the domain of Archaea and are defined by their ability to generate methane as a byproduct of their main energy generating pathway. Methanogens also have significantly higher Fe-S cluster content compared to ...


Does Thermotolerance In Daphnia Depend On The Mitochondrial Function?, Rajib Hasan Aug 2019

Does Thermotolerance In Daphnia Depend On The Mitochondrial Function?, Rajib Hasan

Electronic Theses and Dissertations

Thermotolerance limit in aquatic organism is set by the ability to sustain aerobic scope to sudden temperature shifts. This study tested the genetic and plastic differences in thermotolerance of Daphnia that can be explained by the differences in the ability to retain mitochondrial integrity at high temperatures. Five genotypes with different biogeographic origins were acclimated to 18C and 25C. We developed a rhodamine 123 in-vivo assay to measure mitochondrial membrane potential and observed higher fluorescent in heat damaged tissues as the disruption of the mitochondrial membrane potential. Significant effects on temperature tolerance were observed with CCCP ...


High-Fat Diet In A Mouse Insulin-Resistant Model Induces Widespread Rewiring Of The Phosphotyrosine Signaling Network, Antje Dittmann, Norman J. Kennedy, Nina L. Soltero, Nader Morshed, Miyeko D. Mana, Omer H. Yilmaz, Roger J. Davis, Forest M. White Aug 2019

High-Fat Diet In A Mouse Insulin-Resistant Model Induces Widespread Rewiring Of The Phosphotyrosine Signaling Network, Antje Dittmann, Norman J. Kennedy, Nina L. Soltero, Nader Morshed, Miyeko D. Mana, Omer H. Yilmaz, Roger J. Davis, Forest M. White

Open Access Articles

Obesity-associated type 2 diabetes and accompanying diseases have developed into a leading human health risk across industrialized and developing countries. The complex molecular underpinnings of how lipid overload and lipid metabolites lead to the deregulation of metabolic processes are incompletely understood. We assessed hepatic post-translational alterations in response to treatment of cells with saturated and unsaturated free fatty acids and the consumption of a high-fat diet by mice. These data revealed widespread tyrosine phosphorylation changes affecting a large number of enzymes involved in metabolic processes as well as canonical receptor-mediated signal transduction networks. Targeting two of the most prominently affected ...


Temporal Gene Expression Of Mesenchymal Cells In The Pediatric Lung, Quinlen F. Marshall, Soumyaroop Bhattacharya, Gautam Bandyopadhyay, Ravi Misra, Thomas Mariani, Gloria Pryhuber Aug 2019

Temporal Gene Expression Of Mesenchymal Cells In The Pediatric Lung, Quinlen F. Marshall, Soumyaroop Bhattacharya, Gautam Bandyopadhyay, Ravi Misra, Thomas Mariani, Gloria Pryhuber

Chemistry Student Work

INTRODUCTION: The newborn lung undergoes vast biochemical and physiological changes during adaptation from the intrauterine to the extrauterine environment. Lung morphogenesis continues from birth into early childhood, mediated by dynamic gene expression and a diversity of pulmonary cell types (Whitsett, JA. et al. Physiol. Rev, 2019). Murine models demonstrate that pulmonary mesenchymal cells exhibit remarkable heterogeneity in function and morphology during development, however, confirmation of their role is lacking in human neonates and early childhood (Guo, M. et al. Nat. Comm, 2019). In addition, many current human genomic studies of lung maturation suffer from limited sample size, limiting their applicability ...


Ipsc Based Gene Correction And Disease Model Of A New Class Of Lgmd Due To Poglut1 Mutation, Jose Ortiz-Vitali Aug 2019

Ipsc Based Gene Correction And Disease Model Of A New Class Of Lgmd Due To Poglut1 Mutation, Jose Ortiz-Vitali

UT GSBS Dissertations and Theses (Open Access)

Recently, a novel class of muscular dystrophy has been discovered in a family due to autosomal recessive missense mutation in POGLUT1. Mutation of this enzyme leads to decreased O-glucosyltransferase activity and impaired Notch signaling, the pathways important for skeletal muscle stem cell (satellite cells) quiescence and activation. We hypothesize that reduced POGLUT1 activity and impaired Notch signaling is causative of this limb girdle muscular dystrophy through dysfunction of muscle stem cells and myogenic progenitors.

To test this, we have used iPSCs for disease modeling and rescue experiments. Using a CRISPR based gene targeting method, we aimed to correct the point ...


Intron And Small Rna Localization In Mammalian Neurons, Harleen Saini Jul 2019

Intron And Small Rna Localization In Mammalian Neurons, Harleen Saini

GSBS Dissertations and Theses

RNA molecules are diverse in form and function. They include messenger RNAs (mRNAs) that are templates for proteins, splice products such as introns that can generate functional noncoding RNAs, and a slew of smaller RNAs such as transfer RNAs (tRNAs) that help decode mRNAs into proteins. RNAs can show distinct patterns of subcellular localization that play an important role in protein localization. However, RNA distribution in cells is incompletely understood, with prior studies focusing primarily on RNAs that are long (>200 nucleotides), fully processed, and polyadenylated. We examined the distribution of RNAs in neurons. Neuronal compartments can be separated by ...


Impact Of Obesity On Ovotoxicity Induced By 7,12-Dimethylbenz[A]Anthracene In Mice, Jackson Nteeba, Shanthi Ganesan, Aileen F. Keating Jul 2019

Impact Of Obesity On Ovotoxicity Induced By 7,12-Dimethylbenz[A]Anthracene In Mice, Jackson Nteeba, Shanthi Ganesan, Aileen F. Keating

Aileen Keating

Insulin, elevated during obesity, regulates xenobiotic biotransformation enzymes, potentially through phosphatidylinositol 3-kinase (PI3K) signaling, in extraovarian tissues. PI3K regulates oocyte viability, follicular activation, and ovarian chemical biotransformation. 7,12-Dimethylbenz[a]anthracene (DMBA), a carcinogen and ovotoxicant, destroys all stages of follicles, leading to premature ovarian failure. Obesity has been reported to promote DMBA-induced tumors, but it remains unknown whether obesity affects ovarian xenobiotic metabolism. Therefore, we investigated ovarian expression of xenobiotic metabolism genes—microsomal epoxide hydrolase (Ephx1), glutathione S-transferase (GST) class Pi (Gstp1) and class mu 1 (Gstm1), and PI3K-signaling members (protein kinase B [AKT] alpha [Akt1], beta [Akt2], and ...


Glutathione S-Transferase Class Mu Regulation Of Apoptosis Signal-Regulating Kinase 1 Protein During Vcd-Induced Ovotoxicity In Neonatal Rat Ovaries, Poulomi Bhattacharya, Jill A. Madden, Nivedita Sen, Patricia B. Hoyer, Aileen F. Keating Jul 2019

Glutathione S-Transferase Class Mu Regulation Of Apoptosis Signal-Regulating Kinase 1 Protein During Vcd-Induced Ovotoxicity In Neonatal Rat Ovaries, Poulomi Bhattacharya, Jill A. Madden, Nivedita Sen, Patricia B. Hoyer, Aileen F. Keating

Aileen Keating

4-vinylcyclohexene diepoxide (VCD) destroys ovarian primordial and small primary follicles via apoptosis. In mice, VCD exposure induces ovarian mRNA expression of glutathione S-transferase (GST) family members, including isoform mu (Gstm). Extra-ovarian GSTM negatively regulates pro-apoptotic apoptosis signal-related kinase 1 (ASK1) through protein complex formation, which dissociates during stress, thereby initiating ASK1-induced apoptosis. The present study investigated the ovarian response of Gstm mRNA and protein to VCD. Induction of Ask1 mRNA at VCD-induced follicle loss onset was determined. Ovarian GSTM:ASK1 protein complex formation was investigated and VCD exposure effects thereon evaluated. Phosphatidylinositol-3 kinase (PI3K) regulation of GSTM protein was also ...


Nonnative Structure In A Peptide Model Of The Unfolded State Of Sod1: Implications For Als-Linked Aggregation, Noah R. Cohen, Jill A. Zitzewitz, Osman Bilsel, C. Robert Matthews Jul 2019

Nonnative Structure In A Peptide Model Of The Unfolded State Of Sod1: Implications For Als-Linked Aggregation, Noah R. Cohen, Jill A. Zitzewitz, Osman Bilsel, C. Robert Matthews

Open Access Articles

Dozens of mutations throughout the sequence of the gene encoding superoxide dismutase 1 (SOD1) have been linked to toxic protein aggregation in the neurodegenerative disease amyotrophic lateral sclerosis (ALS). A parsimonious explanation for numerous genotypes resulting in a common phenotype would be mutation-induced perturbation of the folding free-energy surface that increases the populations of high-energy states prone to aggregation. The absence of intermediates in the folding of monomeric SOD1 suggests that the unfolded ensemble is a potential source of aggregation. To test this hypothesis, here we dissected SOD1 into a set of peptides end-labeled with FRET probes to model the ...


Rapid Irreversible Transcriptional Reprogramming In Human Stem Cells Accompanied By Discordance Between Replication Timing And Chromatin Compartment, Vishnu Dileep, Rachel Patton Mccord, Job Dekker, David M. Gilbert Jul 2019

Rapid Irreversible Transcriptional Reprogramming In Human Stem Cells Accompanied By Discordance Between Replication Timing And Chromatin Compartment, Vishnu Dileep, Rachel Patton Mccord, Job Dekker, David M. Gilbert

Open Access Articles

The temporal order of DNA replication is regulated during development and is highly correlated with gene expression, histone modifications and 3D genome architecture. We tracked changes in replication timing, gene expression, and chromatin conformation capture (Hi-C) A/B compartments over the first two cell cycles during differentiation of human embryonic stem cells to definitive endoderm. Remarkably, transcriptional programs were irreversibly reprogrammed within the first cell cycle and were largely but not universally coordinated with replication timing changes. Moreover, changes in A/B compartment and several histone modifications that normally correlate strongly with replication timing showed weak correlation during the early ...


Systems Approach Reveals Photosensitivity And Per2 Level As Determinants Of Clock-Modulator Efficacy, Dae Wook Kim, Cheng Chang, Xian Chen, Angela C. Doran, Francois Gaudreault, Travis Wager, George J. Demarco, Jae Kyoung Kim Jul 2019

Systems Approach Reveals Photosensitivity And Per2 Level As Determinants Of Clock-Modulator Efficacy, Dae Wook Kim, Cheng Chang, Xian Chen, Angela C. Doran, Francois Gaudreault, Travis Wager, George J. Demarco, Jae Kyoung Kim

Open Access Articles

In mammals, the master circadian clock synchronizes daily rhythms of physiology and behavior with the day-night cycle. Failure of synchrony, which increases the risk for numerous chronic diseases, can be treated by phase adjustment of the circadian clock pharmacologically, for example, with melatonin, or a CK1delta/epsilon inhibitor. Here, using in silico experiments with a systems pharmacology model describing molecular interactions, and pharmacokinetic and behavioral experiments in cynomolgus monkeys, we find that the circadian phase delay caused by CK1delta/epsilon inhibition is more strongly attenuated by light in diurnal monkeys and humans than in nocturnal mice, which are common preclinical ...


Molecular And Structural Mechanism Of Pan-Genotypic Hcv Ns3/4a Protease Inhibition By Glecaprevir, Jennifer Timm, Klajdi Kosovrasti, Mina Henes, Florian Leidner, Shurong Hou, Akbar Ali, Nese Kurt Yilmaz, Celia A. Schiffer Jul 2019

Molecular And Structural Mechanism Of Pan-Genotypic Hcv Ns3/4a Protease Inhibition By Glecaprevir, Jennifer Timm, Klajdi Kosovrasti, Mina Henes, Florian Leidner, Shurong Hou, Akbar Ali, Nese Kurt Yilmaz, Celia A. Schiffer

University of Massachusetts Medical School Faculty Publications

Hepatitis C virus (HCV), causative agent of chronic viral hepatitis, infects 71 million people worldwide and is divided into seven genotypes and multiple subtypes with sequence identities between 68 to 82%. While older generation direct-acting antivirals (DAAs) had varying effectiveness against different genotypes, the newest NS3/4A protease inhibitors including glecaprevir (GLE) have pan-genotypic activity. The structural basis for pan-genotypic inhibition and effects of polymorphisms on inhibitor potency were not well known due to lack of crystal structures of GLE-bound NS3/4A or genotypes other than 1. In this study, we determined the crystal structures of NS3/4A from genotypes ...


Endogenous Force Transmission Between Epithelial Cells And A Role For Α-Catenin, Sandeep Dumbali Jul 2019

Endogenous Force Transmission Between Epithelial Cells And A Role For Α-Catenin, Sandeep Dumbali

Mechanical & Aerospace Engineering Theses & Dissertations

In epithelial tissues, epithelial cells adhere to each other as well as to the underlying extra-cellular matrix (ECM). E-cadherin-based intercellular junctions play an important role in tissue integrity. These junctions experience cell-generated mechanical forces via apparent adaptor proteins such as beta (β) catenin, alpha (α) catenin and vinculin. Abnormalities in these junctions may result in skin related diseases and cancers. Here, I devised methods to determine the endogenous intercellular force within cell pairs as well as in large epithelial islands. I further ascertained the factors that affect the level of inter-cellular tension.

Experiments with pairs of epithelial cells exogenously expressing ...


The Expression Of Connexin-43 By Cd11c+ Dendritic Cells Is Required To Maintain Cd4+ Foxp3+ Regulatory T Cell Population In Peripheral Lymphoid Organs, Caroline Titus Miller Jul 2019

The Expression Of Connexin-43 By Cd11c+ Dendritic Cells Is Required To Maintain Cd4+ Foxp3+ Regulatory T Cell Population In Peripheral Lymphoid Organs, Caroline Titus Miller

Biological Sciences Theses & Dissertations

Foxp3+ regulatory T cells (TR) are an immunosuppressive subset of CD4+ T cells that maintain homeostasis of the immune system. They are sustained by the interaction between the Major Histocompatibility Complex (MHC) molecules present on antigen presenting dendritic cells and the T Cell Receptor (TCR) expressed on TR cells that is specific for the MHC loaded with an antigenic peptide. Here, we show that in addition to MHC/TCR interaction, Connexin-43 (Cx43) expression by dendritic cells is required to maintain the TR cell population. CD11c+ dendritic cells represent a major subset of antigen presenting cells. Using flow cytometry ...


Knocking Out A Negative Regulator Of Hedgehog Signaling Blocks Differentiation Of Cells Into Neurons, Danielle Margaret Spice, Gregory M. Kelly Ph.D. Jun 2019

Knocking Out A Negative Regulator Of Hedgehog Signaling Blocks Differentiation Of Cells Into Neurons, Danielle Margaret Spice, Gregory M. Kelly Ph.D.

Western Research Forum

Hedgehog (Hh) signaling, one of many different protein signaling pathways found in mammals, is vital in many stage of neural development. A major negative regulator of Hh signaling is a protein known as Suppressor of Fused (SUFU), which acts to sequester the full length Gli transcription factors, proteins that can turn genes on and off, in the cytoplasm or facilitates its conversion to a repressive form. The P19 embryonal carcinoma cell line is a model of hind-brain neuronal differentiation and the involvement of Hh signaling, in particular the role of SUFU in this process has yet to be explored. We ...


Iron-Sulfur Cluster Biosynthesis In Methanogens, Cuiping Zhao Jun 2019

Iron-Sulfur Cluster Biosynthesis In Methanogens, Cuiping Zhao

LSU Doctoral Dissertations

Methanogens live in a syntrophic consortium with bacteria, taking advantage of the metabolic abilities of their syntrophic partners to overcome energetic barriers and break down compounds that they cannot digest by themselves. Interspecies electron transfer, which is a major type of microbial communication in syntrophic processes, improves methanogenesis and anaerobic oxidization of methane (AOM) processes involved in syntrophic consortia. These processes have a significant impact on the global carbon cycle. Most of the essential enzymes involved in methanogenesis are iron-sulfur proteins. Iron-sulfur clusters are one of the oldest and most versatile cofactors present in all domains of life. To date ...


In Situ Structure Of Rotavirus Vp1 Rna-Dependent Rna Polymerase, Simon Jenni, Eric N. Salgado, Tobias Herrmann, Zongli Li, Timothy Grant, Nikolaus Grigorieff, Stefano Trapani, Leandro F. Estrozi, Stephen C. Harrison Jun 2019

In Situ Structure Of Rotavirus Vp1 Rna-Dependent Rna Polymerase, Simon Jenni, Eric N. Salgado, Tobias Herrmann, Zongli Li, Timothy Grant, Nikolaus Grigorieff, Stefano Trapani, Leandro F. Estrozi, Stephen C. Harrison

Open Access Articles

Rotaviruses, like other non-enveloped, double-strand RNA viruses, package an RNA-dependent RNA polymerase (RdRp) with each duplex of their segmented genomes. Rotavirus cell entry results in loss of an outer protein layer and delivery into the cytosol of an intact, inner capsid particle (the "double-layer particle," or DLP). The RdRp, designated VP1, is active inside the DLP; each VP1 achieves many rounds of mRNA transcription from its associated genome segment. Previous work has shown that one VP1 molecule lies close to each 5-fold axis of the icosahedrally symmetric DLP, just beneath the inner surface of its protein shell, embedded in tightly ...


A Chromosome Folding Intermediate At The Condensin-To-Cohesin Transition During Telophase, Kristin Abramo, Anne-Laure Valton, Sergey V. Venev, Hakan Ozadam, A. Nicole Fox, Job Dekker Jun 2019

A Chromosome Folding Intermediate At The Condensin-To-Cohesin Transition During Telophase, Kristin Abramo, Anne-Laure Valton, Sergey V. Venev, Hakan Ozadam, A. Nicole Fox, Job Dekker

University of Massachusetts Medical School Faculty Publications

Chromosome folding is extensively modulated as cells progress through the cell cycle. During mitosis, condensin complexes fold chromosomes in helically arranged nested loop arrays. In interphase, the cohesin complex generates loops that can be stalled at CTCF sites leading to positioned loops and topologically associating domains (TADs), while a separate process of compartmentalization drives the spatial segregation of active and inactive chromatin domains. We used synchronized cell cultures to determine how the mitotic chromosome conformation is transformed into the interphase state. Using Hi-C, chromatin binding assays, and immunofluorescence we show that by telophase condensin-mediated loops are lost and a transient ...


Extracellular-Signal Regulated Kinase: A Central Molecule Driving Epithelial-Mesenchymal Transition In Cancer, Monserrat Olea-Flores, Miriam Daniela Zuniga-Eulogio, Miguel Angel Mendoza-Catalan, Hugo Alberto Rodriguez-Ruiz, Eduardo Castaneda-Saucedo, Carlos Ortuno-Pineda, Teresita Padilla-Benavides, Napoleon Navarro-Tito Jun 2019

Extracellular-Signal Regulated Kinase: A Central Molecule Driving Epithelial-Mesenchymal Transition In Cancer, Monserrat Olea-Flores, Miriam Daniela Zuniga-Eulogio, Miguel Angel Mendoza-Catalan, Hugo Alberto Rodriguez-Ruiz, Eduardo Castaneda-Saucedo, Carlos Ortuno-Pineda, Teresita Padilla-Benavides, Napoleon Navarro-Tito

Open Access Articles

Epithelial-mesenchymal transition (EMT) is a reversible cellular process, characterized by changes in gene expression and activation of proteins, favoring the trans-differentiation of the epithelial phenotype to a mesenchymal phenotype. This process increases cell migration and invasion of tumor cells, progression of the cell cycle, and resistance to apoptosis and chemotherapy, all of which support tumor progression. One of the signaling pathways involved in tumor progression is the MAPK pathway. Within this family, the ERK subfamily of proteins is known for its contributions to EMT. The ERK subfamily is divided into typical (ERK 1/2/5), and atypical (ERK 3/4 ...