Poster abstracts

Poster number 59 submitted by Susan Russell

Heat Shock-Induced Changes in Post-transcriptional Modifications in RNA

Susan Russell (Chemistry, University of Cincinnati), Patrick Limbach (Chemistry, University of Cincinnati)

Abstract:
Modified nucleosides in RNA are formed post-transcriptionally by modifying enzymes. The functional significance and structural role of modified nucleosides in ribosomal RNA (rRNA) and in transfer RNA (tRNA), remain poorly understood except for the tRNA anticodon region. These modified nucleosides are important in stabilization of the tertiary structure of tRNA and are essential to proper decoding (codon/anticodon interactions). Modification levels of tRNA have been shown to increase with increasing culture temperature and post-transcriptional modification in tRNA contributes to thermal stabilization in hyperthermophilic archea. The transcription of at least one tRNA modifiying enzyme, miaA, has also been found to increase during heat shock. The heat shock response is a mechanism which allows a cell to cope with a sudden increase in temperature or other environmental stress. We are interested in using the selectivity and sensitivity of LC-MS based techniques to investigate the changes in global modification patterns in rRNA and tRNA as the result of heat shock. Investigating how post-transcriptional modifications change in response to cellular stress may help us to understand the functional significance of these modifications. The relative amounts of modified nucleosides present in RNA isolated from heat shocked and normal E. coli cell cultures will be presented.

Keywords: tRNA, modified nucleosides, heat shock