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Full-Text Articles in Biochemistry, Biophysics, and Structural Biology
Identification Of Ires Activity In Cellular Mrnas And Viral Rna Using A Circular Rna Construct, Priyanka Sehta
Identification Of Ires Activity In Cellular Mrnas And Viral Rna Using A Circular Rna Construct, Priyanka Sehta
Legacy Theses & Dissertations (2009 - 2024)
Translation initiation is a critical step in the process of protein synthesis. The canonical way of translation initiation involves ribosomes being recruited to the 7-methyl guanosine cap present at the 5’end of the untranslated region (5’ UTR) of the RNAs. However, viral RNAs and some cellular mRNAs lack this 5’ cap structure and thus deploy an alternate non-canonical translation initiation mechanism. In non-canonical translation initiation, ribosome recruitment is facilitated by the RNA secondary structures called Internal Ribosome Entry Site (IRES) present most often in the 5’ UTR. To measure IRES-mediated translation, the dual luciferase assay has been the gold standard. …
Regulation Of Gene Expression Through Ribosome-Associated Proteins, Clare Margaret Miller
Regulation Of Gene Expression Through Ribosome-Associated Proteins, Clare Margaret Miller
Legacy Theses & Dissertations (2009 - 2024)
Translation is a crucial mechanism for generating proteins to carry out cellular processes and for ensuring proper cell functions. Ribosomes are at the center of translation and are complex pieces of machinery. They consist of at least 80 core eukaryotic ribosomal proteins, which are conserved from prokaryotes, and four ribosomal RNAs (rRNAs): 18S, 28S, 5,8A 5S. In addition, numerous translation factors aid the ribosome in protein production. While ribosomes are typically described by these core features, they are known to exist in a heterogenous pool with variations in protein composition, modifications of rRNA, and an assortment of non-ribosomal proteins that …
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 …
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 …
Epitranscriptomic Writer Systems And Codon Bias Regulate The Response To Environmental Stress, Andrea Leonardi
Epitranscriptomic Writer Systems And Codon Bias Regulate The Response To Environmental Stress, Andrea Leonardi
Legacy Theses & Dissertations (2009 - 2024)
Epitranscriptomic marks in the form of enzyme-catalyzed modifications to RNA nucleosides can be important regulators of translation and play integral roles in the response to stress. Dynamic changes in tRNA modification status can regulate the translation of stress response proteins whose transcripts have distinct codon biases. The epitranscriptomic writer Alkylation repair homolog 8 (ALKBH8) plays a crucial part in the translation of codon biased transcripts, as it regulates stop codon recoding, which is a specialized form of translation used to generate selenoproteins. ALKBH8 modifies the wobble uridine of selenocysteine tRNA (tRNASec) to promote the decoding of an internal UGA codon …
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 …
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.
Vitamin D Regulates Metabolic Gene Expression, Glutamate And Glutamine Utilization, And Mitochondrial Function In Human Mammary Epithelial Cells, Sarah Beaudin
Legacy Theses & Dissertations (2009 - 2024)
Exposure to 1,25-Dihydroxyvitamin D (1,25D) decreases proliferation and induces differentiation in telomerase-immortalized human mammary epithelial (hTERT-HME1) cells. The studies described here addressed the mechanisms by which these effects are exerted. Microarray experiments were used to identify a subset of metabolic genes and pathways that are altered by 1,25D. In particular, genes involved in glutamate and glutamine utilization, including SLC1A1 and GLUL, were studied. Interestingly, qPCR analysis in a panel of six cell lines, representing either normal epithelial tissue or breast cancer, demonstrated diverse gene expression responses to 1,25D. In an isogenic model of mammary cell transformation, 1,25D altered gene expression …
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 …
The Sxrna Platform : Biophysical Characterization Of Trans-Acting Rna Switches For Gene Expression Control, Christine Bazinet
The Sxrna Platform : Biophysical Characterization Of Trans-Acting Rna Switches For Gene Expression Control, Christine Bazinet
Legacy Theses & Dissertations (2009 - 2024)
In the past decade, microRNAs (miRNAs) have become a hot topic in biochemical research. These very short ~ 22 nucleotide strands of RNA have been recognized as a functional RNA group and found to play a key role in mediating gene regulation along with RNA-binding proteins (RBPs). For example, by binding to the histone stem-loop (HSL) region of the target mRNA, normally in the 3'- untranslated region (UTR), gene expression can either be activated or deactivated for up or down regulation of the gene product. The majority of miRNAs have been found to down regulate gene expression upon binding to …
Gld-1 Represses Its Puf Mrna Targets Prior To/At Initiation Of Translation In The C.Elegans Germline, Gautham Sarathy
Gld-1 Represses Its Puf Mrna Targets Prior To/At Initiation Of Translation In The C.Elegans Germline, Gautham Sarathy
Legacy Theses & Dissertations (2009 - 2024)
The C.elegans germline offers an ideal system to study posttranscriptional regulation of gene expression as it is a major mechanism through which the control over gene expression is achieved. GLD-1 (defective in GermLine Development) is a maxi-KH motif containing RNA binding protein that controls various aspects of germline development from decision over germcell proliferation vs. meiotic entry to the production of mature gametes suggesting that GLD-1 likely controls many mRNA targets.