Morbillivirus cell entry: by focusing on canine distemper and measles virus fusion machinery

Morbilliviruses contain infectious pathogens causing important economic and health impact in livestock and wild animal as well as human, respectively. 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 via its cuboidal head domain and then it leads to conformational changes resulting in F-triggering. In addition, the F-protein experiences a series of irreversible structural rearrangements that induces the merging of the viral envelope with the host cell plasma membrane and forming fusion pore. Morbilliviruses uses signalling lymphocyte activation molecule (SLAM/CD۱۵۰) and Nectin۴ as cellular receptors in immune and epithelial cells, respectively. Prior studies have shown the H protein adopts unique and overlapping receptor binding sites. Blades (β۴-β۶ or β۴-β۵) serve as receptor binding sites on H protein. Furthermore, Blades β۴ and β۵ form a hydrophobic pocket that engage in Nectin۴ 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. 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 impede this process by targeting attachment glycoprotein.

کلیدواژه ها:

Fusion protein ، Hemagglutinin ، Membrane fusion ، Morbilliviruses