Investigation of TRAIP activity in normal and cancerous cells.

DNA replication is a highly evolutionarily conserved process, however there is still much to discover about how eukaryotes regulate genome duplication. Recently, we have identified TRAIP ubiquitin ligase as the enzyme essential for ubiquitylation of replication machinery to remove it from chromatin when it was erroneously retained on DNA from S-phase all the way through to mitosis.
TRAIP is known to be important for resolution of problems arising during DNA replication and mutations in TRAIP in patients leads to Seckel syndrome and primordial dwarfism.
TRAIP is a pleiotropic ubiquitin ligase involved in a number of cellular processes, but our recent work has suggested that the essential role of TRAIP is during S-phase to help cells resolve genome stability problems arising from collisions between replication and transcription machineries. Without TRAIP, cancer derived cells show signs of DNA damage response during S-phase and stop proliferating. This project aims at understanding in more depth the function and importance of TRAIP activity in normal immortalized human cells and cancer derived cell lines of different genetic backgrounds. In particular, we will test whether cancer cell lines with increased replication/transcription collisions due to oncogene activation are more sensitive to TRAIP downregulation.
Our second aim is to screen for TRAIP inhibitor in collaboration with AstraZeneca small molecule screening platform. We will characterize biophysically, biochemically and through cell biology any interesting compounds identified.
Finally, we will explore potential synthetic interactions between inhibition of TRAIP activity and other genome integrity targeting treatments to assess whether TRAIP downregulation could sensitize cells to other treatments.
The results of this project will answer fundamental questions about the process of DNA replication coordination with other simultaneous processes such as transcription.