E3 & E2 & E1

Chikungunya virus (CHIKV) p62 is a structural polyprotein precursor that undergoes furin-mediated cleavage to generate the E3 and E2 glycoproteins. Co-translational association with the fusion protein E1 in the endoplasmic reticulum produces p62–E1 heterodimers that ensure proper folding and spike assembly. Following E3 removal, the mature E2–E1 complex organizes into trimeric spikes on the virion surface, mediating receptor binding and pH-triggered membrane fusion during cell entry. This coordinated processing is essential for CHIKV infectivity and immunogenicity, driving efficient virus assembly.