Human T-cell lymphotropic virus type 1 envelope glycoprotein gp62 (HTLV-1 gp62)

Human T-cell lymphotropic virus type 1 (HTLV-1) envelope glycoprotein gp62 is the precursor protein responsible for viral entry into host T-cells. Encoded by the env gene, gp62 is post-translationally cleaved by host cell furin-like proteases into two functional subunits: the surface glycoprotein gp46 (SU) and the transmembrane glycoprotein gp21 (TM) (UniProt P03381; PMID: 15140983). The gp46 subunit facilitates initial binding to host receptors, including glucose transporter 1 (GLUT1), neuropilin-1 (NRP1), and heparan sulfate proteoglycans (HSPGs), while gp21 mediates the fusion of the viral and cellular membranes (PMID: 15548760). Because it is exposed on the surface of the virion and infected cells, gp62 is a primary target for neutralizing antibodies and the development of prophylactic and therapeutic vaccines. HTLV-1 infection is the etiological agent of severe conditions such as adult T-cell leukemia/lymphoma (ATL) and the chronic inflammatory neurological disorder HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) (NIH/NCI). Current therapeutic research focuses on blocking the gp46-receptor interaction or inhibiting the conformational changes in gp21 required for fusion to halt the spread of the virus within the host.

Other names

HTLV-1 EnvEnvelope glycoprotein gp62Pr62gp61Envelope polyproteinHTLV-1 gp46/gp21 precursor

Neutralization of viral particles and inhibition of gp46-mediated receptor binding or gp21-mediated membrane fusion to prevent host cell infection and cell-to-cell spread.