RNA Editing at Baseline and Following Endoplasmic Reticulum Stress.

[摘要] RNA sequences are expected to be identical to the DNA template. However, some RNA processing steps, such as RNA editing, can lead to differences in the RNA sequence that affect the fate of the RNA transcripts or the resultant proteins. My thesis focuses on the regulation of the canonical A-to-G editing and non-canonical RNA-DNA sequence Differences (RDD). My work contributed to the identification of RDDs throughout the human transcriptome. We identified all 12 types of single base differences across multiple individuals and various tissue types. We also detected peptides matching the RDD-encoded sequences suggesting that RDDs are translated into proteins. In subsequent work, we found that the non-canonical RDDs are found in nascent RNA. Through the use of nuclear run-on assays, we found that RDD occurs within seconds of exiting the RNA polymerase complex. Chapters 4 and 5 discuss my study of canonical A-to-G editing mediated by Adenosine Deaminase Acting on RNA (ADAR). First, we found that A-to-G editing levels differ across individuals. I searched for and identified genetic variants whose alleles are associated with editing levels of sites in the same gene. These data demonstrate that ADAR editing is cis regulated and can lead to individual variability in editing levels. Furthermore, by utilizing individual variability in editing and studying the relationship between editing sites, I learned how ADAR edits multiple sites in a given transcript. My data support a model where ADAR edits multiple sites along one side of a double-stranded RNA structure. To learn about the biological significance of RNA editing, I focused on endoplasmic reticulum (ER) stress. I found that editing levels change following ER stress suggesting that these RNA processing steps play a role in the ER stress response. Together, this work sheds light on the regulation of RNA editing and RDDs in the human transcriptome and aids in the understanding of how these processes may play a role in cellular response to stress.

[发布机构] University of Michigan

[效力级别] Genetics

[关键词] RNA Editing;Genetics;Science;Human Genetics