A mechanism for MEX-5-driven disassembly of PGL-3/RNA condensates in vitro

• 成果类型: Article
• 署名作者: Lewis, Natasha S.; Zedlitz, Silja; Ausserwoger, Hannes; McCall, Patrick M.; Hubatsch, Lars; Nousch, Marco; Gruss, Martine Ruer -; Hoege, Carsten; Juelicher, Frank; Eckmann, Christian R.; Knowles, Tuomas P. J.; Hyman, Anthony A.
• 署名单位: Max Planck Society; University of Cambridge; Technische Universitat Dresden; Leibniz Institut fur Polymerforschung Dresden; Max Planck Society; Martin Luther University Halle Wittenberg; University of Cambridge
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10352
• DOI: 10.1073/pnas.2412218122
• 发表日期: 2025-05-12
• 关键词: caenorhabditis-elegans; p-granules; embryonic polarity; liquid droplets; germ granules; mex-5; components; cells; asymmetry; proteins

摘要

MEX-5 regulates the formation and dissolution of P granules in Caenorhabditis elegans embryos, yet the thermodynamic basis of its activity remains unclear. Here, using a time-resolved in vitro reconstitution system, we show that MEX-5 dissolves preassembled liquid-like PGL-3/RNA condensates by altering RNA availability and shifting the phase boundary. We develop a microfluidic assay to systematically analyze how MEX-5 influences phase separation. By measuring the contribution of PGL-3 to phase separation, we show that MEX-5 reduces the free energy of PGL-3, shifting the equilibrium toward dissolution. Our findings provide a quantitative framework for understanding how RNA-binding proteins modulate condensate stability and demonstrate the power of microfluidics in precisely mapping phase transitions.