Alphavirus nsP3 ADP-ribosylhydrolase Activity Disrupts Stress Granule Formation

Aravinth Kumar Jayabalan; Diane E. Griffin; Anthony K. L. Leung

Using G32E as an example, we characterized further whether the foci formed by nsP3 mutants with G3BP1 and eIF3b share the properties of SGs. To test this possibility, cells expressing either the WT nsP3 or G32E mutant nsP3 were treated with arsenite and cycloheximide (cf. Fig. 1b) . WT nsP3 remained co-localized with G3BP1, but not with eIF3b. On the contrary, while mutant nsP3 appeared as foci, eIF3b and the majority of G3BP1 did not (Fig. 2c) . Therefore, mutant nsP3/G3BP1/eIF3b foci shared the cycloheximide-sensitive nature of canonical SGs. In addition, G32E expression also resulted in the co-localization of G3BP1 and eIF3b in response to other types of stress such as clotrimazole and thapsigargin (Fig. S2b, c) , suggesting that the observed phenotype is common to multiple stressors that induce SGs. All rights reserved. No reuse allowed without permission.