Function of chikungunya virus structural proteins

Abstract

Chikungunya virus (CHIKV) belongs to the genus Alphavirus (within the family Togaviridae), which includes over 29 species that may cause encephalitis, febrile illness, and arthralgia in humans. CHIKV has a single-stranded, positive sense RNA genome of approximately 12 kb in length, although some size variation exists between different lineages. The icosahedral virions have a diameter of 60-70 nm and consist of a nucleocapsid enveloped by a host-derived phospholipid membrane. The viral structural polyprotein is translated from a ~5 kb subgenomic mRNA and is co- and post-translationally cleaved into capsid protein (C), two major envelope glycoproteins (E1, E2), and three smaller accessory proteins (E3, 6K, and the transframe protein TF). Together, the structural proteins encapsidate the viral genomic RNA to form the viral progeny. The different functions of the individual CHIKV structural proteins in virion assembly, egress, binding, and fusion are reviewed in this chapter.