Targeted protein degradation: expanding the toolbox.

Area of Science:

• Biochemistry
• Molecular Biology
• Drug Discovery

Background:

• Proteolysis-targeting chimeras (PROTACs) represent a novel therapeutic modality leveraging the ubiquitin-proteasome system for targeted protein degradation.
• PROTACs offer potential benefits over traditional inhibitors, including improved dosing, reduced side effects, overcoming drug resistance, and targeting previously undruggable proteins.
• The field of PROTAC technology is still developing, with ongoing efforts to define optimal design principles for successful drug development.

Purpose of the Study:

• To review the current landscape of targeted protein degradation using PROTACs.
• To identify and characterize human E3 ubiquitin ligases that can be utilized to expand the PROTAC discovery toolbox.
• To discuss lessons learned in chemical biology and drug discovery related to targeted protein degradation.

Main Methods:

• Systematic review of human E3 ubiquitin ligases.
• Analysis of E3 ligase expression profiles.
• Evaluation of E3 ligase domain architecture.
• Assessment of E3 ligase chemical tractability.

Main Results:

• Fewer than 10 of the over 600 human E3 ubiquitin ligases have been exploited for targeted protein degradation to date.
• Identification of key characteristics of E3 ligases relevant for PROTAC development, including expression, structure, and druggability.
• A significant opportunity exists to expand the repertoire of E3 ligases for PROTAC applications.

Conclusions:

• Expanding the knowledge and utilization of diverse E3 ubiquitin ligases is essential for advancing PROTAC technology.
• Systematic characterization of E3 ligases provides a roadmap for discovering novel PROTACs.
• Further research into E3 ligase biology and chemistry will accelerate the development of targeted protein degradation therapeutics.