RT Journal Article
SR Electronic
T1 Structures of virus-like capsids formed by the Drosophila neuronal Arc proteins
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 697193
DO 10.1101/697193
A1 Simon Erlendsson
A1 Dustin R. Morado
A1 Jason D. Shepherd
A1 John A. G. Briggs
YR 2019
UL http://biorxiv.org/content/early/2019/07/10/697193.abstract
AB The neuronal protein Arc is a critical mediator of synaptic plasticity. Arc originated in tetrapods and flies through domestication of retrotransposon Gag genes. Recent studies have suggested that Arc mediates intercellular mRNA transfer and like Gag, can form capsid-like structures. Here we report that Drosophila proteins dArc1 and dArc2 assemble virus-like capsids. We determine the capsid structures to 2.8 Å and 3.7 Å resolution, respectively, finding similarity to capsids of retroviruses and retrotransposons. Differences between dArc1 and dArc2 capsids, including the presence of a structured zinc-finger pair in dArc1, are consistent with differential RNA-binding specificity. Our data support a model in which ancestral capsid-forming and RNA-binding properties of Arc remain under positive selection pressure and have been repurposed to function in neuronal signalling.