Dissertation/Thesis Abstract

Transcriptional regulation of magnesium transporters contributes to cellular homeostasis in bacteria
by Kriner, Michelle Ann, Ph.D., Yale University, 2016, 251; 10160865
Abstract (Summary)

Magnesium (Mg2+) is an essential element in biology due to its abundance and unique chemical properties. However, the dynamics of Mg2+ homeostasis and the role of this process in cellular physiology are not well understood. I have characterized two mechanisms in the bacterium Salmonella enterica serovar Typhimurium that regulate expression of Mg2+ transporters. First, structural elements in the mRNA leader of the Mg2+ channel gene corA couple accessibility of a binding site for the transcription termination factor Rho to translation of a short open reading frame, leading to an inverse relationship between corA transcription and translational efficiency. Similar mechanisms regulate all three Mg2+ transporters in Salmonella, indicating that increased Mg2+ uptake may be beneficial during translational impairment. Second, the small molecule alarmone (p)ppGpp represses transcription of all Mg2+ transporter genes in Salmonella to prevent deleterious Mg2+ accumulation during programmed translational arrest. Because Rho and (p)ppGpp both balance transcription and translation—two highly Mg2+-dependent processes—on a cell-wide basis, I propose that Rho- and (p)ppGpp-mediated regulation of Mg2+ uptake stabilizes gene expression at large and thus broadly contributes to cellular homeostasis.

Indexing (document details)
Advisor: Groisman, Eduardo
School: Yale University
School Location: United States -- Connecticut
Source: DAI-B 78/01(E), Dissertation Abstracts International
Subjects: Molecular biology, Genetics, Microbiology
Keywords: RNA, Rho-Dependent Termination, Stringent Response, Translation, corA
Publication Number: 10160865
ISBN: 978-1-369-15760-4
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