Biochemistry, Biophysics, and Structural Biology Commons^™

Dpc29 Promotes Mitochondrial Translation Post-Initation In Saccharomyces Cerevisiae, Kyle Andrew Hubble

Graduate School of Biomedical Sciences Theses and Dissertations

Although the cytosolic and bacterial translation systems are well studied, much less is known about translation in mitochondria. In the yeast Saccharomyces cerevisiae, mitochondrial gene expression is predominately regulated by translational activators. These regulators are thought to promote translation by binding the elongated 5’-UTRs on their target mRNAs. Since mammalian mitochondrial mRNAs generally lack 5’-UTRs, they must regulate translation by other mechanisms. As expected, most yeast translational activators lack orthologues in mammals. Recently, a mitochondrial gene-specific translational activator, TACO1, was reported in mice and humans. To better define its role in mitochondrial translation I examined the yeast TACO1 orthologue, DPC29. …

Chemical Damage To Mrna And Its Impact On Ribosome Quality-Control And Stress-Response Pathways In Eukaryotic Cells, Liewei Yan

Arts & Sciences Electronic Theses and Dissertations

Ribosome often faces defective adducts that disrupt its movement along the mRNA template. These adducts are primarily caused by chemical damage to mRNA and are highly detrimental to the decoding process on the ribosome. Hence, unless dealt with, chemical damage to RNA has been hypothesized to lead to the production of toxic protein products. Even more detrimental is the ability of damaged mRNA to drastically affect ribosome homeostasis through stalling. This in turn would lead to greatly diminished translation capacity of cells. Therefore, the inability of cells to recognize and resolve translational-stalling events is detrimental to proteostasis and could even …

Cytoplasmic Polyadenylation Element Binding Protein 2 Alternative Splicing Regulates Hif1Α During Chronic Hypoxia, Emily M. Mayo

USF Tampa Graduate Theses and Dissertations

Chronic pulmonary hypoxia commonly results in the sustained expression of HIF1 (hypoxia inducible factor 1), a heterodimeric transcription factor, that, if unrestrained, can result in dramatic vasculature remodeling, pulmonary arterial hypertension, and right-sided heart failure. Together, these pulmonary disorders cost approximately $100 billion annually to treat due to the limited therapeutic targets designed to inhibit HIF1 expression. In this study, we introduce a translational regulator of HIF1 expression, known as Cytosolic polyadenylation element binding proteins 2 (CPEB2). Our lab has previously demonstrated in cancer cells that alternatively spliced isoforms of CPEB2 regulate the translation of the HIF1 oxygen-dependent subunit, HIF1α, …

Iojap: Morphological And Physiological Phenotype Characterization In Arabidopsis, Thomas Jay Payne

Doctoral Dissertations

IOJAP protein is found in all organisms that contain a ribosome of bacterial origin. The majority of studies suggest that IOJAP plays a role in translation, although this has yet to be thoroughly investigated in plants. Using Arabidopsis thaliana, an extensive phenotype characterization of iojap mutants was performed. Many processes of plant growth were slightly impaired at optimal temperature (22˚C) but became severely hindered at low temperature (12˚C and 4˚C). These cold temperature defects manifested in an overall reduction of plant growth as well as variegation, chlorosis, leaf hyponasty, as well as reduced maximum quantum yield (F_v/F …

Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell

Arts & Sciences Electronic Theses and Dissertations

Regulation of gene expression is essential to life. Post-transcriptional regulation of gene expression is a complex process with many inputs that lead to changes in localization, translation and stability of mRNAs. The translation and stability of many mRNAs is regulated by cis-elements, such as mRNA-structure or codon optimality; and by trans-acting factors such as RBPs and miRNAs. Here I report on the complex interactions between RBPs, miRNAs and characteristics of their target mRNAs in respect to effects on translation and RNA stability.

Using a reporter based approach we studied modulation of microRNA-mediated repression by various mRNA characteristics. We observed the …

The Role Of Trm9 In Stress Responses, Ashish Ravindra Patil

Legacy Theses & Dissertations (2009 - 2024)

Cells need to respond appropriately to environmental changes in order to maintain homeostasis. The cellular response to an environmental stress is regulated at transcriptional, translational and post translational levels. The tRNA, which acts as an adaptor molecule between the mRNA and the protein, plays an important role in the translational regulation of cellular responses to stress and is one of the most heavily modified biomolecules. In Saccharomyces cerevisiae , the wobble uracil of the tRNA(3'-UCU-5') Arg, tRNA(3'-UUC-5') Glu and certain other specific tRNAs are modified to 5-methoxycarbonylmethyluridine (mcm5U) and 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U) residues by the tRNA methyltransferase 9 (Trm9). Modifications at …