Competing Protein-RNA Interaction Networks Control Multiphase Intracellular Organization

Cell. 2020 Apr 16;181(2):306-324.e28. doi: 10.1016/j.cell.2020.03.050.


Liquid-liquid phase separation (LLPS) mediates formation of membraneless condensates such as those associated with RNA processing, but the rules that dictate their assembly, substructure, and coexistence with other liquid-like compartments remain elusive. Here, we address the biophysical mechanism of this multiphase organization using quantitative reconstitution of cytoplasmic stress granules (SGs) with attached P-bodies in human cells. Protein-interaction networks can be viewed as interconnected complexes (nodes) of RNA-binding domains (RBDs), whose integrated RNA-binding capacity determines whether LLPS occurs upon RNA influx. Surprisingly, both RBD-RNA specificity and disordered segments of key proteins are non-essential, but modulate multiphase condensation. Instead, stoichiometry-dependent competition between protein networks for connecting nodes determines SG and P-body composition and miscibility, while competitive binding of unconnected proteins disengages networks and prevents LLPS. Inspired by patchy colloid theory, we propose a general framework by which competing networks give rise to compositionally specific and tunable condensates, while relative linkage between nodes underlies multiphase organization.

Keywords: G3BP; P-bodies; RNA binding; UBAP2L; USP10; condensates; membraneless organelles; multiphase; phase separation; stress granules.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biophysical Phenomena
  • Cell Line, Tumor
  • Cytoplasm / metabolism
  • Cytoplasmic Granules / physiology*
  • Cytoplasmic Structures / physiology*
  • Humans
  • Intrinsically Disordered Proteins / genetics
  • Liquid-Liquid Extraction / methods
  • Organelles / chemistry
  • Protein Interaction Maps / physiology*
  • RNA / metabolism
  • RNA Recognition Motif Proteins / metabolism
  • RNA Recognition Motif Proteins / physiology


  • Intrinsically Disordered Proteins
  • RNA Recognition Motif Proteins
  • RNA