Single-molecule imaging reveals dynamic biphasic partition of RNA-binding proteins in stress granules.

ABSTRACT: Stress granules (SGs) are cytosolic, nonmembranous RNA-protein complexes. In vitro experiments suggested that they are formed by liquid-liquid phase separation; however, their properties in mammalian cells remain unclear. We analyzed the distribution and dynamics of two paradigmatic RNA-binding proteins (RBPs), Ras GTPase-activating protein SH3-domain-binding protein (G3BP1) and insulin-like growth factor II mRNA-binding protein 1 (IMP1), with single-molecule resolution in living neuronal cells. Both RBPs exhibited different exchange kinetics between SGs. Within SGs, single-molecule localization microscopy revealed distributed hotspots of immobilized G3BP1 and IMP1 that reflect the presence of relatively immobile nanometer-sized nanocores. We demonstrate alternating binding in nanocores an

SUBMITTER: Niewidok B 

PROVIDER: S-EPMC5881506 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature