Nuclear factors are involved in hepatitis C virus RNA replication.
Unraveling the molecular basis of the life cycle of hepatitis C virus (HCV), a prevalent agent of human liver disease, entails the identification of cell-encoded factors that participate in the replication of the viral RNA genome. This study provides evidence that the so-called NF/NFAR proteins, namely, NF90/NFAR-1, NF110/NFAR-2, NF45, and RNA helicase A (RHA), which mostly belong to the dsRBM protein family, are involved in the HCV RNA replication process. NF/NFAR proteins were shown to specifically bind to replication signals in the HCV genomic 5' and 3' termini and to promote the formation of a looplike structure of the viral RNA. In cells containing replicating HCV RNA, the generally nuclear NF/NFAR proteins accumulate in the cytoplasmic viral replication complexes, and the prototype NFAR protein, NF90/NFAR-1, stably interacts with a viral protein. HCV replication was inhibited in cells where RNAi depleted RHA from the cytoplasm. Likewise, HCV replication was hindered in cells that contained another NF/NFAR protein recruiting virus. The recruitment of NF/NFAR proteins by HCV is assumed to serve two major purposes: to support 5'-3' interactions of the viral RNA for the coordination of viral protein and RNA synthesis and to weaken host-defense mechanisms.
Isken
Olaf
O
Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
Baroth
Martina
M
Grassmann
Claus W
CW
Weinlich
Susan
S
Ostareck
Dirk H
DH
Ostareck-Lederer
Antje
A
Behrens
Sven-Erik
SE
D001483:Base Sequence; D002467:Cell Nucleus / Q000737:chemistry; D016174:Hepacivirus / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D022661:RNA, Untranslated / Q000737:chemistry / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
D022661:RNA, Untranslated; D012367:RNA, Viral; D014764:Viral Proteins