Synthetic Diubiquitin Fluorogenic Substrates to Study DUBs.

Area of Science:

• Biochemistry
• Enzymology
• Proteomics

Background:

• Deubiquitinating proteases (DUBs) regulate cellular processes by cleaving ubiquitin chains.
• Understanding DUB selectivity is crucial for their functional classification and therapeutic targeting.
• Semi-synthetic ubiquitin-based reagents facilitate DUB characterization.

Purpose of the Study:

• To present a protocol for profiling deubiquitinating protease selectivity using fluorogenic assay reagents.
• To investigate the poly-ubiquitin chain selectivity of TRABID, an ovarian tumor domain (OTU)-containing DUB.

Main Methods:

• Development and utilization of semi-synthetic ubiquitin (Ub)-based reagents.
• Employing fluorogenic assay reagents that emit a fluorescent signal upon DUB-mediated cleavage.
• Profiling the selectivity of TRABID against various poly-ubiquitin chain linkages.

Main Results:

• The study successfully adapted a fluorogenic assay for DUB selectivity profiling.
• The assay enabled the characterization of TRABID's preference for specific poly-ubiquitin chain types.
• TRABID's selectivity profile was elucidated using this biochemical approach.

Conclusions:

• Fluorogenic ubiquitin-based assays are effective tools for characterizing DUB selectivity.
• This method provides valuable insights into the substrate specificity of DUBs like TRABID.
• The findings contribute to the classification of DUBs and understanding their biological roles.