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

These data suggest that the interaction of VPg with eIF4G is important for complex 320 formation with ribosomal proteins and that that G3BP1 contributes in some manner 321 to the formation of this complex. The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/571455 doi: bioRxiv preprint capacity of the incoming parental viral RNA to assemble into translationally active 329 complexes, a stage often referred to as the "maiden round" of RNA virus genome 330 translation. To this aim, cells were infected with MNV in the presence of 2CMC and 331 polysomes profiling on extracts prepared from cells at 4 and 9 hours post infection 332 performed (Fig 10A) . Quantification of the viral RNA levels in cells in the presence of 333 2CMC confirmed that the absence of G3BP1 has no impact on the overall levels 334 present at the time points examined (data not shown). We noted that even in the 335 presence of 2CMC, which inhibits viral RNA synthesis, there was a small but 336 measurable increase in free 80S ribosomes over time in WT cells but not in cells 337 lacking G3BP1 (Fig 10A) . We have previously found that MNV infection results in 338 translation shut off and that this effect is at least partuialkly due to the activity of the 339 NS6 protease (Emmott et al., 2017) . The fact we observed 80S accumulation in WT 340 cells, even in the absence of viral RNA synthesis, but not in cells lacking G3BP1, 341