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Investigating The Impact Of Nonenzymatic Lysine Acetylation On The Function Of The Bacterial Ribosome, Sarah Caldwell Feid

Dissertations

An under-investigated target of lysine acetylation is the bacterial ribosome. Although lysine acetylations on the ribosome are common and conversed in diverse bacterial species, little work has been done to understand how lysine acetylation affects the bacterial ribosome. The goal of this work is to determine if lysine acetylation has functional impact on the bacterial ribosome.I have identified in vitro and in vivo effects of nonenzymatic, AcP-dependent lysine acetylation on translation and the ribosome. In vitro acetylation of transcription-translation reactions causes a translation-specific defect that is unaffected by the addition of the CobB deacetylase. This suggests certain AcP-sensitive residues that …

Advancing Our Understanding Of Mechanosensitive Microtubule Acetylation In Neurons, Margaret Earl Utgaard

Master's Theses

Stiffness is a signaling cue in the brain, and neuronal response to stiffness impacts development, injury and disease. Mechanotransduction is the process of cells interpreting and converting mechanical cues to biochemical signals. Tubulin acetylation increases microtubule stability and could be mechanosensitive. The impact of stiffness on tubulin acetylation and role of septins is the focus of this project.It was hypothesized that stiffer surfaces would increase tubulin acetylation. SH-SY5Y cells were plated on varying stiffness and the ratio of acetylated to alpha tubulin was measured using immunocytochemistry. This study found SH-SY5Y cells had the highest acetylation on hard surfaces. SH-SY5Y cells …

Regulation Of Acetyl Phosphate-Dependent Acetylation And Identification Of Novel Lysine Acetyltransferases In Escherichia Coli, David George Christensen

Dissertations

Over billions of years, organisms have organized chemical reactions into metabolic pathways to sustain life. However, metabolic substrates can undergo many uncatalyzed, extra-metabolic reactions. Acetyl phosphate (AcP), an intermediate of the acetate fermentation pathway in E. coli, is one such metabolite that has been shown to non-enzymatically acetylate hundreds of proteins. This diverse set of targets suggests that acetylation could be a way for the cell to sense its nutritional status and regulate protein activity accordingly. However, how E. coli regulates acetylation, if at all, is unknown.Previous work showed that acetylation becomes pronounced in stationary phase cells. I determined that …

Mutual Regulation Of Crp And N(Epsilon)-Lysine Acetylation In Escherichia Coli, Robert James Davis

Dissertations

Post-translational modifications, such as N(epsilon)-lysine acetylation, are known to alter the behavior of transcriptional regulators in eukaryotes, but very little is known about the consequences of acetylation on transcriptional regulation in bacteria. Here, I provide evidence that a global transcriptional regulator of carbon metabolism, cAMP Receptor Protein (CRP), promotes both enzymatic and non-enzymatic lysine acetylation in E. coli. Non-enzymatic lysine acetylation occurs when cells ferment acetate, such as during growth on high concentrations of glucose. Intriguingly, CRP can be non-enzymatically acetylated on several lysines, including lysine 100 (K100). I provide evidence that neutralization of the K100 positive charge, as would …

Going Beyond Phosphorylation: Acetylphosphate-Mediated Ran Polymerase Acetylation And Caper Phosphorylation Co-Regulate Transcription Of Escherichia Coli Stress-Responsive Gene Cpxp, Bruno P. Lima

Dissertations

The ability of bacteria to sense and adapt to environmental changes has al-lowed these organisms to thrive in all parts of the globe and to establish many complex interactions with the environments they live as well as other members of these environments. Crucial to monitoring extracellular conditions is a group of signaling pathways known as two-component signal transduction system (2CST). These systems relay information from the extracellular environment to the interior of the cell via a transfer of phosphoryl groups from the sensory protein know as sensor kinase (SK) to the output protein known as response regulator (RR).

In addition …

The Role Of Cyp33 In Mll Mediated Gene Repression, Steven D. Poppen

Dissertations

Mixed Lineage Leukemia (MLL) is a multidomain protein whose gene is translocated in a subset of AML leukemias. Translocation of the MLL gene is present in approximately five percent of adult acute leukemias and ten percent of pediatric leukemias (Daser, A 2004, Look, A 1997, Huret, J 2001) Patients presenting in the clinic at the time of diagnosis with an MLL fusion have been shown to respond poorly to treatment and have a worse prognosis than matched wild type MLL patients (Rubnitz, J 1994, Rubnitz, J 1999). Novel therapies therefore are needed in order to more effectively treat patients with …

The Effect Of Glucose On Transcription At Cpxr- And Ompr-Regulated Promoters, Andrew Charles Cosgrove

Master's Theses

While reversible acetylation of proteins has been well studied in eukaryotes and is now recognized in bacteria, global protein acetylation in bacteria is a recently appreciated phenomenon. Protein acetylation is known to affect almost every aspect of cellular physiology in eukaryotes and there is proteomic evidence that this may also hold true in bacteria. In eukaryotes, lysines are acetylated by acetyltransferases that use acetyl-CoA as the acetyl group source, and de-acetylated by deacetylases. In bacteria, this reversible process uses enzymes homologous to those used by eukaryotes.

Our lab has recently found that acetylation of RNA polymerase (RNAP) can activate transcription …