| Autor: |
Gable M. Wadsworth, Walter J. Zahurancik, Xiangze Zeng, Paul Pullara, Lien B. Lai, Vaishnavi Sidharthan, Rohit V. Pappu, Venkat Gopalan, Priya R. Banerjee |
| Rok vydání: |
2022 |
| Popis: |
Co-phase separation of RNAs and RNA-binding proteins is thought to drive 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 RNAs of various types undergo phase transitions with system-specific lower critical solution temperatures (LCSTs). This entropically-driven phase behavior requires Mg2+ions and is an intrinsic feature of the phosphate backbone that is modulated by RNA bases. RNA-only condensates can additionally undergo enthalpically favorable percolation transitions within dense phases. This is enabled by a combination of Mg2+-dependent bridging interactions among phosphate groups and RNA base-stacking / base-pairing. Phase separation coupled to percolation can cause dynamical arrest of RNAs within condensates and can suppress the catalytic activity of an RNase P ribozyme. Our work highlights the need to incorporate RNA-driven phase transitions into models for RNP granule biogenesis. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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