title: Post-translational regulation and modifications of flavivirus structural proteins.
abstract: Flaviviruses are a group of single-stranded, positive-sense RNA viruses that generally circulate between arthropod vectors and susceptible vertebrate hosts, producing significant human and veterinary disease burdens. Intensive research efforts have broadened our scientific understanding of the replication cycles of these viruses and have revealed several elegant and tightly co-ordinated post-translational modifications that regulate the activity of viral proteins. The three structural proteins in particular - capsid (C), pre-membrane (prM) and envelope (E) - are subjected to strict regulatory modifications as they progress from translation through virus particle assembly and egress. The timing of proteolytic cleavage events at the C-prM junction directly influences the degree of genomic RNA packaging into nascent virions. Proteolytic maturation of prM by host furin during Golgi transit facilitates rearrangement of the E proteins at the virion surface, exposing the fusion loop and thus increasing particle infectivity. Specific interactions between the prM and E proteins are also important for particle assembly, as prM acts as a chaperone, facilitating correct conformational folding of E. It is only once prM/E heterodimers form that these proteins can be secreted efficiently. The addition of branched glycans to the prM and E proteins during virion transit also plays a key role in modulating the rate of secretion, pH sensitivity and infectivity of flavivirus particles. The insights gained from research into post-translational regulation of structural proteins are beginning to be applied in the rational design of improved flavivirus vaccine candidates and make attractive targets for the development of novel therapeutics.
authors.affiliation: 1Australian Infectious Diseases Research Centre, The University of Queensland, Australia 2School of Chemistry and Molecular Biosciences, The University of Queensland, Australia.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Roby
authors.affiliation: 1Australian Infectious Diseases Research Centre, The University of Queensland, Australia 2School of Chemistry and Molecular Biosciences, The University of Queensland, Australia.
authors.forename: Yin Xiang
authors.initials: YX
authors.lastname: Setoh
authors.affiliation: 1Australian Infectious Diseases Research Centre, The University of Queensland, Australia 2School of Chemistry and Molecular Biosciences, The University of Queensland, Australia.
authors.forename: Roy A
authors.initials: RA
authors.lastname: Hall
authors.affiliation: 1Australian Infectious Diseases Research Centre, The University of Queensland, Australia 2School of Chemistry and Molecular Biosciences, The University of Queensland, Australia.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Khromykh
mesh_terms: D036022:Capsid Proteins / Q000378:metabolism*; D005416:Flavivirus / Q000502:physiology*; D015967:Gene Expression Regulation, Viral; D006031:Glycosylation; D054884:Host-Pathogen Interactions; D006801:Humans; D055503:Protein Multimerization; D011499:Protein Processing, Post-Translational; D059748:Proteolysis; D014759:Viral Envelope Proteins / Q000378:metabolism*; D019065:Virus Assembly; D057074:Virus Release
chemical_list: D036022:Capsid Proteins; D014759:Viral Envelope Proteins; C074932:prM protein, Flavivirus; C065696:glycoprotein E, Flavivirus