Dynamics of Deinococcus Radiodurans tRNA Modifications by Liquid Chromatography tandem Mass Spectrometry upon Ultraviolet Radiation

Abstract

By Spencer Parrish, Medical Laboratory Science

Advisor: Bala Addepalli

Presentation ID: AM_A34

Abstract: Deinococcus radiodurans is called the world’s toughest bacteria because it’s highly resistant to radiation, including ionization and ultraviolet. Ultraviolet radiation affects cell survival through either direct or indirect damage (by generating reactive oxygen species) to the organism’s genetic material. Although studies have shown the DNA and protein repair mechanisms in D. radiodurans, little is known about whether there is RNA repair mechanism.  Transfer RNA (tRNA) is an important component in protein synthesis and is composed of nucleotides which contains a lot of post-transcriptional modifications. To better understand if tRNA is related to the UV resistance of D. radiodurans, tRNAs were analyzed in UV exposed and control groups. Survival of D. radiodurans when exposed to UV was tested to determine the level of exposure which would result in loss of viability of the organism. Reactive oxygen species generated by UV was measured. RNA was then extracted from UV exposed and control groups and the tRNA was isolated from total RNA. Agarose gel was used to check the integrity of the RNA after exposure. The modified nucleoside profiles of D. radiodurans tRNA were identified and quantified by liquid chromatography tandem mass spectrometry (LC-MS/MS). These studies would help us understand how tRNA modifications would respond to oxidative stress in D. radiodurans and whether D. radiodurans adapted to minimize oxidative damage to the translational machinery upon radiation.