Parainfluenza virus type 3 fusion glycoprotein (HPIV3 F)

The Parainfluenza virus type 3 fusion glycoprotein (HPIV3 F) is a viral envelope protein critical for viral entry into host cells. It functions in concert with the hemagglutinin-neuraminidase (HN) glycoprotein: HN binds to sialic acid receptors on the respiratory epithelial cell surface and triggers conformational changes in F, leading to the fusion of the viral envelope with the host cell membrane[1][4][5]. Structurally, F is synthesized as an inactive precursor (F0), which is cleaved by host proteases (e.g., furin, TMPRSS2) into its active form. The functional F protein forms a trimer that undergoes large conformational changes upon activation, driving membrane fusion and allowing delivery of the viral nucleocapsid into the cell[1][6]. HPIV3 F is a major antigenic determinant and a target of potently neutralizing antibodies. Stabilized forms of the prefusion conformation of F glycoprotein are under investigation as vaccine antigens and monoclonal antibody targets due to their enhanced ability to induce immune protection[4][6][7]. HPIV3 F is considered an important therapeutic and vaccine target for the prevention and treatment of severe human parainfluenza virus 3-related respiratory disease[4][6][7].

Other names

HPIV3 F proteinHuman parainfluenza virus type 3 fusion proteinFusion glycoprotein FhPIV3 F protein

Blockade of conformational changes needed for membrane fusion; Stabilization of pre-fusion conformation to prevent viral entry; Antibody-mediated neutralization by binding antigenic sites on F and preventing activation/fusion