Aims
Ras-related nuclear (RAN) protein is a small GTP-binding protein that is indispensable for the translocation of RNA and proteins through the nuclear pore complex. Recent studies have indicated that RAN plays an important role in virus infection. However, the role of RAN in hepatitis C virus (HCV) infection is unclear. The objective of this study was to investigate the role and underlying mechanisms of RAN in HCV infection.
Background and aims
Ras-related nuclear (RAN) protein is a small GTP-binding protein that is indispensable for the translocation of RNA and proteins through the nuclear pore complex. Recent studies have indicated that RAN plays an important role in virus infection. However, the role of RAN in hepatitis C virus (HCV) infection is unclear. The objective of this study was to investigate the role and underlying mechanisms of RAN in HCV infection.
Conclusions
PTB in the host cytoplasm is directly associated with HCV replication. These findings demonstrate that the involvement of RAN in HCV infection is mediated by influencing the cytoplasmic translocation of PTB.
Methods
Huh7.5.1 cells were infected with the JC1-Luc virus for 24 h and then were incubated with complete medium for an additional 48 h. HCV infection and RAN expression were determined using luciferase assay, quantitative reverse transcription-PCR and western blotting. Small interfering RNA was used to silence RAN. Western blotting and immunofluorescence were used to evaluate the cytoplasmic translocation of polypyrimidine tract-binding (PTB), and coimmunoprecipitation was used to examine the interaction between RAN and PTB.
Results
HCV infection significantly induced RAN expression and cytoplasmic redistribution of PTB. Knockdown of RAN dramatically inhibited HCV infection and the cytoplasmic accumulation of PTB. Colocalization of RAN and PTB was determined by immunofluorescence, and a direct interaction of RAN with PTB was demonstrated by coimmunoprecipitation. Conclusions: PTB in the host cytoplasm is directly associated with HCV replication. These findings demonstrate that the involvement of RAN in HCV infection is mediated by influencing the cytoplasmic translocation of PTB.