F protein

The henipavirus Fusion glycoprotein is synthesized as a precursor F₀ that undergoes posttranslational cleavage by host cell Cathepsin L that occurs within the endosomal compartment, most likely during endocytosis and recycling of F to the mature fusiogenic F₁ (a larger carboxy terminal fragment) +F₂ (a smaller amino terminal fragment) subunits that are held together by disulfide bonds through conserved cystine residues.