Dilute phase oligomerization can oppose phase separation and modulate material properties of a ribonucleoprotein condensate

Abstract

A large subclass of biomolecular condensates are linked to RNA regulation and are known as ribonucleoprotein (RNP) bodies. While extensive work has identified driving forces for biomolecular condensate formation, relatively little is known about forces that oppose assembly. Here, using a fungal RNP protein, Whi3, we show that a portion of its intrinsically disordered, glutamine-rich region modulates phase separation by forming transient alpha helical structures that promote the assembly of dilute phase oligomers. These oligomers detour Whi3 proteins from condensates, thereby impacting the driving forces for phase separation, the protein-to-RNA ratio in condensates, and the material properties of condensates. Our findings show how nanoscale conformational and oligomerization equilibria can influence mesoscale phase equilibria.

Document Details

Document Type
Pub Defense Publication
Publication Date
Mar 25, 2022
Source ID
10.1073/pnas.2120799119

Entities

People

  • Ammon E Posey
  • Amy S. Gladfelter
  • Benjamin M. Stormo
  • Daphne Klotsa
  • Ian Seim
  • Rohit V Pappu
  • Wilton T Snead

Organizations

  • Air Force Office of Scientific Research
  • National Institutes of Health
  • University of North Carolina at Chapel Hill
  • Washington University in St. Louis

Tags

Readers

  • Materials Science and Engineering.
  • Molecular Genetics
  • Nanocomposite Materials Science