The heterodimer glycoprotein H-glycoprotein L is required for the fusion of viral and plasma membranes leading to virus entry into the host cell. Acts as a functional inhibitor of gH and maintains gH in an inhibited form. Upon binding to host integrins, gL dissociates from gH leading to activation of the viral fusion glycoproteins gB and gH. Interacts with glycoprotein H (gH); this interaction is necessary for the correct processing and cell surface expression of gH (By similarity). Part of a gH-gL-gO complex (By similarity). gL associates with the extravirion surface through its binding to gH. During virion morphogenesis, this protein probably accumulates in the host trans-Golgi where secondary envelopment occurs. Found in Golgi-like bodies of fibroblasts. In T-lymphocytes, found in the endoplasmic reticulum. Belongs to the herpesviridae glycoprotein L family.