HCV NS5A dimer interface residues regulate HCV replication by controlling its self-interaction, hyperphosphorylation, subcellular localization and interaction with cyclophilin A

  • The HCV NS5A protein plays multiple roles during viral replication, including viral genome replication and virus particle assembly. The crystal structures of the NS5A N-terminal domain indicated the potential existence of the NS5A dimers formed via at least two or more distinct dimeric interfaces. However, it is unknown whether these different forms of NS5A dimers are involved in its numerous functions. To address this question, we mutated the residues lining the two different NS5A dimer interfaces and determined their effects on NS5A self-interaction, NS5A-cyclophilin A (CypA) interaction, HCV RNA replication and infectious virus production. We found that the mutations targeting either of two dimeric interfaces disrupted the NS5A self-interaction in cells. The NS5A dimer-interrupting mutations also inhibited both viral RNA replication and infectious virus production with some genotypic differences. We also determined that reduced NS5A self-interaction was associated with altered NS5A-CypA interaction, NS5A hyperphosphorylation and NS5A subcellular localization, providing the mechanistic bases for the role of NS5A self-interaction in multiple steps of HCV replication. The NS5A oligomers formed via different interfaces are likely its functional form, since the residues at two different dimeric interfaces played similar roles in different aspects of NS5A functions and, consequently, HCV replication. In conclusion, this study provides novel insight into the functional significance of NS5A self-interaction in different steps of the HCV replication, potentially, in the form of oligomers formed via multiple dimeric interfaces.
Author:Saravanabalaji Shanmugam, Alyssa K. Nichols, Dhanaranjani Saravanabalaji, Christoph Welsch, MinKyung Yi
Pubmed Id:https://pubmed.ncbi.nlm.nih.gov/30036383
Parent Title (English):PLoS pathogens
Place of publication:Lawrence, Kan.
Contributor(s):Glenn Randall
Document Type:Article
Year of Completion:2018
Date of first Publication:2018/07/23
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2018/08/14
Tag:Cell cultures; Crystal structure; Dimers (Chemical physics); Intracellular pathogens; Microbial mutation; RNA viruses; Viral core; Viral replication
Issue:(7): e1007177
Page Number:36
First Page:1
Last Page:36
Copyright: © 2018 Shanmugam et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Institutes:Medizin / Medizin
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung 4.0