PROTAC-induced protein structural dynamics in targeted protein degradation.

Area of Science:

• Biochemistry and Molecular Biology
• Drug Discovery and Development
• Structural Biology

Background:

• PROteolysis TArgeting Chimeras (PROTACs) harness the ubiquitin-proteasome system for targeted protein degradation.
• PROTACs function by forming a ternary complex between the target protein and an E3 ligase.
• Ternary complex formation is necessary but not always sufficient for efficient protein degradation.

Purpose of the Study:

• To investigate the structural dynamics of PROTAC-induced degradation complexes.
• To understand how varying PROTAC linkers affect the degradation potency of BRD4(BD1) using CRBN and CRL4A E3 ligases.
• To elucidate the role of protein dynamics in facilitating ubiquitination and subsequent degradation.

Main Methods:

• Computational modeling of protein complex structures.
• Atomistic molecular dynamics simulations.
• Analysis of PROTAC-induced dynamics and residue-interaction networks.

Main Results:

• PROTACs with different linkers, despite forming ternary complexes, exhibited varied degradation potencies for BRD4(BD1).
• Molecular dynamics simulations revealed PROTAC-dependent protein dynamics are crucial for positioning target lysine residues for ubiquitination.
• PROTAC linkers modulated residue-interaction networks, influencing the dynamics essential for the ubiquitination cascade.

Conclusions:

• PROTAC linker design significantly impacts the dynamics of the degradation machinery.
• Understanding these dynamics provides critical insights for optimizing PROTAC efficacy.
• This study offers a structure-dynamic perspective to guide the rational design of novel PROTACs.