Phase Separation and the Centrosome: A Fait Accompli?

Area of Science:

• Cell Biology
• Biophysics
• Molecular Biology

Background:

• Membraneless organelles are increasingly thought to form via phase separation into liquid-like biomolecular condensates.
• This model is appealing for complex organelles like centrosomes, suggesting efficient molecular diffusion and interaction.
• However, the physical state of centrosomes remains debated, with possibilities including liquid-like or solid scaffold structures.

Purpose of the Study:

• To review recent studies on centrosome assembly in the context of biomolecular condensate theory.
• To evaluate the evidence supporting liquid-like versus solid scaffold models for centrosomes.
• To discuss the implications and limitations of the biomolecular condensate concept for understanding membraneless organelles.

Main Methods:

• Literature review of recent experimental and theoretical studies on centrosome structure and dynamics.
• Analysis of evidence for and against phase separation models in centrosome assembly.
• Conceptual discussion integrating findings with the broader field of biomolecular condensates.

Main Results:

• Recent studies present conflicting evidence regarding the liquid-like nature of centrosomes.
• Some research supports a liquid-like centrosome model, while other findings suggest a more solid, stable scaffold.
• Distinguishing between these possibilities experimentally may be challenging.

Conclusions:

• The biomolecular condensate concept is a significant advancement in cell biology with broad implications.
• It is premature to definitively classify centrosomes, and potentially other membraneless organelles, solely as liquid-like phase-separated condensates.
• Further research is needed to elucidate the precise physical nature and assembly mechanisms of complex membraneless organelles.