All cellular organisms contain genomic DNA which provides the instructions for their correct development and functioning. Damage to this DNA may interfere with critical cellular processes such as... Show moreAll cellular organisms contain genomic DNA which provides the instructions for their correct development and functioning. Damage to this DNA may interfere with critical cellular processes such as transcription and replication and has the potential to drive mutagenesis. In turn, this may underlie inherited disorders and accelerate progression of diseases such as cancer and neurodegenerative disorders. The protection of cells and organisms against these devastating effects of DNA damage relies on the DNA damage response (DDR), which comprises a complex network of signaling and repair pathways that coordinate the sensing, signaling and repair of DNA lesions while accommodating suitable adjustments in for instance chromatin structure and cell cycle progression. Not only does the DDR dictate the appropriate repair pathway for several types of DNA damage, including DNA double-strand breaks (DSB), it also modulates replication fork surveillance mechanisms in response to DNA replication stress (RS). While many core proteins have been studied in detail, the full repertoire of factors involved in these pathways remains unknown. Clearly, extending our knowledge on regulators of the DDR will contribute to our understanding of the development, and possibly the treatment, of the numerous disorders that are associated with defects in the DDR. The research described in this thesis has successfully identified and characterized novel factors in DSB repair and the RS response. Show less
This thesis aims to gain a better understanding of NER, to elucidate new molecular mechanisms and proteins that orchestrate how DNA repair is carried out on genomic DNA that is tightly packed in... Show moreThis thesis aims to gain a better understanding of NER, to elucidate new molecular mechanisms and proteins that orchestrate how DNA repair is carried out on genomic DNA that is tightly packed in chromatin inside the living cell. It is important to obtain a better clinical picture of how inherited defects in DNA repair genes shapes phenotypes in patients with DNA repair-deficiency disorders. Show less
The cellular response to transcription-blocking DNA lesions involves the stalling of elongating RNA Polymerase II (RNAPIIo) at the lesion as well as a global shutdown of transcription. The stalling... Show moreThe cellular response to transcription-blocking DNA lesions involves the stalling of elongating RNA Polymerase II (RNAPIIo) at the lesion as well as a global shutdown of transcription. The stalling of RNAPIIo at such lesions initiates the transcription-coupled nucleotide excision repair pathway (TCR) to efficiently remove the damage and restore transcription. The TCR proteins, CSB, CSA, and UVSSA, are essential for the repair of transcription-blocking DNA lesions, but how the interplay between these proteins targets the core repair machinery, including the TFIIH complex, to lesion stalled RNAPIIo remains largely unknown.Here, we demonstrate a sequential and highly cooperative assembly of TCR proteins and unveil the mechanism for TFIIH recruitment to DNA damage-stalled RNAPIIo. Importantly, we identified the previously uncharacterized ELOF1 gene as a core TCR factor with an additional role in preventing DNA damage during DNA replication. Show less
