Poster number 14 submitted by Sun Jeong Im
Role of Modified Nucleotides in Mediating Structure and Oxidative Damage of U2 snRNA
Sun Jeong Im (Department of Chemistry, Wayne State University), Christine S. Chow (Department of Chemistry, Wayne State University)
Reactive oxygen species (ROS) are free radicals that are necessary for cellular processes. However, imbalanced levels of ROS cause oxidative stress in biological systems, leading to undesired side effects such as damage to biomolecules. A number of laboratories have carried out research to understand how ROS reacts with DNA and proteins, but the relationship between ROS and RNA is much less understood. For this project, the impact of ROS on structure and chemical stability of variants of the highly modified U2 small nuclear RNA (snRNA) is being determined. U2 snRNA is a key component of the spliceosome. This RNA contains two different modified nucleotides in the stem I region. Disruption of the U2 snRNA structure due to ROS could lead to dysfunction of pre-mRNA splicing. We hypothesize that modified nucleotides will mediate the damage responses. Chemically synthesized and in vitro transcribed stem I U2 snRNA variants with and without modifications are being analyzed by circular dichroism and 1D 1H NMR spectroscopy to assess their global and secondary structures, respectively. In addition, the U2 snRNA responses towards hydroxyl radicals (•OH) are being studied to elucidate which nucleotide modifications at specific sites will impact radical reactivity. The outcomes of this project will contribute to a better understanding of oxidative damage to RNA molecules and the relationship to modification status, structure, and human diseases.
Keywords: Oxidative damage, U2 snRNA