posted on 2023-12-15, 15:35authored byMandeep
K. Mann, Esther Wolf, Madhushika Silva, Haejin Angela Kwak, Brian Wilson, Albina Bolotokova, Derek J. Wilson, Rachel J. Harding, Matthieu Schapira
Zinc-finger ubiquitin-binding
domains (ZnF-UBDs) are noncatalytic
domains mostly found in deubiquitylases (DUBs) such as USP3. They
represent an underexplored opportunity for the development of deubiquitylase-targeting
chimeras (DUBTACs) to pharmacologically induce the deubiquitylation
of target proteins. We previously showed that ZnF-UBDs are ligandable
domains. Here, a focused small molecule library screen against a panel
of 11 ZnF-UBDs led to the identification of compound 59, a ligand
engaging the ZnF-UBD of USP3 with a KD of 14 μM. The compound binds the expected C-terminal ubiquitin
binding pocket of USP3 as shown by hydrogen–deuterium exchange
mass spectrometry experiments and does not inhibit the cleavage of
K48-linked diubiquitin by USP3. As such, this molecule is a chemical
starting point toward chemical tools that could be used to interrogate
the function of the USP3 Znf-UBD and the consequences of recruiting
USP3 to ubiquitylated proteins.