Transcriptional and post-transcriptional regulation of the ionizing radiation response by ATM and p53

• Published in: Scientific reports 2017-03, Vol.7 (1), p.43598, Article 43598
• Main Authors: Venkata Narayanan, Ishwarya, Paulsen, Michelle T., Bedi, Karan, Berg, Nathan, Ljungman, Emily A., Francia, Sofia, Veloso, Artur, Magnuson, Brian, di Fagagna, Fabrizio d’Adda, Wilson, Thomas E., Ljungman, Mats
• Format: Article
• Language: English
• Subjects: 38/91; 631/337/2019; 631/67/1059/485; Ataxia Telangiectasia Mutated Proteins - metabolism; Cell Line; DNA damage; DNA Damage - radiation effects; Enhancer Elements, Genetic; Fibroblasts - drug effects; Fibroblasts - metabolism; Gene expression; Gene Expression Profiling; Gene Expression Regulation - radiation effects; Gene regulation; Humanities and Social Sciences; Humans; I.R. radiation; Ionizing radiation; Kinases; multidisciplinary; p53 Protein; Post-transcription; Radiation, Ionizing; RNA Processing, Post-Transcriptional; RNA Stability - radiation effects; Science; Signal transduction; Transcription, Genetic; Transcriptional Activation; Tumor Suppressor Protein p53 - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep43598

In response to ionizing radiation (IR), cells activate a DNA damage response (DDR) pathway to re-program gene expression. Previous studies using total cellular RNA analyses have shown that the stress kinase ATM and the transcription factor p53 are integral components required for induction of IR-induced gene expression. These studies did not distinguish between changes in RNA synthesis and RNA turnover and did not address the role of enhancer elements in DDR-mediated transcriptional regulation. To determine the contribution of synthesis and degradation of RNA and monitor the activity of enhancer elements following exposure to IR, we used the recently developed Bru-seq, BruChase-seq and BruUV-seq techniques. Our results show that ATM and p53 regulate both RNA synthesis and stability as well as enhancer element activity following exposure to IR. Importantly, many genes in the p53-signaling pathway were coordinately up-regulated by both increased synthesis and RNA stability while down-regulated genes were suppressed either by reduced synthesis or stability. Our study is the first of its kind that independently assessed the effects of ionizing radiation on transcription and post-transcriptional regulation in normal human cells.