Novel Mechanisms of Rotavirus Replication

Suzuki H

Published on: 2022-11-28

Abstract

Rotavirus (RV) cell entry and virion morphogenesis are complex processes that are not yet fully understood even at the molecular level. Slowing down infectious human rotavirus A (RVA) replication in cell culture on ice allowed morphological visualization of the virus particle entry and the assembly of triple-layered particles (virion). Findings suggeste two routes for virus entry and virion assembly. The virus enters the cell by perforating the plasma membrane by a fusion mechanism involving VP5* of the cleaved VP4 protein. After assembling double-layered particles (DLPs) in cytoplasm, they appear to be connected with the endoplasmic reticulum (ER) membrane and become coated with outer capsid proteins (VP4 and VP7) in a coating process. The perforation of the ER membrane is caused by an unknown mechanism following interaction between non-structural protein 4 (NSP4) and the inner capsid protein VP6 of the DLPs. The coating process is closely related to the formation of a hetero-oligomeric complex (NSP4, VP4 andVP7). These lines of evidence suggest the existence of novel mechanisms of RV morphogenesis.