Open AccessReticulon 3 interacts with NS4B of the hepatitis C virus and negatively regulates viral replication by disrupting NS4B self‐interaction
Author(s) -
Wu MingJhan,
Ke PoYuan,
Hsu John T.A.,
Yeh ChauTing,
Horng JimTong
Publication year - 2014
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/cmi.12318
Subject(s) - biology , viral replication , endoplasmic reticulum , replicon , replication factor c , virology , host factor , microbiology and biotechnology , transfection , viral protein , virus , control of chromosome duplication , cell culture , dna replication , gene , biochemistry , plasmid , genetics
Summary The non‐structural protein 4B ( NS4B ) of the hepatitis C virus ( HCV ) is an endoplasmic reticulum ( ER ) membrane protein comprising two consecutive amphipathic α‐helical domains ( AH 1 and AH 2). Its self‐oligomerization via the AH 2 domain is required for the formation of the membranous web that is necessary for viral replication. Previously, we reported that the host‐encoded ER ‐associated reticulon 3 ( RTN 3) protein is involved in the formation of the replication‐associated membranes of (+) RNA enteroviruses during viral replication. In this study, we demonstrated that the second transmembrane region of RTN 3 competed for, and bound to, the AH 2 domain of NS4B , thus abolishing NS4B self‐interaction and leading to the downregulation of viral replication. This interaction was mediated by two crucial residues, lysine 52 and tyrosine 63, of AH 2, and was regulated by the AH 1 domain. The silencing of RTN 3 in Huh 7 and AVA 5 cells harbouring an HCV replicon enhanced the replication of HCV , which was counteracted by the overexpression of recombinant RTN 3. The synthesis of viral RNA was also increased in siRNA ‐transfected human primary hepatocytes infected with HCV derived from cell culture. Our results demonstrated that RTN 3 acted as a restriction factor to limit the replication of HCV .