FNU Ibtisam

DNA-damage Inducible I Homolog II (Ddi2) is a multi-domain protein that contains a retroviral aspartic protease similar to HIV protease. Recently, it has been reported that Ddi2 plays a role in the activation of the transcription factors Nrf1 and Nrf3. Meanwhile, Nrf1 and Nrf3 are significantly elevated in many cancers. However, these transcription factors are not easily druggable. Unlike Nrf1 and Nrf3, Ddi2 is much more easily druggable because its proteolytic properties are more easily deactivated. To validate Ddi2 as a potential target and to achieve the goal of our study, there are two complementary strategies: 1) site-directed mutagenesis of Ddi2 active-site and/or knock-out and knock-in of the gene, 2) a chemical biology approach using small molecule inhibitors and peptide substrate cleavage.
We are currently pursuing the first strategy to study the pathway by which Ddi2 is involved in the survival of cancer cells through quantification of changes in the gene expression at the DNA and RNA level (exome genomes sequencing and RNA sequencing). For this purpose, we use three different CRISPR knock-outs of the Ddi2 cell line.
Moreover, as part of this project, we will also use a second strategy through the development of tools that will enable biochemical studies of Ddi2 using an activity-based probes inhibitor and the FRET-peptide substrate.