HSV-1/2 gD

Entry of HSV into a host cell involves several glycoproteins on the surface of the enveloped virus binding to their transmembrane receptors on the cell surface. In the case of a herpes virus, initial interactions occur when two viral envelope glycoprotein called glycoprotein C (gC) and glycoprotein B (gB) bind to a cell surface particle called heparan sulfate. Next, the major receptor binding protein, glycoprotein D (gD), binds specifically to at least one of three known entry receptors. These cell receptors include herpesvirus entry mediator (HVEM), nectin-1 and 3-O sulfated heparan sulfate. The nectin receptors usually produce cell-cell adhesion, so provide a strong point of attachment for the virus to the host cell. These interactions bring the membrane surfaces into mutual proximity and allow for other glycoproteins embedded in the viral envelope to interact with other cell surface molecules. Once bound to the HVEM, gD changes its conformation and interacts with viral glycoproteins H (gH) and L (gL), which form a complex. The interaction of these membrane proteins may result in a hemifusion state. gB interaction with the gH/gL complex creates an entry pore for the viral capsid. gB interacts with glycosaminoglycans on the surface of the host cell.