ABSTRACT
The interactions between herpes simplex virus gD and its nectin1 receptor or between gD, gB, and gH were analyzed by complementation of the N and C portions of split enhanced green fluorescent protein (EGFP) fused to the glycoproteins. The gDN-NectC complex was readily detected; the gDN-gCC complex was undetectable, highlighting the specificity of the assay. Split EGFP complementation was detected between proteins designated gDN+gHC, gDN+gBC, and gHN+gBC+wtgD (gB was deleted of endocytosis motifs), both in cells transfected with two-tree glycoproteins and in syncytia. The in situ assay provides evidence that gD interacts with gH and gB independently of each other and supports a model whereby gH and gB in complex exert their activities to gD.