Endogenous retrovirus group V member 2 envelope glycoprotein (ERVV-2)

Endogenous retrovirus group V member 2 envelope glycoprotein (ERVV-2) is encoded by the *ERVV-2* gene in the human genome and represents a remnant of ancient retroviral infection. This gene is embedded within a human endogenous retrovirus (HERV) provirus on chromosome 19 and contains inactivating mutations in the gag and pol regions, meaning the env gene is selectively preserved and potentially functional[1]. The protein is primarily expressed in human placental tissue, though in humans and many other primate lineages it has lost the cell-fusion (fusogenic) activity typically possessed by related envelope proteins ("syncytins") in other species[1]. In Old World monkeys, this Env protein acts as a syncytin—facilitating cell-cell fusion to form syncytiotrophoblasts, a process vital for placental development[1]. In humans, however, it serves as an example of an endogenous retroviral protein that is no longer active in cell fusion, and its functional relevance is unclear. It is not a recognized therapeutic target, receptor, enzyme, transporter, nor is it directly related to canonical disease processes in humans[1]. No drugs or biomarker relationships have been described for this protein, and it is typically studied for its evolutionary, epigenetic, or placental biology implications.

Other names

Endogenous retrovirus group V member 2 Env polyproteinENVV2HERV-V_19q13.41 provirus ancestral Env polyprotein 2mac-syncytin-3HERV-V2endogenous retrovirus HSV2endogenous retrovirus group V, member 2, envelope glycoprotein ENVV2envelope protein ENVV2