Chikungunya virus structural polyprotein (CHIKV structural polyprotein)

The Chikungunya virus (CHIKV) structural polyprotein is a large precursor polypeptide synthesized from the 26S subgenomic mRNA during the viral replication cycle [1]. It undergoes complex post-translational processing, including autoproteolysis and cleavage by host cell proteases, to produce five mature proteins: capsid (C), E3, E2, 6K (or transframe TF), and E1 [1][3]. These components are fundamental to the virus's architecture, where the C protein forms the nucleocapsid and the E1/E2 glycoproteins form the envelope spikes required for host cell recognition and entry. Specifically, E2 facilitates attachment to host receptors such as Mxra8, while E1 triggers pH-dependent membrane fusion within the endosome [3]. Because these proteins are highly exposed on the surface of the mature virion, they are the primary targets for neutralizing antibodies and vaccine development. The recently FDA-approved vaccine Ixchiq (VLA1553) utilizes a live-attenuated version of the virus containing these structural elements to induce protective immunity [2]. Therapeutic monoclonal antibodies also target specific epitopes on the E1 and E2 domains to block viral dissemination and prevent the debilitating joint pain characteristic of Chikungunya fever.

Other names

Structural polyprotein (C-E3-E2-6K-E1)CHIKV-SPCHIKV structural proteinsC-E3-E2-6K-E1 polyprotein

Drugs and vaccines targeting the structural polyprotein primarily function by inducing or providing neutralizing antibodies that bind to the E2 or E1 subunits to prevent viral attachment to host receptors and subsequent membrane fusion, or by mimicking the virion structure to elicit a robust immune response [2][3].