(
2018-04)
Langdon, Erin M.; Qiu, Yupeng; Ghanbari Niaki, Amirhossein; McLaughlin, Grace A.; Weidmann, Chase; Gerbich, Therese M.; Smith, Jean A.; Crutchley, John M.; Termini, Christina M.; Weeks, Kevin M.; Myong, Sua; Gladfelter, Amy S.
RNA promotes liquid-liquid phase separation (LLPS) to build membrane-less compartments in
cells. How distinct molecular compositions are established and maintained in these liquid
compartments is unknown. Here we report that secondary structure allows mRNAs to self-associate
and determines if an mRNA is recruited to or excluded from liquid compartments. The
polyQ-protein Whi3 induces conformational changes in RNA structure and generates distinct
molecular fluctuations depending on the RNA sequence. These data support a model in which
structure-based, RNA-RNA interactions promote assembly of distinct droplets and protein-driven,
conformational dynamics of the RNA maintain this identity. Thus, the shape of RNA can promote
the formation and coexistence of the diverse array of RNA-rich liquid compartments found in a
single cell.
