DNAProteinCrossRep · Identification of DNA-Protein-Crosslink Repair Factors

Identification of DNA-Protein-Crosslink Repair Factors

All living organisms are constantly challenged by many different sources that damage the DNA. It is essential for the individual’s health but also for the transmission of genetic information throughout generations that damages are recognized and faithfully repaired. Inadequate repair leads inevitably to mutations and/or cell death. These are the underlying cause for aging in general but also many severe and unfortunately widespread diseases such as cancer and neurodegeneration. The cell’s response to a distinct type of damage is highly specific and tightly regulated. By now, most repair pathways are relatively well described but how cells respond to DNA-protein crosslinks (DPCs) is less well established. DPCs are formed when either DNA-modifying enzymes get trapped on the DNA while they execute their function or when reactive agents unspecifically crosslink proteins to DNA. In any case, DPCs are large structures that block vital DNA related processes like DNA transcription or replication, and thus are deleterious for the cell, if left unrepaired. It is known that upon DPC recognition, the protein part is removed and degraded, leaving the DNA with a smaller lesion, which subsequently is removed by well-known repair pathways. The protease DVC1 (SPRTN, SPRTN-1 in C. elegans or Wss1 in yeast) was established as a main player of the pathway. The protein is targeting to the DPC via a ubiquitin signal and breaks down the crosslinked protein allowing for downstream processing. It is largely unknown whether alternative factors exist that act similar to DVC1 and how the pathway is regulated. The main objective of this project was to identify and characterize new factors of the DPC repair pathway. I wanted to combine the human cell culture system, a great tool to perform genome wide screens and to study molecular processes, with the power of an in vivo system, the nematode C. elegans. Studying protein function in the worm would allow me to conduct various dedicated studies for newly identified DPC repair factors, e.g., in proliferating and non-proliferating tissues, at the various developmental stages as well as assess the impact on overall organismal fitness and hereby advance my research on the newly identified factors in a physiological relevant context. We performed a genome wide screen for DPC repair factors and could identify candidates that function in the dedicated repair pathway. After initial verification experiments of candidates, we were able to characterize the function of one of the candidate proteins in detail and show its recruitment to the DPCs in a SUMO dependent manner and that its function is required for worm survival after induction of DPCs. Work on a second candidate is still ongoing.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз