Abstract
Co-phase separation of RNAs and RNA-binding proteins drives the biogenesis of ribonucleoprotein granules. RNAs can also undergo phase transitions in the absence of proteins. However, the physicochemical driving forces of protein-free, RNA-driven phase transitions remain unclear. Here we report that various types of RNA undergo phase separation with system-specific lower critical solution temperatures. This entropically driven phase separation is an intrinsic feature of the phosphate backbone that requires Mg2+ ions and is modulated by RNA bases. RNA-only condensates can additionally undergo enthalpically favourable percolation transitions within dense phases. This is enabled by a combination of Mg2+-dependent bridging interactions between phosphate groups and RNA-specific base stacking and base pairing. Phase separation coupled to percolation can cause dynamic arrest of RNAs within condensates and suppress the catalytic activity of an RNase P ribozyme. Our work highlights the need to incorporate RNA-driven phase transitions into models for ribonucleoprotein granule biogenesis. [Figure not available: see fulltext.].
Original language | English |
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Pages (from-to) | 1693-1704 |
Number of pages | 12 |
Journal | Nature Chemistry |
Volume | 15 |
Issue number | 12 |
Early online date | 6 Nov 2023 |
DOIs | |
Publication status | Published - Dec 2023 |
Scopus Subject Areas
- General Chemistry
- General Chemical Engineering