The Accumulation Of Rotavirus Nsp3 Dimers Does Not Correlate With The Extent Of Host Cell Translation Inhibition

Aim:We aimed to determine the functionality of rotavirus NSP3 dimers.Materials & methods:We expressed rhesus rotavirus NSP3 and determined the kinetics of host cell translation inhibition and the levels of accumulated dimerization intermediates and dimers.Results:We observed a linear kinetics of host cell translation inhibition, which correlated well with the sum of the dimerization intermediates and dimers. Treatment with 17-dimethylaminoethylamino-17-demethoxygeldanamycin reduced the accumulation of NSP3 dimers and potentiated host cell translation inhibition.Conclusion:Our results show that NSP3 dimer formation does not correlate with host cell translation inhibition and suggest that both NSP3 dimers and dimerization intermediates are functional and inhibit host cell translation.Lay abstract Aim:Two rotavirus NSP3 proteins join together to form 'rotavirus protein synthesis regulator (NSP3) two-subunit assemblages'. We aimed to determine the functionality of NSP3 two-subunit assemblages, which inhibit the synthesis of host proteins.Materials & method:We expressed NSP3 in cells and measured the level of host protein synthesis and the levels of partially formed NSP3 assemblages and fully formed NSP3 assemblages.Results:As inhibition of host protein synthesis increased linearly, so did the level of partially formed NSP3 assemblages and fully formed NSP3 assemblages. Treatment with alvespimycin (an inhibitor of NSP3 assemblage formation) reduced the accumulation of fully formed NSP3 assemblages and did not affect the accumulation of partially formed NSP3. Treatment with alvespimycin increased the inhibition of host protein synthesis.Conclusion:Our results showed that the level of NSP3 assemblages does not correlate with the level of inhibition of host protein synthesis. This suggests that both partially formed NSP3 assemblages and fully formed NSP3 assemblages are functional.