The Deubiquitinase Targeting Chimera (DUBTAC) platform (Figure 1) was developed to therapeutically target aberrantly degraded proteins by removing ubiquitin chains (tags on proteins that signal the cell to degrade and eliminate the protein using the cell’s protein disposal system) from specific proteins to stop their degradation and stabilize their levels for therapeutic benefit. DUBTACs, developed through an academic-industry collaboration between Professor Daniel Nomura, his research group at UC Berkeley and scientists at the Novartis Institutes for BioMedical Research, are bifunctional small molecules consisting of a protein-targeting ligand connected via a linker to a deubiquitinase (DUB) recruiter. In a unique application of induced-proximity biology, DUBTACs bring a DUB into the vicinity of a ubiquitin-tagged protein to remove the ubiquitin chain and subsequently prevent degradation of the target protein.
In a hallmark study published in Nature Chemical Biology, Dr. Nomura, the Nomura Lab and Novartis colleagues discovered covalent allosteric recruiters against OTUB1, a known DUB. They showed that this covalent OTUB1 recruiter could be linked to various protein-targeting ligands to stabilize the levels of aberrantly degraded proteins, including the mutated chloride channel CFTR that causes cystic fibrosis and the tumor suppressor WEE1 kinase in cancer cells.
Vicinitas Therapeutics has exclusively licensed the DUBTAC platform from both UC Berkeley and Novartis and aims to become the leading company in targeted protein stabilization by developing next-generation disease therapies against an entire class of previously inaccessible aberrantly degraded proteins. The company is initially focused on developing therapies in cancer and monogenic diseases.