SAP-ERASER - Targeted Protein Degradation using SAP effectors

SAP-ERASER is an ambitious high-risk/high-gain program to deliver a radically novel Targeted Protein Degradation (TPD) technology. SAP effectors are secreted bacterial proteins that mediate the degradation of host transcription factors using different mechanisms. SAP05 effectors directly bind a 26S proteasome component leading to the degradation of protein substrates independently of E3 ligases and ubiquitination. SAP05 mode of action is unique because other proteolysis-targeting systems, such as PROTAC, depend on substrate ubiquitination and E3 ligases for proteasome-dependent degradation. SAP05 acts as a molecular glue that sandwiches a substrate and the 26S proteasome receptor RPN10 leading to efficient degradation of the substrate. Thus SAP05 offers the opportunity for a unique protein knock-down technology with many applications in biotechnology and biomedicine that complement existing gene knock-down tools, such as CRISPR-Cas and RNA interference. Here, I will combine biophysical, biochemical and genetic approaches to determine how SAP05 effectors selectively recruit proteins for degradation and to develop synthetic SAP05 variants with novel substrate binding specificities. I designed the project around three interconnected and complementary Work Packages (WPs), which are biophysics, substrate binding specificity and protein degradation technology. The gained knowledge will serve as a framework to develop the SAP-ERASER technology as an impactful targeted protein degradation tool for research, therapeutic and biotechnological applications in a variety of organisms, including humans, animals, yeast and plants.