Reentrant DNA shells tune polyphosphate condensate size

Summary

Polyphosphate (polyP) is an inorganic polymer that interacts with DNA and magnesium ions (Mg2+), forming condensates that exhibit reentrant behavior, meaning they form and then dissolve as Mg2+ concentration increases.

Highlights

• PolyP forms condensates with Mg2+ that exhibit reentrant behavior.
• DNA interacts with polyP-Mg2+ condensates, forming shells around them.
• The formation of DNA shells is dependent on Mg2+ concentration and DNA length.
• Cryo-electron tomography (cryo-ET) reveals distinct morphologies of DNA shells on polyP-Mg2+ condensates.
• DNA concentration and length modulate the size of polyP-Mg2+ droplets.
• PolyP-Mg2+ condensates can be tuned by DNA properties, such as length and concentration.
• The study suggests a potential framework for understanding polyP-chromatin interactions.

Key Insights

• The interaction between polyP and DNA is mediated by Mg2+ ions, which play a crucial role in the formation of condensates and DNA shells.
• The reentrant behavior of polyP-Mg2+ condensates is a result of the balance between the attractive and repulsive forces between polyP, DNA, and Mg2+ ions.
• The formation of DNA shells on polyP-Mg2+ condensates is a complex process that involves the interplay of thermodynamic and kinetic factors.
• The properties of DNA, such as length and concentration, can modulate the size and morphology of polyP-Mg2+ droplets, suggesting a potential mechanism for regulating chromatin structure and function.
• The study highlights the importance of considering the interactions between polyP, DNA, and Mg2+ ions in understanding the behavior of chromatin in vivo.
• The findings of this study have implications for our understanding of the role of polyP in chromatin biology and its potential applications in fields such as biotechnology and medicine.
• The use of cryo-ET and other advanced imaging techniques has enabled the visualization of the complex structures and interactions involved in polyP-chromatin interactions, providing new insights into the mechanisms underlying these processes.

Mindmap

Citation

Chawla, R., Tom, J. K. A., Boyd, T., Tu, N. H., Bai, T., Grotjahn, D. A., Park, D., Deniz, A. A., & Racki, L. R. (2024). Reentrant DNA shells tune polyphosphate condensate size. In Nature Communications (Vol. 15, Issue 1). Springer Science and Business Media LLC. https://doi.org/10.1038/s41467-024-53469-x