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 (By similarity). In human cytomegalovirus, forms two distincts complexes to mediate viral entry, a trimer and a pentamer at the surface of the virion envelope. The gH-gL-gO trimer is required for infection in fibroblasts by interacting with host PDGFRA. The gH-gL-UL128-UL130-UL131A pentamer is essential for viral entry in epithelial, endothelial and myeloid cells via interaction with host NRP2 (By similarity). Interacts with glycoprotein H (gH); this interaction is necessary for the correct processing and cell surface expression of gH (By similarity). Forms the envelope pentamer complex (PC) composed of gH, gL, UL128, UL130, and UL131A. The pentamer interacts with host NRP2. Forms the envelope trimer complex composed of gH, gL, and gO. The trimer interacts with host PDGFRA (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. Belongs to the herpesviridae glycoprotein L family.