Abstract 1413: Replication obstacles formed within common fragile sites under replication stress are targeted by the global genomic nucleotide excision repair pathway

Abstract

Abstract CFS’s are genomic loci present in higher vertebrates that are particularly sensitive to various forms of replication stress and suffer from increased breakage and rearrangements in tumors. They have rather enigmatic evolutionary role and employ various DNA repair and checkpoint mechanisms promoting their stability. We used an original approach for identification of CFS’s associated factors based on DNA probe designed to match the high flexibility island sequences typically present in some of the highly expressed CFS’s. This probe was used as affinity bait for fishing specifically enriched proteins which were further identified using SILAC and quantitative mass spectrometry. Among already known CFS’s stabilizers we identified also hits so far not implicated in CFS’s maintenance. Interestingly, most of these novel hits are components of the global genomic nucleotide excision repair pathway (GG-NER). Knock down-based functional experiments revealed that GG-NER works most likely as an important trigger turning the CFS’s-associated replication obstacles into DNA lesion further recognized by the ATR-promoted cellular checkpoint which function is to block an escape of DNA replication intermediates into mitosis and the next cell generation. Work was supported by the Grant Agency of the Czech Republic 13-17555S, Czech-BioImaging project (LM2015062 funded by MEYS, CR) and Ministry of Education of the Czech Republic (LO1304). Citation Format: Martin Mistrik, Lucie Beresova, Eva Vesela, Ivo Chamrad, Jiri Voller, Masayuki Yamada, Tomas Furst, Rene Lenobel, Katarina Chroma, Jan Gursky, Jiri Bartek. Replication obstacles formed within common fragile sites under replication stress are targeted by the global genomic nucleotide excision repair pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1413. doi:10.1158/1538-7445.AM2017-1413