Noroviruses subvert the core stress granule component G3BP1 to promote viral VPg-dependent translation

Myra Hosmillo; Jia Lu; Michael R. McAllaster; James B. Eaglesham; Xinjie Wang; Edward Emmott; Patricia Domingues; Yasmin Chaudhry; Timothy J Fitzmaurice; Matthew K.H. Tung; Marc Panas; Gerald McInerney; Nicholas Locker; Craig B. Willen; Ian Goodfellow

in Fig 10A & B) in the absence of G3BP1 cells and, in comparison to WT cells, very 346 little viral RNA was found in fractions containing polysomes ( Fig 10B) . Extending the 347 fractionation to include the free RNA and ribonucleoprotein complexes at the top of 348 each gradient confirmed that in the absence of G3BP1 norovirus RNA is less 349 efficient at assembling into polysomal fractions, suggesting a defect at the level of 350 viral protein synthesis ( Fig 10C) . Together these data support the hypothesis that 351 prepared from WT and ΔG3BP1 cell lines (Fig 11A) , whereas norovirus VPg-362 dependent translation was reduced ( Fig 11B) . Quantification of multiple experiments 363 indicated that translation in nuclease treated extracts was on average reduced by 364 ~40-50% because of G3BP1 ablation (Fig 11C) . A similar reduction in in vitro 365 translation was observed across multiple time points (Fig S11C) . 366