Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 24 of 24
Full-Text Articles in Entire DC Network
An Interaction Between Centrosome Scaffold Proteins And A Retrotransposon Nucleocapsid Protein May Alter Asymmetric Centrosome Inheritance, Lanilei Doctora
An Interaction Between Centrosome Scaffold Proteins And A Retrotransposon Nucleocapsid Protein May Alter Asymmetric Centrosome Inheritance, Lanilei Doctora
Legacy Theses & Dissertations (2009 - 2024)
Nearly all eukaryotic genomes harbor mobile genetic elements known as retrotransposons. The mRNA ofthese elements undergo reverse transcription, yielding cDNA that is inserted in a new location in the host genome. We study Saccharomyces cerevisiae Ty1 elements, an active family of retrovirus-like retrotransposons, and the mechanism behind its regulation of spindle pole body (SPB) inheritance. Ty1 retromobility is activated during growth at 20˚C. In a manuscript that includes my work (Murphy et al., 2022, manuscript in preparation), we report that essential SPB proteins Nud1 and Spc42 are sequestered in the Ty1 retrosome, the site of Ty1 nucleocapsid assembly, in a …
Translation Control Tunes Drosophila Oogenesis, Elliot T. Martin
Translation Control Tunes Drosophila Oogenesis, Elliot T. Martin
Legacy Theses & Dissertations (2009 - 2024)
The decision of a stem cell to either self-renew or differentiate is controlled by specific cellularpathways that can act at the level of transcription, translation, or post-translation. To study the regulation of these pathways in-vivo, I have used the female Drosophila germline as a model system. Each of the steps from germline stem cell (GSC) to egg require changes in cellular pathways. These changes can occur at the level of transcription, post-transciption, translation, or post-translation . Decades of research has elucidated many of the changes to gene that occur during oogenesis, however, many players in this process still remain mysterious. …
Exploring The Response To Arsenic Using Trna Modification Detection, Writer Mediated Protection And Codon Usage Analytics, Anwesha Sarkar
Exploring The Response To Arsenic Using Trna Modification Detection, Writer Mediated Protection And Codon Usage Analytics, Anwesha Sarkar
Legacy Theses & Dissertations (2009 - 2024)
Transfer ribonucleic acid (tRNA) is a non-coding RNA which interacts with the messenger RNA (mRNA) to facilitate protein synthesis. tRNA is also one of the most heavily modified RNAs with the collection of modifications, termed as the tRNA epitranscriptome, ranging from simple methylation to complex hypermodification catalyzed by RNA epitranscriptomic writers. Detecting tRNA modifications is an evolving field and the state-of-the-art technologies that include next generation sequencing and mass spectrometry of intact and derivatized RNAs is described in the chapter one. Liquid chromatography coupled with mass spectrometry has previously been used to show that arsenic promotes increases in the levels …
Modulation Of Rho Termination : Expectation Vs Reality, Kavya Sri Sai Chegireddy
Modulation Of Rho Termination : Expectation Vs Reality, Kavya Sri Sai Chegireddy
Legacy Theses & Dissertations (2009 - 2024)
Transcription termination factor Rho is an essential protein in many bacteria. Rho is an ATP-dependent RNA helicase that accounts for 20-50% of termination events in Escherichia coli and plays an important role in preventing pervasive transcription that otherwise might be lethal to bacteria. Rho termination usually occurs in the 3’ UTRs and non-coding regions of the DNA, and the actively transcribing RNA is believed to be protected by translating ribosomes from Rho termination since both transcription and translation are a simultaneous process in prokaryotes. However, in reality, Rho terminates transcription of some protein-coding genes, and fails to terminate transcription of …
Epitranscriptomic Writer Regulation Of Gene Expression In Escherichia Coli, William Eugene Gasperi
Epitranscriptomic Writer Regulation Of Gene Expression In Escherichia Coli, William Eugene Gasperi
Legacy Theses & Dissertations (2009 - 2024)
The epitranscriptome is composed of enzyme catalyzed RNA modifications that can regulate tRNA, mRNA, and rRNA structure and function. RNA modifications can play key roles in regulating gene expression by controlling the when and how much of translation of specific transcripts. The SelU catalyzed tRNA wobble uridine (U) modification, occurs on tRNA lysine, glutamic acid, and glutamine. We have shown that E. coli deficient in selU gene are more sensitive to the antibiotic chloramphenicol (CAM) than their wild type counterparts. CAM works by inhibiting protein synthesis by binding to the ribosome and preventing peptide chain formation. We hypothesize that SelU …
Tfap2e/Ap-2e Is A Transcriptional Regulator Controlling Neuronal Identity And Circuitry Formation In The Mouse Accessory Olfactory System, Jennifer M. Lin
Tfap2e/Ap-2e Is A Transcriptional Regulator Controlling Neuronal Identity And Circuitry Formation In The Mouse Accessory Olfactory System, Jennifer M. Lin
Legacy Theses & Dissertations (2009 - 2024)
Developmental progression is driven by specific spatiotemporal gene expression, which give rise to consistently patterned organisms despite environmental and genetic variation. The specific activation of robust gene regulatory networks that define tissue structure and individual cellular identity are necessary for tissue and cell specific programs to be activated. Cellular specification is guided by the interplay of intrinsic and extrinsic signals at specific developmental timepoints. The molecular mechanisms underlying the acquisition and maintenance of individual cellular identity remains a fundamental question across biological systems. Understanding the regulatory networks controlling the acquisition of neuronal identity, diversity, and connectivity in the formation of …
Launching The Next Generation : Transcriptional Regulation During Oogenesis, Alicia K. Mccarthy
Launching The Next Generation : Transcriptional Regulation During Oogenesis, Alicia K. Mccarthy
Legacy Theses & Dissertations (2009 - 2024)
Germ cells give rise to gametes and link generations by passing genetic information from parent to offspring. Gametes arise from, in many sexually reproducing organisms, germline stem cells (GSCs) which are set aside early during development. GSCs have an amazing capacity to undergo self-renewal to give rise to a pool of undifferentiated cells, while also differentiating to generate specialized germ cells such as haploid gametes. Upon female GSC differentiation, mitotically dividing germ cells can initiate meiosis, and mature within a follicle. During maturation, the specified oocyte is provided with a trust fund of RNAs and proteins for the next generation …
Development Of Small Molecule Antibiotics Against A Conserved Rna Gene Regulatory Element In Gram-Positive Bacteria, Ville Yrjö Petteri Väre
Development Of Small Molecule Antibiotics Against A Conserved Rna Gene Regulatory Element In Gram-Positive Bacteria, Ville Yrjö Petteri Väre
Legacy Theses & Dissertations (2009 - 2024)
Bacterial infections and the rise of antibiotic resistance, especially multidrug resistant strains, have generated a clear need for discovery of novel therapeutics. Most antibiotics in use today are derivatives of previous antibiotics to which resistance mechanisms already exist, and traditionally they have a single target: either a protein or rRNA. Gram-positive bacteria regulate the expression of several essential genes or operons using a mechanism called the T-box. The T-box is a structurally conserved riboswitch-like gene regulator in the 5’-untranslated region (UTR) of numerous essential genes of Gram-positive bacteria. T-boxes are stabilized by cognate, unacylated tRNA ligands, allowing the formation of …
Premature Rho-Dependent Transcription Termination In Escherichia Coli : Link To Translation And Gene Regulation, Gabriele Baniulyte
Premature Rho-Dependent Transcription Termination In Escherichia Coli : Link To Translation And Gene Regulation, Gabriele Baniulyte
Legacy Theses & Dissertations (2009 - 2024)
Transcription termination factor Rho is an essential protein in Escherichia coli and related bacteria. The primary function of Rho is to clear unproductive RNA polymerases from the DNA template to minimize negative effects associated with uncontrolled transcription. Although most of the Rho termination events are constitutive, premature Rho-mediated termination was observed at 3% of all affected transcripts indicating active regulation of Rho activity. In this work, we investigated the regulatory mechanism behind premature Rho-dependent transcription termination in two unrelated genes: suhB and topAI. We show that in both cases transcription is terminated inside the coding gene as a consequence of …
Of Donuts And Promo : In Silico Approaches To Identification Of Transcriptional Regulators Of Salivary Acinar Differentiation, Connor Cillian Duffy
Of Donuts And Promo : In Silico Approaches To Identification Of Transcriptional Regulators Of Salivary Acinar Differentiation, Connor Cillian Duffy
Legacy Theses & Dissertations (2009 - 2024)
The salivary gland is an organ often taken for granted by most people. However, its proper function is essential for several everyday activities, such as speaking, swallowing, and tasting. As such, impaired salivary gland function, such as that caused by Sjögren’s Syndrome or radiotherapy for head and neck cancers, can lead to a significantly reduced quality of life. The cells that produce saliva in salivary glands are known as acinar cells, which arise from proacinar cells generated during embryonic development. As such, in studying the promoter regions of proacinar and acinar genes, it may be possible to identify common transcription …
Post-Translational Modifications And Functional Studies Of Dksa In Escherichia Coli, Andrew Charles Isidoridy
Post-Translational Modifications And Functional Studies Of Dksa In Escherichia Coli, Andrew Charles Isidoridy
Legacy Theses & Dissertations (2009 - 2024)
DksA is a bacterial gene regulator that functions synergistically with the stress alarmone ppGpp to mediate the stringent response. DksA also functions independently of ppGpp to regulate transcription of a number of genes. DksA function is dependent on its binding affinity to RNA polymerase and requires specific interactions between RNAP and catalytic amino acids located on the coiled coil tip, D74 and A76. While much of the previous work on DksA has focused on understanding the mechanisms of action and the numerous gene targets for transcriptional regulation, little is known about the mechanisms by which DksA expression and function may …
Novel Mass Spectrometric Approaches For Deciphering The Epitranscriptomic Code, William D. Mcintyre
Novel Mass Spectrometric Approaches For Deciphering The Epitranscriptomic Code, William D. Mcintyre
Legacy Theses & Dissertations (2009 - 2024)
According to the results of the Human Genome Project, less than 5% of our genome consists of sequences that code for actual proteins. At the same time, however, ~90% of these non-coding sequences are transcribed into a myriad of classes of ribonucleic acids collectively known as ncRNAs, which have been recognized as essential regulatory factors. It has been recently shown that the activity of ncRNAs can be in turn modulated by post-transcriptional modifications (PTMs), covalent marks that can be established/removed by tightly regulated enzymatic pathways. Now, the race is on to understand the new set of controls of cellular functions …
Transcriptional Regulation Of Dksa In E. Coli, Daniel Thomas Woods
Transcriptional Regulation Of Dksa In E. Coli, Daniel Thomas Woods
Legacy Theses & Dissertations (2009 - 2024)
DksA is a global transcription factor that binds RNAP directly to regulate the expression of many genes and operons, including ribosomal RNA, in a ppGpp-dependent or ppGpp–independent manner. It is also involved in facilitating the process of DNA replication by removing stalled transcription elongation complexes that could block the progress of the replication fork. In addition, DksA is important for colonization, establishment of biofilms, and pathogenesis. In order to sustain these various functions, an adequate level of cellular DksA is required. This work tested the hypothesis that the E. coli dksA is substantially regulated at the level of transcription. Using …
Regulated Transcriptional Silencing Promotes Germline Stem Cell Differentiation In Drosophila Melanogaster, Pooja Flora
Regulated Transcriptional Silencing Promotes Germline Stem Cell Differentiation In Drosophila Melanogaster, Pooja Flora
Legacy Theses & Dissertations (2009 - 2024)
Germ cells are the only cell in an organism that have the capacity to give rise to a new organism and are passed from one generation to the next. Therefore, to maintain this unique ability of totipotency and immortality, germ cells execute specific functions, such as, repression of a somatic program and contour a germ line-specific pre- and post-transcriptional gene regulatory landscape. In many sexually reproducing organisms, germ cells are formed during the earliest stages of embryogenesis and undergoes several stages of development to eventually get encapsulated by the somatic cells of the gonad. Once, in the gonad, the germ …
Mass Spectrometric Analysis And Machine Learning Enable Microorganism Classification Based On Rna Posttranscriptional Modifications, Colin Christopher Aldrich
Mass Spectrometric Analysis And Machine Learning Enable Microorganism Classification Based On Rna Posttranscriptional Modifications, Colin Christopher Aldrich
Legacy Theses & Dissertations (2009 - 2024)
RNA post-transcriptional modifications (PTMs) are dynamic features that can be up- or down-regulated by the health and metabolic state of a cell. These covalent modifications are installed and removed on RNA nucleosides by enzymes controlled by the activation and deactivation of specific genes. The goal of this research was to demonstrate that RNA PTMs can serve as a unique feature for the classification/identification of microorganisms. We utilized a scheme based on electrospray ionization mass spectrometry (ESI-MS) to obtain global PTM profiles from total RNA extracted from various microorganisms in optimal growth conditions as well as Salmonella typhimurium (S. typhimurium) spiked …
Influence Of The Pre-Initiation Complex On Mediator Recruitment In Saccharomyces Cerevisiae, Elisabeth Rose Knoll
Influence Of The Pre-Initiation Complex On Mediator Recruitment In Saccharomyces Cerevisiae, Elisabeth Rose Knoll
Legacy Theses & Dissertations (2009 - 2024)
The Mediator complex plays a central, highly conserved role in eukaryotic transcription by RNA Polymerase II (Pol II) by stimulating the cooperative assembly of a pre-initiation complex (PIC) and recruitment of Pol II for gene activation. Mediator recruitment has generally been ascribed to sequence-specific activators engaging subunits from the tail module which in turn function to recruit the middle and head for complete assembly at the UAS. Mediator subunits of the middle and head then bridge the enhancer to connect with the PIC at the core promoter. It is reported that Mediator recruitment at the UAS preferentially occurs at SAGA-dependent, …
Structural And Functional Characterization Of An Unusual Camp Responsive Transcription Factor, Cmr, In Tb Complex Mycobacteria, Sridevi Ranganathan
Structural And Functional Characterization Of An Unusual Camp Responsive Transcription Factor, Cmr, In Tb Complex Mycobacteria, Sridevi Ranganathan
Legacy Theses & Dissertations (2009 - 2024)
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis in humans, is an intracellular pathogen that infects millions of people every year. Mtb can survive inside the host for extended periods of time by sensing and adapting to the host environmental stressors. Transcriptional gene regulation plays a critical role in this adaptation. This dissertation focuses on understanding the structural and functional aspects of one such transcriptional regulatory unit, Cmr (Rv1675c), in Mtb.
The Role Of The Mediator Transcriptional Co-Activator Complex And Promoter Dependence In Ty1 Retrotransposition In Saccharomyces Cerevisiae, Alicia Salinero
The Role Of The Mediator Transcriptional Co-Activator Complex And Promoter Dependence In Ty1 Retrotransposition In Saccharomyces Cerevisiae, Alicia Salinero
Legacy Theses & Dissertations (2009 - 2024)
Retrotransposons are mobile genetic elements that replicate via an RNA intermediary and constitute a significant portion of most eukaryotic genomes. Saccharomyces cerevisiae has been invaluable to retrotransposon research due to the presence of an active retroelement known as Ty1. The mobility of Ty1 is regulated both positively and negatively by numerous host factors, including several subunits of the Mediator transcriptional co-activator complex. The Mediator core complex is organized into genetically and structurally defined head, middle, and tail modules, along with a transiently associated kinase module. We show that with the exception of the kinase module, deletion of non-essential subunits from …
Genome-Scale Analyses Of Transcription And Transcriptional Regulation In Bacteria, Devon Marie Fitzgerald
Genome-Scale Analyses Of Transcription And Transcriptional Regulation In Bacteria, Devon Marie Fitzgerald
Legacy Theses & Dissertations (2009 - 2024)
The textbook model of bacterial transcription regulation posits that promoters occur immediately upstream of genes and that transcription factors (TFs) modulate transcription through promoter-proximal binding. However, the recent application of unbiased genome-wide approaches, such as ChIP-seq and RNA-seq, has revealed a much more complex picture, including TF binding and transcription initiation occurring in unexpected locations. This dissertation describes the use of deep sequencing-based approaches to evaluate the genome-wide binding of transcription-related proteins and identify locations of transcription initiation. I have assessed the genome-wide binding of three Escherichia coli TFs and an alternative σ factor. Additionally, I have analyzed genome-wide patterns …
Understanding Transcriptional Enhancement In Monoclonal Antibody-Producing Chinese Hamster Ovary Cells, Sarah E. Nicoletti
Understanding Transcriptional Enhancement In Monoclonal Antibody-Producing Chinese Hamster Ovary Cells, Sarah E. Nicoletti
Legacy Theses & Dissertations (2009 - 2024)
With the demand for monoclonal antibody (mAB) therapeutics continually increasing, the need to better understand what makes a high productivity clone has gained substantial interest. Monoclonal antibody producing Chinese hamster ovary (CHO) cells with different productivities were provided by a biopharmaceutical company for investigation. Gene copy numbers, mRNA levels, and mAb productivities were previously determined for two low producing clones and their amplified progeny. These results showed an increase in mRNA copy number in amplified clones, which correlated to the observed increases in specific productivity of these clones. The presence of multiple copies of mRNA per one copy of DNA …
Post-Translational Modification Regulates Heterogeneous Nuclear Ribonucleoprotein K Function During Axon Outgrowth In Xenopus Laevis, Erica J. Hutchins
Post-Translational Modification Regulates Heterogeneous Nuclear Ribonucleoprotein K Function During Axon Outgrowth In Xenopus Laevis, Erica J. Hutchins
Legacy Theses & Dissertations (2009 - 2024)
The RNA-binding protein, heterogeneous nuclear ribonucleoprotein K (hnRNP K), is required for axon outgrowth. Its suppression in Xenopus embryos causes defects in the translation of mRNAs of multiple cytoskeletal genes. Studies in cell lines have established that hnRNP K shuttles between the nucleus and the cytoplasm to bind and regulate the fates of its target RNAs, from splicing to export and translation. At each step, hnRNP K is regulated through post-translational modifications that alter its nucleic acid and protein interactions, and subcellular localization. Precisely how this happens in developing neurons to coordinate cytoskeletal gene expression with the extracellular signals directing …
The C. Elegans Rna-Binding Protein Gld-1 Recognizes Sequence, Structure And Context Information To Repress Translation Of Its Mrna Targets, Jung Hoon Doh
Legacy Theses & Dissertations (2009 - 2024)
Considering the general suppression of transcription during late oogenesis and early embryo development, post-transcriptional control of maternal mRNAs by RNA binding proteins emerges as an important mechanism in controlling late oogenesis and early embryo development. The C. elegans germline offers an ideal system to understand such processes. GLD-1 (GermLine Development defective) is a maxi-KH motif containing RNA binding protein, which controls many different stages during the C. elegans germline development from decision over germ cell proliferation vs. meiosis entry to production of mature gametes, suggesting that GLD-1 likely controls many mRNA targets. gld-1 mutants have variable germline defects, the major …
The Role Of An Rna Binding Protein Hnrnp K During Axon Development And Regeneration In Xenopus Laevis, Yuanyuan Liu
The Role Of An Rna Binding Protein Hnrnp K During Axon Development And Regeneration In Xenopus Laevis, Yuanyuan Liu
Legacy Theses & Dissertations (2009 - 2024)
Coordinated synthesis and assembly of the cytoskeletal network contribute significantly to morphological changes during axon outgrowth. Previous studies demonstrated that heterogeneous ribonucleoprotein K (hnRNP K), an RNA binding protein, binds to the 3'-untranslated regions of all neurofilament triplet subunits, the most abundant components of the axonal cytoskeleton. These findings raised the hypothesis that hnRNP K post-transcriptionally mediates the coordinated expression of axonal cytoskeletal components. In my thesis, I test this hypothesis during both axonal development and regeneration.
The Role Of Chromatin And Cofactors In The Transcriptional Memory Effect Exerted In Saccharomyces Cerevisiae, Emily Leigh Paul
The Role Of Chromatin And Cofactors In The Transcriptional Memory Effect Exerted In Saccharomyces Cerevisiae, Emily Leigh Paul
Legacy Theses & Dissertations (2009 - 2024)
Abf1 and Rap1 are functionally similar general regulatory factors (GRFs) found in Saccharomyces cerevisiae . Abf1, in its role as a transcriptional activator, exerts a memory effect on some genes under its control. This effect results in transcription levels remaining steady when Abf1 dissociates from its binding site in a conditional mutant. In contrast, Rap1 fails to elicit the same effect on its regulatory targets. Transcriptional memory effects have been observed in many fields of study, including immunology, cancer, and stem cells, and conservation of transcription machinery will allow studies in yeast to be applied to higher organisms.