Insight to morbillivirus cell entry: by focusing the role of membrane fusion

Morbilliviruses contain infectious pathogens causing important economic and health impact. Membrane fusion is critical step to determine the fate of virus (virus cell entry and spread, and finally disease outcome). It is mediated by concerted action of two surface glycoproteins, including the hemagglutinin (H) and fusion protein (F). Initially the H protein binds to the host cell receptor and it leads to conformational changes resulting in F-triggering. In addition, the F-protein also experiences a series of irreversible structural rearrangements that induces the merging of the viral envelope with the host cell plasma membrane and forming pore. Former studies have shown the H protein adopts unique and overlapping receptor binding sites. Blades (β4-β6 or β4-β5) serve as receptor binding sites on H protein. Furthermore, Blades β4 and β5 form a hydrophobic pocket that engage in Nectin4 interaction with H, whereas SLAM does not directly bind into this hydrophobic pocket and bind mostly laterally. Recent studies were confirmed that the central domain of H protein carries short range interaction of F protein. Recently, our knowledge about morbillivirus membrane fusion has greatly increased. It could be useful to obtain a fundamental understanding into the basic mechanisms supporting “receptor-based” host-pathogen interaction and introduces inhibitory molecules that impedes this process by targeting attachment glycoprotein