Expression of herpes simplex virus type 1 glycoprotein L (gL) in transfected mammalian cells: evidence that gL is not independently anchored to cell membranes.

We expressed herpes simplex virus type 1 glycoprotein L (gL) in transfected cells to investigate whether it is independently anchored to plasma membranes or is membrane associated as a result of complex formation with gH. gL was detected by immunofluorescence microscopy at the surfaces of cotransfected cells when it was expressed with gH but not when it was expressed in the absence of gH or with a truncated form of gH, gHTrunc(792), which lacks the membrane-spanning region and terminates at amino acid 792. Immunoprecipitation studies of transfected-cell culture media revealed that gL was secreted from cells when expressed in the absence of gH and was secreted from cotransfected cells complexed with gHTrunc(792). These observations demonstrate that gL is not independently anchored to plasma membranes but is membrane associated as a result of complex formation with gH.