In JoVE (1)
Other Publications (1)
Articles by Thomas Søndergaard Stenum in JoVE
Quantification of the Abundance and Charging Levels of Transfer RNAs in Escherichia coli Thomas Søndergaard Stenum1, Michael A. Sørensen1, Sine Lo Svenningsen1 1Department of Biology, University of Copenhagen Here we present a method for directly measuring transfer RNA charging levels from purified Escherichia coli RNA as well as a way to compare relative levels of transfer RNA, or any other short RNA, across different samples based on the addition of spike-in cells expressing a reference gene.
Other articles by Thomas Søndergaard Stenum on PubMed
Transfer RNA is Highly Unstable During Early Amino Acid Starvation in Escherichia Coli Nucleic Acids Research. Jan, 2017 | Pubmed ID: 27903898 Due to its long half-life compared to messenger RNA, bacterial transfer RNA is known as stable RNA. Here, we show that tRNAs become highly unstable as part of Escherichia coli's response to amino acid starvation. Degradation of the majority of cellular tRNA occurs within twenty minutes of the onset of starvation for each of several amino acids. Both the non-cognate and cognate tRNA for the amino acid that the cell is starving for are degraded, and both charged and uncharged tRNA species are affected. The alarmone ppGpp orchestrates the stringent response to amino acid starvation. However, tRNA degradation occurs in a ppGpp-independent manner, as it occurs with similar kinetics in a relaxed mutant. Further, we also observe rapid tRNA degradation in response to rifampicin treatment, which does not induce the stringent response. We propose a unifying model for these observations, in which the surplus tRNA is degraded whenever the demand for protein synthesis is reduced. Thus, the tRNA pool is a highly regulated, dynamic entity. We propose that degradation of surplus tRNA could function to reduce mistranslation in the stressed cell, because it would reduce competition between cognate and near-cognate charged tRNAs at the ribosomal A-site.