Human T-cell leukemia virus type 1 envelope glycoprotein (HTLV-1 Env)

The Human T-cell leukemia virus type 1 (HTLV-1) envelope glycoprotein is a critical viral protein synthesized as a 62 kDa precursor, known as gp62. This precursor is proteolytically cleaved by cellular furin-like proteases into two subunits: the surface glycoprotein (gp46), which mediates attachment to host cell receptors, and the transmembrane glycoprotein (gp21), which facilitates membrane fusion (UniProt P03381). The gp46 subunit specifically interacts with host receptors including Heparan Sulfate Proteoglycans (HSPGs), Neuropilin-1 (NRP1), and the Glucose Transporter 1 (GLUT1) to initiate infection (Pique and Jones, 2012; Manel et al., 2003). This glycoprotein complex is essential for both cell-free infection and the highly efficient cell-to-cell spread that characterizes HTLV-1 pathogenesis. Because it is the only viral protein exposed on the surface of the virion, it serves as the primary target for neutralizing antibodies and is a central focus for vaccine development and entry inhibitor research. Dysfunctional immune responses to the envelope protein or high viral loads are associated with the development of Adult T-cell leukemia/lymphoma (ATL) and the neuroinflammatory condition HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) (Ghez et al., 2006).

Other names

gp62Envelope polyproteingp46/gp21 complexHTLV-1 gp62Surface and transmembrane glycoprotein

Neutralization of viral particles and inhibition of syncytia formation by blocking receptor binding (gp46) or membrane fusion (gp21).