Protein Condensate Formation via Controlled Multimerization of Intrinsically Disordered Sequences

Area of Science:

• Biochemistry
• Cell Biology
• Synthetic Biology

Background:

• Intrinsically disordered regions (IDRs) drive liquid-liquid phase separation (LLPS) to form functional cellular condensates.
• Controlling LLPS is crucial for engineering synthetic membraneless organelles.
• Previous methods focused on enzymatic control of valency.

Purpose of the Study:

• To develop noncovalent strategies for regulating the phase separation of a specific IDR, the LAF-1 RGG domain.
• To demonstrate tunable control over condensate formation in vitro and in live cells.
• To explore modular tools for promoting IDR phase separation.

Main Methods:

• Modular dimerization of RGG domains using high-affinity coiled-coil pairs.
• Temporal control of phase separation using FKBP-rapamycin-FRB system.
• Optically induced condensation using photocaged dimerizers in cell-sized emulsions and live cells.

Main Results:

• Stable condensates formed via RGG domain dimerization in vitro.
• Temporal control of phase separation achieved using chemical dimerizers.
• Optical control of condensation demonstrated in cellular environments.

Conclusions:

• Noncovalent strategies provide versatile tools for controlling IDR-based condensate assembly.
• These methods enable tunable and inducible formation of synthetic organelles.
• The developed tools advance the engineering of biomolecular condensates for cellular regulation.