Characteristics and functions of human cytomegalovirus UL128 gene/protein

Human cytomegalovirus (HCMV) ORF UL128 protein is highly conserved among viral field isolates and functions in two different molecular forms, monomeric UL128 protein and in a complex with glycoproteins gH, gL, UL130, and UL131A protein. Monomeric UL128 protein works as soluble chemokine analogue to attract peripheral blood mononuclear cells (PBMCs) and selectively induces expression of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) in PBMCs. The gH/gL/UL128/UL130/UL131A complex is indispensable for entry into both endothelial and epithelial cells. In conclusion, UL128 plays an important role in HCMV infection.