Dynamics of mRNA entry into stress granules

Abstract

Stressed eukaryotic cells store mRNAs in protein-rich condensates called stress granules. Using single-molecule tracking techniques to examine how mRNAs enter stress granules, a new study shows that mRNAs make transient contacts with the granule surface before stable association, and become largely immobile after entry.

Fig. 1 ∣. A model for mRNA entry into stress granules.

mRNA (black line) undergoing translation in a stressed cell is unable to reinitiate translation and condense as ribosomes (orange) run off. The condensed mRNA diffuses freely in the cytoplasm until a chance encounter with a stress granule (green). The mRNA makes transient contact with the granule surface and visits a P-body (blue) before entering the stress granule. Contacts are mediated by transient pairing interactions with resident granule mRNAs (grey), whose ends extend past the granule surface.