Open AccessAmphipathic α-Helix AH2 Is a Major Determinant for the Oligomerization of Hepatitis C Virus Nonstructural Protein 4B
Author(s) -
Jérôme Gouttenoire,
Philippe Roingeard,
François Pénin,
Darius Moradpour
Publication year - 2010
Publication title -
journal of virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.617
H-Index - 292
eISSN - 1070-6321
pISSN - 0022-538X
DOI - 10.1128/jvi.01798-10
Subject(s) - biology , viral replication , förster resonance energy transfer , ns3 , microbiology and biotechnology , immunoprecipitation , rna , ns5a , virology , hepatitis c virus , virus , genetics , gene , hepacivirus , fluorescence , physics , quantum mechanics
Nonstructural protein 4B (NS4B) is a key organizer of hepatitis C virus (HCV) replication complex formation. It induces a specific membrane rearrangement, designated membranous web, that serves as a scaffold for the HCV replication complex. However, the mechanisms underlying membranous web formation are poorly understood. Based on fluorescence resonance energy transfer (FRET) and confirmatory coimmunoprecipitation analyses, we provide evidence for an oligomerization of NS4B in the membrane environment of intact cells. Several conserved determinants were found to be involved in NS4B oligomerization, through homotypic and heterotypic interactions. N-terminal amphipathic α-helix AH2, comprising amino acids 42 to 66, was identified as a major determinant for NS4B oligomerization. Mutations that affected the oligomerization of NS4B disrupted membranous web formation and HCV RNA replication, implying that oligomerization of NS4B is required for the creation of a functional replication complex. These findings enhance our understanding of the functional architecture of the HCV replication complex and may provide new angles for therapeutic intervention. At the same time, they expand the list of positive-strand RNA virus replicase components acting as oligomers.