In vitro reconstitution shows how HIV-1 Gag assemblies on membranes can package the RNA genome in the presence of a vast excess of competing cellular RNAs, and that selectivity and immature lattice assembly are deeply intertwined with one another.
The packaging signal in HIV-1 genomic RNA supports in vitro particle assembly more efficiently than control RNAs, probably explaining its selective packaging during virus assembly in vivo.
A cell-free reaction that reconstitutes the selective sorting of a miRNA into exosomes reveals an RNA-binding protein, YBX1, as a critical sorting factor.
In rotaviruses, the selective packaging of eleven distinct genomic RNA segments requires virus-encoded protein NSP2 to alter the RNA structures, facilitating their interactions with each other.
A screen using artificially barcoded, exosomal microRNAs, paired with CRISPR guide RNAs, helped identify new players in multivesicular endosome exocytosis and a role for Wnt signaling.
A mathematical model that combines stochasticity and spatial structure describes the dynamics of the viral population during an infection cycle, and fitting the model to RNA and virus abundances over time shows that poliovirus follows a geometric replication mode.