Viral assembly

Budding - membrane curvature

(Neufeldt 2020 doi: 10.1101/2020.06.23.167064) Even at high densities, in the absence of vRNPs, S trimer accumulation did not coincide with positive membrane curvature (Fig. 3B and C), indicating that S alone is unable to initiate virus budding. Early budding events with a positively curved membrane were decorated on the lumenal side with S and on the cytosolic side with vRNPs (Fig. 3D and E) in all observed events (n = 19), supporting the model where the viral transmembrane M protein acts as an organization assembly hub, interacting with both the S and the N protein (20, 21).