Excision repair hotspots of UV-induced DNA damage in the human genome

We recently developed high-throughput sequencing approaches, eXcision Repair sequencing (XR-seq) and Damage-seq, to generate genome-wide mapping of DNA damage formation and excision repair, respectively, with single-nucleotide resolution. Here, we adopted time-course XR-seq data to profile UV-induced excision repair dynamics, paired with Damage-seq data to quantify the overall induced DNA damage. We identified genome-wide repair hotspots that are subject to exemplified amount of repair very soon after UV irradiation. We show that such repair hotspots do not result from hypersensitivity to DNA damage and are thus not damage hotspots. We find that the earliest repair occur preferentially in promoters and enhancers from open-chromatin regions. The repair hotspots are also significantly enriched for frequently interacting regions and super-enhancers, both of which are hotspots for local chromatin interactions. We further extend the interrogation of chromatin organization to DNA replication timing and conclude that early-repair hotspots are enriched for early-replication domains. Collectively, we report genome-wide early-repair hotspots of UV-induced damage, in association with chromatin states and epigenetic compartmentalization of the human genome. Overall design: Determination of repair hotspots and coldspots of UV-induced DNA damage in the human genome.