Hepatitis C virus E1 envelope glycoprotein (E1) (E1)

The Hepatitis C virus (HCV) E1 envelope glycoprotein is a 192-amino acid type I transmembrane protein that forms a non-covalent heterodimer with the E2 glycoprotein on the viral surface (PubMed: 27834201). This E1-E2 complex is essential for viral entry, where E1 is specifically implicated in the fusion of the viral envelope with the host cell endosomal membrane via a putative fusion peptide (PubMed: 25142596). E1 also acts as a chaperone to assist in the proper folding of E2 and is involved in the assembly and morphogenesis of new virions (PubMed: 28834856). As a surface-exposed protein, E1 is a primary target for neutralizing antibodies, such as IGH526, which block infection by interfering with the entry process (PubMed: 24920614). Despite its importance, E1 remains a challenging therapeutic target due to its high genetic variability and the presence of N-linked glycans that shield critical epitopes from the immune system (PubMed: 27834201). While current direct-acting antivirals (DAAs) primarily target non-structural proteins, E1 remains a significant target for entry inhibitors and passive immunization strategies aimed at preventing or treating HCV infection (NIH).

Other names

E1 proteinHCV E1Envelope glycoprotein E1Hepatitis C virus E1 envelope glycoprotein antigen

Neutralizing antibodies and entry inhibitors bind to the E1 protein or the E1-E2 heterodimer to block viral attachment to host receptors and inhibit the pH-dependent membrane fusion process required for viral entry (PubMed: 27834201). Prophylactic vaccines are designed to elicit a humoral immune response that produces these neutralizing antibodies (NIH).