Human endogenous retrovirus K envelope glycoprotein (HERV-K Env) (HERV-K Env)

The Human endogenous retrovirus K (HERV-K) envelope glycoprotein is a protein encoded by the most recently integrated and biologically active family of endogenous retroviruses in the human genome (UniProt P61566). While typically silenced in healthy adult tissues through epigenetic mechanisms, HERV-K Env is frequently reactivated and overexpressed in various malignancies, including melanoma, breast cancer, and germ cell tumors, as well as in neurodegenerative conditions like amyotrophic lateral sclerosis (ALS) (PubMed: 26424568). The protein is synthesized as a GP160 precursor and cleaved into a surface subunit (GP95) and a transmembrane subunit (GP41), which can facilitate cell-cell fusion and modulate host immune responses via an immunosuppressive domain (PubMed: 22232437). In oncology, HERV-K Env serves as a tumor-associated antigen, making it a target for monoclonal antibodies and chimeric antigen receptor (CAR) T-cell therapies designed to induce tumor cell lysis. In the context of ALS, the protein has been shown to be neurotoxic to motor neurons, leading to the development of neutralizing antibodies as a potential therapeutic strategy to slow disease progression (GeNeuro, 2023).

Other names

HERV-K Env proteinERVK envelope proteinEnvelope polyprotein GP160Surface protein GP95Transmembrane protein GP41K-Env

Monoclonal antibody-mediated neutralization of the envelope protein to prevent neurotoxicity or immunosuppression, and CAR-T cell-directed cytotoxicity against Env-expressing tumor cells (PubMed: 29042366).